Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Resizable virtual memory filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 2000 Linus Torvalds. |
| 5 | * 2000 Transmeta Corp. |
| 6 | * 2000-2001 Christoph Rohland |
| 7 | * 2000-2001 SAP AG |
| 8 | * 2002 Red Hat Inc. |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 9 | * Copyright (C) 2002-2011 Hugh Dickins. |
| 10 | * Copyright (C) 2011 Google Inc. |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 11 | * Copyright (C) 2002-2005 VERITAS Software Corporation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Copyright (C) 2004 Andi Kleen, SuSE Labs |
| 13 | * |
| 14 | * Extended attribute support for tmpfs: |
| 15 | * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> |
| 16 | * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 17 | * |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 18 | * tiny-shmem: |
| 19 | * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com> |
| 20 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | * This file is released under the GPL. |
| 22 | */ |
| 23 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 24 | #include <linux/fs.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/vfs.h> |
| 27 | #include <linux/mount.h> |
Andrew Morton | 250297e | 2013-04-29 15:06:12 -0700 | [diff] [blame] | 28 | #include <linux/ramfs.h> |
Hugh Dickins | caefba1 | 2009-04-13 14:40:12 -0700 | [diff] [blame] | 29 | #include <linux/pagemap.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 30 | #include <linux/file.h> |
| 31 | #include <linux/mm.h> |
Arnd Bergmann | 46c9a94 | 2018-08-17 15:45:09 -0700 | [diff] [blame] | 32 | #include <linux/random.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 33 | #include <linux/sched/signal.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 34 | #include <linux/export.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 35 | #include <linux/swap.h> |
Christoph Hellwig | e2e40f2 | 2015-02-22 08:58:50 -0800 | [diff] [blame] | 36 | #include <linux/uio.h> |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 37 | #include <linux/khugepaged.h> |
Mike Kravetz | 749df87 | 2017-09-06 16:24:16 -0700 | [diff] [blame] | 38 | #include <linux/hugetlb.h> |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 39 | #include <linux/frontswap.h> |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 40 | #include <linux/fs_parser.h> |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 41 | |
Andrea Arcangeli | 95cc09d | 2017-02-22 15:43:31 -0800 | [diff] [blame] | 42 | #include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */ |
| 43 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 44 | static struct vfsmount *shm_mnt; |
| 45 | |
| 46 | #ifdef CONFIG_SHMEM |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | /* |
| 48 | * This virtual memory filesystem is heavily based on the ramfs. It |
| 49 | * extends ramfs by the ability to use swap and honor resource limits |
| 50 | * which makes it a completely usable filesystem. |
| 51 | */ |
| 52 | |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 53 | #include <linux/xattr.h> |
Christoph Hellwig | a569425 | 2007-07-17 04:04:28 -0700 | [diff] [blame] | 54 | #include <linux/exportfs.h> |
Christoph Hellwig | 1c7c474 | 2009-11-03 16:44:44 +0100 | [diff] [blame] | 55 | #include <linux/posix_acl.h> |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 56 | #include <linux/posix_acl_xattr.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | #include <linux/mman.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | #include <linux/string.h> |
| 59 | #include <linux/slab.h> |
| 60 | #include <linux/backing-dev.h> |
| 61 | #include <linux/shmem_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | #include <linux/blkdev.h> |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 64 | #include <linux/pagevec.h> |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 65 | #include <linux/percpu_counter.h> |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 66 | #include <linux/falloc.h> |
Hugh Dickins | 708e350 | 2011-07-25 17:12:32 -0700 | [diff] [blame] | 67 | #include <linux/splice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | #include <linux/security.h> |
| 69 | #include <linux/swapops.h> |
| 70 | #include <linux/mempolicy.h> |
| 71 | #include <linux/namei.h> |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 72 | #include <linux/ctype.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 73 | #include <linux/migrate.h> |
Christoph Lameter | c1f60a5 | 2006-09-25 23:31:11 -0700 | [diff] [blame] | 74 | #include <linux/highmem.h> |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 75 | #include <linux/seq_file.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 76 | #include <linux/magic.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 77 | #include <linux/syscalls.h> |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 78 | #include <linux/fcntl.h> |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 79 | #include <uapi/linux/memfd.h> |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 80 | #include <linux/userfaultfd_k.h> |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 81 | #include <linux/rmap.h> |
Amir Goldstein | 2b4db79 | 2017-05-18 15:29:33 +0300 | [diff] [blame] | 82 | #include <linux/uuid.h> |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 83 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 84 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Mel Gorman | dd56b04 | 2015-11-06 16:28:43 -0800 | [diff] [blame] | 86 | #include "internal.h" |
| 87 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 88 | #define BLOCKS_PER_PAGE (PAGE_SIZE/512) |
| 89 | #define VM_ACCT(size) (PAGE_ALIGN(size) >> PAGE_SHIFT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | /* Pretend that each entry is of this size in directory's i_size */ |
| 92 | #define BOGO_DIRENT_SIZE 20 |
| 93 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 94 | /* Symlink up to this size is kmalloc'ed instead of using a swappable page */ |
| 95 | #define SHORT_SYMLINK_LEN 128 |
| 96 | |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 97 | /* |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 98 | * shmem_fallocate communicates with shmem_fault or shmem_writepage via |
| 99 | * inode->i_private (with i_mutex making sure that it has only one user at |
| 100 | * a time): we would prefer not to enlarge the shmem inode just for that. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 101 | */ |
| 102 | struct shmem_falloc { |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 103 | wait_queue_head_t *waitq; /* faults into hole wait for punch to end */ |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 104 | pgoff_t start; /* start of range currently being fallocated */ |
| 105 | pgoff_t next; /* the next page offset to be fallocated */ |
| 106 | pgoff_t nr_falloced; /* how many new pages have been fallocated */ |
| 107 | pgoff_t nr_unswapped; /* how often writepage refused to swap out */ |
| 108 | }; |
| 109 | |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 110 | struct shmem_options { |
| 111 | unsigned long long blocks; |
| 112 | unsigned long long inodes; |
| 113 | struct mempolicy *mpol; |
| 114 | kuid_t uid; |
| 115 | kgid_t gid; |
| 116 | umode_t mode; |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 117 | bool full_inums; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 118 | int huge; |
| 119 | int seen; |
| 120 | #define SHMEM_SEEN_BLOCKS 1 |
| 121 | #define SHMEM_SEEN_INODES 2 |
| 122 | #define SHMEM_SEEN_HUGE 4 |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 123 | #define SHMEM_SEEN_INUMS 8 |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 124 | }; |
| 125 | |
Andrew Morton | b76db735 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 126 | #ifdef CONFIG_TMPFS |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 127 | static unsigned long shmem_default_max_blocks(void) |
| 128 | { |
Arun KS | ca79b0c | 2018-12-28 00:34:29 -0800 | [diff] [blame] | 129 | return totalram_pages() / 2; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | static unsigned long shmem_default_max_inodes(void) |
| 133 | { |
Arun KS | ca79b0c | 2018-12-28 00:34:29 -0800 | [diff] [blame] | 134 | unsigned long nr_pages = totalram_pages(); |
| 135 | |
| 136 | return min(nr_pages - totalhigh_pages(), nr_pages / 2); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 137 | } |
Andrew Morton | b76db735 | 2008-02-08 04:21:49 -0800 | [diff] [blame] | 138 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 139 | |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 140 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp); |
| 141 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 142 | struct shmem_inode_info *info, pgoff_t index); |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 143 | static int shmem_swapin_page(struct inode *inode, pgoff_t index, |
| 144 | struct page **pagep, enum sgp_type sgp, |
| 145 | gfp_t gfp, struct vm_area_struct *vma, |
| 146 | vm_fault_t *fault_type); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 147 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 148 | struct page **pagep, enum sgp_type sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 149 | gfp_t gfp, struct vm_area_struct *vma, |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 150 | struct vm_fault *vmf, vm_fault_t *fault_type); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 151 | |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 152 | int shmem_getpage(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 153 | struct page **pagep, enum sgp_type sgp) |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 154 | { |
| 155 | return shmem_getpage_gfp(inode, index, pagep, sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 156 | mapping_gfp_mask(inode->i_mapping), NULL, NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 157 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) |
| 160 | { |
| 161 | return sb->s_fs_info; |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * shmem_file_setup pre-accounts the whole fixed size of a VM object, |
| 166 | * for shared memory and for shared anonymous (/dev/zero) mappings |
| 167 | * (unless MAP_NORESERVE and sysctl_overcommit_memory <= 1), |
| 168 | * consistent with the pre-accounting of private mappings ... |
| 169 | */ |
| 170 | static inline int shmem_acct_size(unsigned long flags, loff_t size) |
| 171 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 172 | return (flags & VM_NORESERVE) ? |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 173 | 0 : security_vm_enough_memory_mm(current->mm, VM_ACCT(size)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | static inline void shmem_unacct_size(unsigned long flags, loff_t size) |
| 177 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 178 | if (!(flags & VM_NORESERVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | vm_unacct_memory(VM_ACCT(size)); |
| 180 | } |
| 181 | |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 182 | static inline int shmem_reacct_size(unsigned long flags, |
| 183 | loff_t oldsize, loff_t newsize) |
| 184 | { |
| 185 | if (!(flags & VM_NORESERVE)) { |
| 186 | if (VM_ACCT(newsize) > VM_ACCT(oldsize)) |
| 187 | return security_vm_enough_memory_mm(current->mm, |
| 188 | VM_ACCT(newsize) - VM_ACCT(oldsize)); |
| 189 | else if (VM_ACCT(newsize) < VM_ACCT(oldsize)) |
| 190 | vm_unacct_memory(VM_ACCT(oldsize) - VM_ACCT(newsize)); |
| 191 | } |
| 192 | return 0; |
| 193 | } |
| 194 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | /* |
| 196 | * ... whereas tmpfs objects are accounted incrementally as |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 197 | * pages are allocated, in order to allow large sparse files. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, |
| 199 | * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. |
| 200 | */ |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 201 | static inline int shmem_acct_block(unsigned long flags, long pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 203 | if (!(flags & VM_NORESERVE)) |
| 204 | return 0; |
| 205 | |
| 206 | return security_vm_enough_memory_mm(current->mm, |
| 207 | pages * VM_ACCT(PAGE_SIZE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | static inline void shmem_unacct_blocks(unsigned long flags, long pages) |
| 211 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 212 | if (flags & VM_NORESERVE) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 213 | vm_unacct_memory(pages * VM_ACCT(PAGE_SIZE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 216 | static inline bool shmem_inode_acct_block(struct inode *inode, long pages) |
| 217 | { |
| 218 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 219 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 220 | |
| 221 | if (shmem_acct_block(info->flags, pages)) |
| 222 | return false; |
| 223 | |
| 224 | if (sbinfo->max_blocks) { |
| 225 | if (percpu_counter_compare(&sbinfo->used_blocks, |
| 226 | sbinfo->max_blocks - pages) > 0) |
| 227 | goto unacct; |
| 228 | percpu_counter_add(&sbinfo->used_blocks, pages); |
| 229 | } |
| 230 | |
| 231 | return true; |
| 232 | |
| 233 | unacct: |
| 234 | shmem_unacct_blocks(info->flags, pages); |
| 235 | return false; |
| 236 | } |
| 237 | |
| 238 | static inline void shmem_inode_unacct_blocks(struct inode *inode, long pages) |
| 239 | { |
| 240 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 241 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 242 | |
| 243 | if (sbinfo->max_blocks) |
| 244 | percpu_counter_sub(&sbinfo->used_blocks, pages); |
| 245 | shmem_unacct_blocks(info->flags, pages); |
| 246 | } |
| 247 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 248 | static const struct super_operations shmem_ops; |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 249 | static const struct address_space_operations shmem_aops; |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 250 | static const struct file_operations shmem_file_operations; |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 251 | static const struct inode_operations shmem_inode_operations; |
| 252 | static const struct inode_operations shmem_dir_inode_operations; |
| 253 | static const struct inode_operations shmem_special_inode_operations; |
Alexey Dobriyan | f0f37e2f | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 254 | static const struct vm_operations_struct shmem_vm_ops; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 255 | static struct file_system_type shmem_fs_type; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | |
Mike Rapoport | b0506e4 | 2017-02-22 15:43:28 -0800 | [diff] [blame] | 257 | bool vma_is_shmem(struct vm_area_struct *vma) |
| 258 | { |
| 259 | return vma->vm_ops == &shmem_vm_ops; |
| 260 | } |
| 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | static LIST_HEAD(shmem_swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 263 | static DEFINE_MUTEX(shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 265 | /* |
| 266 | * shmem_reserve_inode() performs bookkeeping to reserve a shmem inode, and |
| 267 | * produces a novel ino for the newly allocated inode. |
| 268 | * |
| 269 | * It may also be called when making a hard link to permit the space needed by |
| 270 | * each dentry. However, in that case, no new inode number is needed since that |
| 271 | * internally draws from another pool of inode numbers (currently global |
| 272 | * get_next_ino()). This case is indicated by passing NULL as inop. |
| 273 | */ |
| 274 | #define SHMEM_INO_BATCH 1024 |
| 275 | static int shmem_reserve_inode(struct super_block *sb, ino_t *inop) |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 276 | { |
| 277 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 278 | ino_t ino; |
| 279 | |
| 280 | if (!(sb->s_flags & SB_KERNMOUNT)) { |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 281 | spin_lock(&sbinfo->stat_lock); |
| 282 | if (!sbinfo->free_inodes) { |
| 283 | spin_unlock(&sbinfo->stat_lock); |
| 284 | return -ENOSPC; |
| 285 | } |
| 286 | sbinfo->free_inodes--; |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 287 | if (inop) { |
| 288 | ino = sbinfo->next_ino++; |
| 289 | if (unlikely(is_zero_ino(ino))) |
| 290 | ino = sbinfo->next_ino++; |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 291 | if (unlikely(!sbinfo->full_inums && |
| 292 | ino > UINT_MAX)) { |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 293 | /* |
| 294 | * Emulate get_next_ino uint wraparound for |
| 295 | * compatibility |
| 296 | */ |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 297 | if (IS_ENABLED(CONFIG_64BIT)) |
| 298 | pr_warn("%s: inode number overflow on device %d, consider using inode64 mount option\n", |
| 299 | __func__, MINOR(sb->s_dev)); |
| 300 | sbinfo->next_ino = 1; |
| 301 | ino = sbinfo->next_ino++; |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 302 | } |
| 303 | *inop = ino; |
| 304 | } |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 305 | spin_unlock(&sbinfo->stat_lock); |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 306 | } else if (inop) { |
| 307 | /* |
| 308 | * __shmem_file_setup, one of our callers, is lock-free: it |
| 309 | * doesn't hold stat_lock in shmem_reserve_inode since |
| 310 | * max_inodes is always 0, and is called from potentially |
| 311 | * unknown contexts. As such, use a per-cpu batched allocator |
| 312 | * which doesn't require the per-sb stat_lock unless we are at |
| 313 | * the batch boundary. |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 314 | * |
| 315 | * We don't need to worry about inode{32,64} since SB_KERNMOUNT |
| 316 | * shmem mounts are not exposed to userspace, so we don't need |
| 317 | * to worry about things like glibc compatibility. |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 318 | */ |
| 319 | ino_t *next_ino; |
| 320 | next_ino = per_cpu_ptr(sbinfo->ino_batch, get_cpu()); |
| 321 | ino = *next_ino; |
| 322 | if (unlikely(ino % SHMEM_INO_BATCH == 0)) { |
| 323 | spin_lock(&sbinfo->stat_lock); |
| 324 | ino = sbinfo->next_ino; |
| 325 | sbinfo->next_ino += SHMEM_INO_BATCH; |
| 326 | spin_unlock(&sbinfo->stat_lock); |
| 327 | if (unlikely(is_zero_ino(ino))) |
| 328 | ino++; |
| 329 | } |
| 330 | *inop = ino; |
| 331 | *next_ino = ++ino; |
| 332 | put_cpu(); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 333 | } |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 334 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 335 | return 0; |
| 336 | } |
| 337 | |
| 338 | static void shmem_free_inode(struct super_block *sb) |
| 339 | { |
| 340 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 341 | if (sbinfo->max_inodes) { |
| 342 | spin_lock(&sbinfo->stat_lock); |
| 343 | sbinfo->free_inodes++; |
| 344 | spin_unlock(&sbinfo->stat_lock); |
| 345 | } |
| 346 | } |
| 347 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 348 | /** |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 349 | * shmem_recalc_inode - recalculate the block usage of an inode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | * @inode: inode to recalc |
| 351 | * |
| 352 | * We have to calculate the free blocks since the mm can drop |
| 353 | * undirtied hole pages behind our back. |
| 354 | * |
| 355 | * But normally info->alloced == inode->i_mapping->nrpages + info->swapped |
| 356 | * So mm freed is info->alloced - (inode->i_mapping->nrpages + info->swapped) |
| 357 | * |
| 358 | * It has to be called with the spinlock held. |
| 359 | */ |
| 360 | static void shmem_recalc_inode(struct inode *inode) |
| 361 | { |
| 362 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 363 | long freed; |
| 364 | |
| 365 | freed = info->alloced - info->swapped - inode->i_mapping->nrpages; |
| 366 | if (freed > 0) { |
| 367 | info->alloced -= freed; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 368 | inode->i_blocks -= freed * BLOCKS_PER_PAGE; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 369 | shmem_inode_unacct_blocks(inode, freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | } |
| 371 | } |
| 372 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 373 | bool shmem_charge(struct inode *inode, long pages) |
| 374 | { |
| 375 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 376 | unsigned long flags; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 377 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 378 | if (!shmem_inode_acct_block(inode, pages)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 379 | return false; |
Mike Rapoport | b1cc94a | 2017-09-06 16:22:56 -0700 | [diff] [blame] | 380 | |
Hugh Dickins | aaa52e3 | 2018-11-30 14:10:29 -0800 | [diff] [blame] | 381 | /* nrpages adjustment first, then shmem_recalc_inode() when balanced */ |
| 382 | inode->i_mapping->nrpages += pages; |
| 383 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 384 | spin_lock_irqsave(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 385 | info->alloced += pages; |
| 386 | inode->i_blocks += pages * BLOCKS_PER_PAGE; |
| 387 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 388 | spin_unlock_irqrestore(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 389 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 390 | return true; |
| 391 | } |
| 392 | |
| 393 | void shmem_uncharge(struct inode *inode, long pages) |
| 394 | { |
| 395 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 396 | unsigned long flags; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 397 | |
Hugh Dickins | aaa52e3 | 2018-11-30 14:10:29 -0800 | [diff] [blame] | 398 | /* nrpages adjustment done by __delete_from_page_cache() or caller */ |
| 399 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 400 | spin_lock_irqsave(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 401 | info->alloced -= pages; |
| 402 | inode->i_blocks -= pages * BLOCKS_PER_PAGE; |
| 403 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 404 | spin_unlock_irqrestore(&info->lock, flags); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 405 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 406 | shmem_inode_unacct_blocks(inode, pages); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 407 | } |
| 408 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 409 | /* |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 410 | * Replace item expected in xarray by a new item, while holding xa_lock. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 411 | */ |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 412 | static int shmem_replace_entry(struct address_space *mapping, |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 413 | pgoff_t index, void *expected, void *replacement) |
| 414 | { |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 415 | XA_STATE(xas, &mapping->i_pages, index); |
Johannes Weiner | 6dbaf22c | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 416 | void *item; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 417 | |
| 418 | VM_BUG_ON(!expected); |
Johannes Weiner | 6dbaf22c | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 419 | VM_BUG_ON(!replacement); |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 420 | item = xas_load(&xas); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 421 | if (item != expected) |
| 422 | return -ENOENT; |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 423 | xas_store(&xas, replacement); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 424 | return 0; |
| 425 | } |
| 426 | |
| 427 | /* |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 428 | * Sometimes, before we decide whether to proceed or to fail, we must check |
| 429 | * that an entry was not already brought back from swap by a racing thread. |
| 430 | * |
| 431 | * Checking page is not enough: by the time a SwapCache page is locked, it |
| 432 | * might be reused, and again be SwapCache, using the same swap as before. |
| 433 | */ |
| 434 | static bool shmem_confirm_swap(struct address_space *mapping, |
| 435 | pgoff_t index, swp_entry_t swap) |
| 436 | { |
Matthew Wilcox | a12831b | 2017-11-22 08:34:58 -0500 | [diff] [blame] | 437 | return xa_load(&mapping->i_pages, index) == swp_to_radix_entry(swap); |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 438 | } |
| 439 | |
| 440 | /* |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 441 | * Definitions for "huge tmpfs": tmpfs mounted with the huge= option |
| 442 | * |
| 443 | * SHMEM_HUGE_NEVER: |
| 444 | * disables huge pages for the mount; |
| 445 | * SHMEM_HUGE_ALWAYS: |
| 446 | * enables huge pages for the mount; |
| 447 | * SHMEM_HUGE_WITHIN_SIZE: |
| 448 | * only allocate huge pages if the page will be fully within i_size, |
| 449 | * also respect fadvise()/madvise() hints; |
| 450 | * SHMEM_HUGE_ADVISE: |
| 451 | * only allocate huge pages if requested with fadvise()/madvise(); |
| 452 | */ |
| 453 | |
| 454 | #define SHMEM_HUGE_NEVER 0 |
| 455 | #define SHMEM_HUGE_ALWAYS 1 |
| 456 | #define SHMEM_HUGE_WITHIN_SIZE 2 |
| 457 | #define SHMEM_HUGE_ADVISE 3 |
| 458 | |
| 459 | /* |
| 460 | * Special values. |
| 461 | * Only can be set via /sys/kernel/mm/transparent_hugepage/shmem_enabled: |
| 462 | * |
| 463 | * SHMEM_HUGE_DENY: |
| 464 | * disables huge on shm_mnt and all mounts, for emergency use; |
| 465 | * SHMEM_HUGE_FORCE: |
| 466 | * enables huge on shm_mnt and all mounts, w/o needing option, for testing; |
| 467 | * |
| 468 | */ |
| 469 | #define SHMEM_HUGE_DENY (-1) |
| 470 | #define SHMEM_HUGE_FORCE (-2) |
| 471 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 472 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 473 | /* ifdef here to avoid bloating shmem.o when not necessary */ |
| 474 | |
Mike Kravetz | 5b9c98f | 2018-06-07 17:05:53 -0700 | [diff] [blame] | 475 | static int shmem_huge __read_mostly; |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 476 | |
Arnd Bergmann | e5f2249 | 2019-07-16 16:25:51 -0700 | [diff] [blame] | 477 | #if defined(CONFIG_SYSFS) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 478 | static int shmem_parse_huge(const char *str) |
| 479 | { |
| 480 | if (!strcmp(str, "never")) |
| 481 | return SHMEM_HUGE_NEVER; |
| 482 | if (!strcmp(str, "always")) |
| 483 | return SHMEM_HUGE_ALWAYS; |
| 484 | if (!strcmp(str, "within_size")) |
| 485 | return SHMEM_HUGE_WITHIN_SIZE; |
| 486 | if (!strcmp(str, "advise")) |
| 487 | return SHMEM_HUGE_ADVISE; |
| 488 | if (!strcmp(str, "deny")) |
| 489 | return SHMEM_HUGE_DENY; |
| 490 | if (!strcmp(str, "force")) |
| 491 | return SHMEM_HUGE_FORCE; |
| 492 | return -EINVAL; |
| 493 | } |
Arnd Bergmann | e5f2249 | 2019-07-16 16:25:51 -0700 | [diff] [blame] | 494 | #endif |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 495 | |
Arnd Bergmann | e5f2249 | 2019-07-16 16:25:51 -0700 | [diff] [blame] | 496 | #if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 497 | static const char *shmem_format_huge(int huge) |
| 498 | { |
| 499 | switch (huge) { |
| 500 | case SHMEM_HUGE_NEVER: |
| 501 | return "never"; |
| 502 | case SHMEM_HUGE_ALWAYS: |
| 503 | return "always"; |
| 504 | case SHMEM_HUGE_WITHIN_SIZE: |
| 505 | return "within_size"; |
| 506 | case SHMEM_HUGE_ADVISE: |
| 507 | return "advise"; |
| 508 | case SHMEM_HUGE_DENY: |
| 509 | return "deny"; |
| 510 | case SHMEM_HUGE_FORCE: |
| 511 | return "force"; |
| 512 | default: |
| 513 | VM_BUG_ON(1); |
| 514 | return "bad_val"; |
| 515 | } |
| 516 | } |
Jérémy Lefaure | f1f5929 | 2016-12-12 16:43:23 -0800 | [diff] [blame] | 517 | #endif |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 518 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 519 | static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, |
| 520 | struct shrink_control *sc, unsigned long nr_to_split) |
| 521 | { |
| 522 | LIST_HEAD(list), *pos, *next; |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 523 | LIST_HEAD(to_remove); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 524 | struct inode *inode; |
| 525 | struct shmem_inode_info *info; |
| 526 | struct page *page; |
| 527 | unsigned long batch = sc ? sc->nr_to_scan : 128; |
| 528 | int removed = 0, split = 0; |
| 529 | |
| 530 | if (list_empty(&sbinfo->shrinklist)) |
| 531 | return SHRINK_STOP; |
| 532 | |
| 533 | spin_lock(&sbinfo->shrinklist_lock); |
| 534 | list_for_each_safe(pos, next, &sbinfo->shrinklist) { |
| 535 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 536 | |
| 537 | /* pin the inode */ |
| 538 | inode = igrab(&info->vfs_inode); |
| 539 | |
| 540 | /* inode is about to be evicted */ |
| 541 | if (!inode) { |
| 542 | list_del_init(&info->shrinklist); |
| 543 | removed++; |
| 544 | goto next; |
| 545 | } |
| 546 | |
| 547 | /* Check if there's anything to gain */ |
| 548 | if (round_up(inode->i_size, PAGE_SIZE) == |
| 549 | round_up(inode->i_size, HPAGE_PMD_SIZE)) { |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 550 | list_move(&info->shrinklist, &to_remove); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 551 | removed++; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 552 | goto next; |
| 553 | } |
| 554 | |
| 555 | list_move(&info->shrinklist, &list); |
| 556 | next: |
| 557 | if (!--batch) |
| 558 | break; |
| 559 | } |
| 560 | spin_unlock(&sbinfo->shrinklist_lock); |
| 561 | |
Kirill A. Shutemov | 253fd0f | 2017-02-03 13:13:15 -0800 | [diff] [blame] | 562 | list_for_each_safe(pos, next, &to_remove) { |
| 563 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 564 | inode = &info->vfs_inode; |
| 565 | list_del_init(&info->shrinklist); |
| 566 | iput(inode); |
| 567 | } |
| 568 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 569 | list_for_each_safe(pos, next, &list) { |
| 570 | int ret; |
| 571 | |
| 572 | info = list_entry(pos, struct shmem_inode_info, shrinklist); |
| 573 | inode = &info->vfs_inode; |
| 574 | |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 575 | if (nr_to_split && split >= nr_to_split) |
| 576 | goto leave; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 577 | |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 578 | page = find_get_page(inode->i_mapping, |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 579 | (inode->i_size & HPAGE_PMD_MASK) >> PAGE_SHIFT); |
| 580 | if (!page) |
| 581 | goto drop; |
| 582 | |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 583 | /* No huge page at the end of the file: nothing to split */ |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 584 | if (!PageTransHuge(page)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 585 | put_page(page); |
| 586 | goto drop; |
| 587 | } |
| 588 | |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 589 | /* |
| 590 | * Leave the inode on the list if we failed to lock |
| 591 | * the page at this time. |
| 592 | * |
| 593 | * Waiting for the lock may lead to deadlock in the |
| 594 | * reclaim path. |
| 595 | */ |
| 596 | if (!trylock_page(page)) { |
| 597 | put_page(page); |
| 598 | goto leave; |
| 599 | } |
| 600 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 601 | ret = split_huge_page(page); |
| 602 | unlock_page(page); |
| 603 | put_page(page); |
| 604 | |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 605 | /* If split failed leave the inode on the list */ |
| 606 | if (ret) |
| 607 | goto leave; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 608 | |
| 609 | split++; |
| 610 | drop: |
| 611 | list_del_init(&info->shrinklist); |
| 612 | removed++; |
Kirill A. Shutemov | b3cd54b | 2018-03-22 16:17:35 -0700 | [diff] [blame] | 613 | leave: |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 614 | iput(inode); |
| 615 | } |
| 616 | |
| 617 | spin_lock(&sbinfo->shrinklist_lock); |
| 618 | list_splice_tail(&list, &sbinfo->shrinklist); |
| 619 | sbinfo->shrinklist_len -= removed; |
| 620 | spin_unlock(&sbinfo->shrinklist_lock); |
| 621 | |
| 622 | return split; |
| 623 | } |
| 624 | |
| 625 | static long shmem_unused_huge_scan(struct super_block *sb, |
| 626 | struct shrink_control *sc) |
| 627 | { |
| 628 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 629 | |
| 630 | if (!READ_ONCE(sbinfo->shrinklist_len)) |
| 631 | return SHRINK_STOP; |
| 632 | |
| 633 | return shmem_unused_huge_shrink(sbinfo, sc, 0); |
| 634 | } |
| 635 | |
| 636 | static long shmem_unused_huge_count(struct super_block *sb, |
| 637 | struct shrink_control *sc) |
| 638 | { |
| 639 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 640 | return READ_ONCE(sbinfo->shrinklist_len); |
| 641 | } |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 642 | #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 643 | |
| 644 | #define shmem_huge SHMEM_HUGE_DENY |
| 645 | |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 646 | static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, |
| 647 | struct shrink_control *sc, unsigned long nr_to_split) |
| 648 | { |
| 649 | return 0; |
| 650 | } |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 651 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 652 | |
Yang Shi | 89fdcd2 | 2018-06-07 17:06:59 -0700 | [diff] [blame] | 653 | static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo) |
| 654 | { |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 655 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && |
Yang Shi | 89fdcd2 | 2018-06-07 17:06:59 -0700 | [diff] [blame] | 656 | (shmem_huge == SHMEM_HUGE_FORCE || sbinfo->huge) && |
| 657 | shmem_huge != SHMEM_HUGE_DENY) |
| 658 | return true; |
| 659 | return false; |
| 660 | } |
| 661 | |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 662 | /* |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 663 | * Like add_to_page_cache_locked, but error if expected item has gone. |
| 664 | */ |
| 665 | static int shmem_add_to_page_cache(struct page *page, |
| 666 | struct address_space *mapping, |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 667 | pgoff_t index, void *expected, gfp_t gfp, |
| 668 | struct mm_struct *charge_mm) |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 669 | { |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 670 | XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page)); |
| 671 | unsigned long i = 0; |
Matthew Wilcox (Oracle) | d8c6546 | 2019-09-23 15:34:30 -0700 | [diff] [blame] | 672 | unsigned long nr = compound_nr(page); |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 673 | int error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 674 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 675 | VM_BUG_ON_PAGE(PageTail(page), page); |
| 676 | VM_BUG_ON_PAGE(index != round_down(index, nr), page); |
Sasha Levin | 309381fea | 2014-01-23 15:52:54 -0800 | [diff] [blame] | 677 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
| 678 | VM_BUG_ON_PAGE(!PageSwapBacked(page), page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 679 | VM_BUG_ON(expected && PageTransHuge(page)); |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 680 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 681 | page_ref_add(page, nr); |
Hugh Dickins | b065b43 | 2012-07-11 14:02:48 -0700 | [diff] [blame] | 682 | page->mapping = mapping; |
| 683 | page->index = index; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 684 | |
Johannes Weiner | 4c6355b | 2020-06-03 16:02:17 -0700 | [diff] [blame] | 685 | if (!PageSwapCache(page)) { |
Johannes Weiner | d9eb1ea | 2020-06-03 16:02:24 -0700 | [diff] [blame] | 686 | error = mem_cgroup_charge(page, charge_mm, gfp); |
Johannes Weiner | 4c6355b | 2020-06-03 16:02:17 -0700 | [diff] [blame] | 687 | if (error) { |
| 688 | if (PageTransHuge(page)) { |
| 689 | count_vm_event(THP_FILE_FALLBACK); |
| 690 | count_vm_event(THP_FILE_FALLBACK_CHARGE); |
| 691 | } |
| 692 | goto error; |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 693 | } |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 694 | } |
| 695 | cgroup_throttle_swaprate(page, gfp); |
| 696 | |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 697 | do { |
| 698 | void *entry; |
| 699 | xas_lock_irq(&xas); |
| 700 | entry = xas_find_conflict(&xas); |
| 701 | if (entry != expected) |
| 702 | xas_set_err(&xas, -EEXIST); |
| 703 | xas_create_range(&xas); |
| 704 | if (xas_error(&xas)) |
| 705 | goto unlock; |
| 706 | next: |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 707 | xas_store(&xas, page); |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 708 | if (++i < nr) { |
| 709 | xas_next(&xas); |
| 710 | goto next; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 711 | } |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 712 | if (PageTransHuge(page)) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 713 | count_vm_event(THP_FILE_ALLOC); |
Mel Gorman | 11fb998 | 2016-07-28 15:46:20 -0700 | [diff] [blame] | 714 | __inc_node_page_state(page, NR_SHMEM_THPS); |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 715 | } |
| 716 | mapping->nrpages += nr; |
Johannes Weiner | 0d1c207 | 2020-06-03 16:01:54 -0700 | [diff] [blame] | 717 | __mod_lruvec_page_state(page, NR_FILE_PAGES, nr); |
| 718 | __mod_lruvec_page_state(page, NR_SHMEM, nr); |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 719 | unlock: |
| 720 | xas_unlock_irq(&xas); |
| 721 | } while (xas_nomem(&xas, gfp)); |
| 722 | |
| 723 | if (xas_error(&xas)) { |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 724 | error = xas_error(&xas); |
| 725 | goto error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 726 | } |
Matthew Wilcox | 552446a | 2017-12-01 13:25:14 -0500 | [diff] [blame] | 727 | |
| 728 | return 0; |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 729 | error: |
| 730 | page->mapping = NULL; |
| 731 | page_ref_sub(page, nr); |
| 732 | return error; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 733 | } |
| 734 | |
| 735 | /* |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 736 | * Like delete_from_page_cache, but substitutes swap for page. |
| 737 | */ |
| 738 | static void shmem_delete_from_page_cache(struct page *page, void *radswap) |
| 739 | { |
| 740 | struct address_space *mapping = page->mapping; |
| 741 | int error; |
| 742 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 743 | VM_BUG_ON_PAGE(PageCompound(page), page); |
| 744 | |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 745 | xa_lock_irq(&mapping->i_pages); |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 746 | error = shmem_replace_entry(mapping, page->index, page, radswap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 747 | page->mapping = NULL; |
| 748 | mapping->nrpages--; |
Johannes Weiner | 0d1c207 | 2020-06-03 16:01:54 -0700 | [diff] [blame] | 749 | __dec_lruvec_page_state(page, NR_FILE_PAGES); |
| 750 | __dec_lruvec_page_state(page, NR_SHMEM); |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 751 | xa_unlock_irq(&mapping->i_pages); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 752 | put_page(page); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 753 | BUG_ON(error); |
| 754 | } |
| 755 | |
| 756 | /* |
Matthew Wilcox | c121d3b | 2017-12-04 03:13:54 -0500 | [diff] [blame] | 757 | * Remove swap entry from page cache, free the swap and its page cache. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 758 | */ |
| 759 | static int shmem_free_swap(struct address_space *mapping, |
| 760 | pgoff_t index, void *radswap) |
| 761 | { |
Johannes Weiner | 6dbaf22c | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 762 | void *old; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 763 | |
Matthew Wilcox | 55f3f7e | 2018-11-26 16:08:43 -0500 | [diff] [blame] | 764 | old = xa_cmpxchg_irq(&mapping->i_pages, index, radswap, NULL, 0); |
Johannes Weiner | 6dbaf22c | 2014-04-03 14:47:41 -0700 | [diff] [blame] | 765 | if (old != radswap) |
| 766 | return -ENOENT; |
| 767 | free_swap_and_cache(radix_to_swp_entry(radswap)); |
| 768 | return 0; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 769 | } |
| 770 | |
| 771 | /* |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 772 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 773 | * given offsets are swapped out. |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 774 | * |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 775 | * This is safe to call without i_mutex or the i_pages lock thanks to RCU, |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 776 | * as long as the inode doesn't go away and racy results are not a problem. |
| 777 | */ |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 778 | unsigned long shmem_partial_swap_usage(struct address_space *mapping, |
| 779 | pgoff_t start, pgoff_t end) |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 780 | { |
Matthew Wilcox | 7ae3424 | 2017-12-04 03:28:00 -0500 | [diff] [blame] | 781 | XA_STATE(xas, &mapping->i_pages, start); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 782 | struct page *page; |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 783 | unsigned long swapped = 0; |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 784 | |
| 785 | rcu_read_lock(); |
Matthew Wilcox | 7ae3424 | 2017-12-04 03:28:00 -0500 | [diff] [blame] | 786 | xas_for_each(&xas, page, end - 1) { |
| 787 | if (xas_retry(&xas, page)) |
Matthew Wilcox | 2cf938a | 2016-03-17 14:22:03 -0700 | [diff] [blame] | 788 | continue; |
Matthew Wilcox | 3159f94 | 2017-11-03 13:30:42 -0400 | [diff] [blame] | 789 | if (xa_is_value(page)) |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 790 | swapped++; |
| 791 | |
| 792 | if (need_resched()) { |
Matthew Wilcox | 7ae3424 | 2017-12-04 03:28:00 -0500 | [diff] [blame] | 793 | xas_pause(&xas); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 794 | cond_resched_rcu(); |
Vlastimil Babka | 6a15a37 | 2016-01-14 15:19:20 -0800 | [diff] [blame] | 795 | } |
| 796 | } |
| 797 | |
| 798 | rcu_read_unlock(); |
| 799 | |
| 800 | return swapped << PAGE_SHIFT; |
| 801 | } |
| 802 | |
| 803 | /* |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 804 | * Determine (in bytes) how many of the shmem object's pages mapped by the |
| 805 | * given vma is swapped out. |
| 806 | * |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 807 | * This is safe to call without i_mutex or the i_pages lock thanks to RCU, |
Vlastimil Babka | 48131e0 | 2016-01-14 15:19:23 -0800 | [diff] [blame] | 808 | * as long as the inode doesn't go away and racy results are not a problem. |
| 809 | */ |
| 810 | unsigned long shmem_swap_usage(struct vm_area_struct *vma) |
| 811 | { |
| 812 | struct inode *inode = file_inode(vma->vm_file); |
| 813 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 814 | struct address_space *mapping = inode->i_mapping; |
| 815 | unsigned long swapped; |
| 816 | |
| 817 | /* Be careful as we don't hold info->lock */ |
| 818 | swapped = READ_ONCE(info->swapped); |
| 819 | |
| 820 | /* |
| 821 | * The easier cases are when the shmem object has nothing in swap, or |
| 822 | * the vma maps it whole. Then we can simply use the stats that we |
| 823 | * already track. |
| 824 | */ |
| 825 | if (!swapped) |
| 826 | return 0; |
| 827 | |
| 828 | if (!vma->vm_pgoff && vma->vm_end - vma->vm_start >= inode->i_size) |
| 829 | return swapped << PAGE_SHIFT; |
| 830 | |
| 831 | /* Here comes the more involved part */ |
| 832 | return shmem_partial_swap_usage(mapping, |
| 833 | linear_page_index(vma, vma->vm_start), |
| 834 | linear_page_index(vma, vma->vm_end)); |
| 835 | } |
| 836 | |
| 837 | /* |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 838 | * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists. |
| 839 | */ |
| 840 | void shmem_unlock_mapping(struct address_space *mapping) |
| 841 | { |
| 842 | struct pagevec pvec; |
| 843 | pgoff_t indices[PAGEVEC_SIZE]; |
| 844 | pgoff_t index = 0; |
| 845 | |
Mel Gorman | 8667982 | 2017-11-15 17:37:52 -0800 | [diff] [blame] | 846 | pagevec_init(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 847 | /* |
| 848 | * Minor point, but we might as well stop if someone else SHM_LOCKs it. |
| 849 | */ |
| 850 | while (!mapping_unevictable(mapping)) { |
| 851 | /* |
| 852 | * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it |
| 853 | * has finished, if it hits a row of PAGEVEC_SIZE swap entries. |
| 854 | */ |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 855 | pvec.nr = find_get_entries(mapping, index, |
| 856 | PAGEVEC_SIZE, pvec.pages, indices); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 857 | if (!pvec.nr) |
| 858 | break; |
| 859 | index = indices[pvec.nr - 1] + 1; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 860 | pagevec_remove_exceptionals(&pvec); |
Kuo-Hsin Yang | 64e3d12 | 2018-11-06 13:23:24 +0000 | [diff] [blame] | 861 | check_move_unevictable_pages(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 862 | pagevec_release(&pvec); |
| 863 | cond_resched(); |
| 864 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 865 | } |
| 866 | |
| 867 | /* |
Hugh Dickins | 71725ed | 2020-04-06 20:07:57 -0700 | [diff] [blame] | 868 | * Check whether a hole-punch or truncation needs to split a huge page, |
| 869 | * returning true if no split was required, or the split has been successful. |
| 870 | * |
| 871 | * Eviction (or truncation to 0 size) should never need to split a huge page; |
| 872 | * but in rare cases might do so, if shmem_undo_range() failed to trylock on |
| 873 | * head, and then succeeded to trylock on tail. |
| 874 | * |
| 875 | * A split can only succeed when there are no additional references on the |
| 876 | * huge page: so the split below relies upon find_get_entries() having stopped |
| 877 | * when it found a subpage of the huge page, without getting further references. |
| 878 | */ |
| 879 | static bool shmem_punch_compound(struct page *page, pgoff_t start, pgoff_t end) |
| 880 | { |
| 881 | if (!PageTransCompound(page)) |
| 882 | return true; |
| 883 | |
| 884 | /* Just proceed to delete a huge page wholly within the range punched */ |
| 885 | if (PageHead(page) && |
| 886 | page->index >= start && page->index + HPAGE_PMD_NR <= end) |
| 887 | return true; |
| 888 | |
| 889 | /* Try to split huge page, so we can truly punch the hole or truncate */ |
| 890 | return split_huge_page(page) >= 0; |
| 891 | } |
| 892 | |
| 893 | /* |
Matthew Wilcox | 7f4446e | 2017-12-04 03:31:13 -0500 | [diff] [blame] | 894 | * Remove range of pages and swap entries from page cache, and free them. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 895 | * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 896 | */ |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 897 | static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, |
| 898 | bool unfalloc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | { |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 900 | struct address_space *mapping = inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 902 | pgoff_t start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 903 | pgoff_t end = (lend + 1) >> PAGE_SHIFT; |
| 904 | unsigned int partial_start = lstart & (PAGE_SIZE - 1); |
| 905 | unsigned int partial_end = (lend + 1) & (PAGE_SIZE - 1); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 906 | struct pagevec pvec; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 907 | pgoff_t indices[PAGEVEC_SIZE]; |
| 908 | long nr_swaps_freed = 0; |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 909 | pgoff_t index; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 910 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 912 | if (lend == -1) |
| 913 | end = -1; /* unsigned, so actually very big */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 914 | |
Mel Gorman | 8667982 | 2017-11-15 17:37:52 -0800 | [diff] [blame] | 915 | pagevec_init(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 916 | index = start; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 917 | while (index < end) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 918 | pvec.nr = find_get_entries(mapping, index, |
| 919 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
| 920 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 921 | if (!pvec.nr) |
| 922 | break; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 923 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 924 | struct page *page = pvec.pages[i]; |
| 925 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 926 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 927 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 928 | break; |
| 929 | |
Matthew Wilcox | 3159f94 | 2017-11-03 13:30:42 -0400 | [diff] [blame] | 930 | if (xa_is_value(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 931 | if (unfalloc) |
| 932 | continue; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 933 | nr_swaps_freed += !shmem_free_swap(mapping, |
| 934 | index, page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 935 | continue; |
| 936 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 937 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 938 | VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page); |
| 939 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 940 | if (!trylock_page(page)) |
| 941 | continue; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 942 | |
Hugh Dickins | 71725ed | 2020-04-06 20:07:57 -0700 | [diff] [blame] | 943 | if ((!unfalloc || !PageUptodate(page)) && |
| 944 | page_mapping(page) == mapping) { |
| 945 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
| 946 | if (shmem_punch_compound(page, start, end)) |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 947 | truncate_inode_page(mapping, page); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 948 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 949 | unlock_page(page); |
| 950 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 951 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 952 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 953 | cond_resched(); |
| 954 | index++; |
| 955 | } |
| 956 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 957 | if (partial_start) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 958 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 959 | shmem_getpage(inode, start - 1, &page, SGP_READ); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 960 | if (page) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 961 | unsigned int top = PAGE_SIZE; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 962 | if (start > end) { |
| 963 | top = partial_end; |
| 964 | partial_end = 0; |
| 965 | } |
| 966 | zero_user_segment(page, partial_start, top); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 967 | set_page_dirty(page); |
| 968 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 969 | put_page(page); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 970 | } |
| 971 | } |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 972 | if (partial_end) { |
| 973 | struct page *page = NULL; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 974 | shmem_getpage(inode, end, &page, SGP_READ); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 975 | if (page) { |
| 976 | zero_user_segment(page, 0, partial_end); |
| 977 | set_page_dirty(page); |
| 978 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 979 | put_page(page); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 980 | } |
| 981 | } |
| 982 | if (start >= end) |
| 983 | return; |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 984 | |
| 985 | index = start; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 986 | while (index < end) { |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 987 | cond_resched(); |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 988 | |
| 989 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 990 | min(end - index, (pgoff_t)PAGEVEC_SIZE), |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 991 | pvec.pages, indices); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 992 | if (!pvec.nr) { |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 993 | /* If all gone or hole-punch or unfalloc, we're done */ |
| 994 | if (index == start || end != -1) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 995 | break; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 996 | /* But if truncating, restart to make sure all gone */ |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 997 | index = start; |
| 998 | continue; |
| 999 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1000 | for (i = 0; i < pagevec_count(&pvec); i++) { |
| 1001 | struct page *page = pvec.pages[i]; |
| 1002 | |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 1003 | index = indices[i]; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 1004 | if (index >= end) |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1005 | break; |
| 1006 | |
Matthew Wilcox | 3159f94 | 2017-11-03 13:30:42 -0400 | [diff] [blame] | 1007 | if (xa_is_value(page)) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1008 | if (unfalloc) |
| 1009 | continue; |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 1010 | if (shmem_free_swap(mapping, index, page)) { |
| 1011 | /* Swap was replaced by page: retry */ |
| 1012 | index--; |
| 1013 | break; |
| 1014 | } |
| 1015 | nr_swaps_freed++; |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 1016 | continue; |
| 1017 | } |
| 1018 | |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1019 | lock_page(page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1020 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1021 | if (!unfalloc || !PageUptodate(page)) { |
Hugh Dickins | 71725ed | 2020-04-06 20:07:57 -0700 | [diff] [blame] | 1022 | if (page_mapping(page) != mapping) { |
Hugh Dickins | b1a3665 | 2014-07-23 14:00:13 -0700 | [diff] [blame] | 1023 | /* Page was replaced by swap: retry */ |
| 1024 | unlock_page(page); |
| 1025 | index--; |
| 1026 | break; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1027 | } |
Hugh Dickins | 71725ed | 2020-04-06 20:07:57 -0700 | [diff] [blame] | 1028 | VM_BUG_ON_PAGE(PageWriteback(page), page); |
| 1029 | if (shmem_punch_compound(page, start, end)) |
| 1030 | truncate_inode_page(mapping, page); |
Hugh Dickins | 0783ac9 | 2020-04-20 18:14:07 -0700 | [diff] [blame] | 1031 | else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { |
Hugh Dickins | 71725ed | 2020-04-06 20:07:57 -0700 | [diff] [blame] | 1032 | /* Wipe the page and don't get stuck */ |
| 1033 | clear_highpage(page); |
| 1034 | flush_dcache_page(page); |
| 1035 | set_page_dirty(page); |
| 1036 | if (index < |
| 1037 | round_up(start, HPAGE_PMD_NR)) |
| 1038 | start = index + 1; |
| 1039 | } |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 1040 | } |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1041 | unlock_page(page); |
| 1042 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 1043 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 1044 | pagevec_release(&pvec); |
Hugh Dickins | bda97ea | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1045 | index++; |
| 1046 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1047 | |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1048 | spin_lock_irq(&info->lock); |
Hugh Dickins | 7a5d0fb | 2011-08-03 16:21:22 -0700 | [diff] [blame] | 1049 | info->swapped -= nr_swaps_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1051 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1052 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1054 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
| 1055 | { |
| 1056 | shmem_undo_range(inode, lstart, lend, false); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 1057 | inode->i_ctime = inode->i_mtime = current_time(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1058 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1059 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1060 | |
David Howells | a528d35 | 2017-01-31 16:46:22 +0000 | [diff] [blame] | 1061 | static int shmem_getattr(const struct path *path, struct kstat *stat, |
| 1062 | u32 request_mask, unsigned int query_flags) |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1063 | { |
David Howells | a528d35 | 2017-01-31 16:46:22 +0000 | [diff] [blame] | 1064 | struct inode *inode = path->dentry->d_inode; |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1065 | struct shmem_inode_info *info = SHMEM_I(inode); |
Yang Shi | 89fdcd2 | 2018-06-07 17:06:59 -0700 | [diff] [blame] | 1066 | struct shmem_sb_info *sb_info = SHMEM_SB(inode->i_sb); |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1067 | |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1068 | if (info->alloced - info->swapped != inode->i_mapping->nrpages) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1069 | spin_lock_irq(&info->lock); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1070 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1071 | spin_unlock_irq(&info->lock); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1072 | } |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1073 | generic_fillattr(inode, stat); |
Yang Shi | 89fdcd2 | 2018-06-07 17:06:59 -0700 | [diff] [blame] | 1074 | |
| 1075 | if (is_huge_enabled(sb_info)) |
| 1076 | stat->blksize = HPAGE_PMD_SIZE; |
| 1077 | |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 1078 | return 0; |
| 1079 | } |
| 1080 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1081 | static int shmem_setattr(struct dentry *dentry, struct iattr *attr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 1083 | struct inode *inode = d_inode(dentry); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1084 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1085 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | int error; |
| 1087 | |
Jan Kara | 31051c8 | 2016-05-26 16:55:18 +0200 | [diff] [blame] | 1088 | error = setattr_prepare(dentry, attr); |
Christoph Hellwig | db78b877 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1089 | if (error) |
| 1090 | return error; |
| 1091 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1092 | if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { |
| 1093 | loff_t oldsize = inode->i_size; |
| 1094 | loff_t newsize = attr->ia_size; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1095 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 1096 | /* protected by i_mutex */ |
| 1097 | if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) || |
| 1098 | (newsize > oldsize && (info->seals & F_SEAL_GROW))) |
| 1099 | return -EPERM; |
| 1100 | |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1101 | if (newsize != oldsize) { |
Konstantin Khlebnikov | 7714251 | 2014-08-06 16:06:34 -0700 | [diff] [blame] | 1102 | error = shmem_reacct_size(SHMEM_I(inode)->flags, |
| 1103 | oldsize, newsize); |
| 1104 | if (error) |
| 1105 | return error; |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1106 | i_size_write(inode, newsize); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 1107 | inode->i_ctime = inode->i_mtime = current_time(inode); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1108 | } |
Josef Bacik | afa2db2 | 2015-06-24 16:58:45 -0700 | [diff] [blame] | 1109 | if (newsize <= oldsize) { |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1110 | loff_t holebegin = round_up(newsize, PAGE_SIZE); |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1111 | if (oldsize > holebegin) |
| 1112 | unmap_mapping_range(inode->i_mapping, |
| 1113 | holebegin, 0, 1); |
| 1114 | if (info->alloced) |
| 1115 | shmem_truncate_range(inode, |
| 1116 | newsize, (loff_t)-1); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1117 | /* unmap again to remove racily COWed private pages */ |
Hugh Dickins | d0424c4 | 2015-11-05 18:50:34 -0800 | [diff] [blame] | 1118 | if (oldsize > holebegin) |
| 1119 | unmap_mapping_range(inode->i_mapping, |
| 1120 | holebegin, 0, 1); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1121 | |
| 1122 | /* |
| 1123 | * Part of the huge page can be beyond i_size: subject |
| 1124 | * to shrink under memory pressure. |
| 1125 | */ |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 1126 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1127 | spin_lock(&sbinfo->shrinklist_lock); |
Cong Wang | d041353 | 2017-08-10 15:24:24 -0700 | [diff] [blame] | 1128 | /* |
| 1129 | * _careful to defend against unlocked access to |
| 1130 | * ->shrink_list in shmem_unused_huge_shrink() |
| 1131 | */ |
| 1132 | if (list_empty_careful(&info->shrinklist)) { |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1133 | list_add_tail(&info->shrinklist, |
| 1134 | &sbinfo->shrinklist); |
| 1135 | sbinfo->shrinklist_len++; |
| 1136 | } |
| 1137 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1138 | } |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 1139 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | } |
| 1141 | |
Christoph Hellwig | db78b877 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1142 | setattr_copy(inode, attr); |
Christoph Hellwig | db78b877 | 2010-06-04 11:30:03 +0200 | [diff] [blame] | 1143 | if (attr->ia_valid & ATTR_MODE) |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 1144 | error = posix_acl_chmod(inode, inode->i_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | return error; |
| 1146 | } |
| 1147 | |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 1148 | static void shmem_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1151 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1153 | if (inode->i_mapping->a_ops == &shmem_aops) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1154 | shmem_unacct_size(info->flags, inode->i_size); |
| 1155 | inode->i_size = 0; |
npiggin@suse.de | 3889e6e | 2010-05-27 01:05:36 +1000 | [diff] [blame] | 1156 | shmem_truncate_range(inode, 0, (loff_t)-1); |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 1157 | if (!list_empty(&info->shrinklist)) { |
| 1158 | spin_lock(&sbinfo->shrinklist_lock); |
| 1159 | if (!list_empty(&info->shrinklist)) { |
| 1160 | list_del_init(&info->shrinklist); |
| 1161 | sbinfo->shrinklist_len--; |
| 1162 | } |
| 1163 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1164 | } |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 1165 | while (!list_empty(&info->swaplist)) { |
| 1166 | /* Wait while shmem_unuse() is scanning this inode... */ |
| 1167 | wait_var_event(&info->stop_eviction, |
| 1168 | !atomic_read(&info->stop_eviction)); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1169 | mutex_lock(&shmem_swaplist_mutex); |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 1170 | /* ...but beware of the race if we peeked too early */ |
| 1171 | if (!atomic_read(&info->stop_eviction)) |
| 1172 | list_del_init(&info->swaplist); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1173 | mutex_unlock(&shmem_swaplist_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | } |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 1175 | } |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 1176 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 1177 | simple_xattrs_free(&info->xattrs); |
Hugh Dickins | 0f3c42f | 2012-11-16 14:15:04 -0800 | [diff] [blame] | 1178 | WARN_ON(inode->i_blocks); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 1179 | shmem_free_inode(inode->i_sb); |
Jan Kara | dbd5768 | 2012-05-03 14:48:02 +0200 | [diff] [blame] | 1180 | clear_inode(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | } |
| 1182 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1183 | extern struct swap_info_struct *swap_info[]; |
| 1184 | |
| 1185 | static int shmem_find_swap_entries(struct address_space *mapping, |
| 1186 | pgoff_t start, unsigned int nr_entries, |
| 1187 | struct page **entries, pgoff_t *indices, |
Hugh Dickins | 8703954 | 2019-04-18 17:49:58 -0700 | [diff] [blame] | 1188 | unsigned int type, bool frontswap) |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1189 | { |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1190 | XA_STATE(xas, &mapping->i_pages, start); |
| 1191 | struct page *page; |
Hugh Dickins | 8703954 | 2019-04-18 17:49:58 -0700 | [diff] [blame] | 1192 | swp_entry_t entry; |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1193 | unsigned int ret = 0; |
| 1194 | |
| 1195 | if (!nr_entries) |
| 1196 | return 0; |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1197 | |
| 1198 | rcu_read_lock(); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1199 | xas_for_each(&xas, page, ULONG_MAX) { |
| 1200 | if (xas_retry(&xas, page)) |
Mike Kravetz | 5b9c98f | 2018-06-07 17:05:53 -0700 | [diff] [blame] | 1201 | continue; |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1202 | |
| 1203 | if (!xa_is_value(page)) |
| 1204 | continue; |
| 1205 | |
Hugh Dickins | 8703954 | 2019-04-18 17:49:58 -0700 | [diff] [blame] | 1206 | entry = radix_to_swp_entry(page); |
| 1207 | if (swp_type(entry) != type) |
| 1208 | continue; |
| 1209 | if (frontswap && |
| 1210 | !frontswap_test(swap_info[type], swp_offset(entry))) |
| 1211 | continue; |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1212 | |
| 1213 | indices[ret] = xas.xa_index; |
| 1214 | entries[ret] = page; |
| 1215 | |
| 1216 | if (need_resched()) { |
| 1217 | xas_pause(&xas); |
| 1218 | cond_resched_rcu(); |
| 1219 | } |
| 1220 | if (++ret == nr_entries) |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1221 | break; |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1222 | } |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1223 | rcu_read_unlock(); |
Matthew Wilcox | e21a295 | 2017-11-22 08:36:00 -0500 | [diff] [blame] | 1224 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1225 | return ret; |
| 1226 | } |
| 1227 | |
| 1228 | /* |
| 1229 | * Move the swapped pages for an inode to page cache. Returns the count |
| 1230 | * of pages swapped in, or the error in case of failure. |
| 1231 | */ |
| 1232 | static int shmem_unuse_swap_entries(struct inode *inode, struct pagevec pvec, |
| 1233 | pgoff_t *indices) |
| 1234 | { |
| 1235 | int i = 0; |
| 1236 | int ret = 0; |
| 1237 | int error = 0; |
| 1238 | struct address_space *mapping = inode->i_mapping; |
| 1239 | |
| 1240 | for (i = 0; i < pvec.nr; i++) { |
| 1241 | struct page *page = pvec.pages[i]; |
| 1242 | |
| 1243 | if (!xa_is_value(page)) |
| 1244 | continue; |
| 1245 | error = shmem_swapin_page(inode, indices[i], |
| 1246 | &page, SGP_CACHE, |
| 1247 | mapping_gfp_mask(mapping), |
| 1248 | NULL, NULL); |
| 1249 | if (error == 0) { |
| 1250 | unlock_page(page); |
| 1251 | put_page(page); |
| 1252 | ret++; |
| 1253 | } |
| 1254 | if (error == -ENOMEM) |
| 1255 | break; |
| 1256 | error = 0; |
| 1257 | } |
| 1258 | return error ? error : ret; |
Matthew Wilcox | 478922e | 2016-12-14 15:08:52 -0800 | [diff] [blame] | 1259 | } |
| 1260 | |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1261 | /* |
| 1262 | * If swap found in inode, free it and move page from swapcache to filecache. |
| 1263 | */ |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1264 | static int shmem_unuse_inode(struct inode *inode, unsigned int type, |
| 1265 | bool frontswap, unsigned long *fs_pages_to_unuse) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1266 | { |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1267 | struct address_space *mapping = inode->i_mapping; |
| 1268 | pgoff_t start = 0; |
| 1269 | struct pagevec pvec; |
| 1270 | pgoff_t indices[PAGEVEC_SIZE]; |
| 1271 | bool frontswap_partial = (frontswap && *fs_pages_to_unuse > 0); |
| 1272 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1273 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1274 | pagevec_init(&pvec); |
| 1275 | do { |
| 1276 | unsigned int nr_entries = PAGEVEC_SIZE; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 1277 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1278 | if (frontswap_partial && *fs_pages_to_unuse < PAGEVEC_SIZE) |
| 1279 | nr_entries = *fs_pages_to_unuse; |
Hugh Dickins | 2e0e26c | 2008-02-04 22:28:53 -0800 | [diff] [blame] | 1280 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1281 | pvec.nr = shmem_find_swap_entries(mapping, start, nr_entries, |
| 1282 | pvec.pages, indices, |
Hugh Dickins | 8703954 | 2019-04-18 17:49:58 -0700 | [diff] [blame] | 1283 | type, frontswap); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1284 | if (pvec.nr == 0) { |
| 1285 | ret = 0; |
| 1286 | break; |
Hugh Dickins | 46f65ec | 2011-08-03 16:21:23 -0700 | [diff] [blame] | 1287 | } |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1288 | |
| 1289 | ret = shmem_unuse_swap_entries(inode, pvec, indices); |
| 1290 | if (ret < 0) |
| 1291 | break; |
| 1292 | |
| 1293 | if (frontswap_partial) { |
| 1294 | *fs_pages_to_unuse -= ret; |
| 1295 | if (*fs_pages_to_unuse == 0) { |
| 1296 | ret = FRONTSWAP_PAGES_UNUSED; |
| 1297 | break; |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | start = indices[pvec.nr - 1]; |
| 1302 | } while (true); |
| 1303 | |
| 1304 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1305 | } |
| 1306 | |
| 1307 | /* |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1308 | * Read all the shared memory data that resides in the swap |
| 1309 | * device 'type' back into memory, so the swap device can be |
| 1310 | * unused. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | */ |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1312 | int shmem_unuse(unsigned int type, bool frontswap, |
| 1313 | unsigned long *fs_pages_to_unuse) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | { |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1315 | struct shmem_inode_info *info, *next; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1316 | int error = 0; |
| 1317 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1318 | if (list_empty(&shmem_swaplist)) |
| 1319 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1321 | mutex_lock(&shmem_swaplist_mutex); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1322 | list_for_each_entry_safe(info, next, &shmem_swaplist, swaplist) { |
| 1323 | if (!info->swapped) { |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1324 | list_del_init(&info->swaplist); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1325 | continue; |
| 1326 | } |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 1327 | /* |
| 1328 | * Drop the swaplist mutex while searching the inode for swap; |
| 1329 | * but before doing so, make sure shmem_evict_inode() will not |
| 1330 | * remove placeholder inode from swaplist, nor let it be freed |
| 1331 | * (igrab() would protect from unlink, but not from unmount). |
| 1332 | */ |
| 1333 | atomic_inc(&info->stop_eviction); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1334 | mutex_unlock(&shmem_swaplist_mutex); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1335 | |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 1336 | error = shmem_unuse_inode(&info->vfs_inode, type, frontswap, |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1337 | fs_pages_to_unuse); |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1338 | cond_resched(); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1339 | |
| 1340 | mutex_lock(&shmem_swaplist_mutex); |
| 1341 | next = list_next_entry(info, swaplist); |
| 1342 | if (!info->swapped) |
| 1343 | list_del_init(&info->swaplist); |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 1344 | if (atomic_dec_and_test(&info->stop_eviction)) |
| 1345 | wake_up_var(&info->stop_eviction); |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1346 | if (error) |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1347 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | } |
Hugh Dickins | cb5f7b9 | 2008-02-04 22:28:52 -0800 | [diff] [blame] | 1349 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1350 | |
Hugh Dickins | 778dd89 | 2011-05-11 15:13:37 -0700 | [diff] [blame] | 1351 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | } |
| 1353 | |
| 1354 | /* |
| 1355 | * Move the page from the page cache to the swap cache. |
| 1356 | */ |
| 1357 | static int shmem_writepage(struct page *page, struct writeback_control *wbc) |
| 1358 | { |
| 1359 | struct shmem_inode_info *info; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1360 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1361 | struct inode *inode; |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1362 | swp_entry_t swap; |
| 1363 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1365 | VM_BUG_ON_PAGE(PageCompound(page), page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | mapping = page->mapping; |
| 1368 | index = page->index; |
| 1369 | inode = mapping->host; |
| 1370 | info = SHMEM_I(inode); |
| 1371 | if (info->flags & VM_LOCKED) |
| 1372 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1373 | if (!total_swap_pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | goto redirty; |
| 1375 | |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1376 | /* |
Christoph Hellwig | 97b713b | 2015-01-14 10:42:31 +0100 | [diff] [blame] | 1377 | * Our capabilities prevent regular writeback or sync from ever calling |
| 1378 | * shmem_writepage; but a stacking filesystem might use ->writepage of |
| 1379 | * its underlying filesystem, in which case tmpfs should write out to |
| 1380 | * swap only in response to memory pressure, and not for the writeback |
| 1381 | * threads or sync. |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1382 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1383 | if (!wbc->for_reclaim) { |
| 1384 | WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ |
| 1385 | goto redirty; |
| 1386 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1387 | |
| 1388 | /* |
| 1389 | * This is somewhat ridiculous, but without plumbing a SWAP_MAP_FALLOC |
| 1390 | * value into swapfile.c, the only way we can correctly account for a |
| 1391 | * fallocated page arriving here is now to initialize it and write it. |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1392 | * |
| 1393 | * That's okay for a page already fallocated earlier, but if we have |
| 1394 | * not yet completed the fallocation, then (a) we want to keep track |
| 1395 | * of this page in case we have to undo it, and (b) it may not be a |
| 1396 | * good idea to continue anyway, once we're pushing into swap. So |
| 1397 | * reactivate the page, and let shmem_fallocate() quit when too many. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1398 | */ |
| 1399 | if (!PageUptodate(page)) { |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1400 | if (inode->i_private) { |
| 1401 | struct shmem_falloc *shmem_falloc; |
| 1402 | spin_lock(&inode->i_lock); |
| 1403 | shmem_falloc = inode->i_private; |
| 1404 | if (shmem_falloc && |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 1405 | !shmem_falloc->waitq && |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1406 | index >= shmem_falloc->start && |
| 1407 | index < shmem_falloc->next) |
| 1408 | shmem_falloc->nr_unswapped++; |
| 1409 | else |
| 1410 | shmem_falloc = NULL; |
| 1411 | spin_unlock(&inode->i_lock); |
| 1412 | if (shmem_falloc) |
| 1413 | goto redirty; |
| 1414 | } |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1415 | clear_highpage(page); |
| 1416 | flush_dcache_page(page); |
| 1417 | SetPageUptodate(page); |
| 1418 | } |
| 1419 | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 1420 | swap = get_swap_page(page); |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1421 | if (!swap.val) |
| 1422 | goto redirty; |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1423 | |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1424 | /* |
| 1425 | * Add inode to shmem_unuse()'s list of swapped-out inodes, |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1426 | * if it's not already there. Do it now before the page is |
| 1427 | * moved to swap cache, when its pagelock no longer protects |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1428 | * the inode from eviction. But don't unlock the mutex until |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1429 | * we've incremented swapped, because shmem_unuse_inode() will |
| 1430 | * prune a !swapped inode from the swaplist under this mutex. |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1431 | */ |
Hugh Dickins | 48f170f | 2011-07-25 17:12:37 -0700 | [diff] [blame] | 1432 | mutex_lock(&shmem_swaplist_mutex); |
| 1433 | if (list_empty(&info->swaplist)) |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 1434 | list_add(&info->swaplist, &shmem_swaplist); |
Hugh Dickins | b1dea80 | 2011-05-11 15:13:36 -0700 | [diff] [blame] | 1435 | |
Yang Shi | 4afab1c | 2019-11-30 17:58:07 -0800 | [diff] [blame] | 1436 | if (add_to_swap_cache(page, swap, |
Joonsoo Kim | 3852f67 | 2020-08-11 18:30:47 -0700 | [diff] [blame] | 1437 | __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN, |
| 1438 | NULL) == 0) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1439 | spin_lock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1440 | shmem_recalc_inode(inode); |
| 1441 | info->swapped++; |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1442 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1443 | |
Hugh Dickins | aaa4686 | 2009-12-14 17:58:47 -0800 | [diff] [blame] | 1444 | swap_shmem_alloc(swap); |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1445 | shmem_delete_from_page_cache(page, swp_to_radix_entry(swap)); |
| 1446 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1447 | mutex_unlock(&shmem_swaplist_mutex); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1448 | BUG_ON(page_mapped(page)); |
Hugh Dickins | 9fab561 | 2009-03-31 15:23:33 -0700 | [diff] [blame] | 1449 | swap_writepage(page, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | return 0; |
| 1451 | } |
| 1452 | |
Hugh Dickins | 6922c0c | 2011-08-03 16:21:25 -0700 | [diff] [blame] | 1453 | mutex_unlock(&shmem_swaplist_mutex); |
Minchan Kim | 75f6d6d | 2017-07-06 15:37:21 -0700 | [diff] [blame] | 1454 | put_swap_page(page, swap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1455 | redirty: |
| 1456 | set_page_dirty(page); |
Hugh Dickins | d9fe526 | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 1457 | if (wbc->for_reclaim) |
| 1458 | return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ |
| 1459 | unlock_page(page); |
| 1460 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | } |
| 1462 | |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1463 | #if defined(CONFIG_NUMA) && defined(CONFIG_TMPFS) |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1464 | static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1465 | { |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1466 | char buffer[64]; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1467 | |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1468 | if (!mpol || mpol->mode == MPOL_DEFAULT) |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1469 | return; /* show nothing */ |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1470 | |
Hugh Dickins | a7a88b2 | 2013-01-02 02:04:23 -0800 | [diff] [blame] | 1471 | mpol_to_str(buffer, sizeof(buffer), mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1472 | |
Lee Schermerhorn | 095f1fc | 2008-04-28 02:13:23 -0700 | [diff] [blame] | 1473 | seq_printf(seq, ",mpol=%s", buffer); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1474 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1475 | |
| 1476 | static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 1477 | { |
| 1478 | struct mempolicy *mpol = NULL; |
| 1479 | if (sbinfo->mpol) { |
| 1480 | spin_lock(&sbinfo->stat_lock); /* prevent replace/use races */ |
| 1481 | mpol = sbinfo->mpol; |
| 1482 | mpol_get(mpol); |
| 1483 | spin_unlock(&sbinfo->stat_lock); |
| 1484 | } |
| 1485 | return mpol; |
| 1486 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1487 | #else /* !CONFIG_NUMA || !CONFIG_TMPFS */ |
| 1488 | static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) |
| 1489 | { |
| 1490 | } |
| 1491 | static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) |
| 1492 | { |
| 1493 | return NULL; |
| 1494 | } |
| 1495 | #endif /* CONFIG_NUMA && CONFIG_TMPFS */ |
| 1496 | #ifndef CONFIG_NUMA |
| 1497 | #define vm_policy vm_private_data |
| 1498 | #endif |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 1499 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1500 | static void shmem_pseudo_vma_init(struct vm_area_struct *vma, |
| 1501 | struct shmem_inode_info *info, pgoff_t index) |
| 1502 | { |
| 1503 | /* Create a pseudo vma that just contains the policy */ |
Kirill A. Shutemov | 2c4541e | 2018-07-26 16:37:30 -0700 | [diff] [blame] | 1504 | vma_init(vma, NULL); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1505 | /* Bias interleave by inode number to distribute better across nodes */ |
| 1506 | vma->vm_pgoff = index + info->vfs_inode.i_ino; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1507 | vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index); |
| 1508 | } |
| 1509 | |
| 1510 | static void shmem_pseudo_vma_destroy(struct vm_area_struct *vma) |
| 1511 | { |
| 1512 | /* Drop reference taken by mpol_shared_policy_lookup() */ |
| 1513 | mpol_cond_put(vma->vm_policy); |
| 1514 | } |
| 1515 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1516 | static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, |
| 1517 | struct shmem_inode_info *info, pgoff_t index) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | struct vm_area_struct pvma; |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1520 | struct page *page; |
Minchan Kim | e9e9b7e | 2018-04-05 16:23:42 -0700 | [diff] [blame] | 1521 | struct vm_fault vmf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1523 | shmem_pseudo_vma_init(&pvma, info, index); |
Minchan Kim | e9e9b7e | 2018-04-05 16:23:42 -0700 | [diff] [blame] | 1524 | vmf.vma = &pvma; |
| 1525 | vmf.address = 0; |
| 1526 | page = swap_cluster_readahead(swap, gfp, &vmf); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1527 | shmem_pseudo_vma_destroy(&pvma); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1528 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1529 | return page; |
| 1530 | } |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1531 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1532 | static struct page *shmem_alloc_hugepage(gfp_t gfp, |
| 1533 | struct shmem_inode_info *info, pgoff_t index) |
| 1534 | { |
| 1535 | struct vm_area_struct pvma; |
Matthew Wilcox | 7b8d046 | 2017-12-01 22:13:06 -0500 | [diff] [blame] | 1536 | struct address_space *mapping = info->vfs_inode.i_mapping; |
| 1537 | pgoff_t hindex; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1538 | struct page *page; |
| 1539 | |
Geert Uytterhoeven | 4620a06 | 2016-08-03 19:58:19 +0200 | [diff] [blame] | 1540 | hindex = round_down(index, HPAGE_PMD_NR); |
Matthew Wilcox | 7b8d046 | 2017-12-01 22:13:06 -0500 | [diff] [blame] | 1541 | if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1, |
| 1542 | XA_PRESENT)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1543 | return NULL; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1544 | |
| 1545 | shmem_pseudo_vma_init(&pvma, info, hindex); |
| 1546 | page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, |
David Rientjes | 19deb76 | 2019-09-04 12:54:20 -0700 | [diff] [blame] | 1547 | HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), true); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1548 | shmem_pseudo_vma_destroy(&pvma); |
| 1549 | if (page) |
| 1550 | prep_transhuge_page(page); |
David Rientjes | dcdf11e | 2020-04-06 20:04:25 -0700 | [diff] [blame] | 1551 | else |
| 1552 | count_vm_event(THP_FILE_FALLBACK); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1553 | return page; |
| 1554 | } |
| 1555 | |
| 1556 | static struct page *shmem_alloc_page(gfp_t gfp, |
| 1557 | struct shmem_inode_info *info, pgoff_t index) |
| 1558 | { |
| 1559 | struct vm_area_struct pvma; |
| 1560 | struct page *page; |
| 1561 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1562 | shmem_pseudo_vma_init(&pvma, info, index); |
| 1563 | page = alloc_page_vma(gfp, &pvma, 0); |
| 1564 | shmem_pseudo_vma_destroy(&pvma); |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1565 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1566 | return page; |
| 1567 | } |
| 1568 | |
| 1569 | static struct page *shmem_alloc_and_acct_page(gfp_t gfp, |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1570 | struct inode *inode, |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1571 | pgoff_t index, bool huge) |
| 1572 | { |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1573 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1574 | struct page *page; |
| 1575 | int nr; |
| 1576 | int err = -ENOSPC; |
| 1577 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 1578 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1579 | huge = false; |
| 1580 | nr = huge ? HPAGE_PMD_NR : 1; |
| 1581 | |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1582 | if (!shmem_inode_acct_block(inode, nr)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1583 | goto failed; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1584 | |
| 1585 | if (huge) |
| 1586 | page = shmem_alloc_hugepage(gfp, info, index); |
| 1587 | else |
| 1588 | page = shmem_alloc_page(gfp, info, index); |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1589 | if (page) { |
| 1590 | __SetPageLocked(page); |
| 1591 | __SetPageSwapBacked(page); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1592 | return page; |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1593 | } |
Mel Gorman | 18a2f37 | 2012-12-05 14:01:41 -0800 | [diff] [blame] | 1594 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1595 | err = -ENOMEM; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 1596 | shmem_inode_unacct_blocks(inode, nr); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1597 | failed: |
| 1598 | return ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1599 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 1600 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1601 | /* |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1602 | * When a page is moved from swapcache to shmem filecache (either by the |
| 1603 | * usual swapin of shmem_getpage_gfp(), or by the less common swapoff of |
| 1604 | * shmem_unuse_inode()), it may have been read in earlier from swap, in |
| 1605 | * ignorance of the mapping it belongs to. If that mapping has special |
| 1606 | * constraints (like the gma500 GEM driver, which requires RAM below 4GB), |
| 1607 | * we may need to copy to a suitable page before moving to filecache. |
| 1608 | * |
| 1609 | * In a future release, this may well be extended to respect cpuset and |
| 1610 | * NUMA mempolicy, and applied also to anonymous pages in do_swap_page(); |
| 1611 | * but for now it is a simple matter of zone. |
| 1612 | */ |
| 1613 | static bool shmem_should_replace_page(struct page *page, gfp_t gfp) |
| 1614 | { |
| 1615 | return page_zonenum(page) > gfp_zone(gfp); |
| 1616 | } |
| 1617 | |
| 1618 | static int shmem_replace_page(struct page **pagep, gfp_t gfp, |
| 1619 | struct shmem_inode_info *info, pgoff_t index) |
| 1620 | { |
| 1621 | struct page *oldpage, *newpage; |
| 1622 | struct address_space *swap_mapping; |
Yu Zhao | c1cb20d | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1623 | swp_entry_t entry; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1624 | pgoff_t swap_index; |
| 1625 | int error; |
| 1626 | |
| 1627 | oldpage = *pagep; |
Yu Zhao | c1cb20d | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1628 | entry.val = page_private(oldpage); |
| 1629 | swap_index = swp_offset(entry); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1630 | swap_mapping = page_mapping(oldpage); |
| 1631 | |
| 1632 | /* |
| 1633 | * We have arrived here because our zones are constrained, so don't |
| 1634 | * limit chance of success by further cpuset and node constraints. |
| 1635 | */ |
| 1636 | gfp &= ~GFP_CONSTRAINT_MASK; |
| 1637 | newpage = shmem_alloc_page(gfp, info, index); |
| 1638 | if (!newpage) |
| 1639 | return -ENOMEM; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1640 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1641 | get_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1642 | copy_highpage(newpage, oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1643 | flush_dcache_page(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1644 | |
Hugh Dickins | 9956edf | 2016-11-10 10:46:11 -0800 | [diff] [blame] | 1645 | __SetPageLocked(newpage); |
| 1646 | __SetPageSwapBacked(newpage); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1647 | SetPageUptodate(newpage); |
Yu Zhao | c1cb20d | 2018-11-30 14:09:03 -0800 | [diff] [blame] | 1648 | set_page_private(newpage, entry.val); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1649 | SetPageSwapCache(newpage); |
| 1650 | |
| 1651 | /* |
| 1652 | * Our caller will very soon move newpage out of swapcache, but it's |
| 1653 | * a nice clean interface for us to replace oldpage by newpage there. |
| 1654 | */ |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 1655 | xa_lock_irq(&swap_mapping->i_pages); |
Matthew Wilcox | 62f945b | 2017-11-17 10:22:37 -0500 | [diff] [blame] | 1656 | error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1657 | if (!error) { |
Johannes Weiner | 0d1c207 | 2020-06-03 16:01:54 -0700 | [diff] [blame] | 1658 | mem_cgroup_migrate(oldpage, newpage); |
| 1659 | __inc_lruvec_page_state(newpage, NR_FILE_PAGES); |
| 1660 | __dec_lruvec_page_state(oldpage, NR_FILE_PAGES); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1661 | } |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 1662 | xa_unlock_irq(&swap_mapping->i_pages); |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1663 | |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1664 | if (unlikely(error)) { |
| 1665 | /* |
| 1666 | * Is this possible? I think not, now that our callers check |
| 1667 | * both PageSwapCache and page_private after getting page lock; |
| 1668 | * but be defensive. Reverse old to newpage for clear and free. |
| 1669 | */ |
| 1670 | oldpage = newpage; |
| 1671 | } else { |
Johannes Weiner | 6058eae | 2020-06-03 16:02:40 -0700 | [diff] [blame] | 1672 | lru_cache_add(newpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1673 | *pagep = newpage; |
| 1674 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1675 | |
| 1676 | ClearPageSwapCache(oldpage); |
| 1677 | set_page_private(oldpage, 0); |
| 1678 | |
| 1679 | unlock_page(oldpage); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1680 | put_page(oldpage); |
| 1681 | put_page(oldpage); |
Hugh Dickins | 0142ef6 | 2012-06-07 14:21:09 -0700 | [diff] [blame] | 1682 | return error; |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1683 | } |
| 1684 | |
| 1685 | /* |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1686 | * Swap in the page pointed to by *pagep. |
| 1687 | * Caller has to make sure that *pagep contains a valid swapped page. |
| 1688 | * Returns 0 and the page in pagep if success. On failure, returns the |
Randy Dunlap | af44c12 | 2020-08-11 18:33:17 -0700 | [diff] [blame] | 1689 | * error code and NULL in *pagep. |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1690 | */ |
| 1691 | static int shmem_swapin_page(struct inode *inode, pgoff_t index, |
| 1692 | struct page **pagep, enum sgp_type sgp, |
| 1693 | gfp_t gfp, struct vm_area_struct *vma, |
| 1694 | vm_fault_t *fault_type) |
| 1695 | { |
| 1696 | struct address_space *mapping = inode->i_mapping; |
| 1697 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 1698 | struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm; |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1699 | struct page *page; |
| 1700 | swp_entry_t swap; |
| 1701 | int error; |
| 1702 | |
| 1703 | VM_BUG_ON(!*pagep || !xa_is_value(*pagep)); |
| 1704 | swap = radix_to_swp_entry(*pagep); |
| 1705 | *pagep = NULL; |
| 1706 | |
| 1707 | /* Look it up and read it in.. */ |
| 1708 | page = lookup_swap_cache(swap, NULL, 0); |
| 1709 | if (!page) { |
| 1710 | /* Or update major stats only when swapin succeeds?? */ |
| 1711 | if (fault_type) { |
| 1712 | *fault_type |= VM_FAULT_MAJOR; |
| 1713 | count_vm_event(PGMAJFAULT); |
| 1714 | count_memcg_event_mm(charge_mm, PGMAJFAULT); |
| 1715 | } |
| 1716 | /* Here we actually start the io */ |
| 1717 | page = shmem_swapin(swap, gfp, info, index); |
| 1718 | if (!page) { |
| 1719 | error = -ENOMEM; |
| 1720 | goto failed; |
| 1721 | } |
| 1722 | } |
| 1723 | |
| 1724 | /* We have to do this with page locked to prevent races */ |
| 1725 | lock_page(page); |
| 1726 | if (!PageSwapCache(page) || page_private(page) != swap.val || |
| 1727 | !shmem_confirm_swap(mapping, index, swap)) { |
| 1728 | error = -EEXIST; |
| 1729 | goto unlock; |
| 1730 | } |
| 1731 | if (!PageUptodate(page)) { |
| 1732 | error = -EIO; |
| 1733 | goto failed; |
| 1734 | } |
| 1735 | wait_on_page_writeback(page); |
| 1736 | |
| 1737 | if (shmem_should_replace_page(page, gfp)) { |
| 1738 | error = shmem_replace_page(&page, gfp, info, index); |
| 1739 | if (error) |
| 1740 | goto failed; |
| 1741 | } |
| 1742 | |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 1743 | error = shmem_add_to_page_cache(page, mapping, index, |
| 1744 | swp_to_radix_entry(swap), gfp, |
| 1745 | charge_mm); |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1746 | if (error) |
| 1747 | goto failed; |
| 1748 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1749 | spin_lock_irq(&info->lock); |
| 1750 | info->swapped--; |
| 1751 | shmem_recalc_inode(inode); |
| 1752 | spin_unlock_irq(&info->lock); |
| 1753 | |
| 1754 | if (sgp == SGP_WRITE) |
| 1755 | mark_page_accessed(page); |
| 1756 | |
| 1757 | delete_from_swap_cache(page); |
| 1758 | set_page_dirty(page); |
| 1759 | swap_free(swap); |
| 1760 | |
| 1761 | *pagep = page; |
| 1762 | return 0; |
| 1763 | failed: |
| 1764 | if (!shmem_confirm_swap(mapping, index, swap)) |
| 1765 | error = -EEXIST; |
| 1766 | unlock: |
| 1767 | if (page) { |
| 1768 | unlock_page(page); |
| 1769 | put_page(page); |
| 1770 | } |
| 1771 | |
| 1772 | return error; |
| 1773 | } |
| 1774 | |
| 1775 | /* |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 1776 | * shmem_getpage_gfp - find page in cache, or get from swap, or allocate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1777 | * |
| 1778 | * If we allocate a new one we do not mark it dirty. That's up to the |
| 1779 | * vm. If we swap it in we mark it dirty since we also free the swap |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1780 | * entry since a page cannot live in both the swap and page cache. |
| 1781 | * |
Miles Chen | 28eb3c80 | 2019-09-23 15:39:34 -0700 | [diff] [blame] | 1782 | * vmf and fault_type are only supplied by shmem_fault: |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1783 | * otherwise they are NULL. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1784 | */ |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 1785 | static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1786 | struct page **pagep, enum sgp_type sgp, gfp_t gfp, |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 1787 | struct vm_area_struct *vma, struct vm_fault *vmf, |
| 1788 | vm_fault_t *fault_type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1789 | { |
| 1790 | struct address_space *mapping = inode->i_mapping; |
Arnd Bergmann | 23f919d | 2016-12-12 16:42:28 -0800 | [diff] [blame] | 1791 | struct shmem_inode_info *info = SHMEM_I(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1792 | struct shmem_sb_info *sbinfo; |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 1793 | struct mm_struct *charge_mm; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1794 | struct page *page; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1795 | enum sgp_type sgp_huge = sgp; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1796 | pgoff_t hindex = index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1797 | int error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1798 | int once = 0; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1799 | int alloced = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1800 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1801 | if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1802 | return -EFBIG; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 1803 | if (sgp == SGP_NOHUGE || sgp == SGP_HUGE) |
| 1804 | sgp = SGP_CACHE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | repeat: |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1806 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1807 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1808 | return -EINVAL; |
| 1809 | } |
| 1810 | |
| 1811 | sbinfo = SHMEM_SB(inode->i_sb); |
| 1812 | charge_mm = vma ? vma->vm_mm : current->mm; |
| 1813 | |
| 1814 | page = find_lock_entry(mapping, index); |
| 1815 | if (xa_is_value(page)) { |
| 1816 | error = shmem_swapin_page(inode, index, &page, |
| 1817 | sgp, gfp, vma, fault_type); |
| 1818 | if (error == -EEXIST) |
| 1819 | goto repeat; |
| 1820 | |
| 1821 | *pagep = page; |
| 1822 | return error; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1823 | } |
| 1824 | |
Hugh Dickins | 66d2f4d | 2014-07-02 15:22:38 -0700 | [diff] [blame] | 1825 | if (page && sgp == SGP_WRITE) |
| 1826 | mark_page_accessed(page); |
| 1827 | |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1828 | /* fallocated page? */ |
| 1829 | if (page && !PageUptodate(page)) { |
| 1830 | if (sgp != SGP_READ) |
| 1831 | goto clear; |
| 1832 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1833 | put_page(page); |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1834 | page = NULL; |
| 1835 | } |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1836 | if (page || sgp == SGP_READ) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1837 | *pagep = page; |
| 1838 | return 0; |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1839 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1840 | |
| 1841 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1842 | * Fast cache lookup did not find it: |
| 1843 | * bring it back from swap or allocate. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1844 | */ |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 1845 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1846 | if (vma && userfaultfd_missing(vma)) { |
| 1847 | *fault_type = handle_userfault(vmf, VM_UFFD_MISSING); |
| 1848 | return 0; |
| 1849 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1850 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1851 | /* shmem_symlink() */ |
| 1852 | if (mapping->a_ops != &shmem_aops) |
| 1853 | goto alloc_nohuge; |
| 1854 | if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE) |
| 1855 | goto alloc_nohuge; |
| 1856 | if (shmem_huge == SHMEM_HUGE_FORCE) |
| 1857 | goto alloc_huge; |
| 1858 | switch (sbinfo->huge) { |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1859 | case SHMEM_HUGE_NEVER: |
| 1860 | goto alloc_nohuge; |
Kees Cook | 27d80fa2 | 2020-04-06 20:07:51 -0700 | [diff] [blame] | 1861 | case SHMEM_HUGE_WITHIN_SIZE: { |
| 1862 | loff_t i_size; |
| 1863 | pgoff_t off; |
| 1864 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1865 | off = round_up(index, HPAGE_PMD_NR); |
| 1866 | i_size = round_up(i_size_read(inode), PAGE_SIZE); |
| 1867 | if (i_size >= HPAGE_PMD_SIZE && |
| 1868 | i_size >> PAGE_SHIFT >= off) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1869 | goto alloc_huge; |
Kees Cook | 27d80fa2 | 2020-04-06 20:07:51 -0700 | [diff] [blame] | 1870 | |
| 1871 | fallthrough; |
| 1872 | } |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1873 | case SHMEM_HUGE_ADVISE: |
| 1874 | if (sgp_huge == SGP_HUGE) |
| 1875 | goto alloc_huge; |
| 1876 | /* TODO: implement fadvise() hints */ |
| 1877 | goto alloc_nohuge; |
| 1878 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1879 | |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1880 | alloc_huge: |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1881 | page = shmem_alloc_and_acct_page(gfp, inode, index, true); |
| 1882 | if (IS_ERR(page)) { |
| 1883 | alloc_nohuge: |
| 1884 | page = shmem_alloc_and_acct_page(gfp, inode, |
| 1885 | index, false); |
| 1886 | } |
| 1887 | if (IS_ERR(page)) { |
| 1888 | int retry = 5; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1889 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1890 | error = PTR_ERR(page); |
| 1891 | page = NULL; |
| 1892 | if (error != -ENOSPC) |
| 1893 | goto unlock; |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1894 | /* |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1895 | * Try to reclaim some space by splitting a huge page |
| 1896 | * beyond i_size on the filesystem. |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1897 | */ |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1898 | while (retry--) { |
| 1899 | int ret; |
| 1900 | |
| 1901 | ret = shmem_unused_huge_shrink(sbinfo, NULL, 1); |
| 1902 | if (ret == SHRINK_STOP) |
| 1903 | break; |
| 1904 | if (ret) |
| 1905 | goto alloc_nohuge; |
| 1906 | } |
| 1907 | goto unlock; |
| 1908 | } |
| 1909 | |
| 1910 | if (PageTransHuge(page)) |
| 1911 | hindex = round_down(index, HPAGE_PMD_NR); |
| 1912 | else |
| 1913 | hindex = index; |
| 1914 | |
| 1915 | if (sgp == SGP_WRITE) |
| 1916 | __SetPageReferenced(page); |
| 1917 | |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1918 | error = shmem_add_to_page_cache(page, mapping, hindex, |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 1919 | NULL, gfp & GFP_RECLAIM_MASK, |
| 1920 | charge_mm); |
| 1921 | if (error) |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1922 | goto unacct; |
Johannes Weiner | 6058eae | 2020-06-03 16:02:40 -0700 | [diff] [blame] | 1923 | lru_cache_add(page); |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1924 | |
| 1925 | spin_lock_irq(&info->lock); |
Matthew Wilcox (Oracle) | d8c6546 | 2019-09-23 15:34:30 -0700 | [diff] [blame] | 1926 | info->alloced += compound_nr(page); |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1927 | inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page); |
| 1928 | shmem_recalc_inode(inode); |
| 1929 | spin_unlock_irq(&info->lock); |
| 1930 | alloced = true; |
| 1931 | |
| 1932 | if (PageTransHuge(page) && |
| 1933 | DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) < |
| 1934 | hindex + HPAGE_PMD_NR - 1) { |
| 1935 | /* |
| 1936 | * Part of the huge page is beyond i_size: subject |
| 1937 | * to shrink under memory pressure. |
| 1938 | */ |
| 1939 | spin_lock(&sbinfo->shrinklist_lock); |
| 1940 | /* |
| 1941 | * _careful to defend against unlocked access to |
| 1942 | * ->shrink_list in shmem_unused_huge_shrink() |
| 1943 | */ |
| 1944 | if (list_empty_careful(&info->shrinklist)) { |
| 1945 | list_add_tail(&info->shrinklist, |
| 1946 | &sbinfo->shrinklist); |
| 1947 | sbinfo->shrinklist_len++; |
| 1948 | } |
| 1949 | spin_unlock(&sbinfo->shrinklist_lock); |
| 1950 | } |
| 1951 | |
| 1952 | /* |
| 1953 | * Let SGP_FALLOC use the SGP_WRITE optimization on a new page. |
| 1954 | */ |
| 1955 | if (sgp == SGP_FALLOC) |
| 1956 | sgp = SGP_WRITE; |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 1957 | clear: |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1958 | /* |
| 1959 | * Let SGP_WRITE caller clear ends if write does not fill page; |
| 1960 | * but SGP_FALLOC on a page fallocated earlier must initialize |
| 1961 | * it now, lest undo on failure cancel our earlier guarantee. |
| 1962 | */ |
| 1963 | if (sgp != SGP_WRITE && !PageUptodate(page)) { |
| 1964 | struct page *head = compound_head(page); |
| 1965 | int i; |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1966 | |
Matthew Wilcox (Oracle) | d8c6546 | 2019-09-23 15:34:30 -0700 | [diff] [blame] | 1967 | for (i = 0; i < compound_nr(head); i++) { |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1968 | clear_highpage(head + i); |
| 1969 | flush_dcache_page(head + i); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 1970 | } |
Vineeth Remanan Pillai | c5bf121 | 2019-03-05 15:46:58 -0800 | [diff] [blame] | 1971 | SetPageUptodate(head); |
Hugh Dickins | 59a16ea | 2011-05-11 15:13:38 -0700 | [diff] [blame] | 1972 | } |
Hugh Dickins | bde05d1 | 2012-05-29 15:06:38 -0700 | [diff] [blame] | 1973 | |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1974 | /* Perhaps the file has been truncated since we checked */ |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 1975 | if (sgp <= SGP_CACHE && |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1976 | ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) { |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1977 | if (alloced) { |
| 1978 | ClearPageDirty(page); |
| 1979 | delete_from_page_cache(page); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1980 | spin_lock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1981 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 1982 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1983 | } |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1984 | error = -EINVAL; |
Hugh Dickins | 267a4c7 | 2015-12-11 13:40:55 -0800 | [diff] [blame] | 1985 | goto unlock; |
Shaohua Li | ff36b801 | 2010-08-09 17:19:06 -0700 | [diff] [blame] | 1986 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1987 | *pagep = page + index - hindex; |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1988 | return 0; |
Nick Piggin | d00806b | 2007-07-19 01:46:57 -0700 | [diff] [blame] | 1989 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1990 | /* |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1991 | * Error recovery. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1992 | */ |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 1993 | unacct: |
Matthew Wilcox (Oracle) | d8c6546 | 2019-09-23 15:34:30 -0700 | [diff] [blame] | 1994 | shmem_inode_unacct_blocks(inode, compound_nr(page)); |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 1995 | |
| 1996 | if (PageTransHuge(page)) { |
| 1997 | unlock_page(page); |
| 1998 | put_page(page); |
| 1999 | goto alloc_nohuge; |
| 2000 | } |
Hugh Dickins | d189922 | 2012-07-11 14:02:47 -0700 | [diff] [blame] | 2001 | unlock: |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 2002 | if (page) { |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2003 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2004 | put_page(page); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2005 | } |
| 2006 | if (error == -ENOSPC && !once++) { |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 2007 | spin_lock_irq(&info->lock); |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2008 | shmem_recalc_inode(inode); |
Kirill A. Shutemov | 4595ef8 | 2016-07-26 15:26:29 -0700 | [diff] [blame] | 2009 | spin_unlock_irq(&info->lock); |
Hugh Dickins | 27ab700 | 2011-07-25 17:12:36 -0700 | [diff] [blame] | 2010 | goto repeat; |
Josef "Jeff" Sipek | d3ac7f8 | 2006-12-08 02:36:44 -0800 | [diff] [blame] | 2011 | } |
Matthew Wilcox | 7f4446e | 2017-12-04 03:31:13 -0500 | [diff] [blame] | 2012 | if (error == -EEXIST) |
Hugh Dickins | 54af6042 | 2011-08-03 16:21:24 -0700 | [diff] [blame] | 2013 | goto repeat; |
| 2014 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2015 | } |
| 2016 | |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 2017 | /* |
| 2018 | * This is like autoremove_wake_function, but it removes the wait queue |
| 2019 | * entry unconditionally - even if something else had already woken the |
| 2020 | * target. |
| 2021 | */ |
Ingo Molnar | ac6424b | 2017-06-20 12:06:13 +0200 | [diff] [blame] | 2022 | static int synchronous_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 2023 | { |
| 2024 | int ret = default_wake_function(wait, mode, sync, key); |
Ingo Molnar | 2055da9 | 2017-06-20 12:06:46 +0200 | [diff] [blame] | 2025 | list_del_init(&wait->entry); |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 2026 | return ret; |
| 2027 | } |
| 2028 | |
Souptick Joarder | 20acce6 | 2018-06-07 17:09:17 -0700 | [diff] [blame] | 2029 | static vm_fault_t shmem_fault(struct vm_fault *vmf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2030 | { |
Dave Jiang | 11bac80 | 2017-02-24 14:56:41 -0800 | [diff] [blame] | 2031 | struct vm_area_struct *vma = vmf->vma; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2032 | struct inode *inode = file_inode(vma->vm_file); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2033 | gfp_t gfp = mapping_gfp_mask(inode->i_mapping); |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2034 | enum sgp_type sgp; |
Souptick Joarder | 20acce6 | 2018-06-07 17:09:17 -0700 | [diff] [blame] | 2035 | int err; |
| 2036 | vm_fault_t ret = VM_FAULT_LOCKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2038 | /* |
| 2039 | * Trinity finds that probing a hole which tmpfs is punching can |
| 2040 | * prevent the hole-punch from ever completing: which in turn |
| 2041 | * locks writers out with its hold on i_mutex. So refrain from |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2042 | * faulting pages into the hole while it's being punched. Although |
| 2043 | * shmem_undo_range() does remove the additions, it may be unable to |
| 2044 | * keep up, as each new page needs its own unmap_mapping_range() call, |
| 2045 | * and the i_mmap tree grows ever slower to scan if new vmas are added. |
| 2046 | * |
| 2047 | * It does not matter if we sometimes reach this check just before the |
| 2048 | * hole-punch begins, so that one fault then races with the punch: |
| 2049 | * we just need to make racing faults a rare case. |
| 2050 | * |
| 2051 | * The implementation below would be much simpler if we just used a |
| 2052 | * standard mutex or completion: but we cannot take i_mutex in fault, |
| 2053 | * and bloating every shmem inode for this unlikely case would be sad. |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2054 | */ |
| 2055 | if (unlikely(inode->i_private)) { |
| 2056 | struct shmem_falloc *shmem_falloc; |
| 2057 | |
| 2058 | spin_lock(&inode->i_lock); |
| 2059 | shmem_falloc = inode->i_private; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2060 | if (shmem_falloc && |
| 2061 | shmem_falloc->waitq && |
| 2062 | vmf->pgoff >= shmem_falloc->start && |
| 2063 | vmf->pgoff < shmem_falloc->next) { |
Kirill A. Shutemov | 8897c1b | 2019-11-30 17:50:26 -0800 | [diff] [blame] | 2064 | struct file *fpin; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2065 | wait_queue_head_t *shmem_falloc_waitq; |
Linus Torvalds | 10d20bd | 2016-12-05 12:10:29 -0800 | [diff] [blame] | 2066 | DEFINE_WAIT_FUNC(shmem_fault_wait, synchronous_wake_function); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2067 | |
| 2068 | ret = VM_FAULT_NOPAGE; |
Kirill A. Shutemov | 8897c1b | 2019-11-30 17:50:26 -0800 | [diff] [blame] | 2069 | fpin = maybe_unlock_mmap_for_io(vmf, NULL); |
| 2070 | if (fpin) |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2071 | ret = VM_FAULT_RETRY; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2072 | |
| 2073 | shmem_falloc_waitq = shmem_falloc->waitq; |
| 2074 | prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait, |
| 2075 | TASK_UNINTERRUPTIBLE); |
| 2076 | spin_unlock(&inode->i_lock); |
| 2077 | schedule(); |
| 2078 | |
| 2079 | /* |
| 2080 | * shmem_falloc_waitq points into the shmem_fallocate() |
| 2081 | * stack of the hole-punching task: shmem_falloc_waitq |
| 2082 | * is usually invalid by the time we reach here, but |
| 2083 | * finish_wait() does not dereference it in that case; |
| 2084 | * though i_lock needed lest racing with wake_up_all(). |
| 2085 | */ |
| 2086 | spin_lock(&inode->i_lock); |
| 2087 | finish_wait(shmem_falloc_waitq, &shmem_fault_wait); |
| 2088 | spin_unlock(&inode->i_lock); |
Kirill A. Shutemov | 8897c1b | 2019-11-30 17:50:26 -0800 | [diff] [blame] | 2089 | |
| 2090 | if (fpin) |
| 2091 | fput(fpin); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2092 | return ret; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2093 | } |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2094 | spin_unlock(&inode->i_lock); |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2095 | } |
| 2096 | |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2097 | sgp = SGP_CACHE; |
Michal Hocko | 1860033 | 2017-07-10 15:48:02 -0700 | [diff] [blame] | 2098 | |
| 2099 | if ((vma->vm_flags & VM_NOHUGEPAGE) || |
| 2100 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2101 | sgp = SGP_NOHUGE; |
Michal Hocko | 1860033 | 2017-07-10 15:48:02 -0700 | [diff] [blame] | 2102 | else if (vma->vm_flags & VM_HUGEPAGE) |
| 2103 | sgp = SGP_HUGE; |
Kirill A. Shutemov | 657e303 | 2016-07-26 15:26:21 -0700 | [diff] [blame] | 2104 | |
Souptick Joarder | 20acce6 | 2018-06-07 17:09:17 -0700 | [diff] [blame] | 2105 | err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 2106 | gfp, vma, vmf, &ret); |
Souptick Joarder | 20acce6 | 2018-06-07 17:09:17 -0700 | [diff] [blame] | 2107 | if (err) |
| 2108 | return vmf_error(err); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 2109 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2110 | } |
| 2111 | |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2112 | unsigned long shmem_get_unmapped_area(struct file *file, |
| 2113 | unsigned long uaddr, unsigned long len, |
| 2114 | unsigned long pgoff, unsigned long flags) |
| 2115 | { |
| 2116 | unsigned long (*get_area)(struct file *, |
| 2117 | unsigned long, unsigned long, unsigned long, unsigned long); |
| 2118 | unsigned long addr; |
| 2119 | unsigned long offset; |
| 2120 | unsigned long inflated_len; |
| 2121 | unsigned long inflated_addr; |
| 2122 | unsigned long inflated_offset; |
| 2123 | |
| 2124 | if (len > TASK_SIZE) |
| 2125 | return -ENOMEM; |
| 2126 | |
| 2127 | get_area = current->mm->get_unmapped_area; |
| 2128 | addr = get_area(file, uaddr, len, pgoff, flags); |
| 2129 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 2130 | if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2131 | return addr; |
| 2132 | if (IS_ERR_VALUE(addr)) |
| 2133 | return addr; |
| 2134 | if (addr & ~PAGE_MASK) |
| 2135 | return addr; |
| 2136 | if (addr > TASK_SIZE - len) |
| 2137 | return addr; |
| 2138 | |
| 2139 | if (shmem_huge == SHMEM_HUGE_DENY) |
| 2140 | return addr; |
| 2141 | if (len < HPAGE_PMD_SIZE) |
| 2142 | return addr; |
| 2143 | if (flags & MAP_FIXED) |
| 2144 | return addr; |
| 2145 | /* |
| 2146 | * Our priority is to support MAP_SHARED mapped hugely; |
| 2147 | * and support MAP_PRIVATE mapped hugely too, until it is COWed. |
Kirill A. Shutemov | 9915899 | 2020-01-13 16:29:13 -0800 | [diff] [blame] | 2148 | * But if caller specified an address hint and we allocated area there |
| 2149 | * successfully, respect that as before. |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2150 | */ |
Kirill A. Shutemov | 9915899 | 2020-01-13 16:29:13 -0800 | [diff] [blame] | 2151 | if (uaddr == addr) |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2152 | return addr; |
| 2153 | |
| 2154 | if (shmem_huge != SHMEM_HUGE_FORCE) { |
| 2155 | struct super_block *sb; |
| 2156 | |
| 2157 | if (file) { |
| 2158 | VM_BUG_ON(file->f_op != &shmem_file_operations); |
| 2159 | sb = file_inode(file)->i_sb; |
| 2160 | } else { |
| 2161 | /* |
| 2162 | * Called directly from mm/mmap.c, or drivers/char/mem.c |
| 2163 | * for "/dev/zero", to create a shared anonymous object. |
| 2164 | */ |
| 2165 | if (IS_ERR(shm_mnt)) |
| 2166 | return addr; |
| 2167 | sb = shm_mnt->mnt_sb; |
| 2168 | } |
Toshi Kani | 3089bf6 | 2016-09-23 20:21:56 -0700 | [diff] [blame] | 2169 | if (SHMEM_SB(sb)->huge == SHMEM_HUGE_NEVER) |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2170 | return addr; |
| 2171 | } |
| 2172 | |
| 2173 | offset = (pgoff << PAGE_SHIFT) & (HPAGE_PMD_SIZE-1); |
| 2174 | if (offset && offset + len < 2 * HPAGE_PMD_SIZE) |
| 2175 | return addr; |
| 2176 | if ((addr & (HPAGE_PMD_SIZE-1)) == offset) |
| 2177 | return addr; |
| 2178 | |
| 2179 | inflated_len = len + HPAGE_PMD_SIZE - PAGE_SIZE; |
| 2180 | if (inflated_len > TASK_SIZE) |
| 2181 | return addr; |
| 2182 | if (inflated_len < len) |
| 2183 | return addr; |
| 2184 | |
Kirill A. Shutemov | 9915899 | 2020-01-13 16:29:13 -0800 | [diff] [blame] | 2185 | inflated_addr = get_area(NULL, uaddr, inflated_len, 0, flags); |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 2186 | if (IS_ERR_VALUE(inflated_addr)) |
| 2187 | return addr; |
| 2188 | if (inflated_addr & ~PAGE_MASK) |
| 2189 | return addr; |
| 2190 | |
| 2191 | inflated_offset = inflated_addr & (HPAGE_PMD_SIZE-1); |
| 2192 | inflated_addr += offset - inflated_offset; |
| 2193 | if (inflated_offset > offset) |
| 2194 | inflated_addr += HPAGE_PMD_SIZE; |
| 2195 | |
| 2196 | if (inflated_addr > TASK_SIZE - len) |
| 2197 | return addr; |
| 2198 | return inflated_addr; |
| 2199 | } |
| 2200 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2201 | #ifdef CONFIG_NUMA |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2202 | static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2203 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2204 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2205 | return mpol_set_shared_policy(&SHMEM_I(inode)->policy, vma, mpol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2206 | } |
| 2207 | |
Adrian Bunk | d8dc74f | 2007-10-16 01:26:26 -0700 | [diff] [blame] | 2208 | static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma, |
| 2209 | unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2210 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2211 | struct inode *inode = file_inode(vma->vm_file); |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2212 | pgoff_t index; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2213 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2214 | index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; |
| 2215 | return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2216 | } |
| 2217 | #endif |
| 2218 | |
| 2219 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 2220 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2221 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2222 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 2223 | int retval = -ENOMEM; |
| 2224 | |
Hugh Dickins | ea0dfeb | 2020-04-20 18:14:14 -0700 | [diff] [blame] | 2225 | /* |
| 2226 | * What serializes the accesses to info->flags? |
| 2227 | * ipc_lock_object() when called from shmctl_do_lock(), |
| 2228 | * no serialization needed when called from shm_destroy(). |
| 2229 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2230 | if (lock && !(info->flags & VM_LOCKED)) { |
| 2231 | if (!user_shm_lock(inode->i_size, user)) |
| 2232 | goto out_nomem; |
| 2233 | info->flags |= VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2234 | mapping_set_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | } |
| 2236 | if (!lock && (info->flags & VM_LOCKED) && user) { |
| 2237 | user_shm_unlock(inode->i_size, user); |
| 2238 | info->flags &= ~VM_LOCKED; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2239 | mapping_clear_unevictable(file->f_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2240 | } |
| 2241 | retval = 0; |
Lee Schermerhorn | 89e004ea | 2008-10-18 20:26:43 -0700 | [diff] [blame] | 2242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2243 | out_nomem: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2244 | return retval; |
| 2245 | } |
| 2246 | |
Adrian Bunk | 9b83a6a | 2007-02-28 20:11:03 -0800 | [diff] [blame] | 2247 | static int shmem_mmap(struct file *file, struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2248 | { |
Joel Fernandes (Google) | ab3948f | 2019-03-05 15:47:54 -0800 | [diff] [blame] | 2249 | struct shmem_inode_info *info = SHMEM_I(file_inode(file)); |
| 2250 | |
| 2251 | if (info->seals & F_SEAL_FUTURE_WRITE) { |
| 2252 | /* |
| 2253 | * New PROT_WRITE and MAP_SHARED mmaps are not allowed when |
| 2254 | * "future write" seal active. |
| 2255 | */ |
| 2256 | if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) |
| 2257 | return -EPERM; |
| 2258 | |
| 2259 | /* |
Nicolas Geoffray | 05d35110 | 2019-11-30 17:53:28 -0800 | [diff] [blame] | 2260 | * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as |
| 2261 | * MAP_SHARED and read-only, take care to not allow mprotect to |
| 2262 | * revert protections on such mappings. Do this only for shared |
| 2263 | * mappings. For private mappings, don't need to mask |
| 2264 | * VM_MAYWRITE as we still want them to be COW-writable. |
Joel Fernandes (Google) | ab3948f | 2019-03-05 15:47:54 -0800 | [diff] [blame] | 2265 | */ |
Nicolas Geoffray | 05d35110 | 2019-11-30 17:53:28 -0800 | [diff] [blame] | 2266 | if (vma->vm_flags & VM_SHARED) |
| 2267 | vma->vm_flags &= ~(VM_MAYWRITE); |
Joel Fernandes (Google) | ab3948f | 2019-03-05 15:47:54 -0800 | [diff] [blame] | 2268 | } |
| 2269 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2270 | file_accessed(file); |
| 2271 | vma->vm_ops = &shmem_vm_ops; |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 2272 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 2273 | ((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) < |
| 2274 | (vma->vm_end & HPAGE_PMD_MASK)) { |
| 2275 | khugepaged_enter(vma, vma->vm_flags); |
| 2276 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2277 | return 0; |
| 2278 | } |
| 2279 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2280 | static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir, |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 2281 | umode_t mode, dev_t dev, unsigned long flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2282 | { |
| 2283 | struct inode *inode; |
| 2284 | struct shmem_inode_info *info; |
| 2285 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 2286 | ino_t ino; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2287 | |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 2288 | if (shmem_reserve_inode(sb, &ino)) |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2289 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2290 | |
| 2291 | inode = new_inode(sb); |
| 2292 | if (inode) { |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 2293 | inode->i_ino = ino; |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2294 | inode_init_owner(inode, dir, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2295 | inode->i_blocks = 0; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 2296 | inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); |
Arnd Bergmann | 46c9a94 | 2018-08-17 15:45:09 -0700 | [diff] [blame] | 2297 | inode->i_generation = prandom_u32(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2298 | info = SHMEM_I(inode); |
| 2299 | memset(info, 0, (char *)inode - (char *)info); |
| 2300 | spin_lock_init(&info->lock); |
Hugh Dickins | af53d3e | 2019-04-18 17:50:13 -0700 | [diff] [blame] | 2301 | atomic_set(&info->stop_eviction, 0); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2302 | info->seals = F_SEAL_SEAL; |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2303 | info->flags = flags & VM_NORESERVE; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 2304 | INIT_LIST_HEAD(&info->shrinklist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2305 | INIT_LIST_HEAD(&info->swaplist); |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 2306 | simple_xattrs_init(&info->xattrs); |
Al Viro | 72c0490 | 2009-06-24 16:58:48 -0400 | [diff] [blame] | 2307 | cache_no_acl(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2308 | |
| 2309 | switch (mode & S_IFMT) { |
| 2310 | default: |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 2311 | inode->i_op = &shmem_special_inode_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2312 | init_special_inode(inode, mode, dev); |
| 2313 | break; |
| 2314 | case S_IFREG: |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 2315 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2316 | inode->i_op = &shmem_inode_operations; |
| 2317 | inode->i_fop = &shmem_file_operations; |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2318 | mpol_shared_policy_init(&info->policy, |
| 2319 | shmem_get_sbmpol(sbinfo)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | break; |
| 2321 | case S_IFDIR: |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2322 | inc_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2323 | /* Some things misbehave if size == 0 on a directory */ |
| 2324 | inode->i_size = 2 * BOGO_DIRENT_SIZE; |
| 2325 | inode->i_op = &shmem_dir_inode_operations; |
| 2326 | inode->i_fop = &simple_dir_operations; |
| 2327 | break; |
| 2328 | case S_IFLNK: |
| 2329 | /* |
| 2330 | * Must not load anything in the rbtree, |
| 2331 | * mpol_free_shared_policy will not be called. |
| 2332 | */ |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 2333 | mpol_shared_policy_init(&info->policy, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2334 | break; |
| 2335 | } |
Joel Fernandes (Google) | b45d71f | 2018-09-20 12:22:39 -0700 | [diff] [blame] | 2336 | |
| 2337 | lockdep_annotate_inode_mutex_key(inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 2338 | } else |
| 2339 | shmem_free_inode(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2340 | return inode; |
| 2341 | } |
| 2342 | |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2343 | bool shmem_mapping(struct address_space *mapping) |
| 2344 | { |
Hugh Dickins | f800545 | 2017-02-22 15:41:42 -0800 | [diff] [blame] | 2345 | return mapping->a_ops == &shmem_aops; |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2346 | } |
| 2347 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2348 | static int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, |
| 2349 | pmd_t *dst_pmd, |
| 2350 | struct vm_area_struct *dst_vma, |
| 2351 | unsigned long dst_addr, |
| 2352 | unsigned long src_addr, |
| 2353 | bool zeropage, |
| 2354 | struct page **pagep) |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2355 | { |
| 2356 | struct inode *inode = file_inode(dst_vma->vm_file); |
| 2357 | struct shmem_inode_info *info = SHMEM_I(inode); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2358 | struct address_space *mapping = inode->i_mapping; |
| 2359 | gfp_t gfp = mapping_gfp_mask(mapping); |
| 2360 | pgoff_t pgoff = linear_page_index(dst_vma, dst_addr); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2361 | spinlock_t *ptl; |
| 2362 | void *page_kaddr; |
| 2363 | struct page *page; |
| 2364 | pte_t _dst_pte, *dst_pte; |
| 2365 | int ret; |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2366 | pgoff_t offset, max_off; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2367 | |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2368 | ret = -ENOMEM; |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2369 | if (!shmem_inode_acct_block(inode, 1)) |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2370 | goto out; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2371 | |
Andrea Arcangeli | cb658a4 | 2017-02-22 15:43:55 -0800 | [diff] [blame] | 2372 | if (!*pagep) { |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2373 | page = shmem_alloc_page(gfp, info, pgoff); |
| 2374 | if (!page) |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2375 | goto out_unacct_blocks; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2376 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2377 | if (!zeropage) { /* mcopy_atomic */ |
| 2378 | page_kaddr = kmap_atomic(page); |
| 2379 | ret = copy_from_user(page_kaddr, |
| 2380 | (const void __user *)src_addr, |
| 2381 | PAGE_SIZE); |
| 2382 | kunmap_atomic(page_kaddr); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2383 | |
Michel Lespinasse | c1e8d7c | 2020-06-08 21:33:54 -0700 | [diff] [blame] | 2384 | /* fallback to copy_from_user outside mmap_lock */ |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2385 | if (unlikely(ret)) { |
| 2386 | *pagep = page; |
| 2387 | shmem_inode_unacct_blocks(inode, 1); |
| 2388 | /* don't free the page */ |
Andrea Arcangeli | 9e36825 | 2018-11-30 14:09:25 -0800 | [diff] [blame] | 2389 | return -ENOENT; |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2390 | } |
| 2391 | } else { /* mfill_zeropage_atomic */ |
| 2392 | clear_highpage(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2393 | } |
| 2394 | } else { |
| 2395 | page = *pagep; |
| 2396 | *pagep = NULL; |
| 2397 | } |
| 2398 | |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2399 | VM_BUG_ON(PageLocked(page) || PageSwapBacked(page)); |
| 2400 | __SetPageLocked(page); |
| 2401 | __SetPageSwapBacked(page); |
Andrea Arcangeli | a425d35 | 2017-02-22 15:43:52 -0800 | [diff] [blame] | 2402 | __SetPageUptodate(page); |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2403 | |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2404 | ret = -EFAULT; |
| 2405 | offset = linear_page_index(dst_vma, dst_addr); |
| 2406 | max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); |
| 2407 | if (unlikely(offset >= max_off)) |
| 2408 | goto out_release; |
| 2409 | |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 2410 | ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL, |
| 2411 | gfp & GFP_RECLAIM_MASK, dst_mm); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2412 | if (ret) |
| 2413 | goto out_release; |
| 2414 | |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2415 | _dst_pte = mk_pte(page, dst_vma->vm_page_prot); |
| 2416 | if (dst_vma->vm_flags & VM_WRITE) |
| 2417 | _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte)); |
Andrea Arcangeli | dcf7fe9 | 2018-11-30 14:09:43 -0800 | [diff] [blame] | 2418 | else { |
| 2419 | /* |
| 2420 | * We don't set the pte dirty if the vma has no |
| 2421 | * VM_WRITE permission, so mark the page dirty or it |
| 2422 | * could be freed from under us. We could do it |
| 2423 | * unconditionally before unlock_page(), but doing it |
| 2424 | * only if VM_WRITE is not set is faster. |
| 2425 | */ |
| 2426 | set_page_dirty(page); |
| 2427 | } |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2428 | |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2429 | dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl); |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2430 | |
| 2431 | ret = -EFAULT; |
| 2432 | max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); |
| 2433 | if (unlikely(offset >= max_off)) |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 2434 | goto out_release_unlock; |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2435 | |
| 2436 | ret = -EEXIST; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2437 | if (!pte_none(*dst_pte)) |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 2438 | goto out_release_unlock; |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2439 | |
Johannes Weiner | 6058eae | 2020-06-03 16:02:40 -0700 | [diff] [blame] | 2440 | lru_cache_add(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2441 | |
Yang Shi | 94b7cc0 | 2020-04-20 18:14:17 -0700 | [diff] [blame] | 2442 | spin_lock_irq(&info->lock); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2443 | info->alloced++; |
| 2444 | inode->i_blocks += BLOCKS_PER_PAGE; |
| 2445 | shmem_recalc_inode(inode); |
Yang Shi | 94b7cc0 | 2020-04-20 18:14:17 -0700 | [diff] [blame] | 2446 | spin_unlock_irq(&info->lock); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2447 | |
| 2448 | inc_mm_counter(dst_mm, mm_counter_file(page)); |
| 2449 | page_add_file_rmap(page, false); |
| 2450 | set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte); |
| 2451 | |
| 2452 | /* No need to invalidate - it was non-present before */ |
| 2453 | update_mmu_cache(dst_vma, dst_addr, dst_pte); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2454 | pte_unmap_unlock(dst_pte, ptl); |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2455 | unlock_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2456 | ret = 0; |
| 2457 | out: |
| 2458 | return ret; |
Johannes Weiner | 3fea5a4 | 2020-06-03 16:01:41 -0700 | [diff] [blame] | 2459 | out_release_unlock: |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2460 | pte_unmap_unlock(dst_pte, ptl); |
Andrea Arcangeli | dcf7fe9 | 2018-11-30 14:09:43 -0800 | [diff] [blame] | 2461 | ClearPageDirty(page); |
Andrea Arcangeli | e2a50c1 | 2018-11-30 14:09:37 -0800 | [diff] [blame] | 2462 | delete_from_page_cache(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2463 | out_release: |
Andrea Arcangeli | 9cc90c6 | 2017-02-22 15:43:49 -0800 | [diff] [blame] | 2464 | unlock_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2465 | put_page(page); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2466 | out_unacct_blocks: |
Mike Rapoport | 0f07969 | 2017-09-06 16:22:59 -0700 | [diff] [blame] | 2467 | shmem_inode_unacct_blocks(inode, 1); |
Mike Rapoport | 4c27fe4 | 2017-02-22 15:43:25 -0800 | [diff] [blame] | 2468 | goto out; |
| 2469 | } |
| 2470 | |
Mike Rapoport | 8d10396 | 2017-09-06 16:23:02 -0700 | [diff] [blame] | 2471 | int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, |
| 2472 | pmd_t *dst_pmd, |
| 2473 | struct vm_area_struct *dst_vma, |
| 2474 | unsigned long dst_addr, |
| 2475 | unsigned long src_addr, |
| 2476 | struct page **pagep) |
| 2477 | { |
| 2478 | return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, |
| 2479 | dst_addr, src_addr, false, pagep); |
| 2480 | } |
| 2481 | |
| 2482 | int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm, |
| 2483 | pmd_t *dst_pmd, |
| 2484 | struct vm_area_struct *dst_vma, |
| 2485 | unsigned long dst_addr) |
| 2486 | { |
| 2487 | struct page *page = NULL; |
| 2488 | |
| 2489 | return shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, |
| 2490 | dst_addr, 0, true, &page); |
| 2491 | } |
| 2492 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2493 | #ifdef CONFIG_TMPFS |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2494 | static const struct inode_operations shmem_symlink_inode_operations; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 2495 | static const struct inode_operations shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2496 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2497 | #ifdef CONFIG_TMPFS_XATTR |
| 2498 | static int shmem_initxattrs(struct inode *, const struct xattr *, void *); |
| 2499 | #else |
| 2500 | #define shmem_initxattrs NULL |
| 2501 | #endif |
| 2502 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2503 | static int |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2504 | shmem_write_begin(struct file *file, struct address_space *mapping, |
| 2505 | loff_t pos, unsigned len, unsigned flags, |
| 2506 | struct page **pagep, void **fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2507 | { |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2508 | struct inode *inode = mapping->host; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2509 | struct shmem_inode_info *info = SHMEM_I(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2510 | pgoff_t index = pos >> PAGE_SHIFT; |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2511 | |
| 2512 | /* i_mutex is held by caller */ |
Joel Fernandes (Google) | ab3948f | 2019-03-05 15:47:54 -0800 | [diff] [blame] | 2513 | if (unlikely(info->seals & (F_SEAL_GROW | |
| 2514 | F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) { |
| 2515 | if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2516 | return -EPERM; |
| 2517 | if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size) |
| 2518 | return -EPERM; |
| 2519 | } |
| 2520 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2521 | return shmem_getpage(inode, index, pagep, SGP_WRITE); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2522 | } |
| 2523 | |
| 2524 | static int |
| 2525 | shmem_write_end(struct file *file, struct address_space *mapping, |
| 2526 | loff_t pos, unsigned len, unsigned copied, |
| 2527 | struct page *page, void *fsdata) |
| 2528 | { |
| 2529 | struct inode *inode = mapping->host; |
| 2530 | |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2531 | if (pos + copied > inode->i_size) |
| 2532 | i_size_write(inode, pos + copied); |
| 2533 | |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2534 | if (!PageUptodate(page)) { |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 2535 | struct page *head = compound_head(page); |
| 2536 | if (PageTransCompound(page)) { |
| 2537 | int i; |
| 2538 | |
| 2539 | for (i = 0; i < HPAGE_PMD_NR; i++) { |
| 2540 | if (head + i == page) |
| 2541 | continue; |
| 2542 | clear_highpage(head + i); |
| 2543 | flush_dcache_page(head + i); |
| 2544 | } |
| 2545 | } |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2546 | if (copied < PAGE_SIZE) { |
| 2547 | unsigned from = pos & (PAGE_SIZE - 1); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2548 | zero_user_segments(page, 0, from, |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2549 | from + copied, PAGE_SIZE); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2550 | } |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 2551 | SetPageUptodate(head); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 2552 | } |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2553 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 2554 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2555 | put_page(page); |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2556 | |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 2557 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | } |
| 2559 | |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2560 | static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2561 | { |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2562 | struct file *file = iocb->ki_filp; |
| 2563 | struct inode *inode = file_inode(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2564 | struct address_space *mapping = inode->i_mapping; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2565 | pgoff_t index; |
| 2566 | unsigned long offset; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 2567 | enum sgp_type sgp = SGP_READ; |
Geert Uytterhoeven | f7c1d07 | 2014-04-13 20:46:22 +0200 | [diff] [blame] | 2568 | int error = 0; |
Al Viro | cb66a7a | 2014-03-04 15:24:06 -0500 | [diff] [blame] | 2569 | ssize_t retval = 0; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2570 | loff_t *ppos = &iocb->ki_pos; |
Hugh Dickins | a0ee5ec | 2008-02-04 22:28:51 -0800 | [diff] [blame] | 2571 | |
| 2572 | /* |
| 2573 | * Might this read be for a stacking filesystem? Then when reading |
| 2574 | * holes of a sparse file, we actually need to allocate those pages, |
| 2575 | * and even mark them dirty, so it cannot exceed the max_blocks limit. |
| 2576 | */ |
Al Viro | 777eda2 | 2014-12-17 04:46:46 -0500 | [diff] [blame] | 2577 | if (!iter_is_iovec(to)) |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2578 | sgp = SGP_CACHE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2579 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2580 | index = *ppos >> PAGE_SHIFT; |
| 2581 | offset = *ppos & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2582 | |
| 2583 | for (;;) { |
| 2584 | struct page *page = NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2585 | pgoff_t end_index; |
| 2586 | unsigned long nr, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2587 | loff_t i_size = i_size_read(inode); |
| 2588 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2589 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2590 | if (index > end_index) |
| 2591 | break; |
| 2592 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2593 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2594 | if (nr <= offset) |
| 2595 | break; |
| 2596 | } |
| 2597 | |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2598 | error = shmem_getpage(inode, index, &page, sgp); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2599 | if (error) { |
| 2600 | if (error == -EINVAL) |
| 2601 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | break; |
| 2603 | } |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2604 | if (page) { |
| 2605 | if (sgp == SGP_CACHE) |
| 2606 | set_page_dirty(page); |
Hugh Dickins | d360244 | 2008-02-04 22:28:44 -0800 | [diff] [blame] | 2607 | unlock_page(page); |
Hugh Dickins | 75edd34 | 2016-05-19 17:12:44 -0700 | [diff] [blame] | 2608 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2609 | |
| 2610 | /* |
| 2611 | * We must evaluate after, since reads (unlike writes) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2612 | * are called without i_mutex protection against truncate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2613 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2614 | nr = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2615 | i_size = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2616 | end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2617 | if (index == end_index) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2618 | nr = i_size & ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2619 | if (nr <= offset) { |
| 2620 | if (page) |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2621 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2622 | break; |
| 2623 | } |
| 2624 | } |
| 2625 | nr -= offset; |
| 2626 | |
| 2627 | if (page) { |
| 2628 | /* |
| 2629 | * If users can be writing to this page using arbitrary |
| 2630 | * virtual addresses, take care about potential aliasing |
| 2631 | * before reading the page on the kernel side. |
| 2632 | */ |
| 2633 | if (mapping_writably_mapped(mapping)) |
| 2634 | flush_dcache_page(page); |
| 2635 | /* |
| 2636 | * Mark the page accessed if we read the beginning. |
| 2637 | */ |
| 2638 | if (!offset) |
| 2639 | mark_page_accessed(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 2640 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2641 | page = ZERO_PAGE(0); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2642 | get_page(page); |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 2643 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2644 | |
| 2645 | /* |
| 2646 | * Ok, we have the page, and it's up-to-date, so |
| 2647 | * now we can copy it to user space... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2648 | */ |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2649 | ret = copy_page_to_iter(page, offset, nr, to); |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2650 | retval += ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | offset += ret; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2652 | index += offset >> PAGE_SHIFT; |
| 2653 | offset &= ~PAGE_MASK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2654 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2655 | put_page(page); |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 2656 | if (!iov_iter_count(to)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2657 | break; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2658 | if (ret < nr) { |
| 2659 | error = -EFAULT; |
| 2660 | break; |
| 2661 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2662 | cond_resched(); |
| 2663 | } |
| 2664 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2665 | *ppos = ((loff_t) index << PAGE_SHIFT) + offset; |
Al Viro | 6e58e79 | 2014-02-03 17:07:03 -0500 | [diff] [blame] | 2666 | file_accessed(file); |
| 2667 | return retval ? retval : error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | } |
| 2669 | |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2670 | /* |
Matthew Wilcox | 7f4446e | 2017-12-04 03:31:13 -0500 | [diff] [blame] | 2671 | * llseek SEEK_DATA or SEEK_HOLE through the page cache. |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2672 | */ |
| 2673 | static pgoff_t shmem_seek_hole_data(struct address_space *mapping, |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2674 | pgoff_t index, pgoff_t end, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2675 | { |
| 2676 | struct page *page; |
| 2677 | struct pagevec pvec; |
| 2678 | pgoff_t indices[PAGEVEC_SIZE]; |
| 2679 | bool done = false; |
| 2680 | int i; |
| 2681 | |
Mel Gorman | 8667982 | 2017-11-15 17:37:52 -0800 | [diff] [blame] | 2682 | pagevec_init(&pvec); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2683 | pvec.nr = 1; /* start small: we may be there already */ |
| 2684 | while (!done) { |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2685 | pvec.nr = find_get_entries(mapping, index, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2686 | pvec.nr, pvec.pages, indices); |
| 2687 | if (!pvec.nr) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2688 | if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2689 | index = end; |
| 2690 | break; |
| 2691 | } |
| 2692 | for (i = 0; i < pvec.nr; i++, index++) { |
| 2693 | if (index < indices[i]) { |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2694 | if (whence == SEEK_HOLE) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2695 | done = true; |
| 2696 | break; |
| 2697 | } |
| 2698 | index = indices[i]; |
| 2699 | } |
| 2700 | page = pvec.pages[i]; |
Matthew Wilcox | 3159f94 | 2017-11-03 13:30:42 -0400 | [diff] [blame] | 2701 | if (page && !xa_is_value(page)) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2702 | if (!PageUptodate(page)) |
| 2703 | page = NULL; |
| 2704 | } |
| 2705 | if (index >= end || |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2706 | (page && whence == SEEK_DATA) || |
| 2707 | (!page && whence == SEEK_HOLE)) { |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2708 | done = true; |
| 2709 | break; |
| 2710 | } |
| 2711 | } |
Johannes Weiner | 0cd6144 | 2014-04-03 14:47:46 -0700 | [diff] [blame] | 2712 | pagevec_remove_exceptionals(&pvec); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2713 | pagevec_release(&pvec); |
| 2714 | pvec.nr = PAGEVEC_SIZE; |
| 2715 | cond_resched(); |
| 2716 | } |
| 2717 | return index; |
| 2718 | } |
| 2719 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2720 | static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2721 | { |
| 2722 | struct address_space *mapping = file->f_mapping; |
| 2723 | struct inode *inode = mapping->host; |
| 2724 | pgoff_t start, end; |
| 2725 | loff_t new_offset; |
| 2726 | |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2727 | if (whence != SEEK_DATA && whence != SEEK_HOLE) |
| 2728 | return generic_file_llseek_size(file, offset, whence, |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2729 | MAX_LFS_FILESIZE, i_size_read(inode)); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2730 | inode_lock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2731 | /* We're holding i_mutex so we can access i_size directly */ |
| 2732 | |
Yufen Yu | 1a41364 | 2018-11-16 15:08:39 -0800 | [diff] [blame] | 2733 | if (offset < 0 || offset >= inode->i_size) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2734 | offset = -ENXIO; |
| 2735 | else { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2736 | start = offset >> PAGE_SHIFT; |
| 2737 | end = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2738 | new_offset = shmem_seek_hole_data(mapping, start, end, whence); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2739 | new_offset <<= PAGE_SHIFT; |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2740 | if (new_offset > offset) { |
| 2741 | if (new_offset < inode->i_size) |
| 2742 | offset = new_offset; |
Andrew Morton | 965c8e5 | 2012-12-17 15:59:39 -0800 | [diff] [blame] | 2743 | else if (whence == SEEK_DATA) |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2744 | offset = -ENXIO; |
| 2745 | else |
| 2746 | offset = inode->i_size; |
| 2747 | } |
| 2748 | } |
| 2749 | |
Hugh Dickins | 387aae6 | 2013-08-04 11:30:25 -0700 | [diff] [blame] | 2750 | if (offset >= 0) |
| 2751 | offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2752 | inode_unlock(inode); |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 2753 | return offset; |
| 2754 | } |
| 2755 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2756 | static long shmem_fallocate(struct file *file, int mode, loff_t offset, |
| 2757 | loff_t len) |
| 2758 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2759 | struct inode *inode = file_inode(file); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2760 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2761 | struct shmem_inode_info *info = SHMEM_I(inode); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2762 | struct shmem_falloc shmem_falloc; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2763 | pgoff_t start, index, end; |
| 2764 | int error; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2765 | |
Hugh Dickins | 13ace4d | 2014-06-23 13:22:03 -0700 | [diff] [blame] | 2766 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| 2767 | return -EOPNOTSUPP; |
| 2768 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2769 | inode_lock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2770 | |
| 2771 | if (mode & FALLOC_FL_PUNCH_HOLE) { |
| 2772 | struct address_space *mapping = file->f_mapping; |
| 2773 | loff_t unmap_start = round_up(offset, PAGE_SIZE); |
| 2774 | loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2775 | DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2776 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2777 | /* protected by i_mutex */ |
Joel Fernandes (Google) | ab3948f | 2019-03-05 15:47:54 -0800 | [diff] [blame] | 2778 | if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) { |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2779 | error = -EPERM; |
| 2780 | goto out; |
| 2781 | } |
| 2782 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2783 | shmem_falloc.waitq = &shmem_falloc_waitq; |
Chen Jun | aa71ecd | 2019-11-30 17:58:11 -0800 | [diff] [blame] | 2784 | shmem_falloc.start = (u64)unmap_start >> PAGE_SHIFT; |
Hugh Dickins | f00cdc6 | 2014-06-23 13:22:06 -0700 | [diff] [blame] | 2785 | shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT; |
| 2786 | spin_lock(&inode->i_lock); |
| 2787 | inode->i_private = &shmem_falloc; |
| 2788 | spin_unlock(&inode->i_lock); |
| 2789 | |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2790 | if ((u64)unmap_end > (u64)unmap_start) |
| 2791 | unmap_mapping_range(mapping, unmap_start, |
| 2792 | 1 + unmap_end - unmap_start, 0); |
| 2793 | shmem_truncate_range(inode, offset, offset + len - 1); |
| 2794 | /* No need to unmap again: hole-punching leaves COWed pages */ |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2795 | |
| 2796 | spin_lock(&inode->i_lock); |
| 2797 | inode->i_private = NULL; |
| 2798 | wake_up_all(&shmem_falloc_waitq); |
Ingo Molnar | 2055da9 | 2017-06-20 12:06:46 +0200 | [diff] [blame] | 2799 | WARN_ON_ONCE(!list_empty(&shmem_falloc_waitq.head)); |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2800 | spin_unlock(&inode->i_lock); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2801 | error = 0; |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2802 | goto out; |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2803 | } |
| 2804 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2805 | /* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */ |
| 2806 | error = inode_newsize_ok(inode, offset + len); |
| 2807 | if (error) |
| 2808 | goto out; |
| 2809 | |
David Herrmann | 40e041a | 2014-08-08 14:25:27 -0700 | [diff] [blame] | 2810 | if ((info->seals & F_SEAL_GROW) && offset + len > inode->i_size) { |
| 2811 | error = -EPERM; |
| 2812 | goto out; |
| 2813 | } |
| 2814 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2815 | start = offset >> PAGE_SHIFT; |
| 2816 | end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2817 | /* Try to avoid a swapstorm if len is impossible to satisfy */ |
| 2818 | if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) { |
| 2819 | error = -ENOSPC; |
| 2820 | goto out; |
| 2821 | } |
| 2822 | |
Hugh Dickins | 8e205f7 | 2014-07-23 14:00:10 -0700 | [diff] [blame] | 2823 | shmem_falloc.waitq = NULL; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2824 | shmem_falloc.start = start; |
| 2825 | shmem_falloc.next = start; |
| 2826 | shmem_falloc.nr_falloced = 0; |
| 2827 | shmem_falloc.nr_unswapped = 0; |
| 2828 | spin_lock(&inode->i_lock); |
| 2829 | inode->i_private = &shmem_falloc; |
| 2830 | spin_unlock(&inode->i_lock); |
| 2831 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2832 | for (index = start; index < end; index++) { |
| 2833 | struct page *page; |
| 2834 | |
| 2835 | /* |
| 2836 | * Good, the fallocate(2) manpage permits EINTR: we may have |
| 2837 | * been interrupted because we are using up too much memory. |
| 2838 | */ |
| 2839 | if (signal_pending(current)) |
| 2840 | error = -EINTR; |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2841 | else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) |
| 2842 | error = -ENOMEM; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2843 | else |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 2844 | error = shmem_getpage(inode, index, &page, SGP_FALLOC); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2845 | if (error) { |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2846 | /* Remove the !PageUptodate pages we added */ |
Hugh Dickins | 7f55656 | 2016-07-10 16:46:32 -0700 | [diff] [blame] | 2847 | if (index > start) { |
| 2848 | shmem_undo_range(inode, |
| 2849 | (loff_t)start << PAGE_SHIFT, |
| 2850 | ((loff_t)index << PAGE_SHIFT) - 1, true); |
| 2851 | } |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2852 | goto undone; |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2853 | } |
| 2854 | |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2855 | /* |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2856 | * Inform shmem_writepage() how far we have reached. |
| 2857 | * No need for lock or barrier: we have the page lock. |
| 2858 | */ |
| 2859 | shmem_falloc.next++; |
| 2860 | if (!PageUptodate(page)) |
| 2861 | shmem_falloc.nr_falloced++; |
| 2862 | |
| 2863 | /* |
Hugh Dickins | 1635f6a | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2864 | * If !PageUptodate, leave it that way so that freeable pages |
| 2865 | * can be recognized if we need to rollback on error later. |
| 2866 | * But set_page_dirty so that memory pressure will swap rather |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2867 | * than free the pages we are allocating (and SGP_CACHE pages |
| 2868 | * might still be clean: we now need to mark those dirty too). |
| 2869 | */ |
| 2870 | set_page_dirty(page); |
| 2871 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2872 | put_page(page); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2873 | cond_resched(); |
| 2874 | } |
| 2875 | |
| 2876 | if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) |
| 2877 | i_size_write(inode, offset + len); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 2878 | inode->i_ctime = current_time(inode); |
Hugh Dickins | 1aac140 | 2012-05-29 15:06:42 -0700 | [diff] [blame] | 2879 | undone: |
| 2880 | spin_lock(&inode->i_lock); |
| 2881 | inode->i_private = NULL; |
| 2882 | spin_unlock(&inode->i_lock); |
Hugh Dickins | e2d12e2 | 2012-05-29 15:06:41 -0700 | [diff] [blame] | 2883 | out: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 2884 | inode_unlock(inode); |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 2885 | return error; |
| 2886 | } |
| 2887 | |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 2888 | static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2889 | { |
David Howells | 726c334 | 2006-06-23 02:02:58 -0700 | [diff] [blame] | 2890 | struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2891 | |
| 2892 | buf->f_type = TMPFS_MAGIC; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2893 | buf->f_bsize = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2894 | buf->f_namelen = NAME_MAX; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2895 | if (sbinfo->max_blocks) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2896 | buf->f_blocks = sbinfo->max_blocks; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 2897 | buf->f_bavail = |
| 2898 | buf->f_bfree = sbinfo->max_blocks - |
| 2899 | percpu_counter_sum(&sbinfo->used_blocks); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 2900 | } |
| 2901 | if (sbinfo->max_inodes) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2902 | buf->f_files = sbinfo->max_inodes; |
| 2903 | buf->f_ffree = sbinfo->free_inodes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2904 | } |
| 2905 | /* else leave those fields 0 like simple_statfs */ |
| 2906 | return 0; |
| 2907 | } |
| 2908 | |
| 2909 | /* |
| 2910 | * File creation. Allocate an inode, and we're done.. |
| 2911 | */ |
| 2912 | static int |
Al Viro | 1a67aaf | 2011-07-26 01:52:52 -0400 | [diff] [blame] | 2913 | shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2914 | { |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 2915 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2916 | int error = -ENOSPC; |
| 2917 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 2918 | inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2919 | if (inode) { |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2920 | error = simple_acl_create(dir, inode); |
| 2921 | if (error) |
| 2922 | goto out_iput; |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 2923 | error = security_inode_init_security(inode, dir, |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 2924 | &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 2925 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2926 | if (error && error != -EOPNOTSUPP) |
| 2927 | goto out_iput; |
Mimi Zohar | 37ec43c | 2013-04-14 09:21:47 -0400 | [diff] [blame] | 2928 | |
Al Viro | 718deb6 | 2009-12-16 19:35:36 -0500 | [diff] [blame] | 2929 | error = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2930 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 2931 | dir->i_ctime = dir->i_mtime = current_time(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2932 | d_instantiate(dentry, inode); |
| 2933 | dget(dentry); /* Extra count - pin the dentry in core */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2934 | } |
| 2935 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2936 | out_iput: |
| 2937 | iput(inode); |
| 2938 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2939 | } |
| 2940 | |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2941 | static int |
| 2942 | shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) |
| 2943 | { |
| 2944 | struct inode *inode; |
| 2945 | int error = -ENOSPC; |
| 2946 | |
| 2947 | inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE); |
| 2948 | if (inode) { |
| 2949 | error = security_inode_init_security(inode, dir, |
| 2950 | NULL, |
| 2951 | shmem_initxattrs, NULL); |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2952 | if (error && error != -EOPNOTSUPP) |
| 2953 | goto out_iput; |
| 2954 | error = simple_acl_create(dir, inode); |
| 2955 | if (error) |
| 2956 | goto out_iput; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2957 | d_tmpfile(dentry, inode); |
| 2958 | } |
| 2959 | return error; |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 2960 | out_iput: |
| 2961 | iput(inode); |
| 2962 | return error; |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 2963 | } |
| 2964 | |
Al Viro | 18bb1db | 2011-07-26 01:41:39 -0400 | [diff] [blame] | 2965 | static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2966 | { |
| 2967 | int error; |
| 2968 | |
| 2969 | if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0))) |
| 2970 | return error; |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 2971 | inc_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2972 | return 0; |
| 2973 | } |
| 2974 | |
Al Viro | 4acdaf2 | 2011-07-26 01:42:34 -0400 | [diff] [blame] | 2975 | static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
Al Viro | ebfc3b4 | 2012-06-10 18:05:36 -0400 | [diff] [blame] | 2976 | bool excl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2977 | { |
| 2978 | return shmem_mknod(dir, dentry, mode | S_IFREG, 0); |
| 2979 | } |
| 2980 | |
| 2981 | /* |
| 2982 | * Link a file.. |
| 2983 | */ |
| 2984 | static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
| 2985 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 2986 | struct inode *inode = d_inode(old_dentry); |
Darrick J. Wong | 29b00e6 | 2019-02-22 22:35:32 -0800 | [diff] [blame] | 2987 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2988 | |
| 2989 | /* |
| 2990 | * No ordinary (disk based) filesystem counts links as inodes; |
| 2991 | * but each new link needs a new dentry, pinning lowmem, and |
| 2992 | * tmpfs dentries cannot be pruned until they are unlinked. |
Darrick J. Wong | 1062af9 | 2019-02-21 08:48:09 -0800 | [diff] [blame] | 2993 | * But if an O_TMPFILE file is linked into the tmpfs, the |
| 2994 | * first link must skip that, to get the accounting right. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2995 | */ |
Darrick J. Wong | 1062af9 | 2019-02-21 08:48:09 -0800 | [diff] [blame] | 2996 | if (inode->i_nlink) { |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 2997 | ret = shmem_reserve_inode(inode->i_sb, NULL); |
Darrick J. Wong | 1062af9 | 2019-02-21 08:48:09 -0800 | [diff] [blame] | 2998 | if (ret) |
| 2999 | goto out; |
| 3000 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3001 | |
| 3002 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3003 | inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 3004 | inc_nlink(inode); |
Al Viro | 7de9c6ee | 2010-10-23 11:11:40 -0400 | [diff] [blame] | 3005 | ihold(inode); /* New dentry reference */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3006 | dget(dentry); /* Extra pinning count for the created dentry */ |
| 3007 | d_instantiate(dentry, inode); |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 3008 | out: |
| 3009 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3010 | } |
| 3011 | |
| 3012 | static int shmem_unlink(struct inode *dir, struct dentry *dentry) |
| 3013 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3014 | struct inode *inode = d_inode(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3015 | |
Pavel Emelyanov | 5b04c68 | 2008-02-04 22:28:47 -0800 | [diff] [blame] | 3016 | if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) |
| 3017 | shmem_free_inode(inode->i_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3018 | |
| 3019 | dir->i_size -= BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3020 | inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3021 | drop_nlink(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3022 | dput(dentry); /* Undo the count from "create" - this does all the work */ |
| 3023 | return 0; |
| 3024 | } |
| 3025 | |
| 3026 | static int shmem_rmdir(struct inode *dir, struct dentry *dentry) |
| 3027 | { |
| 3028 | if (!simple_empty(dentry)) |
| 3029 | return -ENOTEMPTY; |
| 3030 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3031 | drop_nlink(d_inode(dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3032 | drop_nlink(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3033 | return shmem_unlink(dir, dentry); |
| 3034 | } |
| 3035 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3036 | static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) |
| 3037 | { |
David Howells | e36cb0b | 2015-01-29 12:02:35 +0000 | [diff] [blame] | 3038 | bool old_is_dir = d_is_dir(old_dentry); |
| 3039 | bool new_is_dir = d_is_dir(new_dentry); |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3040 | |
| 3041 | if (old_dir != new_dir && old_is_dir != new_is_dir) { |
| 3042 | if (old_is_dir) { |
| 3043 | drop_nlink(old_dir); |
| 3044 | inc_nlink(new_dir); |
| 3045 | } else { |
| 3046 | drop_nlink(new_dir); |
| 3047 | inc_nlink(old_dir); |
| 3048 | } |
| 3049 | } |
| 3050 | old_dir->i_ctime = old_dir->i_mtime = |
| 3051 | new_dir->i_ctime = new_dir->i_mtime = |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3052 | d_inode(old_dentry)->i_ctime = |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3053 | d_inode(new_dentry)->i_ctime = current_time(old_dir); |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3054 | |
| 3055 | return 0; |
| 3056 | } |
| 3057 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3058 | static int shmem_whiteout(struct inode *old_dir, struct dentry *old_dentry) |
| 3059 | { |
| 3060 | struct dentry *whiteout; |
| 3061 | int error; |
| 3062 | |
| 3063 | whiteout = d_alloc(old_dentry->d_parent, &old_dentry->d_name); |
| 3064 | if (!whiteout) |
| 3065 | return -ENOMEM; |
| 3066 | |
| 3067 | error = shmem_mknod(old_dir, whiteout, |
| 3068 | S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); |
| 3069 | dput(whiteout); |
| 3070 | if (error) |
| 3071 | return error; |
| 3072 | |
| 3073 | /* |
| 3074 | * Cheat and hash the whiteout while the old dentry is still in |
| 3075 | * place, instead of playing games with FS_RENAME_DOES_D_MOVE. |
| 3076 | * |
| 3077 | * d_lookup() will consistently find one of them at this point, |
| 3078 | * not sure which one, but that isn't even important. |
| 3079 | */ |
| 3080 | d_rehash(whiteout); |
| 3081 | return 0; |
| 3082 | } |
| 3083 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3084 | /* |
| 3085 | * The VFS layer already does all the dentry stuff for rename, |
| 3086 | * we just have to decrement the usage count for the target if |
| 3087 | * it exists so that the VFS layer correctly free's it when it |
| 3088 | * gets overwritten. |
| 3089 | */ |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 3090 | static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3091 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3092 | struct inode *inode = d_inode(old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3093 | int they_are_dirs = S_ISDIR(inode->i_mode); |
| 3094 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3095 | if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) |
Miklos Szeredi | 3b69ff5 | 2014-07-23 15:15:33 +0200 | [diff] [blame] | 3096 | return -EINVAL; |
| 3097 | |
Miklos Szeredi | 3745677 | 2014-07-23 15:15:34 +0200 | [diff] [blame] | 3098 | if (flags & RENAME_EXCHANGE) |
| 3099 | return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry); |
| 3100 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3101 | if (!simple_empty(new_dentry)) |
| 3102 | return -ENOTEMPTY; |
| 3103 | |
Miklos Szeredi | 46fdb79 | 2014-10-24 00:14:37 +0200 | [diff] [blame] | 3104 | if (flags & RENAME_WHITEOUT) { |
| 3105 | int error; |
| 3106 | |
| 3107 | error = shmem_whiteout(old_dir, old_dentry); |
| 3108 | if (error) |
| 3109 | return error; |
| 3110 | } |
| 3111 | |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3112 | if (d_really_is_positive(new_dentry)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3113 | (void) shmem_unlink(new_dir, new_dentry); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 3114 | if (they_are_dirs) { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3115 | drop_nlink(d_inode(new_dentry)); |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3116 | drop_nlink(old_dir); |
Miklos Szeredi | b928095 | 2014-09-24 17:56:17 +0200 | [diff] [blame] | 3117 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3118 | } else if (they_are_dirs) { |
Dave Hansen | 9a53c3a | 2006-09-30 23:29:03 -0700 | [diff] [blame] | 3119 | drop_nlink(old_dir); |
Dave Hansen | d8c76e6 | 2006-09-30 23:29:04 -0700 | [diff] [blame] | 3120 | inc_nlink(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3121 | } |
| 3122 | |
| 3123 | old_dir->i_size -= BOGO_DIRENT_SIZE; |
| 3124 | new_dir->i_size += BOGO_DIRENT_SIZE; |
| 3125 | old_dir->i_ctime = old_dir->i_mtime = |
| 3126 | new_dir->i_ctime = new_dir->i_mtime = |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3127 | inode->i_ctime = current_time(old_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3128 | return 0; |
| 3129 | } |
| 3130 | |
| 3131 | static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
| 3132 | { |
| 3133 | int error; |
| 3134 | int len; |
| 3135 | struct inode *inode; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 3136 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3137 | |
| 3138 | len = strlen(symname) + 1; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3139 | if (len > PAGE_SIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3140 | return -ENAMETOOLONG; |
| 3141 | |
Joe Perches | 0825a6f | 2018-06-14 15:27:58 -0700 | [diff] [blame] | 3142 | inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK | 0777, 0, |
| 3143 | VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3144 | if (!inode) |
| 3145 | return -ENOSPC; |
| 3146 | |
Mimi Zohar | 9d8f13b | 2011-06-06 15:29:25 -0400 | [diff] [blame] | 3147 | error = security_inode_init_security(inode, dir, &dentry->d_name, |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3148 | shmem_initxattrs, NULL); |
Mateusz Nosek | 343c3d7 | 2020-04-06 20:07:54 -0700 | [diff] [blame] | 3149 | if (error && error != -EOPNOTSUPP) { |
| 3150 | iput(inode); |
| 3151 | return error; |
Stephen Smalley | 570bc1c | 2005-09-09 13:01:43 -0700 | [diff] [blame] | 3152 | } |
| 3153 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3154 | inode->i_size = len-1; |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3155 | if (len <= SHORT_SYMLINK_LEN) { |
Al Viro | 3ed47db | 2016-01-22 18:08:52 -0500 | [diff] [blame] | 3156 | inode->i_link = kmemdup(symname, len, GFP_KERNEL); |
| 3157 | if (!inode->i_link) { |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3158 | iput(inode); |
| 3159 | return -ENOMEM; |
| 3160 | } |
| 3161 | inode->i_op = &shmem_short_symlink_operations; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3162 | } else { |
Al Viro | e8ecde2 | 2016-01-14 17:52:59 -0500 | [diff] [blame] | 3163 | inode_nohighmem(inode); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 3164 | error = shmem_getpage(inode, 0, &page, SGP_WRITE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3165 | if (error) { |
| 3166 | iput(inode); |
| 3167 | return error; |
| 3168 | } |
Hugh Dickins | 14fcc23 | 2008-07-28 15:46:19 -0700 | [diff] [blame] | 3169 | inode->i_mapping->a_ops = &shmem_aops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3170 | inode->i_op = &shmem_symlink_inode_operations; |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 3171 | memcpy(page_address(page), symname, len); |
Hugh Dickins | ec9516f | 2012-05-29 15:06:39 -0700 | [diff] [blame] | 3172 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3173 | set_page_dirty(page); |
Wu Fengguang | 6746aff | 2009-09-16 11:50:14 +0200 | [diff] [blame] | 3174 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3175 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3176 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3177 | dir->i_size += BOGO_DIRENT_SIZE; |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 3178 | dir->i_ctime = dir->i_mtime = current_time(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3179 | d_instantiate(dentry, inode); |
| 3180 | dget(dentry); |
| 3181 | return 0; |
| 3182 | } |
| 3183 | |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3184 | static void shmem_put_link(void *arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3185 | { |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3186 | mark_page_accessed(arg); |
| 3187 | put_page(arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3188 | } |
| 3189 | |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3190 | static const char *shmem_get_link(struct dentry *dentry, |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3191 | struct inode *inode, |
| 3192 | struct delayed_call *done) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3193 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3194 | struct page *page = NULL; |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3195 | int error; |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 3196 | if (!dentry) { |
| 3197 | page = find_get_page(inode->i_mapping, 0); |
| 3198 | if (!page) |
| 3199 | return ERR_PTR(-ECHILD); |
| 3200 | if (!PageUptodate(page)) { |
| 3201 | put_page(page); |
| 3202 | return ERR_PTR(-ECHILD); |
| 3203 | } |
| 3204 | } else { |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 3205 | error = shmem_getpage(inode, 0, &page, SGP_READ); |
Al Viro | 6a6c990 | 2015-11-17 10:54:32 -0500 | [diff] [blame] | 3206 | if (error) |
| 3207 | return ERR_PTR(error); |
| 3208 | unlock_page(page); |
| 3209 | } |
Al Viro | fceef39 | 2015-12-29 15:58:39 -0500 | [diff] [blame] | 3210 | set_delayed_call(done, shmem_put_link, page); |
Al Viro | 21fc61c | 2015-11-17 01:07:57 -0500 | [diff] [blame] | 3211 | return page_address(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3212 | } |
| 3213 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3214 | #ifdef CONFIG_TMPFS_XATTR |
| 3215 | /* |
| 3216 | * Superblocks without xattr inode operations may get some security.* xattr |
| 3217 | * support from the LSM "for free". As soon as we have any other xattrs |
| 3218 | * like ACLs, we also need to implement the security.* handlers at |
| 3219 | * filesystem level, though. |
| 3220 | */ |
| 3221 | |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3222 | /* |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3223 | * Callback for security_inode_init_security() for acquiring xattrs. |
| 3224 | */ |
| 3225 | static int shmem_initxattrs(struct inode *inode, |
| 3226 | const struct xattr *xattr_array, |
| 3227 | void *fs_info) |
| 3228 | { |
| 3229 | struct shmem_inode_info *info = SHMEM_I(inode); |
| 3230 | const struct xattr *xattr; |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3231 | struct simple_xattr *new_xattr; |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3232 | size_t len; |
| 3233 | |
| 3234 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3235 | new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3236 | if (!new_xattr) |
| 3237 | return -ENOMEM; |
| 3238 | |
| 3239 | len = strlen(xattr->name) + 1; |
| 3240 | new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len, |
| 3241 | GFP_KERNEL); |
| 3242 | if (!new_xattr->name) { |
Chengguang Xu | 3bef735 | 2020-07-23 21:15:14 -0700 | [diff] [blame] | 3243 | kvfree(new_xattr); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3244 | return -ENOMEM; |
| 3245 | } |
| 3246 | |
| 3247 | memcpy(new_xattr->name, XATTR_SECURITY_PREFIX, |
| 3248 | XATTR_SECURITY_PREFIX_LEN); |
| 3249 | memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN, |
| 3250 | xattr->name, len); |
| 3251 | |
Aristeu Rozanski | 38f3865 | 2012-08-23 16:53:28 -0400 | [diff] [blame] | 3252 | simple_xattr_list_add(&info->xattrs, new_xattr); |
Jarkko Sakkinen | 6d9d88d | 2012-03-21 16:34:05 -0700 | [diff] [blame] | 3253 | } |
| 3254 | |
| 3255 | return 0; |
| 3256 | } |
| 3257 | |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3258 | static int shmem_xattr_handler_get(const struct xattr_handler *handler, |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 3259 | struct dentry *unused, struct inode *inode, |
| 3260 | const char *name, void *buffer, size_t size) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3261 | { |
Al Viro | b296821 | 2016-04-10 20:48:24 -0400 | [diff] [blame] | 3262 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3263 | |
| 3264 | name = xattr_full_name(handler, name); |
| 3265 | return simple_xattr_get(&info->xattrs, name, buffer, size); |
| 3266 | } |
| 3267 | |
| 3268 | static int shmem_xattr_handler_set(const struct xattr_handler *handler, |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 3269 | struct dentry *unused, struct inode *inode, |
| 3270 | const char *name, const void *value, |
| 3271 | size_t size, int flags) |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3272 | { |
Al Viro | 5930122 | 2016-05-27 10:19:30 -0400 | [diff] [blame] | 3273 | struct shmem_inode_info *info = SHMEM_I(inode); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3274 | |
| 3275 | name = xattr_full_name(handler, name); |
Daniel Xu | a46a229 | 2020-03-12 13:03:15 -0700 | [diff] [blame] | 3276 | return simple_xattr_set(&info->xattrs, name, value, size, flags, NULL); |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3277 | } |
| 3278 | |
| 3279 | static const struct xattr_handler shmem_security_xattr_handler = { |
| 3280 | .prefix = XATTR_SECURITY_PREFIX, |
| 3281 | .get = shmem_xattr_handler_get, |
| 3282 | .set = shmem_xattr_handler_set, |
| 3283 | }; |
| 3284 | |
| 3285 | static const struct xattr_handler shmem_trusted_xattr_handler = { |
| 3286 | .prefix = XATTR_TRUSTED_PREFIX, |
| 3287 | .get = shmem_xattr_handler_get, |
| 3288 | .set = shmem_xattr_handler_set, |
| 3289 | }; |
| 3290 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3291 | static const struct xattr_handler *shmem_xattr_handlers[] = { |
| 3292 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3293 | &posix_acl_access_xattr_handler, |
| 3294 | &posix_acl_default_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3295 | #endif |
Andreas Gruenbacher | aa7c524 | 2015-12-02 14:44:38 +0100 | [diff] [blame] | 3296 | &shmem_security_xattr_handler, |
| 3297 | &shmem_trusted_xattr_handler, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3298 | NULL |
| 3299 | }; |
| 3300 | |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3301 | static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) |
| 3302 | { |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 3303 | struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); |
Andreas Gruenbacher | 786534b | 2015-12-02 14:44:39 +0100 | [diff] [blame] | 3304 | return simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, size); |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3305 | } |
| 3306 | #endif /* CONFIG_TMPFS_XATTR */ |
| 3307 | |
Hugh Dickins | 69f07ec | 2011-08-03 16:21:26 -0700 | [diff] [blame] | 3308 | static const struct inode_operations shmem_short_symlink_operations = { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3309 | .get_link = simple_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3310 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3311 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3312 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3313 | }; |
| 3314 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3315 | static const struct inode_operations shmem_symlink_inode_operations = { |
Al Viro | 6b25539 | 2015-11-17 10:20:54 -0500 | [diff] [blame] | 3316 | .get_link = shmem_get_link, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3317 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3318 | .listxattr = shmem_listxattr, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3319 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3320 | }; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3321 | |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3322 | static struct dentry *shmem_get_parent(struct dentry *child) |
| 3323 | { |
| 3324 | return ERR_PTR(-ESTALE); |
| 3325 | } |
| 3326 | |
| 3327 | static int shmem_match(struct inode *ino, void *vfh) |
| 3328 | { |
| 3329 | __u32 *fh = vfh; |
| 3330 | __u64 inum = fh[2]; |
| 3331 | inum = (inum << 32) | fh[1]; |
| 3332 | return ino->i_ino == inum && fh[0] == ino->i_generation; |
| 3333 | } |
| 3334 | |
Amir Goldstein | 12ba780 | 2018-06-07 17:07:15 -0700 | [diff] [blame] | 3335 | /* Find any alias of inode, but prefer a hashed alias */ |
| 3336 | static struct dentry *shmem_find_alias(struct inode *inode) |
| 3337 | { |
| 3338 | struct dentry *alias = d_find_alias(inode); |
| 3339 | |
| 3340 | return alias ?: d_find_any_alias(inode); |
| 3341 | } |
| 3342 | |
| 3343 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3344 | static struct dentry *shmem_fh_to_dentry(struct super_block *sb, |
| 3345 | struct fid *fid, int fh_len, int fh_type) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3346 | { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3347 | struct inode *inode; |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3348 | struct dentry *dentry = NULL; |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 3349 | u64 inum; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3350 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3351 | if (fh_len < 3) |
| 3352 | return NULL; |
| 3353 | |
Hugh Dickins | 35c2a7f | 2012-10-07 20:32:51 -0700 | [diff] [blame] | 3354 | inum = fid->raw[2]; |
| 3355 | inum = (inum << 32) | fid->raw[1]; |
| 3356 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3357 | inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), |
| 3358 | shmem_match, fid->raw); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3359 | if (inode) { |
Amir Goldstein | 12ba780 | 2018-06-07 17:07:15 -0700 | [diff] [blame] | 3360 | dentry = shmem_find_alias(inode); |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3361 | iput(inode); |
| 3362 | } |
| 3363 | |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3364 | return dentry; |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3365 | } |
| 3366 | |
Al Viro | b0b0382 | 2012-04-02 14:34:06 -0400 | [diff] [blame] | 3367 | static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, |
| 3368 | struct inode *parent) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3369 | { |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 3370 | if (*len < 3) { |
| 3371 | *len = 3; |
Namjae Jeon | 94e07a75 | 2013-02-17 15:48:11 +0900 | [diff] [blame] | 3372 | return FILEID_INVALID; |
Aneesh Kumar K.V | 5fe0c23 | 2011-01-29 18:43:25 +0530 | [diff] [blame] | 3373 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3374 | |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 3375 | if (inode_unhashed(inode)) { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3376 | /* Unfortunately insert_inode_hash is not idempotent, |
| 3377 | * so as we hash inodes here rather than at creation |
| 3378 | * time, we need a lock to ensure we only try |
| 3379 | * to do it once |
| 3380 | */ |
| 3381 | static DEFINE_SPINLOCK(lock); |
| 3382 | spin_lock(&lock); |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 3383 | if (inode_unhashed(inode)) |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3384 | __insert_inode_hash(inode, |
| 3385 | inode->i_ino + inode->i_generation); |
| 3386 | spin_unlock(&lock); |
| 3387 | } |
| 3388 | |
| 3389 | fh[0] = inode->i_generation; |
| 3390 | fh[1] = inode->i_ino; |
| 3391 | fh[2] = ((__u64)inode->i_ino) >> 32; |
| 3392 | |
| 3393 | *len = 3; |
| 3394 | return 1; |
| 3395 | } |
| 3396 | |
Christoph Hellwig | 3965516 | 2007-10-21 16:42:17 -0700 | [diff] [blame] | 3397 | static const struct export_operations shmem_export_ops = { |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3398 | .get_parent = shmem_get_parent, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3399 | .encode_fh = shmem_encode_fh, |
Christoph Hellwig | 480b116 | 2007-10-21 16:42:13 -0700 | [diff] [blame] | 3400 | .fh_to_dentry = shmem_fh_to_dentry, |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3401 | }; |
| 3402 | |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3403 | enum shmem_param { |
| 3404 | Opt_gid, |
| 3405 | Opt_huge, |
| 3406 | Opt_mode, |
| 3407 | Opt_mpol, |
| 3408 | Opt_nr_blocks, |
| 3409 | Opt_nr_inodes, |
| 3410 | Opt_size, |
| 3411 | Opt_uid, |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3412 | Opt_inode32, |
| 3413 | Opt_inode64, |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3414 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3415 | |
Al Viro | 5eede62 | 2019-12-16 13:33:32 -0500 | [diff] [blame] | 3416 | static const struct constant_table shmem_param_enums_huge[] = { |
Al Viro | 2710c957a | 2019-09-06 22:12:08 -0400 | [diff] [blame] | 3417 | {"never", SHMEM_HUGE_NEVER }, |
| 3418 | {"always", SHMEM_HUGE_ALWAYS }, |
| 3419 | {"within_size", SHMEM_HUGE_WITHIN_SIZE }, |
| 3420 | {"advise", SHMEM_HUGE_ADVISE }, |
Al Viro | 2710c957a | 2019-09-06 22:12:08 -0400 | [diff] [blame] | 3421 | {} |
| 3422 | }; |
| 3423 | |
Al Viro | d7167b1 | 2019-09-07 07:23:15 -0400 | [diff] [blame] | 3424 | const struct fs_parameter_spec shmem_fs_parameters[] = { |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3425 | fsparam_u32 ("gid", Opt_gid), |
Al Viro | 2710c957a | 2019-09-06 22:12:08 -0400 | [diff] [blame] | 3426 | fsparam_enum ("huge", Opt_huge, shmem_param_enums_huge), |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3427 | fsparam_u32oct("mode", Opt_mode), |
| 3428 | fsparam_string("mpol", Opt_mpol), |
| 3429 | fsparam_string("nr_blocks", Opt_nr_blocks), |
| 3430 | fsparam_string("nr_inodes", Opt_nr_inodes), |
| 3431 | fsparam_string("size", Opt_size), |
| 3432 | fsparam_u32 ("uid", Opt_uid), |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3433 | fsparam_flag ("inode32", Opt_inode32), |
| 3434 | fsparam_flag ("inode64", Opt_inode64), |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3435 | {} |
| 3436 | }; |
| 3437 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3438 | static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3439 | { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3440 | struct shmem_options *ctx = fc->fs_private; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3441 | struct fs_parse_result result; |
| 3442 | unsigned long long size; |
| 3443 | char *rest; |
| 3444 | int opt; |
| 3445 | |
Al Viro | d7167b1 | 2019-09-07 07:23:15 -0400 | [diff] [blame] | 3446 | opt = fs_parse(fc, shmem_fs_parameters, param, &result); |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3447 | if (opt < 0) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3448 | return opt; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3449 | |
| 3450 | switch (opt) { |
| 3451 | case Opt_size: |
| 3452 | size = memparse(param->string, &rest); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3453 | if (*rest == '%') { |
| 3454 | size <<= PAGE_SHIFT; |
| 3455 | size *= totalram_pages(); |
| 3456 | do_div(size, 100); |
| 3457 | rest++; |
| 3458 | } |
| 3459 | if (*rest) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3460 | goto bad_value; |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3461 | ctx->blocks = DIV_ROUND_UP(size, PAGE_SIZE); |
| 3462 | ctx->seen |= SHMEM_SEEN_BLOCKS; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3463 | break; |
| 3464 | case Opt_nr_blocks: |
| 3465 | ctx->blocks = memparse(param->string, &rest); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3466 | if (*rest) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3467 | goto bad_value; |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3468 | ctx->seen |= SHMEM_SEEN_BLOCKS; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3469 | break; |
| 3470 | case Opt_nr_inodes: |
| 3471 | ctx->inodes = memparse(param->string, &rest); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3472 | if (*rest) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3473 | goto bad_value; |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3474 | ctx->seen |= SHMEM_SEEN_INODES; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3475 | break; |
| 3476 | case Opt_mode: |
| 3477 | ctx->mode = result.uint_32 & 07777; |
| 3478 | break; |
| 3479 | case Opt_uid: |
| 3480 | ctx->uid = make_kuid(current_user_ns(), result.uint_32); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3481 | if (!uid_valid(ctx->uid)) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3482 | goto bad_value; |
| 3483 | break; |
| 3484 | case Opt_gid: |
| 3485 | ctx->gid = make_kgid(current_user_ns(), result.uint_32); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3486 | if (!gid_valid(ctx->gid)) |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3487 | goto bad_value; |
| 3488 | break; |
| 3489 | case Opt_huge: |
| 3490 | ctx->huge = result.uint_32; |
| 3491 | if (ctx->huge != SHMEM_HUGE_NEVER && |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 3492 | !(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3493 | has_transparent_hugepage())) |
| 3494 | goto unsupported_parameter; |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3495 | ctx->seen |= SHMEM_SEEN_HUGE; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3496 | break; |
| 3497 | case Opt_mpol: |
| 3498 | if (IS_ENABLED(CONFIG_NUMA)) { |
| 3499 | mpol_put(ctx->mpol); |
| 3500 | ctx->mpol = NULL; |
| 3501 | if (mpol_parse_str(param->string, &ctx->mpol)) |
| 3502 | goto bad_value; |
| 3503 | break; |
| 3504 | } |
| 3505 | goto unsupported_parameter; |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3506 | case Opt_inode32: |
| 3507 | ctx->full_inums = false; |
| 3508 | ctx->seen |= SHMEM_SEEN_INUMS; |
| 3509 | break; |
| 3510 | case Opt_inode64: |
| 3511 | if (sizeof(ino_t) < 8) { |
| 3512 | return invalfc(fc, |
| 3513 | "Cannot use inode64 with <64bit inums in kernel\n"); |
| 3514 | } |
| 3515 | ctx->full_inums = true; |
| 3516 | ctx->seen |= SHMEM_SEEN_INUMS; |
| 3517 | break; |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3518 | } |
| 3519 | return 0; |
| 3520 | |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3521 | unsupported_parameter: |
Al Viro | f35aa2b | 2019-12-21 21:35:55 -0500 | [diff] [blame] | 3522 | return invalfc(fc, "Unsupported parameter '%s'", param->key); |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3523 | bad_value: |
Al Viro | f35aa2b | 2019-12-21 21:35:55 -0500 | [diff] [blame] | 3524 | return invalfc(fc, "Bad value for '%s'", param->key); |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3525 | } |
| 3526 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3527 | static int shmem_parse_options(struct fs_context *fc, void *data) |
Al Viro | e04dc42 | 2019-09-08 19:20:12 -0400 | [diff] [blame] | 3528 | { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3529 | char *options = data; |
| 3530 | |
Al Viro | 33f37c6 | 2019-10-09 22:48:01 -0400 | [diff] [blame] | 3531 | if (options) { |
| 3532 | int err = security_sb_eat_lsm_opts(options, &fc->security); |
| 3533 | if (err) |
| 3534 | return err; |
| 3535 | } |
| 3536 | |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 3537 | while (options != NULL) { |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3538 | char *this_char = options; |
Hugh Dickins | b00dc3a | 2006-02-21 23:49:47 +0000 | [diff] [blame] | 3539 | for (;;) { |
| 3540 | /* |
| 3541 | * NUL-terminate this option: unfortunately, |
| 3542 | * mount options form a comma-separated list, |
| 3543 | * but mpol's nodelist may also contain commas. |
| 3544 | */ |
| 3545 | options = strchr(options, ','); |
| 3546 | if (options == NULL) |
| 3547 | break; |
| 3548 | options++; |
| 3549 | if (!isdigit(*options)) { |
| 3550 | options[-1] = '\0'; |
| 3551 | break; |
| 3552 | } |
| 3553 | } |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3554 | if (*this_char) { |
| 3555 | char *value = strchr(this_char,'='); |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3556 | size_t len = 0; |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3557 | int err; |
| 3558 | |
| 3559 | if (value) { |
| 3560 | *value++ = '\0'; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3561 | len = strlen(value); |
Al Viro | 626c392 | 2019-09-08 20:28:06 -0400 | [diff] [blame] | 3562 | } |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3563 | err = vfs_parse_fs_string(fc, this_char, value, len); |
| 3564 | if (err < 0) |
| 3565 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3566 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3567 | } |
| 3568 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3569 | } |
| 3570 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3571 | /* |
| 3572 | * Reconfigure a shmem filesystem. |
| 3573 | * |
| 3574 | * Note that we disallow change from limited->unlimited blocks/inodes while any |
| 3575 | * are in use; but we must separately disallow unlimited->limited, because in |
| 3576 | * that case we have no record of how much is already in use. |
| 3577 | */ |
| 3578 | static int shmem_reconfigure(struct fs_context *fc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3579 | { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3580 | struct shmem_options *ctx = fc->fs_private; |
| 3581 | struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3582 | unsigned long inodes; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3583 | const char *err; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3584 | |
| 3585 | spin_lock(&sbinfo->stat_lock); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3586 | inodes = sbinfo->max_inodes - sbinfo->free_inodes; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3587 | if ((ctx->seen & SHMEM_SEEN_BLOCKS) && ctx->blocks) { |
| 3588 | if (!sbinfo->max_blocks) { |
| 3589 | err = "Cannot retroactively limit size"; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3590 | goto out; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3591 | } |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3592 | if (percpu_counter_compare(&sbinfo->used_blocks, |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3593 | ctx->blocks) > 0) { |
| 3594 | err = "Too small a size for current use"; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3595 | goto out; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3596 | } |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3597 | } |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3598 | if ((ctx->seen & SHMEM_SEEN_INODES) && ctx->inodes) { |
| 3599 | if (!sbinfo->max_inodes) { |
| 3600 | err = "Cannot retroactively limit inodes"; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3601 | goto out; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3602 | } |
| 3603 | if (ctx->inodes < inodes) { |
| 3604 | err = "Too few inodes for current use"; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3605 | goto out; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3606 | } |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3607 | } |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3608 | |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3609 | if ((ctx->seen & SHMEM_SEEN_INUMS) && !ctx->full_inums && |
| 3610 | sbinfo->next_ino > UINT_MAX) { |
| 3611 | err = "Current inum too high to switch to 32-bit inums"; |
| 3612 | goto out; |
| 3613 | } |
| 3614 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3615 | if (ctx->seen & SHMEM_SEEN_HUGE) |
| 3616 | sbinfo->huge = ctx->huge; |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3617 | if (ctx->seen & SHMEM_SEEN_INUMS) |
| 3618 | sbinfo->full_inums = ctx->full_inums; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3619 | if (ctx->seen & SHMEM_SEEN_BLOCKS) |
| 3620 | sbinfo->max_blocks = ctx->blocks; |
| 3621 | if (ctx->seen & SHMEM_SEEN_INODES) { |
| 3622 | sbinfo->max_inodes = ctx->inodes; |
| 3623 | sbinfo->free_inodes = ctx->inodes - inodes; |
Al Viro | 0b5071d | 2019-09-08 18:49:18 -0400 | [diff] [blame] | 3624 | } |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 3625 | |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 3626 | /* |
| 3627 | * Preserve previous mempolicy unless mpol remount option was specified. |
| 3628 | */ |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3629 | if (ctx->mpol) { |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 3630 | mpol_put(sbinfo->mpol); |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3631 | sbinfo->mpol = ctx->mpol; /* transfers initial ref */ |
| 3632 | ctx->mpol = NULL; |
Greg Thelen | 5f00110 | 2013-02-22 16:36:01 -0800 | [diff] [blame] | 3633 | } |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3634 | spin_unlock(&sbinfo->stat_lock); |
| 3635 | return 0; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3636 | out: |
| 3637 | spin_unlock(&sbinfo->stat_lock); |
Al Viro | f35aa2b | 2019-12-21 21:35:55 -0500 | [diff] [blame] | 3638 | return invalfc(fc, "%s", err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3639 | } |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3640 | |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 3641 | static int shmem_show_options(struct seq_file *seq, struct dentry *root) |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3642 | { |
Al Viro | 34c80b1 | 2011-12-08 21:32:45 -0500 | [diff] [blame] | 3643 | struct shmem_sb_info *sbinfo = SHMEM_SB(root->d_sb); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3644 | |
| 3645 | if (sbinfo->max_blocks != shmem_default_max_blocks()) |
| 3646 | seq_printf(seq, ",size=%luk", |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3647 | sbinfo->max_blocks << (PAGE_SHIFT - 10)); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3648 | if (sbinfo->max_inodes != shmem_default_max_inodes()) |
| 3649 | seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); |
Joe Perches | 0825a6f | 2018-06-14 15:27:58 -0700 | [diff] [blame] | 3650 | if (sbinfo->mode != (0777 | S_ISVTX)) |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 3651 | seq_printf(seq, ",mode=%03ho", sbinfo->mode); |
Eric W. Biederman | 8751e03 | 2012-02-07 16:46:12 -0800 | [diff] [blame] | 3652 | if (!uid_eq(sbinfo->uid, GLOBAL_ROOT_UID)) |
| 3653 | seq_printf(seq, ",uid=%u", |
| 3654 | from_kuid_munged(&init_user_ns, sbinfo->uid)); |
| 3655 | if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID)) |
| 3656 | seq_printf(seq, ",gid=%u", |
| 3657 | from_kgid_munged(&init_user_ns, sbinfo->gid)); |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3658 | |
| 3659 | /* |
| 3660 | * Showing inode{64,32} might be useful even if it's the system default, |
| 3661 | * since then people don't have to resort to checking both here and |
| 3662 | * /proc/config.gz to confirm 64-bit inums were successfully applied |
| 3663 | * (which may not even exist if IKCONFIG_PROC isn't enabled). |
| 3664 | * |
| 3665 | * We hide it when inode64 isn't the default and we are using 32-bit |
| 3666 | * inodes, since that probably just means the feature isn't even under |
| 3667 | * consideration. |
| 3668 | * |
| 3669 | * As such: |
| 3670 | * |
| 3671 | * +-----------------+-----------------+ |
| 3672 | * | TMPFS_INODE64=y | TMPFS_INODE64=n | |
| 3673 | * +------------------+-----------------+-----------------+ |
| 3674 | * | full_inums=true | show | show | |
| 3675 | * | full_inums=false | show | hide | |
| 3676 | * +------------------+-----------------+-----------------+ |
| 3677 | * |
| 3678 | */ |
| 3679 | if (IS_ENABLED(CONFIG_TMPFS_INODE64) || sbinfo->full_inums) |
| 3680 | seq_printf(seq, ",inode%d", (sbinfo->full_inums ? 64 : 32)); |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 3681 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3682 | /* Rightly or wrongly, show huge mount option unmasked by shmem_huge */ |
| 3683 | if (sbinfo->huge) |
| 3684 | seq_printf(seq, ",huge=%s", shmem_format_huge(sbinfo->huge)); |
| 3685 | #endif |
Lee Schermerhorn | 71fe804 | 2008-04-28 02:13:26 -0700 | [diff] [blame] | 3686 | shmem_show_mpol(seq, sbinfo->mpol); |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3687 | return 0; |
| 3688 | } |
David Herrmann | 9183df2 | 2014-08-08 14:25:29 -0700 | [diff] [blame] | 3689 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3690 | #endif /* CONFIG_TMPFS */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3691 | |
| 3692 | static void shmem_put_super(struct super_block *sb) |
| 3693 | { |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3694 | struct shmem_sb_info *sbinfo = SHMEM_SB(sb); |
| 3695 | |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 3696 | free_percpu(sbinfo->ino_batch); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3697 | percpu_counter_destroy(&sbinfo->used_blocks); |
Greg Thelen | 49cd0a5 | 2013-02-22 16:36:02 -0800 | [diff] [blame] | 3698 | mpol_put(sbinfo->mpol); |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3699 | kfree(sbinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3700 | sb->s_fs_info = NULL; |
| 3701 | } |
| 3702 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3703 | static int shmem_fill_super(struct super_block *sb, struct fs_context *fc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3704 | { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3705 | struct shmem_options *ctx = fc->fs_private; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3706 | struct inode *inode; |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3707 | struct shmem_sb_info *sbinfo; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3708 | int err = -ENOMEM; |
| 3709 | |
| 3710 | /* Round up to L1_CACHE_BYTES to resist false sharing */ |
Pekka Enberg | 425fbf0 | 2009-09-21 17:03:50 -0700 | [diff] [blame] | 3711 | sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info), |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3712 | L1_CACHE_BYTES), GFP_KERNEL); |
| 3713 | if (!sbinfo) |
| 3714 | return -ENOMEM; |
| 3715 | |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3716 | sb->s_fs_info = sbinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3717 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3718 | #ifdef CONFIG_TMPFS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3719 | /* |
| 3720 | * Per default we only allow half of the physical ram per |
| 3721 | * tmpfs instance, limiting inodes to one per page of lowmem; |
| 3722 | * but the internal instance is left unlimited. |
| 3723 | */ |
Linus Torvalds | 1751e8a | 2017-11-27 13:05:09 -0800 | [diff] [blame] | 3724 | if (!(sb->s_flags & SB_KERNMOUNT)) { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3725 | if (!(ctx->seen & SHMEM_SEEN_BLOCKS)) |
| 3726 | ctx->blocks = shmem_default_max_blocks(); |
| 3727 | if (!(ctx->seen & SHMEM_SEEN_INODES)) |
| 3728 | ctx->inodes = shmem_default_max_inodes(); |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3729 | if (!(ctx->seen & SHMEM_SEEN_INUMS)) |
| 3730 | ctx->full_inums = IS_ENABLED(CONFIG_TMPFS_INODE64); |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3731 | } else { |
Linus Torvalds | 1751e8a | 2017-11-27 13:05:09 -0800 | [diff] [blame] | 3732 | sb->s_flags |= SB_NOUSER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3733 | } |
David M. Grimes | 91828a4 | 2006-10-17 00:09:45 -0700 | [diff] [blame] | 3734 | sb->s_export_op = &shmem_export_ops; |
Linus Torvalds | 1751e8a | 2017-11-27 13:05:09 -0800 | [diff] [blame] | 3735 | sb->s_flags |= SB_NOSEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3736 | #else |
Linus Torvalds | 1751e8a | 2017-11-27 13:05:09 -0800 | [diff] [blame] | 3737 | sb->s_flags |= SB_NOUSER; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3738 | #endif |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3739 | sbinfo->max_blocks = ctx->blocks; |
| 3740 | sbinfo->free_inodes = sbinfo->max_inodes = ctx->inodes; |
Chris Down | e809d5f | 2020-08-06 23:20:20 -0700 | [diff] [blame] | 3741 | if (sb->s_flags & SB_KERNMOUNT) { |
| 3742 | sbinfo->ino_batch = alloc_percpu(ino_t); |
| 3743 | if (!sbinfo->ino_batch) |
| 3744 | goto failed; |
| 3745 | } |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3746 | sbinfo->uid = ctx->uid; |
| 3747 | sbinfo->gid = ctx->gid; |
Chris Down | ea3271f | 2020-08-06 23:20:25 -0700 | [diff] [blame] | 3748 | sbinfo->full_inums = ctx->full_inums; |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3749 | sbinfo->mode = ctx->mode; |
| 3750 | sbinfo->huge = ctx->huge; |
| 3751 | sbinfo->mpol = ctx->mpol; |
| 3752 | ctx->mpol = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3753 | |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3754 | spin_lock_init(&sbinfo->stat_lock); |
Tejun Heo | 908c7f1 | 2014-09-08 09:51:29 +0900 | [diff] [blame] | 3755 | if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL)) |
Hugh Dickins | 602586a | 2010-08-17 15:23:56 -0700 | [diff] [blame] | 3756 | goto failed; |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 3757 | spin_lock_init(&sbinfo->shrinklist_lock); |
| 3758 | INIT_LIST_HEAD(&sbinfo->shrinklist); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3759 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 3760 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 3761 | sb->s_blocksize = PAGE_SIZE; |
| 3762 | sb->s_blocksize_bits = PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3763 | sb->s_magic = TMPFS_MAGIC; |
| 3764 | sb->s_op = &shmem_ops; |
Robin H. Johnson | cfd95a9 | 2006-06-12 21:50:25 +0100 | [diff] [blame] | 3765 | sb->s_time_gran = 1; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3766 | #ifdef CONFIG_TMPFS_XATTR |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3767 | sb->s_xattr = shmem_xattr_handlers; |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3768 | #endif |
| 3769 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Linus Torvalds | 1751e8a | 2017-11-27 13:05:09 -0800 | [diff] [blame] | 3770 | sb->s_flags |= SB_POSIXACL; |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3771 | #endif |
Amir Goldstein | 2b4db79 | 2017-05-18 15:29:33 +0300 | [diff] [blame] | 3772 | uuid_gen(&sb->s_uuid); |
Hugh Dickins | 0edd73b | 2005-06-21 17:15:04 -0700 | [diff] [blame] | 3773 | |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 3774 | inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3775 | if (!inode) |
| 3776 | goto failed; |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3777 | inode->i_uid = sbinfo->uid; |
| 3778 | inode->i_gid = sbinfo->gid; |
Al Viro | 318ceed | 2012-02-12 22:08:01 -0500 | [diff] [blame] | 3779 | sb->s_root = d_make_root(inode); |
| 3780 | if (!sb->s_root) |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 3781 | goto failed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3782 | return 0; |
| 3783 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3784 | failed: |
| 3785 | shmem_put_super(sb); |
| 3786 | return err; |
| 3787 | } |
| 3788 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3789 | static int shmem_get_tree(struct fs_context *fc) |
| 3790 | { |
| 3791 | return get_tree_nodev(fc, shmem_fill_super); |
| 3792 | } |
| 3793 | |
| 3794 | static void shmem_free_fc(struct fs_context *fc) |
| 3795 | { |
| 3796 | struct shmem_options *ctx = fc->fs_private; |
| 3797 | |
| 3798 | if (ctx) { |
| 3799 | mpol_put(ctx->mpol); |
| 3800 | kfree(ctx); |
| 3801 | } |
| 3802 | } |
| 3803 | |
| 3804 | static const struct fs_context_operations shmem_fs_context_ops = { |
| 3805 | .free = shmem_free_fc, |
| 3806 | .get_tree = shmem_get_tree, |
| 3807 | #ifdef CONFIG_TMPFS |
| 3808 | .parse_monolithic = shmem_parse_options, |
| 3809 | .parse_param = shmem_parse_one, |
| 3810 | .reconfigure = shmem_reconfigure, |
| 3811 | #endif |
| 3812 | }; |
| 3813 | |
Pekka Enberg | fcc234f | 2006-03-22 00:08:13 -0800 | [diff] [blame] | 3814 | static struct kmem_cache *shmem_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3815 | |
| 3816 | static struct inode *shmem_alloc_inode(struct super_block *sb) |
| 3817 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3818 | struct shmem_inode_info *info; |
| 3819 | info = kmem_cache_alloc(shmem_inode_cachep, GFP_KERNEL); |
| 3820 | if (!info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3821 | return NULL; |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3822 | return &info->vfs_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3823 | } |
| 3824 | |
Al Viro | 74b1da5 | 2019-04-15 23:19:05 -0400 | [diff] [blame] | 3825 | static void shmem_free_in_core_inode(struct inode *inode) |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3826 | { |
Al Viro | 84e710d | 2016-04-15 00:58:55 -0400 | [diff] [blame] | 3827 | if (S_ISLNK(inode->i_mode)) |
| 3828 | kfree(inode->i_link); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 3829 | kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode)); |
| 3830 | } |
| 3831 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3832 | static void shmem_destroy_inode(struct inode *inode) |
| 3833 | { |
Al Viro | 09208d1 | 2011-07-26 03:15:03 -0400 | [diff] [blame] | 3834 | if (S_ISREG(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3835 | mpol_free_shared_policy(&SHMEM_I(inode)->policy); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3836 | } |
| 3837 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3838 | static void shmem_init_inode(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3839 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3840 | struct shmem_inode_info *info = foo; |
| 3841 | inode_init_once(&info->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3842 | } |
| 3843 | |
weiping zhang | 9a8ec03e | 2017-11-15 17:38:18 -0800 | [diff] [blame] | 3844 | static void shmem_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3845 | { |
| 3846 | shmem_inode_cachep = kmem_cache_create("shmem_inode_cache", |
| 3847 | sizeof(struct shmem_inode_info), |
Vladimir Davydov | 5d09705 | 2016-01-14 15:18:21 -0800 | [diff] [blame] | 3848 | 0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3849 | } |
| 3850 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3851 | static void shmem_destroy_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3852 | { |
Alexey Dobriyan | 1a1d92c | 2006-09-27 01:49:40 -0700 | [diff] [blame] | 3853 | kmem_cache_destroy(shmem_inode_cachep); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3854 | } |
| 3855 | |
Christoph Hellwig | f5e54d6 | 2006-06-28 04:26:44 -0700 | [diff] [blame] | 3856 | static const struct address_space_operations shmem_aops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3857 | .writepage = shmem_writepage, |
Ken Chen | 7671932 | 2007-02-10 01:43:15 -0800 | [diff] [blame] | 3858 | .set_page_dirty = __set_page_dirty_no_writeback, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3859 | #ifdef CONFIG_TMPFS |
Nick Piggin | 800d15a | 2007-10-16 01:25:03 -0700 | [diff] [blame] | 3860 | .write_begin = shmem_write_begin, |
| 3861 | .write_end = shmem_write_end, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3862 | #endif |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3863 | #ifdef CONFIG_MIGRATION |
Lee Schermerhorn | 304dbdb | 2006-04-22 02:35:48 -0700 | [diff] [blame] | 3864 | .migratepage = migrate_page, |
Andrew Morton | 1c93923 | 2014-10-09 15:27:59 -0700 | [diff] [blame] | 3865 | #endif |
Andi Kleen | aa261f5 | 2009-09-16 11:50:16 +0200 | [diff] [blame] | 3866 | .error_remove_page = generic_error_remove_page, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3867 | }; |
| 3868 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 3869 | static const struct file_operations shmem_file_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3870 | .mmap = shmem_mmap, |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 3871 | .get_unmapped_area = shmem_get_unmapped_area, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3872 | #ifdef CONFIG_TMPFS |
Hugh Dickins | 220f2ac | 2012-12-12 13:52:21 -0800 | [diff] [blame] | 3873 | .llseek = shmem_file_llseek, |
Al Viro | 2ba5bbe | 2014-04-02 20:00:02 -0400 | [diff] [blame] | 3874 | .read_iter = shmem_file_read_iter, |
Al Viro | 8174202 | 2014-04-03 03:17:43 -0400 | [diff] [blame] | 3875 | .write_iter = generic_file_write_iter, |
Christoph Hellwig | 1b061d9 | 2010-05-26 17:53:41 +0200 | [diff] [blame] | 3876 | .fsync = noop_fsync, |
Al Viro | 82c156f | 2016-09-22 23:35:42 -0400 | [diff] [blame] | 3877 | .splice_read = generic_file_splice_read, |
Al Viro | f6cb85d | 2014-04-05 04:38:56 -0400 | [diff] [blame] | 3878 | .splice_write = iter_file_splice_write, |
Hugh Dickins | 83e4fa9 | 2012-05-29 15:06:40 -0700 | [diff] [blame] | 3879 | .fallocate = shmem_fallocate, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3880 | #endif |
| 3881 | }; |
| 3882 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3883 | static const struct inode_operations shmem_inode_operations = { |
Yu Zhao | 44a3022 | 2015-09-08 15:03:33 -0700 | [diff] [blame] | 3884 | .getattr = shmem_getattr, |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3885 | .setattr = shmem_setattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3886 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3887 | .listxattr = shmem_listxattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3888 | .set_acl = simple_set_acl, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3889 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3890 | }; |
| 3891 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3892 | static const struct inode_operations shmem_dir_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3893 | #ifdef CONFIG_TMPFS |
| 3894 | .create = shmem_create, |
| 3895 | .lookup = simple_lookup, |
| 3896 | .link = shmem_link, |
| 3897 | .unlink = shmem_unlink, |
| 3898 | .symlink = shmem_symlink, |
| 3899 | .mkdir = shmem_mkdir, |
| 3900 | .rmdir = shmem_rmdir, |
| 3901 | .mknod = shmem_mknod, |
Miklos Szeredi | 2773bf0 | 2016-09-27 11:03:58 +0200 | [diff] [blame] | 3902 | .rename = shmem_rename2, |
Al Viro | 60545d0 | 2013-06-07 01:20:27 -0400 | [diff] [blame] | 3903 | .tmpfile = shmem_tmpfile, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3904 | #endif |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3905 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3906 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3907 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3908 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3909 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3910 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3911 | #endif |
| 3912 | }; |
| 3913 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 3914 | static const struct inode_operations shmem_special_inode_operations = { |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3915 | #ifdef CONFIG_TMPFS_XATTR |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3916 | .listxattr = shmem_listxattr, |
Eric Paris | b09e0fa | 2011-05-24 17:12:39 -0700 | [diff] [blame] | 3917 | #endif |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3918 | #ifdef CONFIG_TMPFS_POSIX_ACL |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 3919 | .setattr = shmem_setattr, |
Christoph Hellwig | feda821 | 2013-12-20 05:16:54 -0800 | [diff] [blame] | 3920 | .set_acl = simple_set_acl, |
Andreas Gruenbacher | 39f0247 | 2006-09-29 02:01:35 -0700 | [diff] [blame] | 3921 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3922 | }; |
| 3923 | |
Hugh Dickins | 759b977 | 2007-03-05 00:30:28 -0800 | [diff] [blame] | 3924 | static const struct super_operations shmem_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3925 | .alloc_inode = shmem_alloc_inode, |
Al Viro | 74b1da5 | 2019-04-15 23:19:05 -0400 | [diff] [blame] | 3926 | .free_inode = shmem_free_in_core_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3927 | .destroy_inode = shmem_destroy_inode, |
| 3928 | #ifdef CONFIG_TMPFS |
| 3929 | .statfs = shmem_statfs, |
akpm@linux-foundation.org | 680d794 | 2008-02-08 04:21:48 -0800 | [diff] [blame] | 3930 | .show_options = shmem_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3931 | #endif |
Al Viro | 1f895f7 | 2010-06-05 19:10:41 -0400 | [diff] [blame] | 3932 | .evict_inode = shmem_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3933 | .drop_inode = generic_delete_inode, |
| 3934 | .put_super = shmem_put_super, |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 3935 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Kirill A. Shutemov | 779750d | 2016-07-26 15:26:38 -0700 | [diff] [blame] | 3936 | .nr_cached_objects = shmem_unused_huge_count, |
| 3937 | .free_cached_objects = shmem_unused_huge_scan, |
| 3938 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3939 | }; |
| 3940 | |
Alexey Dobriyan | f0f37e2f | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 3941 | static const struct vm_operations_struct shmem_vm_ops = { |
Nick Piggin | 54cb882 | 2007-07-19 01:46:59 -0700 | [diff] [blame] | 3942 | .fault = shmem_fault, |
Ning Qu | d7c1755 | 2014-04-07 15:37:24 -0700 | [diff] [blame] | 3943 | .map_pages = filemap_map_pages, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3944 | #ifdef CONFIG_NUMA |
| 3945 | .set_policy = shmem_set_policy, |
| 3946 | .get_policy = shmem_get_policy, |
| 3947 | #endif |
| 3948 | }; |
| 3949 | |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3950 | int shmem_init_fs_context(struct fs_context *fc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3951 | { |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3952 | struct shmem_options *ctx; |
| 3953 | |
| 3954 | ctx = kzalloc(sizeof(struct shmem_options), GFP_KERNEL); |
| 3955 | if (!ctx) |
| 3956 | return -ENOMEM; |
| 3957 | |
| 3958 | ctx->mode = 0777 | S_ISVTX; |
| 3959 | ctx->uid = current_fsuid(); |
| 3960 | ctx->gid = current_fsgid(); |
| 3961 | |
| 3962 | fc->fs_private = ctx; |
| 3963 | fc->ops = &shmem_fs_context_ops; |
| 3964 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3965 | } |
| 3966 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3967 | static struct file_system_type shmem_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3968 | .owner = THIS_MODULE, |
| 3969 | .name = "tmpfs", |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3970 | .init_fs_context = shmem_init_fs_context, |
| 3971 | #ifdef CONFIG_TMPFS |
Al Viro | d7167b1 | 2019-09-07 07:23:15 -0400 | [diff] [blame] | 3972 | .parameters = shmem_fs_parameters, |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 3973 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3974 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 3975 | .fs_flags = FS_USERNS_MOUNT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3976 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3977 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3978 | int __init shmem_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3979 | { |
| 3980 | int error; |
| 3981 | |
weiping zhang | 9a8ec03e | 2017-11-15 17:38:18 -0800 | [diff] [blame] | 3982 | shmem_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3983 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 3984 | error = register_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3985 | if (error) { |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3986 | pr_err("Could not register tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3987 | goto out2; |
| 3988 | } |
Greg Kroah-Hartman | 95dc112 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 3989 | |
Al Viro | ca4e051 | 2013-08-31 12:57:10 -0400 | [diff] [blame] | 3990 | shm_mnt = kern_mount(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3991 | if (IS_ERR(shm_mnt)) { |
| 3992 | error = PTR_ERR(shm_mnt); |
Joe Perches | 1170532 | 2016-03-17 14:19:50 -0700 | [diff] [blame] | 3993 | pr_err("Could not kern_mount tmpfs\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3994 | goto out1; |
| 3995 | } |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3996 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 3997 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Kirill A. Shutemov | 435c0b87 | 2017-08-25 15:55:33 -0700 | [diff] [blame] | 3998 | if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 3999 | SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge; |
| 4000 | else |
| 4001 | shmem_huge = 0; /* just in case it was patched */ |
| 4002 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4003 | return 0; |
| 4004 | |
| 4005 | out1: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4006 | unregister_filesystem(&shmem_fs_type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4007 | out2: |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4008 | shmem_destroy_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4009 | shm_mnt = ERR_PTR(error); |
| 4010 | return error; |
| 4011 | } |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4012 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 4013 | #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SYSFS) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4014 | static ssize_t shmem_enabled_show(struct kobject *kobj, |
| 4015 | struct kobj_attribute *attr, char *buf) |
| 4016 | { |
Colin Ian King | 26083eb6 | 2019-11-30 17:58:04 -0800 | [diff] [blame] | 4017 | static const int values[] = { |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4018 | SHMEM_HUGE_ALWAYS, |
| 4019 | SHMEM_HUGE_WITHIN_SIZE, |
| 4020 | SHMEM_HUGE_ADVISE, |
| 4021 | SHMEM_HUGE_NEVER, |
| 4022 | SHMEM_HUGE_DENY, |
| 4023 | SHMEM_HUGE_FORCE, |
| 4024 | }; |
| 4025 | int i, count; |
| 4026 | |
| 4027 | for (i = 0, count = 0; i < ARRAY_SIZE(values); i++) { |
| 4028 | const char *fmt = shmem_huge == values[i] ? "[%s] " : "%s "; |
| 4029 | |
| 4030 | count += sprintf(buf + count, fmt, |
| 4031 | shmem_format_huge(values[i])); |
| 4032 | } |
| 4033 | buf[count - 1] = '\n'; |
| 4034 | return count; |
| 4035 | } |
| 4036 | |
| 4037 | static ssize_t shmem_enabled_store(struct kobject *kobj, |
| 4038 | struct kobj_attribute *attr, const char *buf, size_t count) |
| 4039 | { |
| 4040 | char tmp[16]; |
| 4041 | int huge; |
| 4042 | |
| 4043 | if (count + 1 > sizeof(tmp)) |
| 4044 | return -EINVAL; |
| 4045 | memcpy(tmp, buf, count); |
| 4046 | tmp[count] = '\0'; |
| 4047 | if (count && tmp[count - 1] == '\n') |
| 4048 | tmp[count - 1] = '\0'; |
| 4049 | |
| 4050 | huge = shmem_parse_huge(tmp); |
| 4051 | if (huge == -EINVAL) |
| 4052 | return -EINVAL; |
| 4053 | if (!has_transparent_hugepage() && |
| 4054 | huge != SHMEM_HUGE_NEVER && huge != SHMEM_HUGE_DENY) |
| 4055 | return -EINVAL; |
| 4056 | |
| 4057 | shmem_huge = huge; |
Kirill A. Shutemov | 435c0b87 | 2017-08-25 15:55:33 -0700 | [diff] [blame] | 4058 | if (shmem_huge > SHMEM_HUGE_DENY) |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4059 | SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge; |
| 4060 | return count; |
| 4061 | } |
| 4062 | |
| 4063 | struct kobj_attribute shmem_enabled_attr = |
| 4064 | __ATTR(shmem_enabled, 0644, shmem_enabled_show, shmem_enabled_store); |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 4065 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE && CONFIG_SYSFS */ |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4066 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 4067 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4068 | bool shmem_huge_enabled(struct vm_area_struct *vma) |
| 4069 | { |
| 4070 | struct inode *inode = file_inode(vma->vm_file); |
| 4071 | struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); |
| 4072 | loff_t i_size; |
| 4073 | pgoff_t off; |
| 4074 | |
Yang Shi | c063066 | 2019-07-18 15:57:27 -0700 | [diff] [blame] | 4075 | if ((vma->vm_flags & VM_NOHUGEPAGE) || |
| 4076 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) |
| 4077 | return false; |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4078 | if (shmem_huge == SHMEM_HUGE_FORCE) |
| 4079 | return true; |
| 4080 | if (shmem_huge == SHMEM_HUGE_DENY) |
| 4081 | return false; |
| 4082 | switch (sbinfo->huge) { |
| 4083 | case SHMEM_HUGE_NEVER: |
| 4084 | return false; |
| 4085 | case SHMEM_HUGE_ALWAYS: |
| 4086 | return true; |
| 4087 | case SHMEM_HUGE_WITHIN_SIZE: |
| 4088 | off = round_up(vma->vm_pgoff, HPAGE_PMD_NR); |
| 4089 | i_size = round_up(i_size_read(inode), PAGE_SIZE); |
| 4090 | if (i_size >= HPAGE_PMD_SIZE && |
| 4091 | i_size >> PAGE_SHIFT >= off) |
| 4092 | return true; |
Joe Perches | e4a9bc5 | 2020-04-06 20:08:39 -0700 | [diff] [blame] | 4093 | fallthrough; |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4094 | case SHMEM_HUGE_ADVISE: |
| 4095 | /* TODO: implement fadvise() hints */ |
| 4096 | return (vma->vm_flags & VM_HUGEPAGE); |
| 4097 | default: |
| 4098 | VM_BUG_ON(1); |
| 4099 | return false; |
| 4100 | } |
| 4101 | } |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 4102 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 4103 | |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4104 | #else /* !CONFIG_SHMEM */ |
| 4105 | |
| 4106 | /* |
| 4107 | * tiny-shmem: simple shmemfs and tmpfs using ramfs code |
| 4108 | * |
| 4109 | * This is intended for small system where the benefits of the full |
| 4110 | * shmem code (swap-backed and resource-limited) are outweighed by |
| 4111 | * their complexity. On systems without swap this code should be |
| 4112 | * effectively equivalent, but much lighter weight. |
| 4113 | */ |
| 4114 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4115 | static struct file_system_type shmem_fs_type = { |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4116 | .name = "tmpfs", |
David Howells | f323562 | 2019-03-25 16:38:31 +0000 | [diff] [blame] | 4117 | .init_fs_context = ramfs_init_fs_context, |
Al Viro | d7167b1 | 2019-09-07 07:23:15 -0400 | [diff] [blame] | 4118 | .parameters = ramfs_fs_parameters, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4119 | .kill_sb = kill_litter_super, |
Eric W. Biederman | 2b8576c | 2013-01-25 16:32:10 -0800 | [diff] [blame] | 4120 | .fs_flags = FS_USERNS_MOUNT, |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4121 | }; |
| 4122 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4123 | int __init shmem_init(void) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4124 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4125 | BUG_ON(register_filesystem(&shmem_fs_type) != 0); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4126 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4127 | shm_mnt = kern_mount(&shmem_fs_type); |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4128 | BUG_ON(IS_ERR(shm_mnt)); |
| 4129 | |
| 4130 | return 0; |
| 4131 | } |
| 4132 | |
Vineeth Remanan Pillai | b56a2d8 | 2019-03-05 15:47:03 -0800 | [diff] [blame] | 4133 | int shmem_unuse(unsigned int type, bool frontswap, |
| 4134 | unsigned long *fs_pages_to_unuse) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4135 | { |
| 4136 | return 0; |
| 4137 | } |
| 4138 | |
Hugh Dickins | 3f96b79 | 2009-09-21 17:03:37 -0700 | [diff] [blame] | 4139 | int shmem_lock(struct file *file, int lock, struct user_struct *user) |
| 4140 | { |
| 4141 | return 0; |
| 4142 | } |
| 4143 | |
Hugh Dickins | 2451326 | 2012-01-20 14:34:21 -0800 | [diff] [blame] | 4144 | void shmem_unlock_mapping(struct address_space *mapping) |
| 4145 | { |
| 4146 | } |
| 4147 | |
Hugh Dickins | c01d5b3 | 2016-07-26 15:26:15 -0700 | [diff] [blame] | 4148 | #ifdef CONFIG_MMU |
| 4149 | unsigned long shmem_get_unmapped_area(struct file *file, |
| 4150 | unsigned long addr, unsigned long len, |
| 4151 | unsigned long pgoff, unsigned long flags) |
| 4152 | { |
| 4153 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); |
| 4154 | } |
| 4155 | #endif |
| 4156 | |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4157 | void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 4158 | { |
Hugh Dickins | 41ffe5d | 2011-08-03 16:21:21 -0700 | [diff] [blame] | 4159 | truncate_inode_pages_range(inode->i_mapping, lstart, lend); |
Hugh Dickins | 94c1e62 | 2011-06-27 16:18:03 -0700 | [diff] [blame] | 4160 | } |
| 4161 | EXPORT_SYMBOL_GPL(shmem_truncate_range); |
| 4162 | |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 4163 | #define shmem_vm_ops generic_file_vm_ops |
| 4164 | #define shmem_file_operations ramfs_file_operations |
Dmitry Monakhov | 454abaf | 2010-03-04 17:32:18 +0300 | [diff] [blame] | 4165 | #define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev) |
Hugh Dickins | 0b0a080 | 2009-02-24 20:51:52 +0000 | [diff] [blame] | 4166 | #define shmem_acct_size(flags, size) 0 |
| 4167 | #define shmem_unacct_size(flags, size) do {} while (0) |
Matt Mackall | 853ac43 | 2009-01-06 14:40:20 -0800 | [diff] [blame] | 4168 | |
| 4169 | #endif /* CONFIG_SHMEM */ |
| 4170 | |
| 4171 | /* common code */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4172 | |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4173 | static struct file *__shmem_file_setup(struct vfsmount *mnt, const char *name, loff_t size, |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4174 | unsigned long flags, unsigned int i_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4175 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4176 | struct inode *inode; |
Al Viro | 93dec2d | 2018-07-08 23:02:03 -0400 | [diff] [blame] | 4177 | struct file *res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4178 | |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4179 | if (IS_ERR(mnt)) |
| 4180 | return ERR_CAST(mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4181 | |
Hugh Dickins | 285b2c4 | 2011-08-03 16:21:20 -0700 | [diff] [blame] | 4182 | if (size < 0 || size > MAX_LFS_FILESIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4183 | return ERR_PTR(-EINVAL); |
| 4184 | |
| 4185 | if (shmem_acct_size(flags, size)) |
| 4186 | return ERR_PTR(-ENOMEM); |
| 4187 | |
Al Viro | 93dec2d | 2018-07-08 23:02:03 -0400 | [diff] [blame] | 4188 | inode = shmem_get_inode(mnt->mnt_sb, NULL, S_IFREG | S_IRWXUGO, 0, |
| 4189 | flags); |
Al Viro | dac2d1f | 2018-06-09 09:27:41 -0400 | [diff] [blame] | 4190 | if (unlikely(!inode)) { |
| 4191 | shmem_unacct_size(flags, size); |
| 4192 | return ERR_PTR(-ENOSPC); |
| 4193 | } |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4194 | inode->i_flags |= i_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4195 | inode->i_size = size; |
Miklos Szeredi | 6d6b77f | 2011-10-28 14:13:28 +0200 | [diff] [blame] | 4196 | clear_nlink(inode); /* It is unlinked */ |
Al Viro | 26567cd | 2013-03-01 20:22:53 -0500 | [diff] [blame] | 4197 | res = ERR_PTR(ramfs_nommu_expand_for_mapping(inode, size)); |
Al Viro | 93dec2d | 2018-07-08 23:02:03 -0400 | [diff] [blame] | 4198 | if (!IS_ERR(res)) |
| 4199 | res = alloc_file_pseudo(inode, mnt, name, O_RDWR, |
| 4200 | &shmem_file_operations); |
Al Viro | 26567cd | 2013-03-01 20:22:53 -0500 | [diff] [blame] | 4201 | if (IS_ERR(res)) |
Al Viro | 93dec2d | 2018-07-08 23:02:03 -0400 | [diff] [blame] | 4202 | iput(inode); |
Al Viro | 6b4d0b2 | 2013-02-14 21:37:26 -0500 | [diff] [blame] | 4203 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4204 | } |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4205 | |
| 4206 | /** |
| 4207 | * shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be |
| 4208 | * kernel internal. There will be NO LSM permission checks against the |
| 4209 | * underlying inode. So users of this interface must do LSM checks at a |
Stephen Smalley | e1832f2 | 2015-08-06 15:46:55 -0700 | [diff] [blame] | 4210 | * higher layer. The users are the big_key and shm implementations. LSM |
| 4211 | * checks are provided at the key or shm level rather than the inode. |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4212 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 4213 | * @size: size to be set for the file |
| 4214 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 4215 | */ |
| 4216 | struct file *shmem_kernel_file_setup(const char *name, loff_t size, unsigned long flags) |
| 4217 | { |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4218 | return __shmem_file_setup(shm_mnt, name, size, flags, S_PRIVATE); |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4219 | } |
| 4220 | |
| 4221 | /** |
| 4222 | * shmem_file_setup - get an unlinked file living in tmpfs |
| 4223 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 4224 | * @size: size to be set for the file |
| 4225 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 4226 | */ |
| 4227 | struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags) |
| 4228 | { |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4229 | return __shmem_file_setup(shm_mnt, name, size, flags, 0); |
Eric Paris | c727709 | 2013-12-02 11:24:19 +0000 | [diff] [blame] | 4230 | } |
Keith Packard | 395e0dd | 2008-06-20 00:08:06 -0700 | [diff] [blame] | 4231 | EXPORT_SYMBOL_GPL(shmem_file_setup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4232 | |
Randy Dunlap | 4671181 | 2008-03-19 17:00:41 -0700 | [diff] [blame] | 4233 | /** |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4234 | * shmem_file_setup_with_mnt - get an unlinked file living in tmpfs |
| 4235 | * @mnt: the tmpfs mount where the file will be created |
| 4236 | * @name: name for dentry (to be seen in /proc/<pid>/maps |
| 4237 | * @size: size to be set for the file |
| 4238 | * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size |
| 4239 | */ |
| 4240 | struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt, const char *name, |
| 4241 | loff_t size, unsigned long flags) |
| 4242 | { |
| 4243 | return __shmem_file_setup(mnt, name, size, flags, 0); |
| 4244 | } |
| 4245 | EXPORT_SYMBOL_GPL(shmem_file_setup_with_mnt); |
| 4246 | |
| 4247 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4248 | * shmem_zero_setup - setup a shared anonymous mapping |
Peter Collingbourne | 45e5530 | 2020-08-06 23:23:37 -0700 | [diff] [blame] | 4249 | * @vma: the vma to be mmapped is prepared by do_mmap |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4250 | */ |
| 4251 | int shmem_zero_setup(struct vm_area_struct *vma) |
| 4252 | { |
| 4253 | struct file *file; |
| 4254 | loff_t size = vma->vm_end - vma->vm_start; |
| 4255 | |
Hugh Dickins | 66fc130 | 2015-06-14 09:48:09 -0700 | [diff] [blame] | 4256 | /* |
Michel Lespinasse | c1e8d7c | 2020-06-08 21:33:54 -0700 | [diff] [blame] | 4257 | * Cloning a new file under mmap_lock leads to a lock ordering conflict |
Hugh Dickins | 66fc130 | 2015-06-14 09:48:09 -0700 | [diff] [blame] | 4258 | * between XFS directory reading and selinux: since this file is only |
| 4259 | * accessible to the user through its mapping, use S_PRIVATE flag to |
| 4260 | * bypass file security, in the same way as shmem_kernel_file_setup(). |
| 4261 | */ |
Matthew Auld | 703321b | 2017-10-06 23:18:13 +0100 | [diff] [blame] | 4262 | file = shmem_kernel_file_setup("dev/zero", size, vma->vm_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4263 | if (IS_ERR(file)) |
| 4264 | return PTR_ERR(file); |
| 4265 | |
| 4266 | if (vma->vm_file) |
| 4267 | fput(vma->vm_file); |
| 4268 | vma->vm_file = file; |
| 4269 | vma->vm_ops = &shmem_vm_ops; |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4270 | |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 4271 | if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && |
Kirill A. Shutemov | f3f0e1d | 2016-07-26 15:26:32 -0700 | [diff] [blame] | 4272 | ((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) < |
| 4273 | (vma->vm_end & HPAGE_PMD_MASK)) { |
| 4274 | khugepaged_enter(vma, vma->vm_flags); |
| 4275 | } |
| 4276 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4277 | return 0; |
| 4278 | } |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4279 | |
| 4280 | /** |
| 4281 | * shmem_read_mapping_page_gfp - read into page cache, using specified page allocation flags. |
| 4282 | * @mapping: the page's address_space |
| 4283 | * @index: the page index |
| 4284 | * @gfp: the page allocator flags to use if allocating |
| 4285 | * |
| 4286 | * This behaves as a tmpfs "read_cache_page_gfp(mapping, index, gfp)", |
| 4287 | * with any new page allocations done using the specified allocation flags. |
| 4288 | * But read_cache_page_gfp() uses the ->readpage() method: which does not |
| 4289 | * suit tmpfs, since it may have pages in swapcache, and needs to find those |
| 4290 | * for itself; although drivers/gpu/drm i915 and ttm rely upon this support. |
| 4291 | * |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4292 | * i915_gem_object_get_pages_gtt() mixes __GFP_NORETRY | __GFP_NOWARN in |
| 4293 | * with the mapping_gfp_mask(), to avoid OOMing the machine unnecessarily. |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4294 | */ |
| 4295 | struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
| 4296 | pgoff_t index, gfp_t gfp) |
| 4297 | { |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4298 | #ifdef CONFIG_SHMEM |
| 4299 | struct inode *inode = mapping->host; |
Hugh Dickins | 9276aad | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4300 | struct page *page; |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4301 | int error; |
| 4302 | |
| 4303 | BUG_ON(mapping->a_ops != &shmem_aops); |
Andres Lagar-Cavilla | 9e18eb2 | 2016-05-19 17:12:47 -0700 | [diff] [blame] | 4304 | error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, |
Mike Rapoport | cfda052 | 2017-02-22 15:43:37 -0800 | [diff] [blame] | 4305 | gfp, NULL, NULL, NULL); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4306 | if (error) |
| 4307 | page = ERR_PTR(error); |
| 4308 | else |
| 4309 | unlock_page(page); |
| 4310 | return page; |
| 4311 | #else |
| 4312 | /* |
| 4313 | * The tiny !SHMEM case uses ramfs without swap |
| 4314 | */ |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4315 | return read_cache_page_gfp(mapping, index, gfp); |
Hugh Dickins | 68da9f0 | 2011-07-25 17:12:34 -0700 | [diff] [blame] | 4316 | #endif |
Hugh Dickins | d9d90e5 | 2011-06-27 16:18:04 -0700 | [diff] [blame] | 4317 | } |
| 4318 | EXPORT_SYMBOL_GPL(shmem_read_mapping_page_gfp); |