Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/drivers/block/loop.c |
| 3 | * |
| 4 | * Written by Theodore Ts'o, 3/29/93 |
| 5 | * |
| 6 | * Copyright 1993 by Theodore Ts'o. Redistribution of this file is |
| 7 | * permitted under the GNU General Public License. |
| 8 | * |
| 9 | * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 |
| 10 | * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 |
| 11 | * |
| 12 | * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 |
| 13 | * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 |
| 14 | * |
| 15 | * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 |
| 16 | * |
| 17 | * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998 |
| 18 | * |
| 19 | * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 |
| 20 | * |
| 21 | * Loadable modules and other fixes by AK, 1998 |
| 22 | * |
| 23 | * Make real block number available to downstream transfer functions, enables |
| 24 | * CBC (and relatives) mode encryption requiring unique IVs per data block. |
| 25 | * Reed H. Petty, rhp@draper.net |
| 26 | * |
| 27 | * Maximum number of loop devices now dynamic via max_loop module parameter. |
| 28 | * Russell Kroll <rkroll@exploits.org> 19990701 |
| 29 | * |
| 30 | * Maximum number of loop devices when compiled-in now selectable by passing |
| 31 | * max_loop=<1-255> to the kernel on boot. |
Jan Engelhardt | 96de0e2 | 2007-10-19 23:21:04 +0200 | [diff] [blame] | 32 | * Erik I. Bolsø, <eriki@himolde.no>, Oct 31, 1999 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | * |
| 34 | * Completely rewrite request handling to be make_request_fn style and |
| 35 | * non blocking, pushing work to a helper thread. Lots of fixes from |
| 36 | * Al Viro too. |
| 37 | * Jens Axboe <axboe@suse.de>, Nov 2000 |
| 38 | * |
| 39 | * Support up to 256 loop devices |
| 40 | * Heinz Mauelshagen <mge@sistina.com>, Feb 2002 |
| 41 | * |
| 42 | * Support for falling back on the write file operation when the address space |
Nick Piggin | 4e02ed4 | 2008-10-29 14:00:55 -0700 | [diff] [blame] | 43 | * operations write_begin is not available on the backing filesystem. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * Anton Altaparmakov, 16 Feb 2005 |
| 45 | * |
| 46 | * Still To Fix: |
| 47 | * - Advisory locking is ignored here. |
| 48 | * - Should use an own CAP_* category instead of CAP_SYS_ADMIN |
| 49 | * |
| 50 | */ |
| 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #include <linux/module.h> |
| 53 | #include <linux/moduleparam.h> |
| 54 | #include <linux/sched.h> |
| 55 | #include <linux/fs.h> |
| 56 | #include <linux/file.h> |
| 57 | #include <linux/stat.h> |
| 58 | #include <linux/errno.h> |
| 59 | #include <linux/major.h> |
| 60 | #include <linux/wait.h> |
| 61 | #include <linux/blkdev.h> |
| 62 | #include <linux/blkpg.h> |
| 63 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | #include <linux/swap.h> |
| 65 | #include <linux/slab.h> |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 66 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | #include <linux/suspend.h> |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 68 | #include <linux/freezer.h> |
Arnd Bergmann | 2a48fc0 | 2010-06-02 14:28:52 +0200 | [diff] [blame] | 69 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #include <linux/completion.h> |
| 72 | #include <linux/highmem.h> |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 73 | #include <linux/kthread.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 74 | #include <linux/splice.h> |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 75 | #include <linux/sysfs.h> |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 76 | #include <linux/miscdevice.h> |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 77 | #include <linux/falloc.h> |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 78 | #include <linux/uio.h> |
Adam Manzanares | d9a08a9 | 2018-05-22 10:52:19 -0700 | [diff] [blame] | 79 | #include <linux/ioprio.h> |
Dennis Zhou | db6638d | 2018-12-05 12:10:35 -0500 | [diff] [blame] | 80 | #include <linux/blk-cgroup.h> |
Adam Manzanares | d9a08a9 | 2018-05-22 10:52:19 -0700 | [diff] [blame] | 81 | |
Al Viro | 83a8761 | 2013-05-12 10:14:07 -0400 | [diff] [blame] | 82 | #include "loop.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -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 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 86 | static DEFINE_IDR(loop_index_idr); |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 87 | static DEFINE_MUTEX(loop_ctl_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 89 | static int max_part; |
| 90 | static int part_shift; |
| 91 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | static int transfer_xor(struct loop_device *lo, int cmd, |
| 93 | struct page *raw_page, unsigned raw_off, |
| 94 | struct page *loop_page, unsigned loop_off, |
| 95 | int size, sector_t real_block) |
| 96 | { |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 97 | char *raw_buf = kmap_atomic(raw_page) + raw_off; |
| 98 | char *loop_buf = kmap_atomic(loop_page) + loop_off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | char *in, *out, *key; |
| 100 | int i, keysize; |
| 101 | |
| 102 | if (cmd == READ) { |
| 103 | in = raw_buf; |
| 104 | out = loop_buf; |
| 105 | } else { |
| 106 | in = loop_buf; |
| 107 | out = raw_buf; |
| 108 | } |
| 109 | |
| 110 | key = lo->lo_encrypt_key; |
| 111 | keysize = lo->lo_encrypt_key_size; |
| 112 | for (i = 0; i < size; i++) |
| 113 | *out++ = *in++ ^ key[(i & 511) % keysize]; |
| 114 | |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 115 | kunmap_atomic(loop_buf); |
| 116 | kunmap_atomic(raw_buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | cond_resched(); |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | static int xor_init(struct loop_device *lo, const struct loop_info64 *info) |
| 122 | { |
| 123 | if (unlikely(info->lo_encrypt_key_size <= 0)) |
| 124 | return -EINVAL; |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static struct loop_func_table none_funcs = { |
| 129 | .number = LO_CRYPT_NONE, |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 130 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | |
| 132 | static struct loop_func_table xor_funcs = { |
| 133 | .number = LO_CRYPT_XOR, |
| 134 | .transfer = transfer_xor, |
| 135 | .init = xor_init |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 136 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
| 138 | /* xfer_funcs[0] is special - its release function is never called */ |
| 139 | static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = { |
| 140 | &none_funcs, |
| 141 | &xor_funcs |
| 142 | }; |
| 143 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 144 | static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | { |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 146 | loff_t loopsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | |
| 148 | /* Compute loopsize in bytes */ |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 149 | loopsize = i_size_read(file->f_mapping->host); |
| 150 | if (offset > 0) |
| 151 | loopsize -= offset; |
| 152 | /* offset is beyond i_size, weird but possible */ |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 153 | if (loopsize < 0) |
| 154 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 156 | if (sizelimit > 0 && sizelimit < loopsize) |
| 157 | loopsize = sizelimit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | /* |
| 159 | * Unfortunately, if we want to do I/O on the device, |
| 160 | * the number of 512-byte sectors has to fit into a sector_t. |
| 161 | */ |
| 162 | return loopsize >> 9; |
| 163 | } |
| 164 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 165 | static loff_t get_loop_size(struct loop_device *lo, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 167 | return get_size(lo->lo_offset, lo->lo_sizelimit, file); |
| 168 | } |
| 169 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 170 | static void __loop_update_dio(struct loop_device *lo, bool dio) |
| 171 | { |
| 172 | struct file *file = lo->lo_backing_file; |
| 173 | struct address_space *mapping = file->f_mapping; |
| 174 | struct inode *inode = mapping->host; |
| 175 | unsigned short sb_bsize = 0; |
| 176 | unsigned dio_align = 0; |
| 177 | bool use_dio; |
| 178 | |
| 179 | if (inode->i_sb->s_bdev) { |
| 180 | sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); |
| 181 | dio_align = sb_bsize - 1; |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * We support direct I/O only if lo_offset is aligned with the |
| 186 | * logical I/O size of backing device, and the logical block |
| 187 | * size of loop is bigger than the backing device's and the loop |
| 188 | * needn't transform transfer. |
| 189 | * |
| 190 | * TODO: the above condition may be loosed in the future, and |
| 191 | * direct I/O may be switched runtime at that time because most |
Masahiro Yamada | 89d790a | 2017-02-27 14:29:01 -0800 | [diff] [blame] | 192 | * of requests in sane applications should be PAGE_SIZE aligned |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 193 | */ |
| 194 | if (dio) { |
| 195 | if (queue_logical_block_size(lo->lo_queue) >= sb_bsize && |
| 196 | !(lo->lo_offset & dio_align) && |
| 197 | mapping->a_ops->direct_IO && |
| 198 | !lo->transfer) |
| 199 | use_dio = true; |
| 200 | else |
| 201 | use_dio = false; |
| 202 | } else { |
| 203 | use_dio = false; |
| 204 | } |
| 205 | |
| 206 | if (lo->use_dio == use_dio) |
| 207 | return; |
| 208 | |
| 209 | /* flush dirty pages before changing direct IO */ |
| 210 | vfs_fsync(file, 0); |
| 211 | |
| 212 | /* |
| 213 | * The flag of LO_FLAGS_DIRECT_IO is handled similarly with |
| 214 | * LO_FLAGS_READ_ONLY, both are set from kernel, and losetup |
| 215 | * will get updated by ioctl(LOOP_GET_STATUS) |
| 216 | */ |
Martijn Coenen | 0fbcf579 | 2020-03-10 14:06:54 +0100 | [diff] [blame] | 217 | if (lo->lo_state == Lo_bound) |
| 218 | blk_mq_freeze_queue(lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 219 | lo->use_dio = use_dio; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 220 | if (use_dio) { |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 221 | blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 222 | lo->lo_flags |= LO_FLAGS_DIRECT_IO; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 223 | } else { |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 224 | blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 225 | lo->lo_flags &= ~LO_FLAGS_DIRECT_IO; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 226 | } |
Martijn Coenen | 0fbcf579 | 2020-03-10 14:06:54 +0100 | [diff] [blame] | 227 | if (lo->lo_state == Lo_bound) |
| 228 | blk_mq_unfreeze_queue(lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 229 | } |
| 230 | |
Martijn Coenen | 5795b6f | 2020-05-13 15:38:37 +0200 | [diff] [blame] | 231 | /** |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 232 | * loop_validate_block_size() - validates the passed in block size |
| 233 | * @bsize: size to validate |
| 234 | */ |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 235 | static int |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 236 | loop_validate_block_size(unsigned short bsize) |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 237 | { |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 238 | if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize)) |
| 239 | return -EINVAL; |
| 240 | |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | /** |
Martijn Coenen | 5795b6f | 2020-05-13 15:38:37 +0200 | [diff] [blame] | 245 | * loop_set_size() - sets device size and notifies userspace |
| 246 | * @lo: struct loop_device to set the size for |
| 247 | * @size: new size of the loop device |
| 248 | * |
| 249 | * Callers must validate that the size passed into this function fits into |
| 250 | * a sector_t, eg using loop_validate_size() |
| 251 | */ |
| 252 | static void loop_set_size(struct loop_device *lo, loff_t size) |
| 253 | { |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 254 | struct block_device *bdev = lo->lo_device; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | |
Christoph Hellwig | 611bee5 | 2020-08-23 11:10:41 +0200 | [diff] [blame] | 256 | bd_set_nr_sectors(bdev, size); |
Martijn Coenen | 716ad09 | 2020-05-13 15:38:38 +0200 | [diff] [blame] | 257 | |
| 258 | set_capacity_revalidate_and_notify(lo->lo_disk, size, false); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | static inline int |
| 262 | lo_do_transfer(struct loop_device *lo, int cmd, |
| 263 | struct page *rpage, unsigned roffs, |
| 264 | struct page *lpage, unsigned loffs, |
| 265 | int size, sector_t rblock) |
| 266 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 267 | int ret; |
| 268 | |
| 269 | ret = lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock); |
| 270 | if (likely(!ret)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | return 0; |
| 272 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 273 | printk_ratelimited(KERN_ERR |
| 274 | "loop: Transfer error at byte offset %llu, length %i.\n", |
| 275 | (unsigned long long)rblock << 9, size); |
| 276 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | } |
| 278 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 279 | static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 281 | struct iov_iter i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | ssize_t bw; |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 283 | |
Christoph Hellwig | b620743 | 2019-06-26 15:49:28 +0200 | [diff] [blame] | 284 | iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 286 | file_start_write(file); |
Christoph Hellwig | abbb6589 | 2017-05-27 11:16:52 +0300 | [diff] [blame] | 287 | bw = vfs_iter_write(file, &i, ppos, 0); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 288 | file_end_write(file); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 289 | |
| 290 | if (likely(bw == bvec->bv_len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | return 0; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 292 | |
| 293 | printk_ratelimited(KERN_ERR |
| 294 | "loop: Write error at byte offset %llu, length %i.\n", |
| 295 | (unsigned long long)*ppos, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | if (bw >= 0) |
| 297 | bw = -EIO; |
| 298 | return bw; |
| 299 | } |
| 300 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 301 | static int lo_write_simple(struct loop_device *lo, struct request *rq, |
| 302 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 304 | struct bio_vec bvec; |
| 305 | struct req_iterator iter; |
| 306 | int ret = 0; |
| 307 | |
| 308 | rq_for_each_segment(bvec, rq, iter) { |
| 309 | ret = lo_write_bvec(lo->lo_backing_file, &bvec, &pos); |
| 310 | if (ret < 0) |
| 311 | break; |
| 312 | cond_resched(); |
| 313 | } |
| 314 | |
| 315 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | } |
| 317 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 318 | /* |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 319 | * This is the slow, transforming version that needs to double buffer the |
| 320 | * data as it cannot do the transformations in place without having direct |
| 321 | * access to the destination pages of the backing file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | */ |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 323 | static int lo_write_transfer(struct loop_device *lo, struct request *rq, |
| 324 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 326 | struct bio_vec bvec, b; |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 327 | struct req_iterator iter; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 328 | struct page *page; |
Kent Overstreet | 7988613 | 2013-11-23 17:19:00 -0800 | [diff] [blame] | 329 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 331 | page = alloc_page(GFP_NOIO); |
| 332 | if (unlikely(!page)) |
| 333 | return -ENOMEM; |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 334 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 335 | rq_for_each_segment(bvec, rq, iter) { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 336 | ret = lo_do_transfer(lo, WRITE, page, 0, bvec.bv_page, |
| 337 | bvec.bv_offset, bvec.bv_len, pos >> 9); |
| 338 | if (unlikely(ret)) |
| 339 | break; |
| 340 | |
| 341 | b.bv_page = page; |
| 342 | b.bv_offset = 0; |
| 343 | b.bv_len = bvec.bv_len; |
| 344 | ret = lo_write_bvec(lo->lo_backing_file, &b, &pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | if (ret < 0) |
| 346 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 348 | |
| 349 | __free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | } |
| 352 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 353 | static int lo_read_simple(struct loop_device *lo, struct request *rq, |
| 354 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | { |
Kent Overstreet | 7988613 | 2013-11-23 17:19:00 -0800 | [diff] [blame] | 356 | struct bio_vec bvec; |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 357 | struct req_iterator iter; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 358 | struct iov_iter i; |
| 359 | ssize_t len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 361 | rq_for_each_segment(bvec, rq, iter) { |
Christoph Hellwig | b620743 | 2019-06-26 15:49:28 +0200 | [diff] [blame] | 362 | iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len); |
Christoph Hellwig | 18e9710 | 2017-05-27 11:16:51 +0300 | [diff] [blame] | 363 | len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 364 | if (len < 0) |
| 365 | return len; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 366 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 367 | flush_dcache_page(bvec.bv_page); |
| 368 | |
| 369 | if (len != bvec.bv_len) { |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 370 | struct bio *bio; |
| 371 | |
| 372 | __rq_for_each_bio(bio, rq) |
| 373 | zero_fill_bio(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | break; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 375 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 376 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 378 | |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 379 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | } |
| 381 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 382 | static int lo_read_transfer(struct loop_device *lo, struct request *rq, |
| 383 | loff_t pos) |
| 384 | { |
| 385 | struct bio_vec bvec, b; |
| 386 | struct req_iterator iter; |
| 387 | struct iov_iter i; |
| 388 | struct page *page; |
| 389 | ssize_t len; |
| 390 | int ret = 0; |
| 391 | |
| 392 | page = alloc_page(GFP_NOIO); |
| 393 | if (unlikely(!page)) |
| 394 | return -ENOMEM; |
| 395 | |
| 396 | rq_for_each_segment(bvec, rq, iter) { |
| 397 | loff_t offset = pos; |
| 398 | |
| 399 | b.bv_page = page; |
| 400 | b.bv_offset = 0; |
| 401 | b.bv_len = bvec.bv_len; |
| 402 | |
Christoph Hellwig | b620743 | 2019-06-26 15:49:28 +0200 | [diff] [blame] | 403 | iov_iter_bvec(&i, READ, &b, 1, b.bv_len); |
Christoph Hellwig | 18e9710 | 2017-05-27 11:16:51 +0300 | [diff] [blame] | 404 | len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 405 | if (len < 0) { |
| 406 | ret = len; |
| 407 | goto out_free_page; |
| 408 | } |
| 409 | |
| 410 | ret = lo_do_transfer(lo, READ, page, 0, bvec.bv_page, |
| 411 | bvec.bv_offset, len, offset >> 9); |
| 412 | if (ret) |
| 413 | goto out_free_page; |
| 414 | |
| 415 | flush_dcache_page(bvec.bv_page); |
| 416 | |
| 417 | if (len != bvec.bv_len) { |
| 418 | struct bio *bio; |
| 419 | |
| 420 | __rq_for_each_bio(bio, rq) |
| 421 | zero_fill_bio(bio); |
| 422 | break; |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | ret = 0; |
| 427 | out_free_page: |
| 428 | __free_page(page); |
| 429 | return ret; |
| 430 | } |
| 431 | |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 432 | static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos, |
| 433 | int mode) |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 434 | { |
| 435 | /* |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 436 | * We use fallocate to manipulate the space mappings used by the image |
| 437 | * a.k.a. discard/zerorange. However we do not support this if |
| 438 | * encryption is enabled, because it may give an attacker useful |
| 439 | * information. |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 440 | */ |
| 441 | struct file *file = lo->lo_backing_file; |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 442 | struct request_queue *q = lo->lo_queue; |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 443 | int ret; |
| 444 | |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 445 | mode |= FALLOC_FL_KEEP_SIZE; |
| 446 | |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 447 | if (!blk_queue_discard(q)) { |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 448 | ret = -EOPNOTSUPP; |
| 449 | goto out; |
| 450 | } |
| 451 | |
| 452 | ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); |
| 453 | if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) |
| 454 | ret = -EIO; |
| 455 | out: |
| 456 | return ret; |
| 457 | } |
| 458 | |
| 459 | static int lo_req_flush(struct loop_device *lo, struct request *rq) |
| 460 | { |
| 461 | struct file *file = lo->lo_backing_file; |
| 462 | int ret = vfs_fsync(file, 0); |
| 463 | if (unlikely(ret && ret != -EINVAL)) |
| 464 | ret = -EIO; |
| 465 | |
| 466 | return ret; |
| 467 | } |
| 468 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 469 | static void lo_complete_rq(struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 470 | { |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 471 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 472 | blk_status_t ret = BLK_STS_OK; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 473 | |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 474 | if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || |
| 475 | req_op(rq) != REQ_OP_READ) { |
| 476 | if (cmd->ret < 0) |
Evan Green | 8cd5508 | 2020-04-03 16:43:03 +0200 | [diff] [blame] | 477 | ret = errno_to_blk_status(cmd->ret); |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 478 | goto end_io; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 479 | } |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 480 | |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 481 | /* |
| 482 | * Short READ - if we got some data, advance our request and |
| 483 | * retry it. If we got no data, end the rest with EIO. |
| 484 | */ |
| 485 | if (cmd->ret) { |
| 486 | blk_update_request(rq, BLK_STS_OK, cmd->ret); |
| 487 | cmd->ret = 0; |
| 488 | blk_mq_requeue_request(rq, true); |
| 489 | } else { |
| 490 | if (cmd->use_aio) { |
| 491 | struct bio *bio = rq->bio; |
| 492 | |
| 493 | while (bio) { |
| 494 | zero_fill_bio(bio); |
| 495 | bio = bio->bi_next; |
| 496 | } |
| 497 | } |
| 498 | ret = BLK_STS_IOERR; |
| 499 | end_io: |
| 500 | blk_mq_end_request(rq, ret); |
| 501 | } |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 502 | } |
| 503 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 504 | static void lo_rw_aio_do_completion(struct loop_cmd *cmd) |
| 505 | { |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 506 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
| 507 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 508 | if (!atomic_dec_and_test(&cmd->ref)) |
| 509 | return; |
| 510 | kfree(cmd->bvec); |
| 511 | cmd->bvec = NULL; |
Christoph Hellwig | 15f73f5 | 2020-06-11 08:44:47 +0200 | [diff] [blame] | 512 | if (likely(!blk_should_fake_timeout(rq->q))) |
| 513 | blk_mq_complete_request(rq); |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 514 | } |
| 515 | |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 516 | static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) |
| 517 | { |
| 518 | struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 519 | |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 520 | if (cmd->css) |
| 521 | css_put(cmd->css); |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 522 | cmd->ret = ret; |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 523 | lo_rw_aio_do_completion(cmd); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 524 | } |
| 525 | |
| 526 | static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, |
| 527 | loff_t pos, bool rw) |
| 528 | { |
| 529 | struct iov_iter iter; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 530 | struct req_iterator rq_iter; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 531 | struct bio_vec *bvec; |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 532 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 533 | struct bio *bio = rq->bio; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 534 | struct file *file = lo->lo_backing_file; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 535 | struct bio_vec tmp; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 536 | unsigned int offset; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 537 | int nr_bvec = 0; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 538 | int ret; |
| 539 | |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 540 | rq_for_each_bvec(tmp, rq, rq_iter) |
| 541 | nr_bvec++; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 542 | |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 543 | if (rq->bio != rq->biotail) { |
| 544 | |
| 545 | bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), |
Kees Cook | 6da2ec5 | 2018-06-12 13:55:00 -0700 | [diff] [blame] | 546 | GFP_NOIO); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 547 | if (!bvec) |
| 548 | return -EIO; |
| 549 | cmd->bvec = bvec; |
| 550 | |
| 551 | /* |
| 552 | * The bios of the request may be started from the middle of |
| 553 | * the 'bvec' because of bio splitting, so we can't directly |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 554 | * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 555 | * API will take care of all details for us. |
| 556 | */ |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 557 | rq_for_each_bvec(tmp, rq, rq_iter) { |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 558 | *bvec = tmp; |
| 559 | bvec++; |
| 560 | } |
| 561 | bvec = cmd->bvec; |
| 562 | offset = 0; |
| 563 | } else { |
| 564 | /* |
| 565 | * Same here, this bio may be started from the middle of the |
| 566 | * 'bvec' because of bio splitting, so offset from the bvec |
| 567 | * must be passed to iov iterator |
| 568 | */ |
| 569 | offset = bio->bi_iter.bi_bvec_done; |
| 570 | bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 571 | } |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 572 | atomic_set(&cmd->ref, 2); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 573 | |
Christoph Hellwig | b620743 | 2019-06-26 15:49:28 +0200 | [diff] [blame] | 574 | iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq)); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 575 | iter.iov_offset = offset; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 576 | |
| 577 | cmd->iocb.ki_pos = pos; |
| 578 | cmd->iocb.ki_filp = file; |
| 579 | cmd->iocb.ki_complete = lo_rw_aio_complete; |
| 580 | cmd->iocb.ki_flags = IOCB_DIRECT; |
Adam Manzanares | d9a08a9 | 2018-05-22 10:52:19 -0700 | [diff] [blame] | 581 | cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 582 | if (cmd->css) |
| 583 | kthread_associate_blkcg(cmd->css); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 584 | |
| 585 | if (rw == WRITE) |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 586 | ret = call_write_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 587 | else |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 588 | ret = call_read_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 589 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 590 | lo_rw_aio_do_completion(cmd); |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 591 | kthread_associate_blkcg(NULL); |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 592 | |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 593 | if (ret != -EIOCBQUEUED) |
| 594 | cmd->iocb.ki_complete(&cmd->iocb, ret, 0); |
| 595 | return 0; |
| 596 | } |
| 597 | |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 598 | static int do_req_filebacked(struct loop_device *lo, struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 599 | { |
| 600 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 601 | loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 602 | |
| 603 | /* |
| 604 | * lo_write_simple and lo_read_simple should have been covered |
| 605 | * by io submit style function like lo_rw_aio(), one blocker |
| 606 | * is that lo_read_simple() need to call flush_dcache_page after |
| 607 | * the page is written from kernel, and it isn't easy to handle |
| 608 | * this in io submit style function which submits all segments |
| 609 | * of the req at one time. And direct read IO doesn't need to |
| 610 | * run flush_dcache_page(). |
| 611 | */ |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 612 | switch (req_op(rq)) { |
| 613 | case REQ_OP_FLUSH: |
| 614 | return lo_req_flush(lo, rq); |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 615 | case REQ_OP_WRITE_ZEROES: |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 616 | /* |
| 617 | * If the caller doesn't want deallocation, call zeroout to |
| 618 | * write zeroes the range. Otherwise, punch them out. |
| 619 | */ |
| 620 | return lo_fallocate(lo, rq, pos, |
| 621 | (rq->cmd_flags & REQ_NOUNMAP) ? |
| 622 | FALLOC_FL_ZERO_RANGE : |
| 623 | FALLOC_FL_PUNCH_HOLE); |
| 624 | case REQ_OP_DISCARD: |
| 625 | return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 626 | case REQ_OP_WRITE: |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 627 | if (lo->transfer) |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 628 | return lo_write_transfer(lo, rq, pos); |
| 629 | else if (cmd->use_aio) |
| 630 | return lo_rw_aio(lo, cmd, pos, WRITE); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 631 | else |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 632 | return lo_write_simple(lo, rq, pos); |
| 633 | case REQ_OP_READ: |
| 634 | if (lo->transfer) |
| 635 | return lo_read_transfer(lo, rq, pos); |
| 636 | else if (cmd->use_aio) |
| 637 | return lo_rw_aio(lo, cmd, pos, READ); |
| 638 | else |
| 639 | return lo_read_simple(lo, rq, pos); |
| 640 | default: |
| 641 | WARN_ON_ONCE(1); |
| 642 | return -EIO; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 643 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | } |
| 645 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 646 | static inline void loop_update_dio(struct loop_device *lo) |
| 647 | { |
Ira Weiny | efbe3c2 | 2020-04-30 07:41:33 -0700 | [diff] [blame] | 648 | __loop_update_dio(lo, (lo->lo_backing_file->f_flags & O_DIRECT) | |
| 649 | lo->use_dio); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 650 | } |
| 651 | |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 652 | static void loop_reread_partitions(struct loop_device *lo, |
| 653 | struct block_device *bdev) |
| 654 | { |
| 655 | int rc; |
| 656 | |
Christoph Hellwig | f0b870d | 2019-11-14 15:34:36 +0100 | [diff] [blame] | 657 | mutex_lock(&bdev->bd_mutex); |
| 658 | rc = bdev_disk_changed(bdev, false); |
| 659 | mutex_unlock(&bdev->bd_mutex); |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 660 | if (rc) |
| 661 | pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n", |
| 662 | __func__, lo->lo_number, lo->lo_file_name, rc); |
| 663 | } |
| 664 | |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 665 | static inline int is_loop_device(struct file *file) |
| 666 | { |
| 667 | struct inode *i = file->f_mapping->host; |
| 668 | |
| 669 | return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; |
| 670 | } |
| 671 | |
| 672 | static int loop_validate_file(struct file *file, struct block_device *bdev) |
| 673 | { |
| 674 | struct inode *inode = file->f_mapping->host; |
| 675 | struct file *f = file; |
| 676 | |
| 677 | /* Avoid recursion */ |
| 678 | while (is_loop_device(f)) { |
| 679 | struct loop_device *l; |
| 680 | |
| 681 | if (f->f_mapping->host->i_bdev == bdev) |
| 682 | return -EBADF; |
| 683 | |
| 684 | l = f->f_mapping->host->i_bdev->bd_disk->private_data; |
Dongli Zhang | f7c8a41 | 2019-03-18 20:23:17 +0800 | [diff] [blame] | 685 | if (l->lo_state != Lo_bound) { |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 686 | return -EINVAL; |
| 687 | } |
| 688 | f = l->lo_backing_file; |
| 689 | } |
| 690 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
| 691 | return -EINVAL; |
| 692 | return 0; |
| 693 | } |
| 694 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | /* |
| 696 | * loop_change_fd switched the backing store of a loopback device to |
| 697 | * a new file. This is useful for operating system installers to free up |
| 698 | * the original file and in High Availability environments to switch to |
| 699 | * an alternative location for the content in case of server meltdown. |
| 700 | * This can only work if the loop device is used read-only, and if the |
| 701 | * new backing store is the same size and type as the old backing store. |
| 702 | */ |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 703 | static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, |
| 704 | unsigned int arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | { |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 706 | struct file *file = NULL, *old_file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 707 | int error; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 708 | bool partscan; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | |
Jan Kara | c28445f | 2018-11-08 14:01:16 +0100 | [diff] [blame] | 710 | error = mutex_lock_killable(&loop_ctl_mutex); |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 711 | if (error) |
| 712 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | error = -ENXIO; |
| 714 | if (lo->lo_state != Lo_bound) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 715 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 716 | |
| 717 | /* the loop device has to be read-only */ |
| 718 | error = -EINVAL; |
| 719 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 720 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | |
| 722 | error = -EBADF; |
| 723 | file = fget(arg); |
| 724 | if (!file) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 725 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 727 | error = loop_validate_file(file, bdev); |
| 728 | if (error) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 729 | goto out_err; |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 730 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | old_file = lo->lo_backing_file; |
| 732 | |
| 733 | error = -EINVAL; |
| 734 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | /* size of the new backing store needs to be the same */ |
| 736 | if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 737 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | |
| 739 | /* and ... switch */ |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame] | 740 | blk_mq_freeze_queue(lo->lo_queue); |
| 741 | mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); |
| 742 | lo->lo_backing_file = file; |
| 743 | lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); |
| 744 | mapping_set_gfp_mask(file->f_mapping, |
| 745 | lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 746 | loop_update_dio(lo); |
| 747 | blk_mq_unfreeze_queue(lo->lo_queue); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 748 | partscan = lo->lo_flags & LO_FLAGS_PARTSCAN; |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 749 | mutex_unlock(&loop_ctl_mutex); |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 750 | /* |
| 751 | * We must drop file reference outside of loop_ctl_mutex as dropping |
| 752 | * the file ref can take bd_mutex which creates circular locking |
| 753 | * dependency. |
| 754 | */ |
| 755 | fput(old_file); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 756 | if (partscan) |
| 757 | loop_reread_partitions(lo, bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | return 0; |
| 759 | |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 760 | out_err: |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 761 | mutex_unlock(&loop_ctl_mutex); |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 762 | if (file) |
| 763 | fput(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | return error; |
| 765 | } |
| 766 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 767 | /* loop sysfs attributes */ |
| 768 | |
| 769 | static ssize_t loop_attr_show(struct device *dev, char *page, |
| 770 | ssize_t (*callback)(struct loop_device *, char *)) |
| 771 | { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 772 | struct gendisk *disk = dev_to_disk(dev); |
| 773 | struct loop_device *lo = disk->private_data; |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 774 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 775 | return callback(lo, page); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 776 | } |
| 777 | |
| 778 | #define LOOP_ATTR_RO(_name) \ |
| 779 | static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ |
| 780 | static ssize_t loop_attr_do_show_##_name(struct device *d, \ |
| 781 | struct device_attribute *attr, char *b) \ |
| 782 | { \ |
| 783 | return loop_attr_show(d, b, loop_attr_##_name##_show); \ |
| 784 | } \ |
| 785 | static struct device_attribute loop_attr_##_name = \ |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 786 | __ATTR(_name, 0444, loop_attr_do_show_##_name, NULL); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 787 | |
| 788 | static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) |
| 789 | { |
| 790 | ssize_t ret; |
| 791 | char *p = NULL; |
| 792 | |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 793 | spin_lock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 794 | if (lo->lo_backing_file) |
Miklos Szeredi | 9bf39ab | 2015-06-19 10:29:13 +0200 | [diff] [blame] | 795 | p = file_path(lo->lo_backing_file, buf, PAGE_SIZE - 1); |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 796 | spin_unlock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 797 | |
| 798 | if (IS_ERR_OR_NULL(p)) |
| 799 | ret = PTR_ERR(p); |
| 800 | else { |
| 801 | ret = strlen(p); |
| 802 | memmove(buf, p, ret); |
| 803 | buf[ret++] = '\n'; |
| 804 | buf[ret] = 0; |
| 805 | } |
| 806 | |
| 807 | return ret; |
| 808 | } |
| 809 | |
| 810 | static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) |
| 811 | { |
| 812 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); |
| 813 | } |
| 814 | |
| 815 | static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) |
| 816 | { |
| 817 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); |
| 818 | } |
| 819 | |
| 820 | static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) |
| 821 | { |
| 822 | int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); |
| 823 | |
| 824 | return sprintf(buf, "%s\n", autoclear ? "1" : "0"); |
| 825 | } |
| 826 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 827 | static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) |
| 828 | { |
| 829 | int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); |
| 830 | |
| 831 | return sprintf(buf, "%s\n", partscan ? "1" : "0"); |
| 832 | } |
| 833 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 834 | static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf) |
| 835 | { |
| 836 | int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO); |
| 837 | |
| 838 | return sprintf(buf, "%s\n", dio ? "1" : "0"); |
| 839 | } |
| 840 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 841 | LOOP_ATTR_RO(backing_file); |
| 842 | LOOP_ATTR_RO(offset); |
| 843 | LOOP_ATTR_RO(sizelimit); |
| 844 | LOOP_ATTR_RO(autoclear); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 845 | LOOP_ATTR_RO(partscan); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 846 | LOOP_ATTR_RO(dio); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 847 | |
| 848 | static struct attribute *loop_attrs[] = { |
| 849 | &loop_attr_backing_file.attr, |
| 850 | &loop_attr_offset.attr, |
| 851 | &loop_attr_sizelimit.attr, |
| 852 | &loop_attr_autoclear.attr, |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 853 | &loop_attr_partscan.attr, |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 854 | &loop_attr_dio.attr, |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 855 | NULL, |
| 856 | }; |
| 857 | |
| 858 | static struct attribute_group loop_attribute_group = { |
| 859 | .name = "loop", |
| 860 | .attrs= loop_attrs, |
| 861 | }; |
| 862 | |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 863 | static void loop_sysfs_init(struct loop_device *lo) |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 864 | { |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 865 | lo->sysfs_inited = !sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 866 | &loop_attribute_group); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 867 | } |
| 868 | |
| 869 | static void loop_sysfs_exit(struct loop_device *lo) |
| 870 | { |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 871 | if (lo->sysfs_inited) |
| 872 | sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 873 | &loop_attribute_group); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 874 | } |
| 875 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 876 | static void loop_config_discard(struct loop_device *lo) |
| 877 | { |
| 878 | struct file *file = lo->lo_backing_file; |
| 879 | struct inode *inode = file->f_mapping->host; |
| 880 | struct request_queue *q = lo->lo_queue; |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 881 | u32 granularity, max_discard_sectors; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 882 | |
| 883 | /* |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 884 | * If the backing device is a block device, mirror its zeroing |
| 885 | * capability. Set the discard sectors to the block device's zeroing |
| 886 | * capabilities because loop discards result in blkdev_issue_zeroout(), |
| 887 | * not blkdev_issue_discard(). This maintains consistent behavior with |
| 888 | * file-backed loop devices: discarded regions read back as zero. |
| 889 | */ |
| 890 | if (S_ISBLK(inode->i_mode) && !lo->lo_encrypt_key_size) { |
| 891 | struct request_queue *backingq; |
| 892 | |
| 893 | backingq = bdev_get_queue(inode->i_bdev); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 894 | |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 895 | max_discard_sectors = backingq->limits.max_write_zeroes_sectors; |
| 896 | granularity = backingq->limits.discard_granularity ?: |
| 897 | queue_physical_block_size(backingq); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 898 | |
| 899 | /* |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 900 | * We use punch hole to reclaim the free space used by the |
Olaf Hering | 12a64d2 | 2014-01-21 14:39:24 -0800 | [diff] [blame] | 901 | * image a.k.a. discard. However we do not support discard if |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 902 | * encryption is enabled, because it may give an attacker |
| 903 | * useful information. |
| 904 | */ |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 905 | } else if (!file->f_op->fallocate || lo->lo_encrypt_key_size) { |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 906 | max_discard_sectors = 0; |
| 907 | granularity = 0; |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 908 | |
| 909 | } else { |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 910 | max_discard_sectors = UINT_MAX >> 9; |
| 911 | granularity = inode->i_sb->s_blocksize; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 912 | } |
| 913 | |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 914 | if (max_discard_sectors) { |
| 915 | q->limits.discard_granularity = granularity; |
| 916 | blk_queue_max_discard_sectors(q, max_discard_sectors); |
| 917 | blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 918 | blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 919 | } else { |
| 920 | q->limits.discard_granularity = 0; |
| 921 | blk_queue_max_discard_sectors(q, 0); |
| 922 | blk_queue_max_write_zeroes_sectors(q, 0); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 923 | blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 924 | } |
| 925 | q->limits.discard_alignment = 0; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 926 | } |
| 927 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 928 | static void loop_unprepare_queue(struct loop_device *lo) |
| 929 | { |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 930 | kthread_flush_worker(&lo->worker); |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 931 | kthread_stop(lo->worker_task); |
| 932 | } |
| 933 | |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 934 | static int loop_kthread_worker_fn(void *worker_ptr) |
| 935 | { |
NeilBrown | a37b071 | 2020-06-01 21:48:18 -0700 | [diff] [blame] | 936 | current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 937 | return kthread_worker_fn(worker_ptr); |
| 938 | } |
| 939 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 940 | static int loop_prepare_queue(struct loop_device *lo) |
| 941 | { |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 942 | kthread_init_worker(&lo->worker); |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 943 | lo->worker_task = kthread_run(loop_kthread_worker_fn, |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 944 | &lo->worker, "loop%d", lo->lo_number); |
| 945 | if (IS_ERR(lo->worker_task)) |
| 946 | return -ENOMEM; |
| 947 | set_user_nice(lo->worker_task, MIN_NICE); |
| 948 | return 0; |
| 949 | } |
| 950 | |
Holger Hoffstätte | 56a85fd | 2019-02-12 15:54:24 -0700 | [diff] [blame] | 951 | static void loop_update_rotational(struct loop_device *lo) |
| 952 | { |
| 953 | struct file *file = lo->lo_backing_file; |
| 954 | struct inode *file_inode = file->f_mapping->host; |
| 955 | struct block_device *file_bdev = file_inode->i_sb->s_bdev; |
| 956 | struct request_queue *q = lo->lo_queue; |
| 957 | bool nonrot = true; |
| 958 | |
| 959 | /* not all filesystems (e.g. tmpfs) have a sb->s_bdev */ |
| 960 | if (file_bdev) |
| 961 | nonrot = blk_queue_nonrot(bdev_get_queue(file_bdev)); |
| 962 | |
| 963 | if (nonrot) |
| 964 | blk_queue_flag_set(QUEUE_FLAG_NONROT, q); |
| 965 | else |
| 966 | blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); |
| 967 | } |
| 968 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 969 | static int |
| 970 | loop_release_xfer(struct loop_device *lo) |
| 971 | { |
| 972 | int err = 0; |
| 973 | struct loop_func_table *xfer = lo->lo_encryption; |
| 974 | |
| 975 | if (xfer) { |
| 976 | if (xfer->release) |
| 977 | err = xfer->release(lo); |
| 978 | lo->transfer = NULL; |
| 979 | lo->lo_encryption = NULL; |
| 980 | module_put(xfer->owner); |
| 981 | } |
| 982 | return err; |
| 983 | } |
| 984 | |
| 985 | static int |
| 986 | loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, |
| 987 | const struct loop_info64 *i) |
| 988 | { |
| 989 | int err = 0; |
| 990 | |
| 991 | if (xfer) { |
| 992 | struct module *owner = xfer->owner; |
| 993 | |
| 994 | if (!try_module_get(owner)) |
| 995 | return -EINVAL; |
| 996 | if (xfer->init) |
| 997 | err = xfer->init(lo, i); |
| 998 | if (err) |
| 999 | module_put(owner); |
| 1000 | else |
| 1001 | lo->lo_encryption = xfer; |
| 1002 | } |
| 1003 | return err; |
| 1004 | } |
| 1005 | |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 1006 | /** |
| 1007 | * loop_set_status_from_info - configure device from loop_info |
| 1008 | * @lo: struct loop_device to configure |
| 1009 | * @info: struct loop_info64 to configure the device with |
| 1010 | * |
| 1011 | * Configures the loop device parameters according to the passed |
| 1012 | * in loop_info64 configuration. |
| 1013 | */ |
| 1014 | static int |
| 1015 | loop_set_status_from_info(struct loop_device *lo, |
| 1016 | const struct loop_info64 *info) |
| 1017 | { |
| 1018 | int err; |
| 1019 | struct loop_func_table *xfer; |
| 1020 | kuid_t uid = current_uid(); |
| 1021 | |
| 1022 | if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) |
| 1023 | return -EINVAL; |
| 1024 | |
| 1025 | err = loop_release_xfer(lo); |
| 1026 | if (err) |
| 1027 | return err; |
| 1028 | |
| 1029 | if (info->lo_encrypt_type) { |
| 1030 | unsigned int type = info->lo_encrypt_type; |
| 1031 | |
| 1032 | if (type >= MAX_LO_CRYPT) |
| 1033 | return -EINVAL; |
| 1034 | xfer = xfer_funcs[type]; |
| 1035 | if (xfer == NULL) |
| 1036 | return -EINVAL; |
| 1037 | } else |
| 1038 | xfer = NULL; |
| 1039 | |
| 1040 | err = loop_init_xfer(lo, xfer, info); |
| 1041 | if (err) |
| 1042 | return err; |
| 1043 | |
| 1044 | lo->lo_offset = info->lo_offset; |
| 1045 | lo->lo_sizelimit = info->lo_sizelimit; |
| 1046 | memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); |
| 1047 | memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); |
| 1048 | lo->lo_file_name[LO_NAME_SIZE-1] = 0; |
| 1049 | lo->lo_crypt_name[LO_NAME_SIZE-1] = 0; |
| 1050 | |
| 1051 | if (!xfer) |
| 1052 | xfer = &none_funcs; |
| 1053 | lo->transfer = xfer->transfer; |
| 1054 | lo->ioctl = xfer->ioctl; |
| 1055 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1056 | lo->lo_flags = info->lo_flags; |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 1057 | |
| 1058 | lo->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1059 | lo->lo_init[0] = info->lo_init[0]; |
| 1060 | lo->lo_init[1] = info->lo_init[1]; |
| 1061 | if (info->lo_encrypt_key_size) { |
| 1062 | memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, |
| 1063 | info->lo_encrypt_key_size); |
| 1064 | lo->lo_key_owner = uid; |
| 1065 | } |
| 1066 | |
| 1067 | return 0; |
| 1068 | } |
| 1069 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1070 | static int loop_configure(struct loop_device *lo, fmode_t mode, |
| 1071 | struct block_device *bdev, |
| 1072 | const struct loop_config *config) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | { |
| 1074 | struct file *file; |
| 1075 | struct inode *inode; |
| 1076 | struct address_space *mapping; |
| 1077 | struct block_device *claimed_bdev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | int error; |
| 1079 | loff_t size; |
| 1080 | bool partscan; |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1081 | unsigned short bsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | |
| 1083 | /* This is safe, since we have a reference from open(). */ |
| 1084 | __module_get(THIS_MODULE); |
| 1085 | |
| 1086 | error = -EBADF; |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1087 | file = fget(config->fd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | if (!file) |
| 1089 | goto out; |
| 1090 | |
| 1091 | /* |
| 1092 | * If we don't hold exclusive handle for the device, upgrade to it |
| 1093 | * here to avoid changing device under exclusive owner. |
| 1094 | */ |
| 1095 | if (!(mode & FMODE_EXCL)) { |
Christoph Hellwig | ecbe6bc | 2020-07-16 16:33:09 +0200 | [diff] [blame] | 1096 | claimed_bdev = bdev->bd_contains; |
| 1097 | error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure); |
| 1098 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1099 | goto out_putf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | } |
| 1101 | |
| 1102 | error = mutex_lock_killable(&loop_ctl_mutex); |
| 1103 | if (error) |
| 1104 | goto out_bdev; |
| 1105 | |
| 1106 | error = -EBUSY; |
| 1107 | if (lo->lo_state != Lo_unbound) |
| 1108 | goto out_unlock; |
| 1109 | |
| 1110 | error = loop_validate_file(file, bdev); |
| 1111 | if (error) |
| 1112 | goto out_unlock; |
| 1113 | |
| 1114 | mapping = file->f_mapping; |
| 1115 | inode = mapping->host; |
| 1116 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1117 | if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { |
| 1118 | error = -EINVAL; |
| 1119 | goto out_unlock; |
| 1120 | } |
| 1121 | |
| 1122 | if (config->block_size) { |
| 1123 | error = loop_validate_block_size(config->block_size); |
| 1124 | if (error) |
| 1125 | goto out_unlock; |
| 1126 | } |
| 1127 | |
| 1128 | error = loop_set_status_from_info(lo, &config->info); |
| 1129 | if (error) |
| 1130 | goto out_unlock; |
| 1131 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || |
| 1133 | !file->f_op->write_iter) |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1134 | lo->lo_flags |= LO_FLAGS_READ_ONLY; |
Martijn Coenen | 083a6a5 | 2020-05-13 15:38:36 +0200 | [diff] [blame] | 1135 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | error = loop_prepare_queue(lo); |
| 1137 | if (error) |
| 1138 | goto out_unlock; |
| 1139 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1140 | set_device_ro(bdev, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1142 | lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | lo->lo_device = bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | lo->lo_backing_file = file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
| 1146 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 1147 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1148 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | blk_queue_write_cache(lo->lo_queue, true, false); |
| 1150 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1151 | if (config->block_size) |
| 1152 | bsize = config->block_size; |
Linus Torvalds | 96ed320 | 2020-06-02 19:45:12 -0700 | [diff] [blame] | 1153 | else if ((lo->lo_backing_file->f_flags & O_DIRECT) && inode->i_sb->s_bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1154 | /* In case of direct I/O, match underlying block size */ |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1155 | bsize = bdev_logical_block_size(inode->i_sb->s_bdev); |
| 1156 | else |
| 1157 | bsize = 512; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1159 | blk_queue_logical_block_size(lo->lo_queue, bsize); |
| 1160 | blk_queue_physical_block_size(lo->lo_queue, bsize); |
| 1161 | blk_queue_io_min(lo->lo_queue, bsize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | |
| 1163 | loop_update_rotational(lo); |
| 1164 | loop_update_dio(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1165 | loop_sysfs_init(lo); |
Martijn Coenen | 79e5dc5 | 2020-08-25 09:18:29 +0200 | [diff] [blame] | 1166 | |
| 1167 | size = get_loop_size(lo, file); |
Martijn Coenen | 5795b6f | 2020-05-13 15:38:37 +0200 | [diff] [blame] | 1168 | loop_set_size(lo, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | |
| 1170 | set_blocksize(bdev, S_ISBLK(inode->i_mode) ? |
| 1171 | block_size(inode->i_bdev) : PAGE_SIZE); |
| 1172 | |
| 1173 | lo->lo_state = Lo_bound; |
| 1174 | if (part_shift) |
| 1175 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
| 1176 | partscan = lo->lo_flags & LO_FLAGS_PARTSCAN; |
Lennart Poettering | fe6a8fc | 2020-08-10 19:16:32 +0200 | [diff] [blame] | 1177 | if (partscan) |
| 1178 | lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1179 | |
| 1180 | /* Grab the block_device to prevent its destruction after we |
| 1181 | * put /dev/loopXX inode. Later in __loop_clr_fd() we bdput(bdev). |
| 1182 | */ |
| 1183 | bdgrab(bdev); |
| 1184 | mutex_unlock(&loop_ctl_mutex); |
| 1185 | if (partscan) |
| 1186 | loop_reread_partitions(lo, bdev); |
| 1187 | if (claimed_bdev) |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1188 | bd_abort_claiming(bdev, claimed_bdev, loop_configure); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | return 0; |
| 1190 | |
| 1191 | out_unlock: |
| 1192 | mutex_unlock(&loop_ctl_mutex); |
| 1193 | out_bdev: |
| 1194 | if (claimed_bdev) |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1195 | bd_abort_claiming(bdev, claimed_bdev, loop_configure); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | out_putf: |
| 1197 | fput(file); |
| 1198 | out: |
| 1199 | /* This is safe: open() is still holding a reference. */ |
| 1200 | module_put(THIS_MODULE); |
| 1201 | return error; |
| 1202 | } |
| 1203 | |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1204 | static int __loop_clr_fd(struct loop_device *lo, bool release) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | { |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1206 | struct file *filp = NULL; |
Al Viro | b4e3ca1 | 2005-10-21 03:22:34 -0400 | [diff] [blame] | 1207 | gfp_t gfp = lo->old_gfp_mask; |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 1208 | struct block_device *bdev = lo->lo_device; |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1209 | int err = 0; |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1210 | bool partscan = false; |
| 1211 | int lo_number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1213 | mutex_lock(&loop_ctl_mutex); |
| 1214 | if (WARN_ON_ONCE(lo->lo_state != Lo_rundown)) { |
| 1215 | err = -ENXIO; |
| 1216 | goto out_unlock; |
| 1217 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1219 | filp = lo->lo_backing_file; |
| 1220 | if (filp == NULL) { |
| 1221 | err = -EINVAL; |
| 1222 | goto out_unlock; |
| 1223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1225 | /* freeze request queue during the transition */ |
| 1226 | blk_mq_freeze_queue(lo->lo_queue); |
| 1227 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | spin_lock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1229 | lo->lo_backing_file = NULL; |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 1230 | spin_unlock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | |
| 1232 | loop_release_xfer(lo); |
| 1233 | lo->transfer = NULL; |
| 1234 | lo->ioctl = NULL; |
| 1235 | lo->lo_device = NULL; |
| 1236 | lo->lo_encryption = NULL; |
| 1237 | lo->lo_offset = 0; |
| 1238 | lo->lo_sizelimit = 0; |
| 1239 | lo->lo_encrypt_key_size = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1240 | memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); |
| 1241 | memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); |
| 1242 | memset(lo->lo_file_name, 0, LO_NAME_SIZE); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1243 | blk_queue_logical_block_size(lo->lo_queue, 512); |
Omar Sandoval | bf09375 | 2017-09-05 14:24:47 -0700 | [diff] [blame] | 1244 | blk_queue_physical_block_size(lo->lo_queue, 512); |
| 1245 | blk_queue_io_min(lo->lo_queue, 512); |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 1246 | if (bdev) { |
| 1247 | bdput(bdev); |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1248 | invalidate_bdev(bdev); |
Jeff Layton | eedffa2 | 2018-05-21 14:35:03 -0400 | [diff] [blame] | 1249 | bdev->bd_inode->i_mapping->wb_err = 0; |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 1250 | } |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1251 | set_capacity(lo->lo_disk, 0); |
Milan Broz | 51a0bb0 | 2010-10-27 19:51:30 -0600 | [diff] [blame] | 1252 | loop_sysfs_exit(lo); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1253 | if (bdev) { |
Christoph Hellwig | 611bee5 | 2020-08-23 11:10:41 +0200 | [diff] [blame] | 1254 | bd_set_nr_sectors(bdev, 0); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1255 | /* let user-space know about this change */ |
| 1256 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
| 1257 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1258 | mapping_set_gfp_mask(filp->f_mapping, gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | /* This is safe: open() is still holding a reference. */ |
| 1260 | module_put(THIS_MODULE); |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1261 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 1262 | |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1263 | partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev; |
| 1264 | lo_number = lo->lo_number; |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1265 | loop_unprepare_queue(lo); |
| 1266 | out_unlock: |
| 1267 | mutex_unlock(&loop_ctl_mutex); |
| 1268 | if (partscan) { |
Jan Kara | d57f337 | 2018-11-08 14:01:12 +0100 | [diff] [blame] | 1269 | /* |
| 1270 | * bd_mutex has been held already in release path, so don't |
| 1271 | * acquire it if this function is called in such case. |
| 1272 | * |
| 1273 | * If the reread partition isn't from release path, lo_refcnt |
| 1274 | * must be at least one and it can only become zero when the |
| 1275 | * current holder is released. |
| 1276 | */ |
Christoph Hellwig | f0b870d | 2019-11-14 15:34:36 +0100 | [diff] [blame] | 1277 | if (!release) |
| 1278 | mutex_lock(&bdev->bd_mutex); |
| 1279 | err = bdev_disk_changed(bdev, false); |
| 1280 | if (!release) |
| 1281 | mutex_unlock(&bdev->bd_mutex); |
Dongli Zhang | 40853d6 | 2019-02-22 22:10:19 +0800 | [diff] [blame] | 1282 | if (err) |
| 1283 | pr_warn("%s: partition scan of loop%d failed (rc=%d)\n", |
| 1284 | __func__, lo_number, err); |
Jan Kara | d57f337 | 2018-11-08 14:01:12 +0100 | [diff] [blame] | 1285 | /* Device is gone, no point in returning error */ |
| 1286 | err = 0; |
| 1287 | } |
Dongli Zhang | 758a58d | 2019-02-22 22:10:20 +0800 | [diff] [blame] | 1288 | |
| 1289 | /* |
| 1290 | * lo->lo_state is set to Lo_unbound here after above partscan has |
| 1291 | * finished. |
| 1292 | * |
| 1293 | * There cannot be anybody else entering __loop_clr_fd() as |
| 1294 | * lo->lo_backing_file is already cleared and Lo_rundown state |
| 1295 | * protects us from all the other places trying to change the 'lo' |
| 1296 | * device. |
| 1297 | */ |
| 1298 | mutex_lock(&loop_ctl_mutex); |
| 1299 | lo->lo_flags = 0; |
| 1300 | if (!part_shift) |
| 1301 | lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; |
| 1302 | lo->lo_state = Lo_unbound; |
| 1303 | mutex_unlock(&loop_ctl_mutex); |
| 1304 | |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1305 | /* |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1306 | * Need not hold loop_ctl_mutex to fput backing file. |
| 1307 | * Calling fput holding loop_ctl_mutex triggers a circular |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1308 | * lock dependency possibility warning as fput can take |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1309 | * bd_mutex which is usually taken before loop_ctl_mutex. |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1310 | */ |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1311 | if (filp) |
| 1312 | fput(filp); |
| 1313 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | } |
| 1315 | |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1316 | static int loop_clr_fd(struct loop_device *lo) |
| 1317 | { |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1318 | int err; |
| 1319 | |
Jan Kara | c28445f | 2018-11-08 14:01:16 +0100 | [diff] [blame] | 1320 | err = mutex_lock_killable(&loop_ctl_mutex); |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1321 | if (err) |
| 1322 | return err; |
| 1323 | if (lo->lo_state != Lo_bound) { |
| 1324 | mutex_unlock(&loop_ctl_mutex); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1325 | return -ENXIO; |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1326 | } |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1327 | /* |
| 1328 | * If we've explicitly asked to tear down the loop device, |
| 1329 | * and it has an elevated reference count, set it for auto-teardown when |
| 1330 | * the last reference goes away. This stops $!~#$@ udev from |
| 1331 | * preventing teardown because it decided that it needs to run blkid on |
| 1332 | * the loopback device whenever they appear. xfstests is notorious for |
| 1333 | * failing tests because blkid via udev races with a losetup |
| 1334 | * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d |
| 1335 | * command to fail with EBUSY. |
| 1336 | */ |
| 1337 | if (atomic_read(&lo->lo_refcnt) > 1) { |
| 1338 | lo->lo_flags |= LO_FLAGS_AUTOCLEAR; |
| 1339 | mutex_unlock(&loop_ctl_mutex); |
| 1340 | return 0; |
| 1341 | } |
| 1342 | lo->lo_state = Lo_rundown; |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1343 | mutex_unlock(&loop_ctl_mutex); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1344 | |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1345 | return __loop_clr_fd(lo, false); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1346 | } |
| 1347 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | static int |
| 1349 | loop_set_status(struct loop_device *lo, const struct loop_info64 *info) |
| 1350 | { |
| 1351 | int err; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1352 | struct block_device *bdev; |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1353 | kuid_t uid = current_uid(); |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1354 | int prev_lo_flags; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1355 | bool partscan = false; |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1356 | bool size_changed = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | |
Jan Kara | c28445f | 2018-11-08 14:01:16 +0100 | [diff] [blame] | 1358 | err = mutex_lock_killable(&loop_ctl_mutex); |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1359 | if (err) |
| 1360 | return err; |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1361 | if (lo->lo_encrypt_key_size && |
Eric W. Biederman | e484973 | 2012-02-11 11:23:51 -0800 | [diff] [blame] | 1362 | !uid_eq(lo->lo_key_owner, uid) && |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1363 | !capable(CAP_SYS_ADMIN)) { |
| 1364 | err = -EPERM; |
| 1365 | goto out_unlock; |
| 1366 | } |
| 1367 | if (lo->lo_state != Lo_bound) { |
| 1368 | err = -ENXIO; |
| 1369 | goto out_unlock; |
| 1370 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1371 | |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1372 | if (lo->lo_offset != info->lo_offset || |
| 1373 | lo->lo_sizelimit != info->lo_sizelimit) { |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1374 | size_changed = true; |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1375 | sync_blockdev(lo->lo_device); |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1376 | invalidate_bdev(lo->lo_device); |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1377 | } |
| 1378 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1379 | /* I/O need to be drained during transfer transition */ |
| 1380 | blk_mq_freeze_queue(lo->lo_queue); |
| 1381 | |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1382 | if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1383 | /* If any pages were dirtied after invalidate_bdev(), try again */ |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1384 | err = -EAGAIN; |
| 1385 | pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", |
| 1386 | __func__, lo->lo_number, lo->lo_file_name, |
| 1387 | lo->lo_device->bd_inode->i_mapping->nrpages); |
| 1388 | goto out_unfreeze; |
| 1389 | } |
| 1390 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1391 | prev_lo_flags = lo->lo_flags; |
| 1392 | |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1393 | err = loop_set_status_from_info(lo, info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | if (err) |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1395 | goto out_unfreeze; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1397 | /* Mask out flags that can't be set using LOOP_SET_STATUS. */ |
Martijn Coenen | 6ac92fb | 2020-06-04 22:25:20 +0200 | [diff] [blame] | 1398 | lo->lo_flags &= LOOP_SET_STATUS_SETTABLE_FLAGS; |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1399 | /* For those flags, use the previous values instead */ |
| 1400 | lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS; |
| 1401 | /* For flags that can't be cleared, use previous values too */ |
| 1402 | lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_CLEARABLE_FLAGS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1403 | |
Martijn Coenen | b0bd158 | 2020-05-13 15:38:39 +0200 | [diff] [blame] | 1404 | if (size_changed) { |
| 1405 | loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit, |
| 1406 | lo->lo_backing_file); |
| 1407 | loop_set_size(lo, new_size); |
Arnd Bergmann | b040ad9 | 2017-06-09 12:19:18 +0200 | [diff] [blame] | 1408 | } |
Guo Chao | 541c742 | 2013-02-21 15:16:46 -0800 | [diff] [blame] | 1409 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 1410 | loop_config_discard(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1411 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 1412 | /* update dio if lo_offset or transfer is changed */ |
| 1413 | __loop_update_dio(lo, lo->use_dio); |
| 1414 | |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1415 | out_unfreeze: |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1416 | blk_mq_unfreeze_queue(lo->lo_queue); |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1417 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1418 | if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) && |
| 1419 | !(prev_lo_flags & LO_FLAGS_PARTSCAN)) { |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1420 | lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1421 | bdev = lo->lo_device; |
| 1422 | partscan = true; |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1423 | } |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1424 | out_unlock: |
| 1425 | mutex_unlock(&loop_ctl_mutex); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1426 | if (partscan) |
| 1427 | loop_reread_partitions(lo, bdev); |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1428 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1429 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | } |
| 1431 | |
| 1432 | static int |
| 1433 | loop_get_status(struct loop_device *lo, struct loop_info64 *info) |
| 1434 | { |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1435 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | struct kstat stat; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1437 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | |
Jan Kara | c28445f | 2018-11-08 14:01:16 +0100 | [diff] [blame] | 1439 | ret = mutex_lock_killable(&loop_ctl_mutex); |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1440 | if (ret) |
| 1441 | return ret; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1442 | if (lo->lo_state != Lo_bound) { |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1443 | mutex_unlock(&loop_ctl_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | return -ENXIO; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1445 | } |
| 1446 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1447 | memset(info, 0, sizeof(*info)); |
| 1448 | info->lo_number = lo->lo_number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | info->lo_offset = lo->lo_offset; |
| 1450 | info->lo_sizelimit = lo->lo_sizelimit; |
| 1451 | info->lo_flags = lo->lo_flags; |
| 1452 | memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); |
| 1453 | memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); |
| 1454 | info->lo_encrypt_type = |
| 1455 | lo->lo_encryption ? lo->lo_encryption->number : 0; |
| 1456 | if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { |
| 1457 | info->lo_encrypt_key_size = lo->lo_encrypt_key_size; |
| 1458 | memcpy(info->lo_encrypt_key, lo->lo_encrypt_key, |
| 1459 | lo->lo_encrypt_key_size); |
| 1460 | } |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1461 | |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1462 | /* Drop loop_ctl_mutex while we call into the filesystem. */ |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1463 | path = lo->lo_backing_file->f_path; |
| 1464 | path_get(&path); |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1465 | mutex_unlock(&loop_ctl_mutex); |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1466 | ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT); |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1467 | if (!ret) { |
| 1468 | info->lo_device = huge_encode_dev(stat.dev); |
| 1469 | info->lo_inode = stat.ino; |
| 1470 | info->lo_rdevice = huge_encode_dev(stat.rdev); |
| 1471 | } |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1472 | path_put(&path); |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1473 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | } |
| 1475 | |
| 1476 | static void |
| 1477 | loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) |
| 1478 | { |
| 1479 | memset(info64, 0, sizeof(*info64)); |
| 1480 | info64->lo_number = info->lo_number; |
| 1481 | info64->lo_device = info->lo_device; |
| 1482 | info64->lo_inode = info->lo_inode; |
| 1483 | info64->lo_rdevice = info->lo_rdevice; |
| 1484 | info64->lo_offset = info->lo_offset; |
| 1485 | info64->lo_sizelimit = 0; |
| 1486 | info64->lo_encrypt_type = info->lo_encrypt_type; |
| 1487 | info64->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1488 | info64->lo_flags = info->lo_flags; |
| 1489 | info64->lo_init[0] = info->lo_init[0]; |
| 1490 | info64->lo_init[1] = info->lo_init[1]; |
| 1491 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1492 | memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE); |
| 1493 | else |
| 1494 | memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); |
| 1495 | memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE); |
| 1496 | } |
| 1497 | |
| 1498 | static int |
| 1499 | loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) |
| 1500 | { |
| 1501 | memset(info, 0, sizeof(*info)); |
| 1502 | info->lo_number = info64->lo_number; |
| 1503 | info->lo_device = info64->lo_device; |
| 1504 | info->lo_inode = info64->lo_inode; |
| 1505 | info->lo_rdevice = info64->lo_rdevice; |
| 1506 | info->lo_offset = info64->lo_offset; |
| 1507 | info->lo_encrypt_type = info64->lo_encrypt_type; |
| 1508 | info->lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1509 | info->lo_flags = info64->lo_flags; |
| 1510 | info->lo_init[0] = info64->lo_init[0]; |
| 1511 | info->lo_init[1] = info64->lo_init[1]; |
| 1512 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1513 | memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1514 | else |
| 1515 | memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1516 | memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1517 | |
| 1518 | /* error in case values were truncated */ |
| 1519 | if (info->lo_device != info64->lo_device || |
| 1520 | info->lo_rdevice != info64->lo_rdevice || |
| 1521 | info->lo_inode != info64->lo_inode || |
| 1522 | info->lo_offset != info64->lo_offset) |
| 1523 | return -EOVERFLOW; |
| 1524 | |
| 1525 | return 0; |
| 1526 | } |
| 1527 | |
| 1528 | static int |
| 1529 | loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) |
| 1530 | { |
| 1531 | struct loop_info info; |
| 1532 | struct loop_info64 info64; |
| 1533 | |
| 1534 | if (copy_from_user(&info, arg, sizeof (struct loop_info))) |
| 1535 | return -EFAULT; |
| 1536 | loop_info64_from_old(&info, &info64); |
| 1537 | return loop_set_status(lo, &info64); |
| 1538 | } |
| 1539 | |
| 1540 | static int |
| 1541 | loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) |
| 1542 | { |
| 1543 | struct loop_info64 info64; |
| 1544 | |
| 1545 | if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) |
| 1546 | return -EFAULT; |
| 1547 | return loop_set_status(lo, &info64); |
| 1548 | } |
| 1549 | |
| 1550 | static int |
| 1551 | loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { |
| 1552 | struct loop_info info; |
| 1553 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1554 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1556 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1557 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1558 | err = loop_get_status(lo, &info64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | if (!err) |
| 1560 | err = loop_info64_to_old(&info64, &info); |
| 1561 | if (!err && copy_to_user(arg, &info, sizeof(info))) |
| 1562 | err = -EFAULT; |
| 1563 | |
| 1564 | return err; |
| 1565 | } |
| 1566 | |
| 1567 | static int |
| 1568 | loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { |
| 1569 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1570 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1571 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1572 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1573 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1574 | err = loop_get_status(lo, &info64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | if (!err && copy_to_user(arg, &info64, sizeof(info64))) |
| 1576 | err = -EFAULT; |
| 1577 | |
| 1578 | return err; |
| 1579 | } |
| 1580 | |
Hannes Reinecke | 51001b7 | 2017-06-08 13:46:44 +0200 | [diff] [blame] | 1581 | static int loop_set_capacity(struct loop_device *lo) |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1582 | { |
Martijn Coenen | 0a6ed1b | 2020-05-13 15:38:40 +0200 | [diff] [blame] | 1583 | loff_t size; |
| 1584 | |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1585 | if (unlikely(lo->lo_state != Lo_bound)) |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 1586 | return -ENXIO; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1587 | |
Martijn Coenen | 0a6ed1b | 2020-05-13 15:38:40 +0200 | [diff] [blame] | 1588 | size = get_loop_size(lo, lo->lo_backing_file); |
| 1589 | loop_set_size(lo, size); |
Martijn Coenen | 083a6a5 | 2020-05-13 15:38:36 +0200 | [diff] [blame] | 1590 | |
| 1591 | return 0; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1592 | } |
| 1593 | |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1594 | static int loop_set_dio(struct loop_device *lo, unsigned long arg) |
| 1595 | { |
| 1596 | int error = -ENXIO; |
| 1597 | if (lo->lo_state != Lo_bound) |
| 1598 | goto out; |
| 1599 | |
| 1600 | __loop_update_dio(lo, !!arg); |
| 1601 | if (lo->use_dio == !!arg) |
| 1602 | return 0; |
| 1603 | error = -EINVAL; |
| 1604 | out: |
| 1605 | return error; |
| 1606 | } |
| 1607 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1608 | static int loop_set_block_size(struct loop_device *lo, unsigned long arg) |
| 1609 | { |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1610 | int err = 0; |
| 1611 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1612 | if (lo->lo_state != Lo_bound) |
| 1613 | return -ENXIO; |
| 1614 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1615 | err = loop_validate_block_size(arg); |
| 1616 | if (err) |
| 1617 | return err; |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1618 | |
Martijn Coenen | 7e81f99 | 2020-03-10 14:12:30 +0100 | [diff] [blame] | 1619 | if (lo->lo_queue->limits.logical_block_size == arg) |
| 1620 | return 0; |
| 1621 | |
| 1622 | sync_blockdev(lo->lo_device); |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1623 | invalidate_bdev(lo->lo_device); |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1624 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1625 | blk_mq_freeze_queue(lo->lo_queue); |
| 1626 | |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1627 | /* invalidate_bdev should have truncated all the pages */ |
Martijn Coenen | 7e81f99 | 2020-03-10 14:12:30 +0100 | [diff] [blame] | 1628 | if (lo->lo_device->bd_inode->i_mapping->nrpages) { |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1629 | err = -EAGAIN; |
| 1630 | pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", |
| 1631 | __func__, lo->lo_number, lo->lo_file_name, |
| 1632 | lo->lo_device->bd_inode->i_mapping->nrpages); |
| 1633 | goto out_unfreeze; |
| 1634 | } |
| 1635 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1636 | blk_queue_logical_block_size(lo->lo_queue, arg); |
Omar Sandoval | bf09375 | 2017-09-05 14:24:47 -0700 | [diff] [blame] | 1637 | blk_queue_physical_block_size(lo->lo_queue, arg); |
| 1638 | blk_queue_io_min(lo->lo_queue, arg); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1639 | loop_update_dio(lo); |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1640 | out_unfreeze: |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1641 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 1642 | |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1643 | return err; |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1644 | } |
| 1645 | |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1646 | static int lo_simple_ioctl(struct loop_device *lo, unsigned int cmd, |
| 1647 | unsigned long arg) |
| 1648 | { |
| 1649 | int err; |
| 1650 | |
Jan Kara | c28445f | 2018-11-08 14:01:16 +0100 | [diff] [blame] | 1651 | err = mutex_lock_killable(&loop_ctl_mutex); |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1652 | if (err) |
| 1653 | return err; |
| 1654 | switch (cmd) { |
| 1655 | case LOOP_SET_CAPACITY: |
| 1656 | err = loop_set_capacity(lo); |
| 1657 | break; |
| 1658 | case LOOP_SET_DIRECT_IO: |
| 1659 | err = loop_set_dio(lo, arg); |
| 1660 | break; |
| 1661 | case LOOP_SET_BLOCK_SIZE: |
| 1662 | err = loop_set_block_size(lo, arg); |
| 1663 | break; |
| 1664 | default: |
| 1665 | err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; |
| 1666 | } |
| 1667 | mutex_unlock(&loop_ctl_mutex); |
| 1668 | return err; |
| 1669 | } |
| 1670 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1671 | static int lo_ioctl(struct block_device *bdev, fmode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1672 | unsigned int cmd, unsigned long arg) |
| 1673 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1674 | struct loop_device *lo = bdev->bd_disk->private_data; |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1675 | void __user *argp = (void __user *) arg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | int err; |
| 1677 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | switch (cmd) { |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1679 | case LOOP_SET_FD: { |
| 1680 | /* |
| 1681 | * Legacy case - pass in a zeroed out struct loop_config with |
| 1682 | * only the file descriptor set , which corresponds with the |
| 1683 | * default parameters we'd have used otherwise. |
| 1684 | */ |
| 1685 | struct loop_config config; |
| 1686 | |
| 1687 | memset(&config, 0, sizeof(config)); |
| 1688 | config.fd = arg; |
| 1689 | |
| 1690 | return loop_configure(lo, mode, bdev, &config); |
| 1691 | } |
| 1692 | case LOOP_CONFIGURE: { |
| 1693 | struct loop_config config; |
| 1694 | |
| 1695 | if (copy_from_user(&config, argp, sizeof(config))) |
| 1696 | return -EFAULT; |
| 1697 | |
| 1698 | return loop_configure(lo, mode, bdev, &config); |
| 1699 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1700 | case LOOP_CHANGE_FD: |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 1701 | return loop_change_fd(lo, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1702 | case LOOP_CLR_FD: |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1703 | return loop_clr_fd(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1704 | case LOOP_SET_STATUS: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1705 | err = -EPERM; |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1706 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1707 | err = loop_set_status_old(lo, argp); |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1708 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1709 | break; |
| 1710 | case LOOP_GET_STATUS: |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1711 | return loop_get_status_old(lo, argp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1712 | case LOOP_SET_STATUS64: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1713 | err = -EPERM; |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1714 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1715 | err = loop_set_status64(lo, argp); |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1716 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1717 | break; |
| 1718 | case LOOP_GET_STATUS64: |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1719 | return loop_get_status64(lo, argp); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1720 | case LOOP_SET_CAPACITY: |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1721 | case LOOP_SET_DIRECT_IO: |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1722 | case LOOP_SET_BLOCK_SIZE: |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1723 | if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) |
| 1724 | return -EPERM; |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1725 | fallthrough; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | default: |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1727 | err = lo_simple_ioctl(lo, cmd, arg); |
| 1728 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1729 | } |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1730 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1731 | return err; |
| 1732 | } |
| 1733 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1734 | #ifdef CONFIG_COMPAT |
| 1735 | struct compat_loop_info { |
| 1736 | compat_int_t lo_number; /* ioctl r/o */ |
| 1737 | compat_dev_t lo_device; /* ioctl r/o */ |
| 1738 | compat_ulong_t lo_inode; /* ioctl r/o */ |
| 1739 | compat_dev_t lo_rdevice; /* ioctl r/o */ |
| 1740 | compat_int_t lo_offset; |
| 1741 | compat_int_t lo_encrypt_type; |
| 1742 | compat_int_t lo_encrypt_key_size; /* ioctl w/o */ |
| 1743 | compat_int_t lo_flags; /* ioctl r/o */ |
| 1744 | char lo_name[LO_NAME_SIZE]; |
| 1745 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ |
| 1746 | compat_ulong_t lo_init[2]; |
| 1747 | char reserved[4]; |
| 1748 | }; |
| 1749 | |
| 1750 | /* |
| 1751 | * Transfer 32-bit compatibility structure in userspace to 64-bit loop info |
| 1752 | * - noinlined to reduce stack space usage in main part of driver |
| 1753 | */ |
| 1754 | static noinline int |
Al Viro | ba674cf | 2006-10-10 22:48:27 +0100 | [diff] [blame] | 1755 | loop_info64_from_compat(const struct compat_loop_info __user *arg, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1756 | struct loop_info64 *info64) |
| 1757 | { |
| 1758 | struct compat_loop_info info; |
| 1759 | |
| 1760 | if (copy_from_user(&info, arg, sizeof(info))) |
| 1761 | return -EFAULT; |
| 1762 | |
| 1763 | memset(info64, 0, sizeof(*info64)); |
| 1764 | info64->lo_number = info.lo_number; |
| 1765 | info64->lo_device = info.lo_device; |
| 1766 | info64->lo_inode = info.lo_inode; |
| 1767 | info64->lo_rdevice = info.lo_rdevice; |
| 1768 | info64->lo_offset = info.lo_offset; |
| 1769 | info64->lo_sizelimit = 0; |
| 1770 | info64->lo_encrypt_type = info.lo_encrypt_type; |
| 1771 | info64->lo_encrypt_key_size = info.lo_encrypt_key_size; |
| 1772 | info64->lo_flags = info.lo_flags; |
| 1773 | info64->lo_init[0] = info.lo_init[0]; |
| 1774 | info64->lo_init[1] = info.lo_init[1]; |
| 1775 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1776 | memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE); |
| 1777 | else |
| 1778 | memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); |
| 1779 | memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE); |
| 1780 | return 0; |
| 1781 | } |
| 1782 | |
| 1783 | /* |
| 1784 | * Transfer 64-bit loop info to 32-bit compatibility structure in userspace |
| 1785 | * - noinlined to reduce stack space usage in main part of driver |
| 1786 | */ |
| 1787 | static noinline int |
| 1788 | loop_info64_to_compat(const struct loop_info64 *info64, |
| 1789 | struct compat_loop_info __user *arg) |
| 1790 | { |
| 1791 | struct compat_loop_info info; |
| 1792 | |
| 1793 | memset(&info, 0, sizeof(info)); |
| 1794 | info.lo_number = info64->lo_number; |
| 1795 | info.lo_device = info64->lo_device; |
| 1796 | info.lo_inode = info64->lo_inode; |
| 1797 | info.lo_rdevice = info64->lo_rdevice; |
| 1798 | info.lo_offset = info64->lo_offset; |
| 1799 | info.lo_encrypt_type = info64->lo_encrypt_type; |
| 1800 | info.lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1801 | info.lo_flags = info64->lo_flags; |
| 1802 | info.lo_init[0] = info64->lo_init[0]; |
| 1803 | info.lo_init[1] = info64->lo_init[1]; |
| 1804 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1805 | memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1806 | else |
| 1807 | memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1808 | memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1809 | |
| 1810 | /* error in case values were truncated */ |
| 1811 | if (info.lo_device != info64->lo_device || |
| 1812 | info.lo_rdevice != info64->lo_rdevice || |
| 1813 | info.lo_inode != info64->lo_inode || |
| 1814 | info.lo_offset != info64->lo_offset || |
| 1815 | info.lo_init[0] != info64->lo_init[0] || |
| 1816 | info.lo_init[1] != info64->lo_init[1]) |
| 1817 | return -EOVERFLOW; |
| 1818 | |
| 1819 | if (copy_to_user(arg, &info, sizeof(info))) |
| 1820 | return -EFAULT; |
| 1821 | return 0; |
| 1822 | } |
| 1823 | |
| 1824 | static int |
| 1825 | loop_set_status_compat(struct loop_device *lo, |
| 1826 | const struct compat_loop_info __user *arg) |
| 1827 | { |
| 1828 | struct loop_info64 info64; |
| 1829 | int ret; |
| 1830 | |
| 1831 | ret = loop_info64_from_compat(arg, &info64); |
| 1832 | if (ret < 0) |
| 1833 | return ret; |
| 1834 | return loop_set_status(lo, &info64); |
| 1835 | } |
| 1836 | |
| 1837 | static int |
| 1838 | loop_get_status_compat(struct loop_device *lo, |
| 1839 | struct compat_loop_info __user *arg) |
| 1840 | { |
| 1841 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1842 | int err; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1843 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1844 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1845 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1846 | err = loop_get_status(lo, &info64); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1847 | if (!err) |
| 1848 | err = loop_info64_to_compat(&info64, arg); |
| 1849 | return err; |
| 1850 | } |
| 1851 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1852 | static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, |
| 1853 | unsigned int cmd, unsigned long arg) |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1854 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1855 | struct loop_device *lo = bdev->bd_disk->private_data; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1856 | int err; |
| 1857 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1858 | switch(cmd) { |
| 1859 | case LOOP_SET_STATUS: |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1860 | err = loop_set_status_compat(lo, |
| 1861 | (const struct compat_loop_info __user *)arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1862 | break; |
| 1863 | case LOOP_GET_STATUS: |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1864 | err = loop_get_status_compat(lo, |
| 1865 | (struct compat_loop_info __user *)arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1866 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1867 | case LOOP_SET_CAPACITY: |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1868 | case LOOP_CLR_FD: |
| 1869 | case LOOP_GET_STATUS64: |
| 1870 | case LOOP_SET_STATUS64: |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1871 | case LOOP_CONFIGURE: |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1872 | arg = (unsigned long) compat_ptr(arg); |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1873 | fallthrough; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1874 | case LOOP_SET_FD: |
| 1875 | case LOOP_CHANGE_FD: |
Evan Green | 9fea4b3 | 2018-07-02 16:03:46 -0700 | [diff] [blame] | 1876 | case LOOP_SET_BLOCK_SIZE: |
Alessio Balsini | fdbe4ee | 2019-08-07 01:48:28 +0100 | [diff] [blame] | 1877 | case LOOP_SET_DIRECT_IO: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1878 | err = lo_ioctl(bdev, mode, cmd, arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1879 | break; |
| 1880 | default: |
| 1881 | err = -ENOIOCTLCMD; |
| 1882 | break; |
| 1883 | } |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1884 | return err; |
| 1885 | } |
| 1886 | #endif |
| 1887 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1888 | static int lo_open(struct block_device *bdev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1889 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1890 | struct loop_device *lo; |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1891 | int err; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1892 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1893 | err = mutex_lock_killable(&loop_ctl_mutex); |
| 1894 | if (err) |
| 1895 | return err; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1896 | lo = bdev->bd_disk->private_data; |
| 1897 | if (!lo) { |
| 1898 | err = -ENXIO; |
| 1899 | goto out; |
| 1900 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1901 | |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1902 | atomic_inc(&lo->lo_refcnt); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1903 | out: |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1904 | mutex_unlock(&loop_ctl_mutex); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1905 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1906 | } |
| 1907 | |
Jan Kara | 967d1dc | 2018-11-08 14:01:03 +0100 | [diff] [blame] | 1908 | static void lo_release(struct gendisk *disk, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1909 | { |
Jan Kara | 967d1dc | 2018-11-08 14:01:03 +0100 | [diff] [blame] | 1910 | struct loop_device *lo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1911 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1912 | mutex_lock(&loop_ctl_mutex); |
Jan Kara | 967d1dc | 2018-11-08 14:01:03 +0100 | [diff] [blame] | 1913 | lo = disk->private_data; |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1914 | if (atomic_dec_return(&lo->lo_refcnt)) |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1915 | goto out_unlock; |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1916 | |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1917 | if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1918 | if (lo->lo_state != Lo_bound) |
| 1919 | goto out_unlock; |
| 1920 | lo->lo_state = Lo_rundown; |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1921 | mutex_unlock(&loop_ctl_mutex); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1922 | /* |
| 1923 | * In autoclear mode, stop the loop thread |
| 1924 | * and remove configuration after last close. |
| 1925 | */ |
Jan Kara | 0da03ca | 2018-11-08 14:01:14 +0100 | [diff] [blame] | 1926 | __loop_clr_fd(lo, true); |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1927 | return; |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame] | 1928 | } else if (lo->lo_state == Lo_bound) { |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1929 | /* |
| 1930 | * Otherwise keep thread (if running) and config, |
| 1931 | * but flush possible ongoing bios in thread. |
| 1932 | */ |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame] | 1933 | blk_mq_freeze_queue(lo->lo_queue); |
| 1934 | blk_mq_unfreeze_queue(lo->lo_queue); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1935 | } |
David Woodhouse | 96c5865 | 2008-02-06 01:36:27 -0800 | [diff] [blame] | 1936 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 1937 | out_unlock: |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1938 | mutex_unlock(&loop_ctl_mutex); |
Linus Torvalds | ae66501 | 2018-01-05 16:26:00 -0800 | [diff] [blame] | 1939 | } |
| 1940 | |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1941 | static const struct block_device_operations lo_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | .owner = THIS_MODULE, |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1943 | .open = lo_open, |
| 1944 | .release = lo_release, |
| 1945 | .ioctl = lo_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1946 | #ifdef CONFIG_COMPAT |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1947 | .compat_ioctl = lo_compat_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1948 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1949 | }; |
| 1950 | |
| 1951 | /* |
| 1952 | * And now the modules code and kernel interface. |
| 1953 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1954 | static int max_loop; |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 1955 | module_param(max_loop, int, 0444); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1956 | MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 1957 | module_param(max_part, int, 0444); |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1958 | MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | MODULE_LICENSE("GPL"); |
| 1960 | MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); |
| 1961 | |
| 1962 | int loop_register_transfer(struct loop_func_table *funcs) |
| 1963 | { |
| 1964 | unsigned int n = funcs->number; |
| 1965 | |
| 1966 | if (n >= MAX_LO_CRYPT || xfer_funcs[n]) |
| 1967 | return -EINVAL; |
| 1968 | xfer_funcs[n] = funcs; |
| 1969 | return 0; |
| 1970 | } |
| 1971 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1972 | static int unregister_transfer_cb(int id, void *ptr, void *data) |
| 1973 | { |
| 1974 | struct loop_device *lo = ptr; |
| 1975 | struct loop_func_table *xfer = data; |
| 1976 | |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1977 | mutex_lock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1978 | if (lo->lo_encryption == xfer) |
| 1979 | loop_release_xfer(lo); |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 1980 | mutex_unlock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1981 | return 0; |
| 1982 | } |
| 1983 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1984 | int loop_unregister_transfer(int number) |
| 1985 | { |
| 1986 | unsigned int n = number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1987 | struct loop_func_table *xfer; |
| 1988 | |
| 1989 | if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL) |
| 1990 | return -EINVAL; |
| 1991 | |
| 1992 | xfer_funcs[n] = NULL; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1993 | idr_for_each(&loop_index_idr, &unregister_transfer_cb, xfer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1994 | return 0; |
| 1995 | } |
| 1996 | |
| 1997 | EXPORT_SYMBOL(loop_register_transfer); |
| 1998 | EXPORT_SYMBOL(loop_unregister_transfer); |
| 1999 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 2000 | static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2001 | const struct blk_mq_queue_data *bd) |
| 2002 | { |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 2003 | struct request *rq = bd->rq; |
| 2004 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
| 2005 | struct loop_device *lo = rq->q->queuedata; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2006 | |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 2007 | blk_mq_start_request(rq); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2008 | |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 2009 | if (lo->lo_state != Lo_bound) |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 2010 | return BLK_STS_IOERR; |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 2011 | |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 2012 | switch (req_op(rq)) { |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 2013 | case REQ_OP_FLUSH: |
| 2014 | case REQ_OP_DISCARD: |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 2015 | case REQ_OP_WRITE_ZEROES: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 2016 | cmd->use_aio = false; |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 2017 | break; |
| 2018 | default: |
| 2019 | cmd->use_aio = lo->use_dio; |
| 2020 | break; |
| 2021 | } |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 2022 | |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 2023 | /* always use the first bio's css */ |
Shaohua Li | 0b508bc | 2017-09-26 11:02:12 -0700 | [diff] [blame] | 2024 | #ifdef CONFIG_BLK_CGROUP |
Dennis Zhou | db6638d | 2018-12-05 12:10:35 -0500 | [diff] [blame] | 2025 | if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { |
| 2026 | cmd->css = &bio_blkcg(rq->bio)->css; |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 2027 | css_get(cmd->css); |
| 2028 | } else |
| 2029 | #endif |
| 2030 | cmd->css = NULL; |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 2031 | kthread_queue_work(&lo->worker, &cmd->work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2032 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 2033 | return BLK_STS_OK; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2034 | } |
| 2035 | |
| 2036 | static void loop_handle_cmd(struct loop_cmd *cmd) |
| 2037 | { |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 2038 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
| 2039 | const bool write = op_is_write(req_op(rq)); |
| 2040 | struct loop_device *lo = rq->q->queuedata; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 2041 | int ret = 0; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2042 | |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 2043 | if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { |
| 2044 | ret = -EIO; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2045 | goto failed; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 2046 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2047 | |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 2048 | ret = do_req_filebacked(lo, rq); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2049 | failed: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 2050 | /* complete non-aio request */ |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 2051 | if (!cmd->use_aio || ret) { |
Evan Green | 8cd5508 | 2020-04-03 16:43:03 +0200 | [diff] [blame] | 2052 | if (ret == -EOPNOTSUPP) |
| 2053 | cmd->ret = ret; |
| 2054 | else |
| 2055 | cmd->ret = ret ? -EIO : 0; |
Christoph Hellwig | 15f73f5 | 2020-06-11 08:44:47 +0200 | [diff] [blame] | 2056 | if (likely(!blk_should_fake_timeout(rq->q))) |
| 2057 | blk_mq_complete_request(rq); |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 2058 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2059 | } |
| 2060 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 2061 | static void loop_queue_work(struct kthread_work *work) |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2062 | { |
| 2063 | struct loop_cmd *cmd = |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 2064 | container_of(work, struct loop_cmd, work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2065 | |
| 2066 | loop_handle_cmd(cmd); |
| 2067 | } |
| 2068 | |
Christoph Hellwig | d6296d39 | 2017-05-01 10:19:08 -0600 | [diff] [blame] | 2069 | static int loop_init_request(struct blk_mq_tag_set *set, struct request *rq, |
| 2070 | unsigned int hctx_idx, unsigned int numa_node) |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2071 | { |
| 2072 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
| 2073 | |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 2074 | kthread_init_work(&cmd->work, loop_queue_work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2075 | return 0; |
| 2076 | } |
| 2077 | |
Eric Biggers | f363b08 | 2017-03-30 13:39:16 -0700 | [diff] [blame] | 2078 | static const struct blk_mq_ops loop_mq_ops = { |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2079 | .queue_rq = loop_queue_rq, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2080 | .init_request = loop_init_request, |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 2081 | .complete = lo_complete_rq, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2082 | }; |
| 2083 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2084 | static int loop_add(struct loop_device **l, int i) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2085 | { |
| 2086 | struct loop_device *lo; |
| 2087 | struct gendisk *disk; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2088 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2089 | |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 2090 | err = -ENOMEM; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2091 | lo = kzalloc(sizeof(*lo), GFP_KERNEL); |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 2092 | if (!lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2093 | goto out; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2094 | |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 2095 | lo->lo_state = Lo_unbound; |
| 2096 | |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 2097 | /* allocate id, if @id >= 0, we're requesting that specific id */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2098 | if (i >= 0) { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 2099 | err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL); |
| 2100 | if (err == -ENOSPC) |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2101 | err = -EEXIST; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2102 | } else { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 2103 | err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2104 | } |
| 2105 | if (err < 0) |
| 2106 | goto out_free_dev; |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 2107 | i = err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2108 | |
Wei Yongjun | 183cfb5 | 2013-03-22 08:59:19 -0600 | [diff] [blame] | 2109 | err = -ENOMEM; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2110 | lo->tag_set.ops = &loop_mq_ops; |
| 2111 | lo->tag_set.nr_hw_queues = 1; |
| 2112 | lo->tag_set.queue_depth = 128; |
| 2113 | lo->tag_set.numa_node = NUMA_NO_NODE; |
| 2114 | lo->tag_set.cmd_size = sizeof(struct loop_cmd); |
Ming Lei | bf0beec | 2020-05-29 15:53:15 +0200 | [diff] [blame] | 2115 | lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2116 | lo->tag_set.driver_data = lo; |
| 2117 | |
| 2118 | err = blk_mq_alloc_tag_set(&lo->tag_set); |
| 2119 | if (err) |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 2120 | goto out_free_idr; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2121 | |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2122 | lo->lo_queue = blk_mq_init_queue(&lo->tag_set); |
Chengguang Xu | 38a3499 | 2018-12-16 17:35:00 +0800 | [diff] [blame] | 2123 | if (IS_ERR(lo->lo_queue)) { |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2124 | err = PTR_ERR(lo->lo_queue); |
| 2125 | goto out_cleanup_tags; |
| 2126 | } |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 2127 | lo->lo_queue->queuedata = lo; |
| 2128 | |
Shaohua Li | 54bb0ad | 2017-08-31 22:09:45 -0700 | [diff] [blame] | 2129 | blk_queue_max_hw_sectors(lo->lo_queue, BLK_DEF_MAX_SECTORS); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 2130 | |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2131 | /* |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 2132 | * By default, we do buffer IO, so it doesn't make sense to enable |
| 2133 | * merge because the I/O submitted to backing file is handled page by |
| 2134 | * page. For directio mode, merge does help to dispatch bigger request |
| 2135 | * to underlayer disk. We will enable merge once directio is enabled. |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2136 | */ |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 2137 | blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2138 | |
Minfei Huang | 7a64973 | 2016-06-07 10:05:15 +0800 | [diff] [blame] | 2139 | err = -ENOMEM; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2140 | disk = lo->lo_disk = alloc_disk(1 << part_shift); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2141 | if (!disk) |
| 2142 | goto out_free_queue; |
| 2143 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 2144 | /* |
| 2145 | * Disable partition scanning by default. The in-kernel partition |
| 2146 | * scanning can be requested individually per-device during its |
| 2147 | * setup. Userspace can always add and remove partitions from all |
| 2148 | * devices. The needed partition minors are allocated from the |
| 2149 | * extended minor space, the main loop device numbers will continue |
| 2150 | * to match the loop minors, regardless of the number of partitions |
| 2151 | * used. |
| 2152 | * |
| 2153 | * If max_part is given, partition scanning is globally enabled for |
| 2154 | * all loop devices. The minors for the main loop devices will be |
| 2155 | * multiples of max_part. |
| 2156 | * |
| 2157 | * Note: Global-for-all-devices, set-only-at-init, read-only module |
| 2158 | * parameteters like 'max_loop' and 'max_part' make things needlessly |
| 2159 | * complicated, are too static, inflexible and may surprise |
| 2160 | * userspace tools. Parameters like this in general should be avoided. |
| 2161 | */ |
| 2162 | if (!part_shift) |
| 2163 | disk->flags |= GENHD_FL_NO_PART_SCAN; |
| 2164 | disk->flags |= GENHD_FL_EXT_DEVT; |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 2165 | atomic_set(&lo->lo_refcnt, 0); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2166 | lo->lo_number = i; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2167 | spin_lock_init(&lo->lo_lock); |
| 2168 | disk->major = LOOP_MAJOR; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2169 | disk->first_minor = i << part_shift; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2170 | disk->fops = &lo_fops; |
| 2171 | disk->private_data = lo; |
| 2172 | disk->queue = lo->lo_queue; |
| 2173 | sprintf(disk->disk_name, "loop%d", i); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2174 | add_disk(disk); |
| 2175 | *l = lo; |
| 2176 | return lo->lo_number; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2177 | |
| 2178 | out_free_queue: |
| 2179 | blk_cleanup_queue(lo->lo_queue); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2180 | out_cleanup_tags: |
| 2181 | blk_mq_free_tag_set(&lo->tag_set); |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 2182 | out_free_idr: |
| 2183 | idr_remove(&loop_index_idr, i); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2184 | out_free_dev: |
| 2185 | kfree(lo); |
| 2186 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2187 | return err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2188 | } |
| 2189 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2190 | static void loop_remove(struct loop_device *lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2191 | { |
NeilBrown | 6cd18e7 | 2015-04-27 14:12:22 +1000 | [diff] [blame] | 2192 | del_gendisk(lo->lo_disk); |
Bart Van Assche | 0fa8ebd | 2018-02-28 10:15:28 -0800 | [diff] [blame] | 2193 | blk_cleanup_queue(lo->lo_queue); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2194 | blk_mq_free_tag_set(&lo->tag_set); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2195 | put_disk(lo->lo_disk); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2196 | kfree(lo); |
| 2197 | } |
| 2198 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2199 | static int find_free_cb(int id, void *ptr, void *data) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2200 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2201 | struct loop_device *lo = ptr; |
| 2202 | struct loop_device **l = data; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2203 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2204 | if (lo->lo_state == Lo_unbound) { |
| 2205 | *l = lo; |
| 2206 | return 1; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2207 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2208 | return 0; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2209 | } |
| 2210 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2211 | static int loop_lookup(struct loop_device **l, int i) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2212 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2213 | struct loop_device *lo; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2214 | int ret = -ENODEV; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2215 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2216 | if (i < 0) { |
| 2217 | int err; |
| 2218 | |
| 2219 | err = idr_for_each(&loop_index_idr, &find_free_cb, &lo); |
| 2220 | if (err == 1) { |
| 2221 | *l = lo; |
| 2222 | ret = lo->lo_number; |
| 2223 | } |
| 2224 | goto out; |
| 2225 | } |
| 2226 | |
| 2227 | /* lookup and return a specific i */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2228 | lo = idr_find(&loop_index_idr, i); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2229 | if (lo) { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2230 | *l = lo; |
| 2231 | ret = lo->lo_number; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2232 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2233 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2234 | return ret; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2235 | } |
| 2236 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2237 | static struct kobject *loop_probe(dev_t dev, int *part, void *data) |
| 2238 | { |
Al Viro | 705962c | 2007-05-13 05:52:32 -0400 | [diff] [blame] | 2239 | struct loop_device *lo; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 2240 | struct kobject *kobj; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2241 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2242 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2243 | mutex_lock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2244 | err = loop_lookup(&lo, MINOR(dev) >> part_shift); |
| 2245 | if (err < 0) |
| 2246 | err = loop_add(&lo, MINOR(dev) >> part_shift); |
| 2247 | if (err < 0) |
Mikulas Patocka | a207f59 | 2013-10-14 12:13:24 -0400 | [diff] [blame] | 2248 | kobj = NULL; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2249 | else |
Jan Kara | 3079c22 | 2018-02-26 13:01:38 +0100 | [diff] [blame] | 2250 | kobj = get_disk_and_module(lo->lo_disk); |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2251 | mutex_unlock(&loop_ctl_mutex); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2252 | |
| 2253 | *part = 0; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 2254 | return kobj; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2255 | } |
| 2256 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2257 | static long loop_control_ioctl(struct file *file, unsigned int cmd, |
| 2258 | unsigned long parm) |
| 2259 | { |
| 2260 | struct loop_device *lo; |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2261 | int ret; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2262 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2263 | ret = mutex_lock_killable(&loop_ctl_mutex); |
| 2264 | if (ret) |
| 2265 | return ret; |
| 2266 | |
| 2267 | ret = -ENOSYS; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2268 | switch (cmd) { |
| 2269 | case LOOP_CTL_ADD: |
| 2270 | ret = loop_lookup(&lo, parm); |
| 2271 | if (ret >= 0) { |
| 2272 | ret = -EEXIST; |
| 2273 | break; |
| 2274 | } |
| 2275 | ret = loop_add(&lo, parm); |
| 2276 | break; |
| 2277 | case LOOP_CTL_REMOVE: |
| 2278 | ret = loop_lookup(&lo, parm); |
| 2279 | if (ret < 0) |
| 2280 | break; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2281 | if (lo->lo_state != Lo_unbound) { |
| 2282 | ret = -EBUSY; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2283 | break; |
| 2284 | } |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 2285 | if (atomic_read(&lo->lo_refcnt) > 0) { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2286 | ret = -EBUSY; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2287 | break; |
| 2288 | } |
| 2289 | lo->lo_disk->private_data = NULL; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2290 | idr_remove(&loop_index_idr, lo->lo_number); |
| 2291 | loop_remove(lo); |
| 2292 | break; |
| 2293 | case LOOP_CTL_GET_FREE: |
| 2294 | ret = loop_lookup(&lo, -1); |
| 2295 | if (ret >= 0) |
| 2296 | break; |
| 2297 | ret = loop_add(&lo, -1); |
| 2298 | } |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2299 | mutex_unlock(&loop_ctl_mutex); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2300 | |
| 2301 | return ret; |
| 2302 | } |
| 2303 | |
| 2304 | static const struct file_operations loop_ctl_fops = { |
| 2305 | .open = nonseekable_open, |
| 2306 | .unlocked_ioctl = loop_control_ioctl, |
| 2307 | .compat_ioctl = loop_control_ioctl, |
| 2308 | .owner = THIS_MODULE, |
| 2309 | .llseek = noop_llseek, |
| 2310 | }; |
| 2311 | |
| 2312 | static struct miscdevice loop_misc = { |
| 2313 | .minor = LOOP_CTRL_MINOR, |
| 2314 | .name = "loop-control", |
| 2315 | .fops = &loop_ctl_fops, |
| 2316 | }; |
| 2317 | |
| 2318 | MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); |
| 2319 | MODULE_ALIAS("devname:loop-control"); |
| 2320 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2321 | static int __init loop_init(void) |
| 2322 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2323 | int i, nr; |
| 2324 | unsigned long range; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2325 | struct loop_device *lo; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2326 | int err; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2327 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2328 | part_shift = 0; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 2329 | if (max_part > 0) { |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2330 | part_shift = fls(max_part); |
| 2331 | |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 2332 | /* |
| 2333 | * Adjust max_part according to part_shift as it is exported |
| 2334 | * to user space so that user can decide correct minor number |
| 2335 | * if [s]he want to create more devices. |
| 2336 | * |
| 2337 | * Note that -1 is required because partition 0 is reserved |
| 2338 | * for the whole disk. |
| 2339 | */ |
| 2340 | max_part = (1UL << part_shift) - 1; |
| 2341 | } |
| 2342 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2343 | if ((1UL << part_shift) > DISK_MAX_PARTS) { |
| 2344 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2345 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2346 | } |
Namhyung Kim | 78f4bb3 | 2011-05-24 16:48:54 +0200 | [diff] [blame] | 2347 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2348 | if (max_loop > 1UL << (MINORBITS - part_shift)) { |
| 2349 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2350 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2351 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2352 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2353 | /* |
| 2354 | * If max_loop is specified, create that many devices upfront. |
| 2355 | * This also becomes a hard limit. If max_loop is not specified, |
| 2356 | * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module |
| 2357 | * init time. Loop devices can be requested on-demand with the |
| 2358 | * /dev/loop-control interface, or be instantiated by accessing |
| 2359 | * a 'dead' device node. |
| 2360 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2361 | if (max_loop) { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2362 | nr = max_loop; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 2363 | range = max_loop << part_shift; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2364 | } else { |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2365 | nr = CONFIG_BLK_DEV_LOOP_MIN_COUNT; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 2366 | range = 1UL << MINORBITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2367 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2368 | |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2369 | err = misc_register(&loop_misc); |
| 2370 | if (err < 0) |
| 2371 | goto err_out; |
| 2372 | |
| 2373 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2374 | if (register_blkdev(LOOP_MAJOR, "loop")) { |
| 2375 | err = -EIO; |
| 2376 | goto misc_out; |
| 2377 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2378 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2379 | blk_register_region(MKDEV(LOOP_MAJOR, 0), range, |
| 2380 | THIS_MODULE, loop_probe, NULL, NULL); |
| 2381 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2382 | /* pre-create number of devices given by config or max_loop */ |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2383 | mutex_lock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2384 | for (i = 0; i < nr; i++) |
| 2385 | loop_add(&lo, i); |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2386 | mutex_unlock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2387 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2388 | printk(KERN_INFO "loop: module loaded\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2389 | return 0; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2390 | |
| 2391 | misc_out: |
| 2392 | misc_deregister(&loop_misc); |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2393 | err_out: |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2394 | return err; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2395 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2396 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2397 | static int loop_exit_cb(int id, void *ptr, void *data) |
| 2398 | { |
| 2399 | struct loop_device *lo = ptr; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2400 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2401 | loop_remove(lo); |
| 2402 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2403 | } |
| 2404 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2405 | static void __exit loop_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2406 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2407 | unsigned long range; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2408 | |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 2409 | range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2410 | |
Luis Chamberlain | 200f933 | 2020-06-19 20:47:27 +0000 | [diff] [blame] | 2411 | mutex_lock(&loop_ctl_mutex); |
| 2412 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2413 | idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2414 | idr_destroy(&loop_index_idr); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2415 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2416 | blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); |
Akinobu Mita | 00d5940 | 2007-07-17 04:03:46 -0700 | [diff] [blame] | 2417 | unregister_blkdev(LOOP_MAJOR, "loop"); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2418 | |
| 2419 | misc_deregister(&loop_misc); |
Luis Chamberlain | 200f933 | 2020-06-19 20:47:27 +0000 | [diff] [blame] | 2420 | |
| 2421 | mutex_unlock(&loop_ctl_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2422 | } |
| 2423 | |
| 2424 | module_init(loop_init); |
| 2425 | module_exit(loop_exit); |
| 2426 | |
| 2427 | #ifndef MODULE |
| 2428 | static int __init max_loop_setup(char *str) |
| 2429 | { |
| 2430 | max_loop = simple_strtol(str, NULL, 0); |
| 2431 | return 1; |
| 2432 | } |
| 2433 | |
| 2434 | __setup("max_loop=", max_loop_setup); |
| 2435 | #endif |