Thomas Gleixner | 457c899 | 2019-05-19 13:08:55 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * linux/fs/buffer.c |
| 4 | * |
| 5 | * Copyright (C) 1991, 1992, 2002 Linus Torvalds |
| 6 | */ |
| 7 | |
| 8 | /* |
| 9 | * Start bdflush() with kernel_thread not syscall - Paul Gortmaker, 12/95 |
| 10 | * |
| 11 | * Removed a lot of unnecessary code and simplified things now that |
| 12 | * the buffer cache isn't our primary cache - Andrew Tridgell 12/96 |
| 13 | * |
| 14 | * Speed up hash, lru, and free list operations. Use gfp() for allocating |
| 15 | * hash table, use SLAB cache for buffer heads. SMP threading. -DaveM |
| 16 | * |
| 17 | * Added 32k buffer block sizes - these are required older ARM systems. - RMK |
| 18 | * |
| 19 | * async buffer flushing, 1999 Andrea Arcangeli <andrea@suse.de> |
| 20 | */ |
| 21 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/kernel.h> |
Ingo Molnar | f361bf4 | 2017-02-03 23:47:37 +0100 | [diff] [blame] | 23 | #include <linux/sched/signal.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/syscalls.h> |
| 25 | #include <linux/fs.h> |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 26 | #include <linux/iomap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/mm.h> |
| 28 | #include <linux/percpu.h> |
| 29 | #include <linux/slab.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 30 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/blkdev.h> |
| 32 | #include <linux/file.h> |
| 33 | #include <linux/quotaops.h> |
| 34 | #include <linux/highmem.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 35 | #include <linux/export.h> |
Tejun Heo | bafc0db | 2015-06-02 08:37:23 -0600 | [diff] [blame] | 36 | #include <linux/backing-dev.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <linux/writeback.h> |
| 38 | #include <linux/hash.h> |
| 39 | #include <linux/suspend.h> |
| 40 | #include <linux/buffer_head.h> |
Andrew Morton | 55e829a | 2006-12-10 02:19:27 -0800 | [diff] [blame] | 41 | #include <linux/task_io_accounting_ops.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <linux/bio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/cpu.h> |
| 44 | #include <linux/bitops.h> |
| 45 | #include <linux/mpage.h> |
Ingo Molnar | fb1c8f9 | 2005-09-10 00:25:56 -0700 | [diff] [blame] | 46 | #include <linux/bit_spinlock.h> |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 47 | #include <linux/pagevec.h> |
Shakeel Butt | f745c6f | 2018-08-17 15:46:44 -0700 | [diff] [blame] | 48 | #include <linux/sched/mm.h> |
Tejun Heo | 5305cb8 | 2013-01-11 13:06:36 -0800 | [diff] [blame] | 49 | #include <trace/events/block.h> |
Eric Biggers | 31fb992 | 2019-10-22 20:33:11 -0700 | [diff] [blame] | 50 | #include <linux/fscrypt.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Ben Dooks | 2b211dc | 2019-11-30 17:49:18 -0800 | [diff] [blame] | 52 | #include "internal.h" |
| 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 55 | static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, |
Christoph Hellwig | c75e707 | 2022-03-04 18:55:56 +0100 | [diff] [blame] | 56 | struct writeback_control *wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers) |
| 59 | |
Tejun Heo | f0059af | 2013-01-11 13:06:35 -0800 | [diff] [blame] | 60 | inline void touch_buffer(struct buffer_head *bh) |
| 61 | { |
Tejun Heo | 5305cb8 | 2013-01-11 13:06:36 -0800 | [diff] [blame] | 62 | trace_block_touch_buffer(bh); |
Tejun Heo | f0059af | 2013-01-11 13:06:35 -0800 | [diff] [blame] | 63 | mark_page_accessed(bh->b_page); |
| 64 | } |
| 65 | EXPORT_SYMBOL(touch_buffer); |
| 66 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 67 | void __lock_buffer(struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | { |
NeilBrown | 7431620 | 2014-07-07 15:16:04 +1000 | [diff] [blame] | 69 | wait_on_bit_lock_io(&bh->b_state, BH_Lock, TASK_UNINTERRUPTIBLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | } |
| 71 | EXPORT_SYMBOL(__lock_buffer); |
| 72 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 73 | void unlock_buffer(struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | { |
Nick Piggin | 51b07fc | 2008-10-18 20:27:00 -0700 | [diff] [blame] | 75 | clear_bit_unlock(BH_Lock, &bh->b_state); |
Peter Zijlstra | 4e857c5 | 2014-03-17 18:06:10 +0100 | [diff] [blame] | 76 | smp_mb__after_atomic(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | wake_up_bit(&bh->b_state, BH_Lock); |
| 78 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 79 | EXPORT_SYMBOL(unlock_buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
| 81 | /* |
Mel Gorman | b459722 | 2013-07-03 15:02:05 -0700 | [diff] [blame] | 82 | * Returns if the page has dirty or writeback buffers. If all the buffers |
| 83 | * are unlocked and clean then the PageDirty information is stale. If |
| 84 | * any of the pages are locked, it is assumed they are locked for IO. |
| 85 | */ |
| 86 | void buffer_check_dirty_writeback(struct page *page, |
| 87 | bool *dirty, bool *writeback) |
| 88 | { |
| 89 | struct buffer_head *head, *bh; |
| 90 | *dirty = false; |
| 91 | *writeback = false; |
| 92 | |
| 93 | BUG_ON(!PageLocked(page)); |
| 94 | |
| 95 | if (!page_has_buffers(page)) |
| 96 | return; |
| 97 | |
| 98 | if (PageWriteback(page)) |
| 99 | *writeback = true; |
| 100 | |
| 101 | head = page_buffers(page); |
| 102 | bh = head; |
| 103 | do { |
| 104 | if (buffer_locked(bh)) |
| 105 | *writeback = true; |
| 106 | |
| 107 | if (buffer_dirty(bh)) |
| 108 | *dirty = true; |
| 109 | |
| 110 | bh = bh->b_this_page; |
| 111 | } while (bh != head); |
| 112 | } |
| 113 | EXPORT_SYMBOL(buffer_check_dirty_writeback); |
| 114 | |
| 115 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | * Block until a buffer comes unlocked. This doesn't stop it |
| 117 | * from becoming locked again - you have to lock it yourself |
| 118 | * if you want to preserve its state. |
| 119 | */ |
| 120 | void __wait_on_buffer(struct buffer_head * bh) |
| 121 | { |
NeilBrown | 7431620 | 2014-07-07 15:16:04 +1000 | [diff] [blame] | 122 | wait_on_bit_io(&bh->b_state, BH_Lock, TASK_UNINTERRUPTIBLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 124 | EXPORT_SYMBOL(__wait_on_buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
Robert Elliott | b744c2a | 2014-10-21 13:55:09 -0600 | [diff] [blame] | 126 | static void buffer_io_error(struct buffer_head *bh, char *msg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | { |
Robert Elliott | 432f16e | 2014-10-21 13:55:11 -0600 | [diff] [blame] | 128 | if (!test_bit(BH_Quiet, &bh->b_state)) |
| 129 | printk_ratelimited(KERN_ERR |
Dmitry Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 130 | "Buffer I/O error on dev %pg, logical block %llu%s\n", |
| 131 | bh->b_bdev, (unsigned long long)bh->b_blocknr, msg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | } |
| 133 | |
| 134 | /* |
Dmitry Monakhov | 68671f3 | 2007-10-16 01:24:47 -0700 | [diff] [blame] | 135 | * End-of-IO handler helper function which does not touch the bh after |
| 136 | * unlocking it. |
| 137 | * Note: unlock_buffer() sort-of does touch the bh after unlocking it, but |
| 138 | * a race there is benign: unlock_buffer() only use the bh's address for |
| 139 | * hashing after unlocking the buffer, so it doesn't actually touch the bh |
| 140 | * itself. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | */ |
Dmitry Monakhov | 68671f3 | 2007-10-16 01:24:47 -0700 | [diff] [blame] | 142 | static void __end_buffer_read_notouch(struct buffer_head *bh, int uptodate) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | { |
| 144 | if (uptodate) { |
| 145 | set_buffer_uptodate(bh); |
| 146 | } else { |
Christoph Hellwig | 7024628 | 2016-07-19 11:28:41 +0200 | [diff] [blame] | 147 | /* This happens, due to failed read-ahead attempts. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | clear_buffer_uptodate(bh); |
| 149 | } |
| 150 | unlock_buffer(bh); |
Dmitry Monakhov | 68671f3 | 2007-10-16 01:24:47 -0700 | [diff] [blame] | 151 | } |
| 152 | |
| 153 | /* |
| 154 | * Default synchronous end-of-IO handler.. Just mark it up-to-date and |
| 155 | * unlock the buffer. This is what ll_rw_block uses too. |
| 156 | */ |
| 157 | void end_buffer_read_sync(struct buffer_head *bh, int uptodate) |
| 158 | { |
| 159 | __end_buffer_read_notouch(bh, uptodate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | put_bh(bh); |
| 161 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 162 | EXPORT_SYMBOL(end_buffer_read_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
| 164 | void end_buffer_write_sync(struct buffer_head *bh, int uptodate) |
| 165 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | if (uptodate) { |
| 167 | set_buffer_uptodate(bh); |
| 168 | } else { |
Robert Elliott | 432f16e | 2014-10-21 13:55:11 -0600 | [diff] [blame] | 169 | buffer_io_error(bh, ", lost sync page write"); |
Jeff Layton | 87354e5 | 2017-07-06 07:02:21 -0400 | [diff] [blame] | 170 | mark_buffer_write_io_error(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | clear_buffer_uptodate(bh); |
| 172 | } |
| 173 | unlock_buffer(bh); |
| 174 | put_bh(bh); |
| 175 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 176 | EXPORT_SYMBOL(end_buffer_write_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | |
| 178 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | * Various filesystems appear to want __find_get_block to be non-blocking. |
| 180 | * But it's the page lock which protects the buffers. To get around this, |
| 181 | * we get exclusion from try_to_free_buffers with the blockdev mapping's |
| 182 | * private_lock. |
| 183 | * |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 184 | * Hack idea: for the blockdev mapping, private_lock contention |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | * may be quite high. This code could TryLock the page, and if that |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 186 | * succeeds, there is no need to take private_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | */ |
| 188 | static struct buffer_head * |
Coywolf Qi Hunt | 385fd4c | 2005-11-07 00:59:39 -0800 | [diff] [blame] | 189 | __find_get_block_slow(struct block_device *bdev, sector_t block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | { |
| 191 | struct inode *bd_inode = bdev->bd_inode; |
| 192 | struct address_space *bd_mapping = bd_inode->i_mapping; |
| 193 | struct buffer_head *ret = NULL; |
| 194 | pgoff_t index; |
| 195 | struct buffer_head *bh; |
| 196 | struct buffer_head *head; |
| 197 | struct page *page; |
| 198 | int all_mapped = 1; |
Tetsuo Handa | 43636c8 | 2019-01-21 22:49:37 +0900 | [diff] [blame] | 199 | static DEFINE_RATELIMIT_STATE(last_warned, HZ, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 201 | index = block >> (PAGE_SHIFT - bd_inode->i_blkbits); |
Mel Gorman | 2457aec | 2014-06-04 16:10:31 -0700 | [diff] [blame] | 202 | page = find_get_page_flags(bd_mapping, index, FGP_ACCESSED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | if (!page) |
| 204 | goto out; |
| 205 | |
| 206 | spin_lock(&bd_mapping->private_lock); |
| 207 | if (!page_has_buffers(page)) |
| 208 | goto out_unlock; |
| 209 | head = page_buffers(page); |
| 210 | bh = head; |
| 211 | do { |
Nikanth Karthikesan | 97f76d3 | 2009-04-02 16:56:46 -0700 | [diff] [blame] | 212 | if (!buffer_mapped(bh)) |
| 213 | all_mapped = 0; |
| 214 | else if (bh->b_blocknr == block) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | ret = bh; |
| 216 | get_bh(bh); |
| 217 | goto out_unlock; |
| 218 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | bh = bh->b_this_page; |
| 220 | } while (bh != head); |
| 221 | |
| 222 | /* we might be here because some of the buffers on this page are |
| 223 | * not mapped. This is due to various races between |
| 224 | * file io on the block device and getblk. It gets dealt with |
| 225 | * elsewhere, don't buffer_error if we had some unmapped buffers |
| 226 | */ |
Tetsuo Handa | 43636c8 | 2019-01-21 22:49:37 +0900 | [diff] [blame] | 227 | ratelimit_set_flags(&last_warned, RATELIMIT_MSG_ON_RELEASE); |
| 228 | if (all_mapped && __ratelimit(&last_warned)) { |
| 229 | printk("__find_get_block_slow() failed. block=%llu, " |
| 230 | "b_blocknr=%llu, b_state=0x%08lx, b_size=%zu, " |
| 231 | "device %pg blocksize: %d\n", |
| 232 | (unsigned long long)block, |
| 233 | (unsigned long long)bh->b_blocknr, |
| 234 | bh->b_state, bh->b_size, bdev, |
| 235 | 1 << bd_inode->i_blkbits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | } |
| 237 | out_unlock: |
| 238 | spin_unlock(&bd_mapping->private_lock); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 239 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | out: |
| 241 | return ret; |
| 242 | } |
| 243 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | static void end_buffer_async_read(struct buffer_head *bh, int uptodate) |
| 245 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | unsigned long flags; |
Nick Piggin | a397220 | 2005-07-07 17:56:56 -0700 | [diff] [blame] | 247 | struct buffer_head *first; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | struct buffer_head *tmp; |
| 249 | struct page *page; |
| 250 | int page_uptodate = 1; |
| 251 | |
| 252 | BUG_ON(!buffer_async_read(bh)); |
| 253 | |
| 254 | page = bh->b_page; |
| 255 | if (uptodate) { |
| 256 | set_buffer_uptodate(bh); |
| 257 | } else { |
| 258 | clear_buffer_uptodate(bh); |
Robert Elliott | 432f16e | 2014-10-21 13:55:11 -0600 | [diff] [blame] | 259 | buffer_io_error(bh, ", async page read"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | SetPageError(page); |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * Be _very_ careful from here on. Bad things can happen if |
| 265 | * two buffer heads end IO at almost the same time and both |
| 266 | * decide that the page is now completely done. |
| 267 | */ |
Nick Piggin | a397220 | 2005-07-07 17:56:56 -0700 | [diff] [blame] | 268 | first = page_buffers(page); |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 269 | spin_lock_irqsave(&first->b_uptodate_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | clear_buffer_async_read(bh); |
| 271 | unlock_buffer(bh); |
| 272 | tmp = bh; |
| 273 | do { |
| 274 | if (!buffer_uptodate(tmp)) |
| 275 | page_uptodate = 0; |
| 276 | if (buffer_async_read(tmp)) { |
| 277 | BUG_ON(!buffer_locked(tmp)); |
| 278 | goto still_busy; |
| 279 | } |
| 280 | tmp = tmp->b_this_page; |
| 281 | } while (tmp != bh); |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 282 | spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | |
| 284 | /* |
| 285 | * If none of the buffers had errors and they are all |
| 286 | * uptodate then we can set the page uptodate. |
| 287 | */ |
| 288 | if (page_uptodate && !PageError(page)) |
| 289 | SetPageUptodate(page); |
| 290 | unlock_page(page); |
| 291 | return; |
| 292 | |
| 293 | still_busy: |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 294 | spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | return; |
| 296 | } |
| 297 | |
Eric Biggers | 31fb992 | 2019-10-22 20:33:11 -0700 | [diff] [blame] | 298 | struct decrypt_bh_ctx { |
| 299 | struct work_struct work; |
| 300 | struct buffer_head *bh; |
| 301 | }; |
| 302 | |
| 303 | static void decrypt_bh(struct work_struct *work) |
| 304 | { |
| 305 | struct decrypt_bh_ctx *ctx = |
| 306 | container_of(work, struct decrypt_bh_ctx, work); |
| 307 | struct buffer_head *bh = ctx->bh; |
| 308 | int err; |
| 309 | |
| 310 | err = fscrypt_decrypt_pagecache_blocks(bh->b_page, bh->b_size, |
| 311 | bh_offset(bh)); |
| 312 | end_buffer_async_read(bh, err == 0); |
| 313 | kfree(ctx); |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * I/O completion handler for block_read_full_page() - pages |
| 318 | * which come unlocked at the end of I/O. |
| 319 | */ |
| 320 | static void end_buffer_async_read_io(struct buffer_head *bh, int uptodate) |
| 321 | { |
| 322 | /* Decrypt if needed */ |
Eric Biggers | 4f74d15 | 2020-07-02 01:56:07 +0000 | [diff] [blame] | 323 | if (uptodate && |
| 324 | fscrypt_inode_uses_fs_layer_crypto(bh->b_page->mapping->host)) { |
Eric Biggers | 31fb992 | 2019-10-22 20:33:11 -0700 | [diff] [blame] | 325 | struct decrypt_bh_ctx *ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC); |
| 326 | |
| 327 | if (ctx) { |
| 328 | INIT_WORK(&ctx->work, decrypt_bh); |
| 329 | ctx->bh = bh; |
| 330 | fscrypt_enqueue_decrypt_work(&ctx->work); |
| 331 | return; |
| 332 | } |
| 333 | uptodate = 0; |
| 334 | } |
| 335 | end_buffer_async_read(bh, uptodate); |
| 336 | } |
| 337 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | /* |
| 339 | * Completion handler for block_write_full_page() - pages which are unlocked |
| 340 | * during I/O, and which have PageWriteback cleared upon I/O completion. |
| 341 | */ |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 342 | void end_buffer_async_write(struct buffer_head *bh, int uptodate) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | unsigned long flags; |
Nick Piggin | a397220 | 2005-07-07 17:56:56 -0700 | [diff] [blame] | 345 | struct buffer_head *first; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | struct buffer_head *tmp; |
| 347 | struct page *page; |
| 348 | |
| 349 | BUG_ON(!buffer_async_write(bh)); |
| 350 | |
| 351 | page = bh->b_page; |
| 352 | if (uptodate) { |
| 353 | set_buffer_uptodate(bh); |
| 354 | } else { |
Robert Elliott | 432f16e | 2014-10-21 13:55:11 -0600 | [diff] [blame] | 355 | buffer_io_error(bh, ", lost async page write"); |
Jeff Layton | 87354e5 | 2017-07-06 07:02:21 -0400 | [diff] [blame] | 356 | mark_buffer_write_io_error(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | clear_buffer_uptodate(bh); |
| 358 | SetPageError(page); |
| 359 | } |
| 360 | |
Nick Piggin | a397220 | 2005-07-07 17:56:56 -0700 | [diff] [blame] | 361 | first = page_buffers(page); |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 362 | spin_lock_irqsave(&first->b_uptodate_lock, flags); |
Nick Piggin | a397220 | 2005-07-07 17:56:56 -0700 | [diff] [blame] | 363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | clear_buffer_async_write(bh); |
| 365 | unlock_buffer(bh); |
| 366 | tmp = bh->b_this_page; |
| 367 | while (tmp != bh) { |
| 368 | if (buffer_async_write(tmp)) { |
| 369 | BUG_ON(!buffer_locked(tmp)); |
| 370 | goto still_busy; |
| 371 | } |
| 372 | tmp = tmp->b_this_page; |
| 373 | } |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 374 | spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | end_page_writeback(page); |
| 376 | return; |
| 377 | |
| 378 | still_busy: |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 379 | spin_unlock_irqrestore(&first->b_uptodate_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | return; |
| 381 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 382 | EXPORT_SYMBOL(end_buffer_async_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | |
| 384 | /* |
| 385 | * If a page's buffers are under async readin (end_buffer_async_read |
| 386 | * completion) then there is a possibility that another thread of |
| 387 | * control could lock one of the buffers after it has completed |
| 388 | * but while some of the other buffers have not completed. This |
| 389 | * locked buffer would confuse end_buffer_async_read() into not unlocking |
| 390 | * the page. So the absence of BH_Async_Read tells end_buffer_async_read() |
| 391 | * that this buffer is not under async I/O. |
| 392 | * |
| 393 | * The page comes unlocked when it has no locked buffer_async buffers |
| 394 | * left. |
| 395 | * |
| 396 | * PageLocked prevents anyone starting new async I/O reads any of |
| 397 | * the buffers. |
| 398 | * |
| 399 | * PageWriteback is used to prevent simultaneous writeout of the same |
| 400 | * page. |
| 401 | * |
| 402 | * PageLocked prevents anyone from starting writeback of a page which is |
| 403 | * under read I/O (PageWriteback is only ever set against a locked page). |
| 404 | */ |
| 405 | static void mark_buffer_async_read(struct buffer_head *bh) |
| 406 | { |
Eric Biggers | 31fb992 | 2019-10-22 20:33:11 -0700 | [diff] [blame] | 407 | bh->b_end_io = end_buffer_async_read_io; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | set_buffer_async_read(bh); |
| 409 | } |
| 410 | |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 411 | static void mark_buffer_async_write_endio(struct buffer_head *bh, |
| 412 | bh_end_io_t *handler) |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 413 | { |
| 414 | bh->b_end_io = handler; |
| 415 | set_buffer_async_write(bh); |
| 416 | } |
| 417 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | void mark_buffer_async_write(struct buffer_head *bh) |
| 419 | { |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 420 | mark_buffer_async_write_endio(bh, end_buffer_async_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | } |
| 422 | EXPORT_SYMBOL(mark_buffer_async_write); |
| 423 | |
| 424 | |
| 425 | /* |
| 426 | * fs/buffer.c contains helper functions for buffer-backed address space's |
| 427 | * fsync functions. A common requirement for buffer-based filesystems is |
| 428 | * that certain data from the backing blockdev needs to be written out for |
| 429 | * a successful fsync(). For example, ext2 indirect blocks need to be |
| 430 | * written back and waited upon before fsync() returns. |
| 431 | * |
| 432 | * The functions mark_buffer_inode_dirty(), fsync_inode_buffers(), |
| 433 | * inode_has_buffers() and invalidate_inode_buffers() are provided for the |
| 434 | * management of a list of dependent buffers at ->i_mapping->private_list. |
| 435 | * |
| 436 | * Locking is a little subtle: try_to_free_buffers() will remove buffers |
| 437 | * from their controlling inode's queue when they are being freed. But |
| 438 | * try_to_free_buffers() will be operating against the *blockdev* mapping |
| 439 | * at the time, not against the S_ISREG file which depends on those buffers. |
| 440 | * So the locking for private_list is via the private_lock in the address_space |
| 441 | * which backs the buffers. Which is different from the address_space |
| 442 | * against which the buffers are listed. So for a particular address_space, |
| 443 | * mapping->private_lock does *not* protect mapping->private_list! In fact, |
| 444 | * mapping->private_list will always be protected by the backing blockdev's |
| 445 | * ->private_lock. |
| 446 | * |
| 447 | * Which introduces a requirement: all buffers on an address_space's |
| 448 | * ->private_list must be from the same address_space: the blockdev's. |
| 449 | * |
| 450 | * address_spaces which do not place buffers at ->private_list via these |
| 451 | * utility functions are free to use private_lock and private_list for |
| 452 | * whatever they want. The only requirement is that list_empty(private_list) |
| 453 | * be true at clear_inode() time. |
| 454 | * |
| 455 | * FIXME: clear_inode should not call invalidate_inode_buffers(). The |
| 456 | * filesystems should do that. invalidate_inode_buffers() should just go |
| 457 | * BUG_ON(!list_empty). |
| 458 | * |
| 459 | * FIXME: mark_buffer_dirty_inode() is a data-plane operation. It should |
| 460 | * take an address_space, not an inode. And it should be called |
| 461 | * mark_buffer_dirty_fsync() to clearly define why those buffers are being |
| 462 | * queued up. |
| 463 | * |
| 464 | * FIXME: mark_buffer_dirty_inode() doesn't need to add the buffer to the |
| 465 | * list if it is already on a list. Because if the buffer is on a list, |
| 466 | * it *must* already be on the right one. If not, the filesystem is being |
| 467 | * silly. This will save a ton of locking. But first we have to ensure |
| 468 | * that buffers are taken *off* the old inode's list when they are freed |
| 469 | * (presumably in truncate). That requires careful auditing of all |
| 470 | * filesystems (do it inside bforget()). It could also be done by bringing |
| 471 | * b_inode back. |
| 472 | */ |
| 473 | |
| 474 | /* |
| 475 | * The buffer's backing address_space's private_lock must be held |
| 476 | */ |
Thomas Petazzoni | dbacefc | 2008-07-29 22:33:47 -0700 | [diff] [blame] | 477 | static void __remove_assoc_queue(struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | { |
| 479 | list_del_init(&bh->b_assoc_buffers); |
Jan Kara | 58ff407b | 2006-10-17 00:10:19 -0700 | [diff] [blame] | 480 | WARN_ON(!bh->b_assoc_map); |
Jan Kara | 58ff407b | 2006-10-17 00:10:19 -0700 | [diff] [blame] | 481 | bh->b_assoc_map = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | } |
| 483 | |
| 484 | int inode_has_buffers(struct inode *inode) |
| 485 | { |
| 486 | return !list_empty(&inode->i_data.private_list); |
| 487 | } |
| 488 | |
| 489 | /* |
| 490 | * osync is designed to support O_SYNC io. It waits synchronously for |
| 491 | * all already-submitted IO to complete, but does not queue any new |
| 492 | * writes to the disk. |
| 493 | * |
| 494 | * To do O_SYNC writes, just queue the buffer writes with ll_rw_block as |
| 495 | * you dirty the buffers, and then use osync_inode_buffers to wait for |
| 496 | * completion. Any other dirty buffers which are not yet queued for |
| 497 | * write will not be flushed to disk by the osync. |
| 498 | */ |
| 499 | static int osync_buffers_list(spinlock_t *lock, struct list_head *list) |
| 500 | { |
| 501 | struct buffer_head *bh; |
| 502 | struct list_head *p; |
| 503 | int err = 0; |
| 504 | |
| 505 | spin_lock(lock); |
| 506 | repeat: |
| 507 | list_for_each_prev(p, list) { |
| 508 | bh = BH_ENTRY(p); |
| 509 | if (buffer_locked(bh)) { |
| 510 | get_bh(bh); |
| 511 | spin_unlock(lock); |
| 512 | wait_on_buffer(bh); |
| 513 | if (!buffer_uptodate(bh)) |
| 514 | err = -EIO; |
| 515 | brelse(bh); |
| 516 | spin_lock(lock); |
| 517 | goto repeat; |
| 518 | } |
| 519 | } |
| 520 | spin_unlock(lock); |
| 521 | return err; |
| 522 | } |
| 523 | |
Mateusz Guzik | 08fdc8a | 2017-10-03 18:17:41 +0200 | [diff] [blame] | 524 | void emergency_thaw_bdev(struct super_block *sb) |
Al Viro | 01a05b3 | 2010-03-23 06:06:58 -0400 | [diff] [blame] | 525 | { |
Christoph Hellwig | 040f04b | 2020-11-24 11:54:06 +0100 | [diff] [blame] | 526 | while (sb->s_bdev && !thaw_bdev(sb->s_bdev)) |
Dmitry Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 527 | printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev); |
Al Viro | 01a05b3 | 2010-03-23 06:06:58 -0400 | [diff] [blame] | 528 | } |
| 529 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | /** |
Randy Dunlap | 78a4a50 | 2008-02-29 22:02:31 -0800 | [diff] [blame] | 531 | * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 532 | * @mapping: the mapping which wants those buffers written |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | * |
| 534 | * Starts I/O against the buffers at mapping->private_list, and waits upon |
| 535 | * that I/O. |
| 536 | * |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 537 | * Basically, this is a convenience function for fsync(). |
| 538 | * @mapping is a file or directory which needs those buffers to be written for |
| 539 | * a successful fsync(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | */ |
| 541 | int sync_mapping_buffers(struct address_space *mapping) |
| 542 | { |
Rafael Aquini | 252aa6f | 2012-12-11 16:02:35 -0800 | [diff] [blame] | 543 | struct address_space *buffer_mapping = mapping->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |
| 545 | if (buffer_mapping == NULL || list_empty(&mapping->private_list)) |
| 546 | return 0; |
| 547 | |
| 548 | return fsync_buffers_list(&buffer_mapping->private_lock, |
| 549 | &mapping->private_list); |
| 550 | } |
| 551 | EXPORT_SYMBOL(sync_mapping_buffers); |
| 552 | |
| 553 | /* |
| 554 | * Called when we've recently written block `bblock', and it is known that |
| 555 | * `bblock' was for a buffer_boundary() buffer. This means that the block at |
| 556 | * `bblock + 1' is probably a dirty indirect block. Hunt it down and, if it's |
| 557 | * dirty, schedule it for IO. So that indirects merge nicely with their data. |
| 558 | */ |
| 559 | void write_boundary_block(struct block_device *bdev, |
| 560 | sector_t bblock, unsigned blocksize) |
| 561 | { |
| 562 | struct buffer_head *bh = __find_get_block(bdev, bblock + 1, blocksize); |
| 563 | if (bh) { |
| 564 | if (buffer_dirty(bh)) |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 565 | ll_rw_block(REQ_OP_WRITE, 0, 1, &bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | put_bh(bh); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode) |
| 571 | { |
| 572 | struct address_space *mapping = inode->i_mapping; |
| 573 | struct address_space *buffer_mapping = bh->b_page->mapping; |
| 574 | |
| 575 | mark_buffer_dirty(bh); |
Rafael Aquini | 252aa6f | 2012-12-11 16:02:35 -0800 | [diff] [blame] | 576 | if (!mapping->private_data) { |
| 577 | mapping->private_data = buffer_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | } else { |
Rafael Aquini | 252aa6f | 2012-12-11 16:02:35 -0800 | [diff] [blame] | 579 | BUG_ON(mapping->private_data != buffer_mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | } |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 581 | if (!bh->b_assoc_map) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | spin_lock(&buffer_mapping->private_lock); |
| 583 | list_move_tail(&bh->b_assoc_buffers, |
| 584 | &mapping->private_list); |
Jan Kara | 58ff407b | 2006-10-17 00:10:19 -0700 | [diff] [blame] | 585 | bh->b_assoc_map = mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | spin_unlock(&buffer_mapping->private_lock); |
| 587 | } |
| 588 | } |
| 589 | EXPORT_SYMBOL(mark_buffer_dirty_inode); |
| 590 | |
| 591 | /* |
| 592 | * Add a page to the dirty page list. |
| 593 | * |
| 594 | * It is a sad fact of life that this function is called from several places |
| 595 | * deeply under spinlocking. It may not sleep. |
| 596 | * |
| 597 | * If the page has buffers, the uptodate buffers are set dirty, to preserve |
| 598 | * dirty-state coherency between the page and the buffers. It the page does |
| 599 | * not have buffers then when they are later attached they will all be set |
| 600 | * dirty. |
| 601 | * |
| 602 | * The buffers are dirtied before the page is dirtied. There's a small race |
| 603 | * window in which a writepage caller may see the page cleanness but not the |
| 604 | * buffer dirtiness. That's fine. If this code were to set the page dirty |
| 605 | * before the buffers, a concurrent writepage caller could clear the page dirty |
| 606 | * bit, see a bunch of clean buffers and we'd end up with dirty buffers/clean |
| 607 | * page on the dirty page list. |
| 608 | * |
| 609 | * We use private_lock to lock against try_to_free_buffers while using the |
| 610 | * page's buffer list. Also use this to protect against clean buffers being |
| 611 | * added to the page after it was set dirty. |
| 612 | * |
| 613 | * FIXME: may need to call ->reservepage here as well. That's rather up to the |
| 614 | * address_space though. |
| 615 | */ |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 616 | bool block_dirty_folio(struct address_space *mapping, struct folio *folio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | { |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 618 | struct buffer_head *head; |
| 619 | bool newly_dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | |
| 621 | spin_lock(&mapping->private_lock); |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 622 | head = folio_buffers(folio); |
| 623 | if (head) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | struct buffer_head *bh = head; |
| 625 | |
| 626 | do { |
| 627 | set_buffer_dirty(bh); |
| 628 | bh = bh->b_this_page; |
| 629 | } while (bh != head); |
| 630 | } |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 631 | /* |
Roman Gushchin | bcfe06b | 2020-12-01 13:58:27 -0800 | [diff] [blame] | 632 | * Lock out page's memcg migration to keep PageDirty |
Johannes Weiner | 81f8c3a | 2016-03-15 14:57:04 -0700 | [diff] [blame] | 633 | * synchronized with per-memcg dirty page counters. |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 634 | */ |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 635 | folio_memcg_lock(folio); |
| 636 | newly_dirty = !folio_test_set_dirty(folio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | spin_unlock(&mapping->private_lock); |
| 638 | |
Linus Torvalds | a8e7d49 | 2009-03-19 11:32:05 -0700 | [diff] [blame] | 639 | if (newly_dirty) |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 640 | __folio_mark_dirty(folio, mapping, 1); |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 641 | |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 642 | folio_memcg_unlock(folio); |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 643 | |
| 644 | if (newly_dirty) |
| 645 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); |
| 646 | |
Linus Torvalds | a8e7d49 | 2009-03-19 11:32:05 -0700 | [diff] [blame] | 647 | return newly_dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | } |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 649 | EXPORT_SYMBOL(block_dirty_folio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | |
| 651 | /* |
| 652 | * Write out and wait upon a list of buffers. |
| 653 | * |
| 654 | * We have conflicting pressures: we want to make sure that all |
| 655 | * initially dirty buffers get waited on, but that any subsequently |
| 656 | * dirtied buffers don't. After all, we don't want fsync to last |
| 657 | * forever if somebody is actively writing to the file. |
| 658 | * |
| 659 | * Do this in two main stages: first we copy dirty buffers to a |
| 660 | * temporary inode list, queueing the writes as we go. Then we clean |
| 661 | * up, waiting for those writes to complete. |
| 662 | * |
| 663 | * During this second stage, any subsequent updates to the file may end |
| 664 | * up refiling the buffer on the original inode's dirty list again, so |
| 665 | * there is a chance we will end up with a buffer queued for write but |
| 666 | * not yet completed on that list. So, as a final cleanup we go through |
| 667 | * the osync code to catch these locked, dirty buffers without requeuing |
| 668 | * any newly dirty buffers for write. |
| 669 | */ |
| 670 | static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) |
| 671 | { |
| 672 | struct buffer_head *bh; |
| 673 | struct list_head tmp; |
Jens Axboe | 7eaceac | 2011-03-10 08:52:07 +0100 | [diff] [blame] | 674 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | int err = 0, err2; |
Jens Axboe | 4ee2491 | 2011-03-17 10:51:40 +0100 | [diff] [blame] | 676 | struct blk_plug plug; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | |
| 678 | INIT_LIST_HEAD(&tmp); |
Jens Axboe | 4ee2491 | 2011-03-17 10:51:40 +0100 | [diff] [blame] | 679 | blk_start_plug(&plug); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | |
| 681 | spin_lock(lock); |
| 682 | while (!list_empty(list)) { |
| 683 | bh = BH_ENTRY(list->next); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 684 | mapping = bh->b_assoc_map; |
Jan Kara | 58ff407b | 2006-10-17 00:10:19 -0700 | [diff] [blame] | 685 | __remove_assoc_queue(bh); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 686 | /* Avoid race with mark_buffer_dirty_inode() which does |
| 687 | * a lockless check and we rely on seeing the dirty bit */ |
| 688 | smp_mb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | if (buffer_dirty(bh) || buffer_locked(bh)) { |
| 690 | list_add(&bh->b_assoc_buffers, &tmp); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 691 | bh->b_assoc_map = mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | if (buffer_dirty(bh)) { |
| 693 | get_bh(bh); |
| 694 | spin_unlock(lock); |
| 695 | /* |
| 696 | * Ensure any pending I/O completes so that |
Christoph Hellwig | 9cb569d | 2010-08-11 17:06:24 +0200 | [diff] [blame] | 697 | * write_dirty_buffer() actually writes the |
| 698 | * current contents - it is a noop if I/O is |
| 699 | * still in flight on potentially older |
| 700 | * contents. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | */ |
Christoph Hellwig | 70fd761 | 2016-11-01 07:40:10 -0600 | [diff] [blame] | 702 | write_dirty_buffer(bh, REQ_SYNC); |
Jens Axboe | 9cf6b72 | 2009-04-06 14:48:03 +0200 | [diff] [blame] | 703 | |
| 704 | /* |
| 705 | * Kick off IO for the previous mapping. Note |
| 706 | * that we will not run the very last mapping, |
| 707 | * wait_on_buffer() will do that for us |
| 708 | * through sync_buffer(). |
| 709 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | brelse(bh); |
| 711 | spin_lock(lock); |
| 712 | } |
| 713 | } |
| 714 | } |
| 715 | |
Jens Axboe | 4ee2491 | 2011-03-17 10:51:40 +0100 | [diff] [blame] | 716 | spin_unlock(lock); |
| 717 | blk_finish_plug(&plug); |
| 718 | spin_lock(lock); |
| 719 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | while (!list_empty(&tmp)) { |
| 721 | bh = BH_ENTRY(tmp.prev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | get_bh(bh); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 723 | mapping = bh->b_assoc_map; |
| 724 | __remove_assoc_queue(bh); |
| 725 | /* Avoid race with mark_buffer_dirty_inode() which does |
| 726 | * a lockless check and we rely on seeing the dirty bit */ |
| 727 | smp_mb(); |
| 728 | if (buffer_dirty(bh)) { |
| 729 | list_add(&bh->b_assoc_buffers, |
Jan Kara | e389229 | 2008-03-04 14:28:33 -0800 | [diff] [blame] | 730 | &mapping->private_list); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 731 | bh->b_assoc_map = mapping; |
| 732 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | spin_unlock(lock); |
| 734 | wait_on_buffer(bh); |
| 735 | if (!buffer_uptodate(bh)) |
| 736 | err = -EIO; |
| 737 | brelse(bh); |
| 738 | spin_lock(lock); |
| 739 | } |
| 740 | |
| 741 | spin_unlock(lock); |
| 742 | err2 = osync_buffers_list(lock, list); |
| 743 | if (err) |
| 744 | return err; |
| 745 | else |
| 746 | return err2; |
| 747 | } |
| 748 | |
| 749 | /* |
| 750 | * Invalidate any and all dirty buffers on a given inode. We are |
| 751 | * probably unmounting the fs, but that doesn't mean we have already |
| 752 | * done a sync(). Just drop the buffers from the inode list. |
| 753 | * |
| 754 | * NOTE: we take the inode's blockdev's mapping's private_lock. Which |
| 755 | * assumes that all the buffers are against the blockdev. Not true |
| 756 | * for reiserfs. |
| 757 | */ |
| 758 | void invalidate_inode_buffers(struct inode *inode) |
| 759 | { |
| 760 | if (inode_has_buffers(inode)) { |
| 761 | struct address_space *mapping = &inode->i_data; |
| 762 | struct list_head *list = &mapping->private_list; |
Rafael Aquini | 252aa6f | 2012-12-11 16:02:35 -0800 | [diff] [blame] | 763 | struct address_space *buffer_mapping = mapping->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | |
| 765 | spin_lock(&buffer_mapping->private_lock); |
| 766 | while (!list_empty(list)) |
| 767 | __remove_assoc_queue(BH_ENTRY(list->next)); |
| 768 | spin_unlock(&buffer_mapping->private_lock); |
| 769 | } |
| 770 | } |
Jan Kara | 52b19ac | 2008-09-23 18:24:08 +0200 | [diff] [blame] | 771 | EXPORT_SYMBOL(invalidate_inode_buffers); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | |
| 773 | /* |
| 774 | * Remove any clean buffers from the inode's buffer list. This is called |
| 775 | * when we're trying to free the inode itself. Those buffers can pin it. |
| 776 | * |
| 777 | * Returns true if all buffers were removed. |
| 778 | */ |
| 779 | int remove_inode_buffers(struct inode *inode) |
| 780 | { |
| 781 | int ret = 1; |
| 782 | |
| 783 | if (inode_has_buffers(inode)) { |
| 784 | struct address_space *mapping = &inode->i_data; |
| 785 | struct list_head *list = &mapping->private_list; |
Rafael Aquini | 252aa6f | 2012-12-11 16:02:35 -0800 | [diff] [blame] | 786 | struct address_space *buffer_mapping = mapping->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | |
| 788 | spin_lock(&buffer_mapping->private_lock); |
| 789 | while (!list_empty(list)) { |
| 790 | struct buffer_head *bh = BH_ENTRY(list->next); |
| 791 | if (buffer_dirty(bh)) { |
| 792 | ret = 0; |
| 793 | break; |
| 794 | } |
| 795 | __remove_assoc_queue(bh); |
| 796 | } |
| 797 | spin_unlock(&buffer_mapping->private_lock); |
| 798 | } |
| 799 | return ret; |
| 800 | } |
| 801 | |
| 802 | /* |
| 803 | * Create the appropriate buffers when given a page for data area and |
| 804 | * the size of each buffer.. Use the bh->b_this_page linked list to |
| 805 | * follow the buffers created. Return NULL if unable to create more |
| 806 | * buffers. |
| 807 | * |
| 808 | * The retry flag is used to differentiate async IO (paging, swapping) |
| 809 | * which may not fail from ordinary buffer allocations. |
| 810 | */ |
| 811 | struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, |
Jens Axboe | 640ab98 | 2017-09-27 05:40:16 -0600 | [diff] [blame] | 812 | bool retry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | { |
| 814 | struct buffer_head *bh, *head; |
Shakeel Butt | f745c6f | 2018-08-17 15:46:44 -0700 | [diff] [blame] | 815 | gfp_t gfp = GFP_NOFS | __GFP_ACCOUNT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | long offset; |
Roman Gushchin | b87d8ce | 2020-10-17 16:13:40 -0700 | [diff] [blame] | 817 | struct mem_cgroup *memcg, *old_memcg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | |
Jens Axboe | 640ab98 | 2017-09-27 05:40:16 -0600 | [diff] [blame] | 819 | if (retry) |
| 820 | gfp |= __GFP_NOFAIL; |
| 821 | |
Johannes Weiner | 6eeb104 | 2021-02-24 12:04:15 -0800 | [diff] [blame] | 822 | /* The page lock pins the memcg */ |
| 823 | memcg = page_memcg(page); |
Roman Gushchin | b87d8ce | 2020-10-17 16:13:40 -0700 | [diff] [blame] | 824 | old_memcg = set_active_memcg(memcg); |
Shakeel Butt | f745c6f | 2018-08-17 15:46:44 -0700 | [diff] [blame] | 825 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | head = NULL; |
| 827 | offset = PAGE_SIZE; |
| 828 | while ((offset -= size) >= 0) { |
Jens Axboe | 640ab98 | 2017-09-27 05:40:16 -0600 | [diff] [blame] | 829 | bh = alloc_buffer_head(gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | if (!bh) |
| 831 | goto no_grow; |
| 832 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | bh->b_this_page = head; |
| 834 | bh->b_blocknr = -1; |
| 835 | head = bh; |
| 836 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | bh->b_size = size; |
| 838 | |
| 839 | /* Link the buffer to its page */ |
| 840 | set_bh_page(bh, page, offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | } |
Shakeel Butt | f745c6f | 2018-08-17 15:46:44 -0700 | [diff] [blame] | 842 | out: |
Roman Gushchin | b87d8ce | 2020-10-17 16:13:40 -0700 | [diff] [blame] | 843 | set_active_memcg(old_memcg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | return head; |
| 845 | /* |
| 846 | * In case anything failed, we just free everything we got. |
| 847 | */ |
| 848 | no_grow: |
| 849 | if (head) { |
| 850 | do { |
| 851 | bh = head; |
| 852 | head = head->b_this_page; |
| 853 | free_buffer_head(bh); |
| 854 | } while (head); |
| 855 | } |
| 856 | |
Shakeel Butt | f745c6f | 2018-08-17 15:46:44 -0700 | [diff] [blame] | 857 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | } |
| 859 | EXPORT_SYMBOL_GPL(alloc_page_buffers); |
| 860 | |
| 861 | static inline void |
| 862 | link_dev_buffers(struct page *page, struct buffer_head *head) |
| 863 | { |
| 864 | struct buffer_head *bh, *tail; |
| 865 | |
| 866 | bh = head; |
| 867 | do { |
| 868 | tail = bh; |
| 869 | bh = bh->b_this_page; |
| 870 | } while (bh); |
| 871 | tail->b_this_page = head; |
Guoqing Jiang | 45dcfc2 | 2020-06-01 21:47:48 -0700 | [diff] [blame] | 872 | attach_page_private(page, head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | } |
| 874 | |
Linus Torvalds | bbec0270 | 2012-11-29 12:31:52 -0800 | [diff] [blame] | 875 | static sector_t blkdev_max_block(struct block_device *bdev, unsigned int size) |
| 876 | { |
| 877 | sector_t retval = ~((sector_t)0); |
Christoph Hellwig | b86058f | 2021-10-18 12:11:09 +0200 | [diff] [blame] | 878 | loff_t sz = bdev_nr_bytes(bdev); |
Linus Torvalds | bbec0270 | 2012-11-29 12:31:52 -0800 | [diff] [blame] | 879 | |
| 880 | if (sz) { |
| 881 | unsigned int sizebits = blksize_bits(size); |
| 882 | retval = (sz >> sizebits); |
| 883 | } |
| 884 | return retval; |
| 885 | } |
| 886 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | /* |
| 888 | * Initialise the state of a blockdev page's buffers. |
| 889 | */ |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 890 | static sector_t |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | init_page_buffers(struct page *page, struct block_device *bdev, |
| 892 | sector_t block, int size) |
| 893 | { |
| 894 | struct buffer_head *head = page_buffers(page); |
| 895 | struct buffer_head *bh = head; |
| 896 | int uptodate = PageUptodate(page); |
Christoph Hellwig | bcd1d06 | 2021-10-18 12:11:10 +0200 | [diff] [blame] | 897 | sector_t end_block = blkdev_max_block(bdev, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | |
| 899 | do { |
| 900 | if (!buffer_mapped(bh)) { |
Eric Biggers | 01950a3 | 2018-01-16 22:25:12 -0800 | [diff] [blame] | 901 | bh->b_end_io = NULL; |
| 902 | bh->b_private = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | bh->b_bdev = bdev; |
| 904 | bh->b_blocknr = block; |
| 905 | if (uptodate) |
| 906 | set_buffer_uptodate(bh); |
Jeff Moyer | 080399a | 2012-05-11 16:34:10 +0200 | [diff] [blame] | 907 | if (block < end_block) |
| 908 | set_buffer_mapped(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 909 | } |
| 910 | block++; |
| 911 | bh = bh->b_this_page; |
| 912 | } while (bh != head); |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 913 | |
| 914 | /* |
| 915 | * Caller needs to validate requested block against end of device. |
| 916 | */ |
| 917 | return end_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 918 | } |
| 919 | |
| 920 | /* |
| 921 | * Create the page-cache page that contains the requested block. |
| 922 | * |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 923 | * This is used purely for blockdev mappings. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | */ |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 925 | static int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | grow_dev_page(struct block_device *bdev, sector_t block, |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 927 | pgoff_t index, int size, int sizebits, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | { |
| 929 | struct inode *inode = bdev->bd_inode; |
| 930 | struct page *page; |
| 931 | struct buffer_head *bh; |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 932 | sector_t end_block; |
Zhiqiang Liu | c4b4c2a | 2020-04-13 13:12:10 +0800 | [diff] [blame] | 933 | int ret = 0; |
Johannes Weiner | 84235de | 2013-10-16 13:47:00 -0700 | [diff] [blame] | 934 | gfp_t gfp_mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | |
Michal Hocko | c62d255 | 2015-11-06 16:28:49 -0800 | [diff] [blame] | 936 | gfp_mask = mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS) | gfp; |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 937 | |
Johannes Weiner | 84235de | 2013-10-16 13:47:00 -0700 | [diff] [blame] | 938 | /* |
| 939 | * XXX: __getblk_slow() can not really deal with failure and |
| 940 | * will endlessly loop on improvised global reclaim. Prefer |
| 941 | * looping in the allocator rather than here, at least that |
| 942 | * code knows what it's doing. |
| 943 | */ |
| 944 | gfp_mask |= __GFP_NOFAIL; |
| 945 | |
| 946 | page = find_or_create_page(inode->i_mapping, index, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | |
Eric Sesterhenn | e827f92 | 2006-03-26 18:24:46 +0200 | [diff] [blame] | 948 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | |
| 950 | if (page_has_buffers(page)) { |
| 951 | bh = page_buffers(page); |
| 952 | if (bh->b_size == size) { |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 953 | end_block = init_page_buffers(page, bdev, |
Anton Altaparmakov | f2d5a94 | 2014-09-22 01:53:03 +0100 | [diff] [blame] | 954 | (sector_t)index << sizebits, |
| 955 | size); |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 956 | goto done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | } |
| 958 | if (!try_to_free_buffers(page)) |
| 959 | goto failed; |
| 960 | } |
| 961 | |
| 962 | /* |
| 963 | * Allocate some buffers for this page |
| 964 | */ |
Jens Axboe | 94dc24c | 2017-09-27 05:45:36 -0600 | [diff] [blame] | 965 | bh = alloc_page_buffers(page, size, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | |
| 967 | /* |
| 968 | * Link the page to the buffers and initialise them. Take the |
| 969 | * lock to be atomic wrt __find_get_block(), which does not |
| 970 | * run under the page lock. |
| 971 | */ |
| 972 | spin_lock(&inode->i_mapping->private_lock); |
| 973 | link_dev_buffers(page, bh); |
Anton Altaparmakov | f2d5a94 | 2014-09-22 01:53:03 +0100 | [diff] [blame] | 974 | end_block = init_page_buffers(page, bdev, (sector_t)index << sizebits, |
| 975 | size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | spin_unlock(&inode->i_mapping->private_lock); |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 977 | done: |
| 978 | ret = (block < end_block) ? 1 : -ENXIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | failed: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 981 | put_page(page); |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 982 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | } |
| 984 | |
| 985 | /* |
| 986 | * Create buffers for the specified block device block's page. If |
| 987 | * that page was dirty, the buffers are set dirty also. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 989 | static int |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 990 | grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | pgoff_t index; |
| 993 | int sizebits; |
| 994 | |
Mikulas Patocka | 90432e6 | 2021-03-22 10:05:05 -0400 | [diff] [blame] | 995 | sizebits = PAGE_SHIFT - __ffs(size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | index = block >> sizebits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | |
Andrew Morton | e565793 | 2006-10-11 01:21:46 -0700 | [diff] [blame] | 998 | /* |
| 999 | * Check for a block which wants to lie outside our maximum possible |
| 1000 | * pagecache index. (this comparison is done using sector_t types). |
| 1001 | */ |
| 1002 | if (unlikely(index != block >> sizebits)) { |
Andrew Morton | e565793 | 2006-10-11 01:21:46 -0700 | [diff] [blame] | 1003 | printk(KERN_ERR "%s: requested out-of-range block %llu for " |
Dmitry Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 1004 | "device %pg\n", |
Harvey Harrison | 8e24eea | 2008-04-30 00:55:09 -0700 | [diff] [blame] | 1005 | __func__, (unsigned long long)block, |
Dmitry Monakhov | a1c6f057 | 2015-04-13 16:31:37 +0400 | [diff] [blame] | 1006 | bdev); |
Andrew Morton | e565793 | 2006-10-11 01:21:46 -0700 | [diff] [blame] | 1007 | return -EIO; |
| 1008 | } |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 1009 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | /* Create a page with the proper size buffers.. */ |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1011 | return grow_dev_page(bdev, block, index, size, sizebits, gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | } |
| 1013 | |
Eric Biggers | 0026ba4 | 2016-09-12 13:30:41 -0700 | [diff] [blame] | 1014 | static struct buffer_head * |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1015 | __getblk_slow(struct block_device *bdev, sector_t block, |
| 1016 | unsigned size, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1017 | { |
| 1018 | /* Size must be multiple of hard sectorsize */ |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 1019 | if (unlikely(size & (bdev_logical_block_size(bdev)-1) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1020 | (size < 512 || size > PAGE_SIZE))) { |
| 1021 | printk(KERN_ERR "getblk(): invalid block size %d requested\n", |
| 1022 | size); |
Martin K. Petersen | e1defc4 | 2009-05-22 17:17:49 -0400 | [diff] [blame] | 1023 | printk(KERN_ERR "logical block size: %d\n", |
| 1024 | bdev_logical_block_size(bdev)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | |
| 1026 | dump_stack(); |
| 1027 | return NULL; |
| 1028 | } |
| 1029 | |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 1030 | for (;;) { |
| 1031 | struct buffer_head *bh; |
| 1032 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | |
| 1034 | bh = __find_get_block(bdev, block, size); |
| 1035 | if (bh) |
| 1036 | return bh; |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 1037 | |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1038 | ret = grow_buffers(bdev, block, size, gfp); |
Hugh Dickins | 676ce6d | 2012-08-23 12:17:36 +0200 | [diff] [blame] | 1039 | if (ret < 0) |
| 1040 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | /* |
| 1045 | * The relationship between dirty buffers and dirty pages: |
| 1046 | * |
| 1047 | * Whenever a page has any dirty buffers, the page's dirty bit is set, and |
Matthew Wilcox | ec82e1c | 2017-12-04 10:40:41 -0500 | [diff] [blame] | 1048 | * the page is tagged dirty in the page cache. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | * |
| 1050 | * At all times, the dirtiness of the buffers represents the dirtiness of |
| 1051 | * subsections of the page. If the page has buffers, the page dirty bit is |
| 1052 | * merely a hint about the true dirty state. |
| 1053 | * |
| 1054 | * When a page is set dirty in its entirety, all its buffers are marked dirty |
| 1055 | * (if the page has buffers). |
| 1056 | * |
| 1057 | * When a buffer is marked dirty, its page is dirtied, but the page's other |
| 1058 | * buffers are not. |
| 1059 | * |
| 1060 | * Also. When blockdev buffers are explicitly read with bread(), they |
| 1061 | * individually become uptodate. But their backing page remains not |
| 1062 | * uptodate - even if all of its buffers are uptodate. A subsequent |
| 1063 | * block_read_full_page() against that page will discover all the uptodate |
| 1064 | * buffers, will set the page uptodate and will perform no I/O. |
| 1065 | */ |
| 1066 | |
| 1067 | /** |
| 1068 | * mark_buffer_dirty - mark a buffer_head as needing writeout |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 1069 | * @bh: the buffer_head to mark dirty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | * |
Matthew Wilcox | ec82e1c | 2017-12-04 10:40:41 -0500 | [diff] [blame] | 1071 | * mark_buffer_dirty() will set the dirty bit against the buffer, then set |
| 1072 | * its backing page dirty, then tag the page as dirty in the page cache |
| 1073 | * and then attach the address_space's inode to its superblock's dirty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | * inode list. |
| 1075 | * |
| 1076 | * mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock, |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 1077 | * i_pages lock and mapping->host->i_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | */ |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1079 | void mark_buffer_dirty(struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1080 | { |
Nick Piggin | 787d2214 | 2007-07-17 04:03:34 -0700 | [diff] [blame] | 1081 | WARN_ON_ONCE(!buffer_uptodate(bh)); |
Linus Torvalds | 1be62dc | 2008-04-04 14:38:17 -0700 | [diff] [blame] | 1082 | |
Tejun Heo | 5305cb8 | 2013-01-11 13:06:36 -0800 | [diff] [blame] | 1083 | trace_block_dirty_buffer(bh); |
| 1084 | |
Linus Torvalds | 1be62dc | 2008-04-04 14:38:17 -0700 | [diff] [blame] | 1085 | /* |
| 1086 | * Very *carefully* optimize the it-is-already-dirty case. |
| 1087 | * |
| 1088 | * Don't let the final "is it dirty" escape to before we |
| 1089 | * perhaps modified the buffer. |
| 1090 | */ |
| 1091 | if (buffer_dirty(bh)) { |
| 1092 | smp_mb(); |
| 1093 | if (buffer_dirty(bh)) |
| 1094 | return; |
| 1095 | } |
| 1096 | |
Linus Torvalds | a8e7d49 | 2009-03-19 11:32:05 -0700 | [diff] [blame] | 1097 | if (!test_set_buffer_dirty(bh)) { |
| 1098 | struct page *page = bh->b_page; |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 1099 | struct address_space *mapping = NULL; |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 1100 | |
Johannes Weiner | 62cccb8 | 2016-03-15 14:57:22 -0700 | [diff] [blame] | 1101 | lock_page_memcg(page); |
Linus Torvalds | 8e9d78e | 2009-08-21 17:40:08 -0700 | [diff] [blame] | 1102 | if (!TestSetPageDirty(page)) { |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 1103 | mapping = page_mapping(page); |
Linus Torvalds | 8e9d78e | 2009-08-21 17:40:08 -0700 | [diff] [blame] | 1104 | if (mapping) |
Johannes Weiner | 62cccb8 | 2016-03-15 14:57:22 -0700 | [diff] [blame] | 1105 | __set_page_dirty(page, mapping, 0); |
Linus Torvalds | 8e9d78e | 2009-08-21 17:40:08 -0700 | [diff] [blame] | 1106 | } |
Johannes Weiner | 62cccb8 | 2016-03-15 14:57:22 -0700 | [diff] [blame] | 1107 | unlock_page_memcg(page); |
Greg Thelen | c4843a7 | 2015-05-22 17:13:16 -0400 | [diff] [blame] | 1108 | if (mapping) |
| 1109 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); |
Linus Torvalds | a8e7d49 | 2009-03-19 11:32:05 -0700 | [diff] [blame] | 1110 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 1112 | EXPORT_SYMBOL(mark_buffer_dirty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1113 | |
Jeff Layton | 87354e5 | 2017-07-06 07:02:21 -0400 | [diff] [blame] | 1114 | void mark_buffer_write_io_error(struct buffer_head *bh) |
| 1115 | { |
Jeff Layton | 485e960 | 2020-06-01 21:45:40 -0700 | [diff] [blame] | 1116 | struct super_block *sb; |
| 1117 | |
Jeff Layton | 87354e5 | 2017-07-06 07:02:21 -0400 | [diff] [blame] | 1118 | set_buffer_write_io_error(bh); |
| 1119 | /* FIXME: do we need to set this in both places? */ |
| 1120 | if (bh->b_page && bh->b_page->mapping) |
| 1121 | mapping_set_error(bh->b_page->mapping, -EIO); |
| 1122 | if (bh->b_assoc_map) |
| 1123 | mapping_set_error(bh->b_assoc_map, -EIO); |
Jeff Layton | 485e960 | 2020-06-01 21:45:40 -0700 | [diff] [blame] | 1124 | rcu_read_lock(); |
| 1125 | sb = READ_ONCE(bh->b_bdev->bd_super); |
| 1126 | if (sb) |
| 1127 | errseq_set(&sb->s_wb_err, -EIO); |
| 1128 | rcu_read_unlock(); |
Jeff Layton | 87354e5 | 2017-07-06 07:02:21 -0400 | [diff] [blame] | 1129 | } |
| 1130 | EXPORT_SYMBOL(mark_buffer_write_io_error); |
| 1131 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | /* |
| 1133 | * Decrement a buffer_head's reference count. If all buffers against a page |
| 1134 | * have zero reference count, are clean and unlocked, and if the page is clean |
| 1135 | * and unlocked then try_to_free_buffers() may strip the buffers from the page |
| 1136 | * in preparation for freeing it (sometimes, rarely, buffers are removed from |
| 1137 | * a page but it ends up not being freed, and buffers may later be reattached). |
| 1138 | */ |
| 1139 | void __brelse(struct buffer_head * buf) |
| 1140 | { |
| 1141 | if (atomic_read(&buf->b_count)) { |
| 1142 | put_bh(buf); |
| 1143 | return; |
| 1144 | } |
Arjan van de Ven | 5c752ad | 2008-07-25 19:45:40 -0700 | [diff] [blame] | 1145 | WARN(1, KERN_ERR "VFS: brelse: Trying to free free buffer\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 1147 | EXPORT_SYMBOL(__brelse); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | |
| 1149 | /* |
| 1150 | * bforget() is like brelse(), except it discards any |
| 1151 | * potentially dirty data. |
| 1152 | */ |
| 1153 | void __bforget(struct buffer_head *bh) |
| 1154 | { |
| 1155 | clear_buffer_dirty(bh); |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 1156 | if (bh->b_assoc_map) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | struct address_space *buffer_mapping = bh->b_page->mapping; |
| 1158 | |
| 1159 | spin_lock(&buffer_mapping->private_lock); |
| 1160 | list_del_init(&bh->b_assoc_buffers); |
Jan Kara | 58ff407b | 2006-10-17 00:10:19 -0700 | [diff] [blame] | 1161 | bh->b_assoc_map = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | spin_unlock(&buffer_mapping->private_lock); |
| 1163 | } |
| 1164 | __brelse(bh); |
| 1165 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 1166 | EXPORT_SYMBOL(__bforget); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | |
| 1168 | static struct buffer_head *__bread_slow(struct buffer_head *bh) |
| 1169 | { |
| 1170 | lock_buffer(bh); |
| 1171 | if (buffer_uptodate(bh)) { |
| 1172 | unlock_buffer(bh); |
| 1173 | return bh; |
| 1174 | } else { |
| 1175 | get_bh(bh); |
| 1176 | bh->b_end_io = end_buffer_read_sync; |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 1177 | submit_bh(REQ_OP_READ, 0, bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | wait_on_buffer(bh); |
| 1179 | if (buffer_uptodate(bh)) |
| 1180 | return bh; |
| 1181 | } |
| 1182 | brelse(bh); |
| 1183 | return NULL; |
| 1184 | } |
| 1185 | |
| 1186 | /* |
| 1187 | * Per-cpu buffer LRU implementation. To reduce the cost of __find_get_block(). |
| 1188 | * The bhs[] array is sorted - newest buffer is at bhs[0]. Buffers have their |
| 1189 | * refcount elevated by one when they're in an LRU. A buffer can only appear |
| 1190 | * once in a particular CPU's LRU. A single buffer can be present in multiple |
| 1191 | * CPU's LRUs at the same time. |
| 1192 | * |
| 1193 | * This is a transparent caching front-end to sb_bread(), sb_getblk() and |
| 1194 | * sb_find_get_block(). |
| 1195 | * |
| 1196 | * The LRUs themselves only need locking against invalidate_bh_lrus. We use |
| 1197 | * a local interrupt disable for that. |
| 1198 | */ |
| 1199 | |
Sebastien Buisson | 86cf78d | 2014-10-09 15:29:38 -0700 | [diff] [blame] | 1200 | #define BH_LRU_SIZE 16 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | |
| 1202 | struct bh_lru { |
| 1203 | struct buffer_head *bhs[BH_LRU_SIZE]; |
| 1204 | }; |
| 1205 | |
| 1206 | static DEFINE_PER_CPU(struct bh_lru, bh_lrus) = {{ NULL }}; |
| 1207 | |
| 1208 | #ifdef CONFIG_SMP |
| 1209 | #define bh_lru_lock() local_irq_disable() |
| 1210 | #define bh_lru_unlock() local_irq_enable() |
| 1211 | #else |
| 1212 | #define bh_lru_lock() preempt_disable() |
| 1213 | #define bh_lru_unlock() preempt_enable() |
| 1214 | #endif |
| 1215 | |
| 1216 | static inline void check_irqs_on(void) |
| 1217 | { |
| 1218 | #ifdef irqs_disabled |
| 1219 | BUG_ON(irqs_disabled()); |
| 1220 | #endif |
| 1221 | } |
| 1222 | |
| 1223 | /* |
Eric Biggers | 241f01f | 2017-07-10 15:47:29 -0700 | [diff] [blame] | 1224 | * Install a buffer_head into this cpu's LRU. If not already in the LRU, it is |
| 1225 | * inserted at the front, and the buffer_head at the back if any is evicted. |
| 1226 | * Or, if already in the LRU it is moved to the front. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1227 | */ |
| 1228 | static void bh_lru_install(struct buffer_head *bh) |
| 1229 | { |
Eric Biggers | 241f01f | 2017-07-10 15:47:29 -0700 | [diff] [blame] | 1230 | struct buffer_head *evictee = bh; |
| 1231 | struct bh_lru *b; |
| 1232 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | |
| 1234 | check_irqs_on(); |
Minchan Kim | c0226eb | 2022-03-22 14:39:34 -0700 | [diff] [blame] | 1235 | bh_lru_lock(); |
| 1236 | |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1237 | /* |
| 1238 | * the refcount of buffer_head in bh_lru prevents dropping the |
| 1239 | * attached page(i.e., try_to_free_buffers) so it could cause |
| 1240 | * failing page migration. |
| 1241 | * Skip putting upcoming bh into bh_lru until migration is done. |
| 1242 | */ |
Minchan Kim | c0226eb | 2022-03-22 14:39:34 -0700 | [diff] [blame] | 1243 | if (lru_cache_disabled()) { |
| 1244 | bh_lru_unlock(); |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1245 | return; |
Minchan Kim | c0226eb | 2022-03-22 14:39:34 -0700 | [diff] [blame] | 1246 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | |
Eric Biggers | 241f01f | 2017-07-10 15:47:29 -0700 | [diff] [blame] | 1248 | b = this_cpu_ptr(&bh_lrus); |
| 1249 | for (i = 0; i < BH_LRU_SIZE; i++) { |
| 1250 | swap(evictee, b->bhs[i]); |
| 1251 | if (evictee == bh) { |
| 1252 | bh_lru_unlock(); |
| 1253 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1254 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | |
Eric Biggers | 241f01f | 2017-07-10 15:47:29 -0700 | [diff] [blame] | 1257 | get_bh(bh); |
| 1258 | bh_lru_unlock(); |
| 1259 | brelse(evictee); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | } |
| 1261 | |
| 1262 | /* |
| 1263 | * Look up the bh in this cpu's LRU. If it's there, move it to the head. |
| 1264 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1265 | static struct buffer_head * |
Tomasz Kvarsin | 3991d3b | 2007-02-12 00:52:14 -0800 | [diff] [blame] | 1266 | lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | { |
| 1268 | struct buffer_head *ret = NULL; |
Tomasz Kvarsin | 3991d3b | 2007-02-12 00:52:14 -0800 | [diff] [blame] | 1269 | unsigned int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1270 | |
| 1271 | check_irqs_on(); |
| 1272 | bh_lru_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1273 | for (i = 0; i < BH_LRU_SIZE; i++) { |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 1274 | struct buffer_head *bh = __this_cpu_read(bh_lrus.bhs[i]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | |
Zach Brown | 9470dd5 | 2014-10-13 15:55:05 -0700 | [diff] [blame] | 1276 | if (bh && bh->b_blocknr == block && bh->b_bdev == bdev && |
| 1277 | bh->b_size == size) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | if (i) { |
| 1279 | while (i) { |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 1280 | __this_cpu_write(bh_lrus.bhs[i], |
| 1281 | __this_cpu_read(bh_lrus.bhs[i - 1])); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1282 | i--; |
| 1283 | } |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 1284 | __this_cpu_write(bh_lrus.bhs[0], bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | } |
| 1286 | get_bh(bh); |
| 1287 | ret = bh; |
| 1288 | break; |
| 1289 | } |
| 1290 | } |
| 1291 | bh_lru_unlock(); |
| 1292 | return ret; |
| 1293 | } |
| 1294 | |
| 1295 | /* |
| 1296 | * Perform a pagecache lookup for the matching buffer. If it's there, refresh |
| 1297 | * it in the LRU and mark it as accessed. If it is not present then return |
| 1298 | * NULL |
| 1299 | */ |
| 1300 | struct buffer_head * |
Tomasz Kvarsin | 3991d3b | 2007-02-12 00:52:14 -0800 | [diff] [blame] | 1301 | __find_get_block(struct block_device *bdev, sector_t block, unsigned size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | { |
| 1303 | struct buffer_head *bh = lookup_bh_lru(bdev, block, size); |
| 1304 | |
| 1305 | if (bh == NULL) { |
Mel Gorman | 2457aec | 2014-06-04 16:10:31 -0700 | [diff] [blame] | 1306 | /* __find_get_block_slow will mark the page accessed */ |
Coywolf Qi Hunt | 385fd4c | 2005-11-07 00:59:39 -0800 | [diff] [blame] | 1307 | bh = __find_get_block_slow(bdev, block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1308 | if (bh) |
| 1309 | bh_lru_install(bh); |
Mel Gorman | 2457aec | 2014-06-04 16:10:31 -0700 | [diff] [blame] | 1310 | } else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | touch_buffer(bh); |
Mel Gorman | 2457aec | 2014-06-04 16:10:31 -0700 | [diff] [blame] | 1312 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | return bh; |
| 1314 | } |
| 1315 | EXPORT_SYMBOL(__find_get_block); |
| 1316 | |
| 1317 | /* |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1318 | * __getblk_gfp() will locate (and, if necessary, create) the buffer_head |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | * which corresponds to the passed block_device, block and size. The |
| 1320 | * returned buffer has its reference count incremented. |
| 1321 | * |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1322 | * __getblk_gfp() will lock up the machine if grow_dev_page's |
| 1323 | * try_to_free_buffers() attempt is failing. FIXME, perhaps? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | */ |
| 1325 | struct buffer_head * |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1326 | __getblk_gfp(struct block_device *bdev, sector_t block, |
| 1327 | unsigned size, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1328 | { |
| 1329 | struct buffer_head *bh = __find_get_block(bdev, block, size); |
| 1330 | |
| 1331 | might_sleep(); |
| 1332 | if (bh == NULL) |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1333 | bh = __getblk_slow(bdev, block, size, gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | return bh; |
| 1335 | } |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1336 | EXPORT_SYMBOL(__getblk_gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | |
| 1338 | /* |
| 1339 | * Do async read-ahead on a buffer.. |
| 1340 | */ |
Tomasz Kvarsin | 3991d3b | 2007-02-12 00:52:14 -0800 | [diff] [blame] | 1341 | void __breadahead(struct block_device *bdev, sector_t block, unsigned size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1342 | { |
| 1343 | struct buffer_head *bh = __getblk(bdev, block, size); |
Andrew Morton | a3e713b | 2005-10-30 15:03:15 -0800 | [diff] [blame] | 1344 | if (likely(bh)) { |
Christoph Hellwig | 7024628 | 2016-07-19 11:28:41 +0200 | [diff] [blame] | 1345 | ll_rw_block(REQ_OP_READ, REQ_RAHEAD, 1, &bh); |
Andrew Morton | a3e713b | 2005-10-30 15:03:15 -0800 | [diff] [blame] | 1346 | brelse(bh); |
| 1347 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | } |
| 1349 | EXPORT_SYMBOL(__breadahead); |
| 1350 | |
Roman Gushchin | d87f639 | 2020-02-28 16:14:11 -0800 | [diff] [blame] | 1351 | void __breadahead_gfp(struct block_device *bdev, sector_t block, unsigned size, |
| 1352 | gfp_t gfp) |
| 1353 | { |
| 1354 | struct buffer_head *bh = __getblk_gfp(bdev, block, size, gfp); |
| 1355 | if (likely(bh)) { |
| 1356 | ll_rw_block(REQ_OP_READ, REQ_RAHEAD, 1, &bh); |
| 1357 | brelse(bh); |
| 1358 | } |
| 1359 | } |
| 1360 | EXPORT_SYMBOL(__breadahead_gfp); |
| 1361 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | /** |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1363 | * __bread_gfp() - reads a specified block and returns the bh |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 1364 | * @bdev: the block_device to read from |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1365 | * @block: number of block |
| 1366 | * @size: size (in bytes) to read |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1367 | * @gfp: page allocation flag |
| 1368 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | * Reads a specified block, and returns buffer head that contains it. |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1370 | * The page cache can be allocated from non-movable area |
| 1371 | * not to prevent page migration if you set gfp to zero. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | * It returns NULL if the block was unreadable. |
| 1373 | */ |
| 1374 | struct buffer_head * |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1375 | __bread_gfp(struct block_device *bdev, sector_t block, |
| 1376 | unsigned size, gfp_t gfp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1377 | { |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1378 | struct buffer_head *bh = __getblk_gfp(bdev, block, size, gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | |
Andrew Morton | a3e713b | 2005-10-30 15:03:15 -0800 | [diff] [blame] | 1380 | if (likely(bh) && !buffer_uptodate(bh)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | bh = __bread_slow(bh); |
| 1382 | return bh; |
| 1383 | } |
Gioh Kim | 3b5e645 | 2014-09-04 22:04:42 -0400 | [diff] [blame] | 1384 | EXPORT_SYMBOL(__bread_gfp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1386 | static void __invalidate_bh_lrus(struct bh_lru *b) |
| 1387 | { |
| 1388 | int i; |
| 1389 | |
| 1390 | for (i = 0; i < BH_LRU_SIZE; i++) { |
| 1391 | brelse(b->bhs[i]); |
| 1392 | b->bhs[i] = NULL; |
| 1393 | } |
| 1394 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | /* |
| 1396 | * invalidate_bh_lrus() is called rarely - but not only at unmount. |
| 1397 | * This doesn't race because it runs in each cpu either in irq |
| 1398 | * or with preempt disabled. |
| 1399 | */ |
| 1400 | static void invalidate_bh_lru(void *arg) |
| 1401 | { |
| 1402 | struct bh_lru *b = &get_cpu_var(bh_lrus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1403 | |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1404 | __invalidate_bh_lrus(b); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1405 | put_cpu_var(bh_lrus); |
| 1406 | } |
Gilad Ben-Yossef | 42be35d | 2012-03-28 14:42:45 -0700 | [diff] [blame] | 1407 | |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1408 | bool has_bh_in_lru(int cpu, void *dummy) |
Gilad Ben-Yossef | 42be35d | 2012-03-28 14:42:45 -0700 | [diff] [blame] | 1409 | { |
| 1410 | struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu); |
| 1411 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | |
Gilad Ben-Yossef | 42be35d | 2012-03-28 14:42:45 -0700 | [diff] [blame] | 1413 | for (i = 0; i < BH_LRU_SIZE; i++) { |
| 1414 | if (b->bhs[i]) |
Saurav Girepunje | 1d70667 | 2019-11-30 17:49:15 -0800 | [diff] [blame] | 1415 | return true; |
Gilad Ben-Yossef | 42be35d | 2012-03-28 14:42:45 -0700 | [diff] [blame] | 1416 | } |
| 1417 | |
Saurav Girepunje | 1d70667 | 2019-11-30 17:49:15 -0800 | [diff] [blame] | 1418 | return false; |
Gilad Ben-Yossef | 42be35d | 2012-03-28 14:42:45 -0700 | [diff] [blame] | 1419 | } |
| 1420 | |
Peter Zijlstra | f9a1439 | 2007-05-06 14:49:55 -0700 | [diff] [blame] | 1421 | void invalidate_bh_lrus(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1422 | { |
Sebastian Andrzej Siewior | cb92315 | 2020-01-17 10:01:37 +0100 | [diff] [blame] | 1423 | on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1424 | } |
Nick Piggin | 9db5579 | 2008-02-08 04:19:49 -0800 | [diff] [blame] | 1425 | EXPORT_SYMBOL_GPL(invalidate_bh_lrus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | |
Minchan Kim | 243418e | 2021-09-24 15:43:47 -0700 | [diff] [blame] | 1427 | /* |
| 1428 | * It's called from workqueue context so we need a bh_lru_lock to close |
| 1429 | * the race with preemption/irq. |
| 1430 | */ |
| 1431 | void invalidate_bh_lrus_cpu(void) |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1432 | { |
| 1433 | struct bh_lru *b; |
| 1434 | |
| 1435 | bh_lru_lock(); |
Minchan Kim | 243418e | 2021-09-24 15:43:47 -0700 | [diff] [blame] | 1436 | b = this_cpu_ptr(&bh_lrus); |
Minchan Kim | 8cc621d | 2021-05-04 18:37:00 -0700 | [diff] [blame] | 1437 | __invalidate_bh_lrus(b); |
| 1438 | bh_lru_unlock(); |
| 1439 | } |
| 1440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | void set_bh_page(struct buffer_head *bh, |
| 1442 | struct page *page, unsigned long offset) |
| 1443 | { |
| 1444 | bh->b_page = page; |
Eric Sesterhenn | e827f92 | 2006-03-26 18:24:46 +0200 | [diff] [blame] | 1445 | BUG_ON(offset >= PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | if (PageHighMem(page)) |
| 1447 | /* |
| 1448 | * This catches illegal uses and preserves the offset: |
| 1449 | */ |
| 1450 | bh->b_data = (char *)(0 + offset); |
| 1451 | else |
| 1452 | bh->b_data = page_address(page) + offset; |
| 1453 | } |
| 1454 | EXPORT_SYMBOL(set_bh_page); |
| 1455 | |
| 1456 | /* |
| 1457 | * Called when truncating a buffer on a page completely. |
| 1458 | */ |
Mel Gorman | e7470ee | 2014-06-04 16:10:29 -0700 | [diff] [blame] | 1459 | |
| 1460 | /* Bits that are cleared during an invalidate */ |
| 1461 | #define BUFFER_FLAGS_DISCARD \ |
| 1462 | (1 << BH_Mapped | 1 << BH_New | 1 << BH_Req | \ |
| 1463 | 1 << BH_Delay | 1 << BH_Unwritten) |
| 1464 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1465 | static void discard_buffer(struct buffer_head * bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1466 | { |
Mel Gorman | e7470ee | 2014-06-04 16:10:29 -0700 | [diff] [blame] | 1467 | unsigned long b_state, b_state_old; |
| 1468 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | lock_buffer(bh); |
| 1470 | clear_buffer_dirty(bh); |
| 1471 | bh->b_bdev = NULL; |
Mel Gorman | e7470ee | 2014-06-04 16:10:29 -0700 | [diff] [blame] | 1472 | b_state = bh->b_state; |
| 1473 | for (;;) { |
| 1474 | b_state_old = cmpxchg(&bh->b_state, b_state, |
| 1475 | (b_state & ~BUFFER_FLAGS_DISCARD)); |
| 1476 | if (b_state_old == b_state) |
| 1477 | break; |
| 1478 | b_state = b_state_old; |
| 1479 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | unlock_buffer(bh); |
| 1481 | } |
| 1482 | |
| 1483 | /** |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1484 | * block_invalidate_folio - Invalidate part or all of a buffer-backed folio. |
| 1485 | * @folio: The folio which is affected. |
Lukas Czerner | d47992f | 2013-05-21 23:17:23 -0400 | [diff] [blame] | 1486 | * @offset: start of the range to invalidate |
| 1487 | * @length: length of the range to invalidate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | * |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1489 | * block_invalidate_folio() is called when all or part of the folio has been |
Wang Sheng-Hui | 814e1d2 | 2011-09-01 08:22:57 +0800 | [diff] [blame] | 1490 | * invalidated by a truncate operation. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1491 | * |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1492 | * block_invalidate_folio() does not have to release all buffers, but it must |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | * ensure that no dirty buffer is left outside @offset and that no I/O |
| 1494 | * is underway against any of the blocks which are outside the truncation |
| 1495 | * point. Because the caller is about to free (and possibly reuse) those |
| 1496 | * blocks on-disk. |
| 1497 | */ |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1498 | void block_invalidate_folio(struct folio *folio, size_t offset, size_t length) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | { |
| 1500 | struct buffer_head *head, *bh, *next; |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1501 | size_t curr_off = 0; |
| 1502 | size_t stop = length + offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1504 | BUG_ON(!folio_test_locked(folio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1505 | |
Lukas Czerner | d47992f | 2013-05-21 23:17:23 -0400 | [diff] [blame] | 1506 | /* |
| 1507 | * Check for overflow |
| 1508 | */ |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1509 | BUG_ON(stop > folio_size(folio) || stop < length); |
Lukas Czerner | d47992f | 2013-05-21 23:17:23 -0400 | [diff] [blame] | 1510 | |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1511 | head = folio_buffers(folio); |
| 1512 | if (!head) |
| 1513 | return; |
| 1514 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | bh = head; |
| 1516 | do { |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1517 | size_t next_off = curr_off + bh->b_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | next = bh->b_this_page; |
| 1519 | |
| 1520 | /* |
Lukas Czerner | d47992f | 2013-05-21 23:17:23 -0400 | [diff] [blame] | 1521 | * Are we still fully in range ? |
| 1522 | */ |
| 1523 | if (next_off > stop) |
| 1524 | goto out; |
| 1525 | |
| 1526 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1527 | * is this block fully invalidated? |
| 1528 | */ |
| 1529 | if (offset <= curr_off) |
| 1530 | discard_buffer(bh); |
| 1531 | curr_off = next_off; |
| 1532 | bh = next; |
| 1533 | } while (bh != head); |
| 1534 | |
| 1535 | /* |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1536 | * We release buffers only if the entire folio is being invalidated. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1537 | * The get_block cached value has been unconditionally invalidated, |
| 1538 | * so real IO is not possible anymore. |
| 1539 | */ |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1540 | if (length == folio_size(folio)) |
| 1541 | filemap_release_folio(folio, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | out: |
NeilBrown | 2ff28e2 | 2006-03-26 01:37:18 -0800 | [diff] [blame] | 1543 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1544 | } |
Matthew Wilcox (Oracle) | 7ba13ab | 2022-02-09 20:21:34 +0000 | [diff] [blame] | 1545 | EXPORT_SYMBOL(block_invalidate_folio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1546 | |
Lukas Czerner | d47992f | 2013-05-21 23:17:23 -0400 | [diff] [blame] | 1547 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1548 | /* |
| 1549 | * We attach and possibly dirty the buffers atomically wrt |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 1550 | * block_dirty_folio() via private_lock. try_to_free_buffers |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1551 | * is already excluded via the page lock. |
| 1552 | */ |
| 1553 | void create_empty_buffers(struct page *page, |
| 1554 | unsigned long blocksize, unsigned long b_state) |
| 1555 | { |
| 1556 | struct buffer_head *bh, *head, *tail; |
| 1557 | |
Jens Axboe | 640ab98 | 2017-09-27 05:40:16 -0600 | [diff] [blame] | 1558 | head = alloc_page_buffers(page, blocksize, true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | bh = head; |
| 1560 | do { |
| 1561 | bh->b_state |= b_state; |
| 1562 | tail = bh; |
| 1563 | bh = bh->b_this_page; |
| 1564 | } while (bh); |
| 1565 | tail->b_this_page = head; |
| 1566 | |
| 1567 | spin_lock(&page->mapping->private_lock); |
| 1568 | if (PageUptodate(page) || PageDirty(page)) { |
| 1569 | bh = head; |
| 1570 | do { |
| 1571 | if (PageDirty(page)) |
| 1572 | set_buffer_dirty(bh); |
| 1573 | if (PageUptodate(page)) |
| 1574 | set_buffer_uptodate(bh); |
| 1575 | bh = bh->b_this_page; |
| 1576 | } while (bh != head); |
| 1577 | } |
Guoqing Jiang | 45dcfc2 | 2020-06-01 21:47:48 -0700 | [diff] [blame] | 1578 | attach_page_private(page, head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | spin_unlock(&page->mapping->private_lock); |
| 1580 | } |
| 1581 | EXPORT_SYMBOL(create_empty_buffers); |
| 1582 | |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1583 | /** |
| 1584 | * clean_bdev_aliases: clean a range of buffers in block device |
| 1585 | * @bdev: Block device to clean buffers in |
| 1586 | * @block: Start of a range of blocks to clean |
| 1587 | * @len: Number of blocks to clean |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | * |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1589 | * We are taking a range of blocks for data and we don't want writeback of any |
| 1590 | * buffer-cache aliases starting from return from this function and until the |
| 1591 | * moment when something will explicitly mark the buffer dirty (hopefully that |
| 1592 | * will not happen until we will free that block ;-) We don't even need to mark |
| 1593 | * it not-uptodate - nobody can expect anything from a newly allocated buffer |
| 1594 | * anyway. We used to use unmap_buffer() for such invalidation, but that was |
| 1595 | * wrong. We definitely don't want to mark the alias unmapped, for example - it |
| 1596 | * would confuse anyone who might pick it with bread() afterwards... |
| 1597 | * |
| 1598 | * Also.. Note that bforget() doesn't lock the buffer. So there can be |
| 1599 | * writeout I/O going on against recently-freed buffers. We don't wait on that |
| 1600 | * I/O in bforget() - it's more efficient to wait on the I/O only if we really |
| 1601 | * need to. That happens here. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1602 | */ |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1603 | void clean_bdev_aliases(struct block_device *bdev, sector_t block, sector_t len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | { |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1605 | struct inode *bd_inode = bdev->bd_inode; |
| 1606 | struct address_space *bd_mapping = bd_inode->i_mapping; |
| 1607 | struct pagevec pvec; |
| 1608 | pgoff_t index = block >> (PAGE_SHIFT - bd_inode->i_blkbits); |
| 1609 | pgoff_t end; |
Jan Kara | c10f778 | 2017-09-06 16:21:24 -0700 | [diff] [blame] | 1610 | int i, count; |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1611 | struct buffer_head *bh; |
| 1612 | struct buffer_head *head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1613 | |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1614 | end = (block + len - 1) >> (PAGE_SHIFT - bd_inode->i_blkbits); |
Mel Gorman | 8667982 | 2017-11-15 17:37:52 -0800 | [diff] [blame] | 1615 | pagevec_init(&pvec); |
Jan Kara | 397162f | 2017-09-06 16:21:43 -0700 | [diff] [blame] | 1616 | while (pagevec_lookup_range(&pvec, bd_mapping, &index, end)) { |
Jan Kara | c10f778 | 2017-09-06 16:21:24 -0700 | [diff] [blame] | 1617 | count = pagevec_count(&pvec); |
| 1618 | for (i = 0; i < count; i++) { |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1619 | struct page *page = pvec.pages[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1620 | |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1621 | if (!page_has_buffers(page)) |
| 1622 | continue; |
| 1623 | /* |
| 1624 | * We use page lock instead of bd_mapping->private_lock |
| 1625 | * to pin buffers here since we can afford to sleep and |
| 1626 | * it scales better than a global spinlock lock. |
| 1627 | */ |
| 1628 | lock_page(page); |
| 1629 | /* Recheck when the page is locked which pins bhs */ |
| 1630 | if (!page_has_buffers(page)) |
| 1631 | goto unlock_page; |
| 1632 | head = page_buffers(page); |
| 1633 | bh = head; |
| 1634 | do { |
Chandan Rajendra | 6c006a9 | 2016-12-25 19:01:03 +0530 | [diff] [blame] | 1635 | if (!buffer_mapped(bh) || (bh->b_blocknr < block)) |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1636 | goto next; |
| 1637 | if (bh->b_blocknr >= block + len) |
| 1638 | break; |
| 1639 | clear_buffer_dirty(bh); |
| 1640 | wait_on_buffer(bh); |
| 1641 | clear_buffer_req(bh); |
| 1642 | next: |
| 1643 | bh = bh->b_this_page; |
| 1644 | } while (bh != head); |
| 1645 | unlock_page: |
| 1646 | unlock_page(page); |
| 1647 | } |
| 1648 | pagevec_release(&pvec); |
| 1649 | cond_resched(); |
Jan Kara | c10f778 | 2017-09-06 16:21:24 -0700 | [diff] [blame] | 1650 | /* End of range already reached? */ |
| 1651 | if (index > end || !index) |
| 1652 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | } |
| 1654 | } |
Jan Kara | 29f3ad7 | 2016-11-04 18:08:11 +0100 | [diff] [blame] | 1655 | EXPORT_SYMBOL(clean_bdev_aliases); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | |
| 1657 | /* |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1658 | * Size is a power-of-two in the range 512..PAGE_SIZE, |
| 1659 | * and the case we care about most is PAGE_SIZE. |
| 1660 | * |
| 1661 | * So this *could* possibly be written with those |
| 1662 | * constraints in mind (relevant mostly if some |
| 1663 | * architecture has a slow bit-scan instruction) |
| 1664 | */ |
| 1665 | static inline int block_size_bits(unsigned int blocksize) |
| 1666 | { |
| 1667 | return ilog2(blocksize); |
| 1668 | } |
| 1669 | |
| 1670 | static struct buffer_head *create_page_buffers(struct page *page, struct inode *inode, unsigned int b_state) |
| 1671 | { |
| 1672 | BUG_ON(!PageLocked(page)); |
| 1673 | |
| 1674 | if (!page_has_buffers(page)) |
Mark Rutland | 6aa7de0 | 2017-10-23 14:07:29 -0700 | [diff] [blame] | 1675 | create_empty_buffers(page, 1 << READ_ONCE(inode->i_blkbits), |
| 1676 | b_state); |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1677 | return page_buffers(page); |
| 1678 | } |
| 1679 | |
| 1680 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1681 | * NOTE! All mapped/uptodate combinations are valid: |
| 1682 | * |
| 1683 | * Mapped Uptodate Meaning |
| 1684 | * |
| 1685 | * No No "unknown" - must do get_block() |
| 1686 | * No Yes "hole" - zero-filled |
| 1687 | * Yes No "allocated" - allocated on disk, not read in |
| 1688 | * Yes Yes "valid" - allocated and up-to-date in memory. |
| 1689 | * |
| 1690 | * "Dirty" is valid only with the last case (mapped+uptodate). |
| 1691 | */ |
| 1692 | |
| 1693 | /* |
| 1694 | * While block_write_full_page is writing back the dirty buffers under |
| 1695 | * the page lock, whoever dirtied the buffers may decide to clean them |
| 1696 | * again at any time. We handle that by only looking at the buffer |
| 1697 | * state inside lock_buffer(). |
| 1698 | * |
| 1699 | * If block_write_full_page() is called for regular writeback |
| 1700 | * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a |
| 1701 | * locked buffer. This only can happen if someone has written the buffer |
| 1702 | * directly, with submit_bh(). At the address_space level PageWriteback |
| 1703 | * prevents this contention from occurring. |
Theodore Ts'o | 6e34eedd | 2009-04-07 18:12:43 -0400 | [diff] [blame] | 1704 | * |
| 1705 | * If block_write_full_page() is called with wbc->sync_mode == |
Christoph Hellwig | 70fd761 | 2016-11-01 07:40:10 -0600 | [diff] [blame] | 1706 | * WB_SYNC_ALL, the writes are posted using REQ_SYNC; this |
Jens Axboe | 721a960 | 2011-03-09 11:56:30 +0100 | [diff] [blame] | 1707 | * causes the writes to be flagged as synchronous writes. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1708 | */ |
Benjamin Marzinski | b4bba38 | 2016-06-27 09:58:40 -0500 | [diff] [blame] | 1709 | int __block_write_full_page(struct inode *inode, struct page *page, |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 1710 | get_block_t *get_block, struct writeback_control *wbc, |
| 1711 | bh_end_io_t *handler) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1712 | { |
| 1713 | int err; |
| 1714 | sector_t block; |
| 1715 | sector_t last_block; |
Andrew Morton | f0fbd5f | 2005-05-05 16:15:48 -0700 | [diff] [blame] | 1716 | struct buffer_head *bh, *head; |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1717 | unsigned int blocksize, bbits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1718 | int nr_underway = 0; |
Jens Axboe | 7637241 | 2016-11-01 10:00:38 -0600 | [diff] [blame] | 1719 | int write_flags = wbc_to_write_flags(wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1720 | |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1721 | head = create_page_buffers(page, inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1722 | (1 << BH_Dirty)|(1 << BH_Uptodate)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1723 | |
| 1724 | /* |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 1725 | * Be very careful. We have no exclusion from block_dirty_folio |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1726 | * here, and the (potentially unmapped) buffers may become dirty at |
| 1727 | * any time. If a buffer becomes dirty here after we've inspected it |
| 1728 | * then we just miss that fact, and the page stays dirty. |
| 1729 | * |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 1730 | * Buffers outside i_size may be dirtied by block_dirty_folio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1731 | * handle that here by just cleaning them. |
| 1732 | */ |
| 1733 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1734 | bh = head; |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1735 | blocksize = bh->b_size; |
| 1736 | bbits = block_size_bits(blocksize); |
| 1737 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1738 | block = (sector_t)page->index << (PAGE_SHIFT - bbits); |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1739 | last_block = (i_size_read(inode) - 1) >> bbits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1740 | |
| 1741 | /* |
| 1742 | * Get all the dirty buffers mapped to disk addresses and |
| 1743 | * handle any aliases from the underlying blockdev's mapping. |
| 1744 | */ |
| 1745 | do { |
| 1746 | if (block > last_block) { |
| 1747 | /* |
| 1748 | * mapped buffers outside i_size will occur, because |
| 1749 | * this page can be outside i_size when there is a |
| 1750 | * truncate in progress. |
| 1751 | */ |
| 1752 | /* |
| 1753 | * The buffer was zeroed by block_write_full_page() |
| 1754 | */ |
| 1755 | clear_buffer_dirty(bh); |
| 1756 | set_buffer_uptodate(bh); |
Alex Tomas | 29a814d | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 1757 | } else if ((!buffer_mapped(bh) || buffer_delay(bh)) && |
| 1758 | buffer_dirty(bh)) { |
Badari Pulavarty | b0cf232 | 2006-03-26 01:38:00 -0800 | [diff] [blame] | 1759 | WARN_ON(bh->b_size != blocksize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1760 | err = get_block(inode, block, bh, 1); |
| 1761 | if (err) |
| 1762 | goto recover; |
Alex Tomas | 29a814d | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 1763 | clear_buffer_delay(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1764 | if (buffer_new(bh)) { |
| 1765 | /* blockdev mappings never come here */ |
| 1766 | clear_buffer_new(bh); |
Jan Kara | e64855c | 2016-11-04 18:08:15 +0100 | [diff] [blame] | 1767 | clean_bdev_bh_alias(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1768 | } |
| 1769 | } |
| 1770 | bh = bh->b_this_page; |
| 1771 | block++; |
| 1772 | } while (bh != head); |
| 1773 | |
| 1774 | do { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1775 | if (!buffer_mapped(bh)) |
| 1776 | continue; |
| 1777 | /* |
| 1778 | * If it's a fully non-blocking write attempt and we cannot |
| 1779 | * lock the buffer then redirty the page. Note that this can |
Jens Axboe | 5b0830c | 2009-09-23 19:37:09 +0200 | [diff] [blame] | 1780 | * potentially cause a busy-wait loop from writeback threads |
| 1781 | * and kswapd activity, but those code paths have their own |
| 1782 | * higher-level throttling. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | */ |
Wu Fengguang | 1b430be | 2010-10-26 14:21:26 -0700 | [diff] [blame] | 1784 | if (wbc->sync_mode != WB_SYNC_NONE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1785 | lock_buffer(bh); |
Nick Piggin | ca5de40 | 2008-08-02 12:02:13 +0200 | [diff] [blame] | 1786 | } else if (!trylock_buffer(bh)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1787 | redirty_page_for_writepage(wbc, page); |
| 1788 | continue; |
| 1789 | } |
| 1790 | if (test_clear_buffer_dirty(bh)) { |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 1791 | mark_buffer_async_write_endio(bh, handler); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1792 | } else { |
| 1793 | unlock_buffer(bh); |
| 1794 | } |
| 1795 | } while ((bh = bh->b_this_page) != head); |
| 1796 | |
| 1797 | /* |
| 1798 | * The page and its buffers are protected by PageWriteback(), so we can |
| 1799 | * drop the bh refcounts early. |
| 1800 | */ |
| 1801 | BUG_ON(PageWriteback(page)); |
| 1802 | set_page_writeback(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1803 | |
| 1804 | do { |
| 1805 | struct buffer_head *next = bh->b_this_page; |
| 1806 | if (buffer_async_write(bh)) { |
Christoph Hellwig | c75e707 | 2022-03-04 18:55:56 +0100 | [diff] [blame] | 1807 | submit_bh_wbc(REQ_OP_WRITE, write_flags, bh, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1808 | nr_underway++; |
| 1809 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1810 | bh = next; |
| 1811 | } while (bh != head); |
Andrew Morton | 05937ba | 2005-05-05 16:15:47 -0700 | [diff] [blame] | 1812 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1813 | |
| 1814 | err = 0; |
| 1815 | done: |
| 1816 | if (nr_underway == 0) { |
| 1817 | /* |
| 1818 | * The page was marked dirty, but the buffers were |
| 1819 | * clean. Someone wrote them back by hand with |
| 1820 | * ll_rw_block/submit_bh. A rare case. |
| 1821 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | end_page_writeback(page); |
Nick Piggin | 3d67f2d | 2007-05-06 14:49:05 -0700 | [diff] [blame] | 1823 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1824 | /* |
| 1825 | * The page and buffer_heads can be released at any time from |
| 1826 | * here on. |
| 1827 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1828 | } |
| 1829 | return err; |
| 1830 | |
| 1831 | recover: |
| 1832 | /* |
| 1833 | * ENOSPC, or some other error. We may already have added some |
| 1834 | * blocks to the file, so we need to write these out to avoid |
| 1835 | * exposing stale data. |
| 1836 | * The page is currently locked and not marked for writeback |
| 1837 | */ |
| 1838 | bh = head; |
| 1839 | /* Recovery: lock and submit the mapped buffers */ |
| 1840 | do { |
Alex Tomas | 29a814d | 2008-07-11 19:27:31 -0400 | [diff] [blame] | 1841 | if (buffer_mapped(bh) && buffer_dirty(bh) && |
| 1842 | !buffer_delay(bh)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1843 | lock_buffer(bh); |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 1844 | mark_buffer_async_write_endio(bh, handler); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | } else { |
| 1846 | /* |
| 1847 | * The buffer may have been set dirty during |
| 1848 | * attachment to a dirty page. |
| 1849 | */ |
| 1850 | clear_buffer_dirty(bh); |
| 1851 | } |
| 1852 | } while ((bh = bh->b_this_page) != head); |
| 1853 | SetPageError(page); |
| 1854 | BUG_ON(PageWriteback(page)); |
Andrew Morton | 7e4c369 | 2007-05-08 00:23:27 -0700 | [diff] [blame] | 1855 | mapping_set_error(page->mapping, err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1856 | set_page_writeback(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1857 | do { |
| 1858 | struct buffer_head *next = bh->b_this_page; |
| 1859 | if (buffer_async_write(bh)) { |
| 1860 | clear_buffer_dirty(bh); |
Christoph Hellwig | c75e707 | 2022-03-04 18:55:56 +0100 | [diff] [blame] | 1861 | submit_bh_wbc(REQ_OP_WRITE, write_flags, bh, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1862 | nr_underway++; |
| 1863 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | bh = next; |
| 1865 | } while (bh != head); |
Nick Piggin | ffda9d3 | 2007-02-20 13:57:54 -0800 | [diff] [blame] | 1866 | unlock_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1867 | goto done; |
| 1868 | } |
Benjamin Marzinski | b4bba38 | 2016-06-27 09:58:40 -0500 | [diff] [blame] | 1869 | EXPORT_SYMBOL(__block_write_full_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 1871 | /* |
| 1872 | * If a page has any new buffers, zero them out here, and mark them uptodate |
| 1873 | * and dirty so they'll be written out (in order to prevent uninitialised |
| 1874 | * block data from leaking). And clear the new bit. |
| 1875 | */ |
| 1876 | void page_zero_new_buffers(struct page *page, unsigned from, unsigned to) |
| 1877 | { |
| 1878 | unsigned int block_start, block_end; |
| 1879 | struct buffer_head *head, *bh; |
| 1880 | |
| 1881 | BUG_ON(!PageLocked(page)); |
| 1882 | if (!page_has_buffers(page)) |
| 1883 | return; |
| 1884 | |
| 1885 | bh = head = page_buffers(page); |
| 1886 | block_start = 0; |
| 1887 | do { |
| 1888 | block_end = block_start + bh->b_size; |
| 1889 | |
| 1890 | if (buffer_new(bh)) { |
| 1891 | if (block_end > from && block_start < to) { |
| 1892 | if (!PageUptodate(page)) { |
| 1893 | unsigned start, size; |
| 1894 | |
| 1895 | start = max(from, block_start); |
| 1896 | size = min(to, block_end) - start; |
| 1897 | |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 1898 | zero_user(page, start, size); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 1899 | set_buffer_uptodate(bh); |
| 1900 | } |
| 1901 | |
| 1902 | clear_buffer_new(bh); |
| 1903 | mark_buffer_dirty(bh); |
| 1904 | } |
| 1905 | } |
| 1906 | |
| 1907 | block_start = block_end; |
| 1908 | bh = bh->b_this_page; |
| 1909 | } while (bh != head); |
| 1910 | } |
| 1911 | EXPORT_SYMBOL(page_zero_new_buffers); |
| 1912 | |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1913 | static void |
| 1914 | iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh, |
Christoph Hellwig | 6d49cc8 | 2021-08-10 18:33:05 -0700 | [diff] [blame] | 1915 | const struct iomap *iomap) |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1916 | { |
| 1917 | loff_t offset = block << inode->i_blkbits; |
| 1918 | |
| 1919 | bh->b_bdev = iomap->bdev; |
| 1920 | |
| 1921 | /* |
| 1922 | * Block points to offset in file we need to map, iomap contains |
| 1923 | * the offset at which the map starts. If the map ends before the |
| 1924 | * current block, then do not map the buffer and let the caller |
| 1925 | * handle it. |
| 1926 | */ |
| 1927 | BUG_ON(offset >= iomap->offset + iomap->length); |
| 1928 | |
| 1929 | switch (iomap->type) { |
| 1930 | case IOMAP_HOLE: |
| 1931 | /* |
| 1932 | * If the buffer is not up to date or beyond the current EOF, |
| 1933 | * we need to mark it as new to ensure sub-block zeroing is |
| 1934 | * executed if necessary. |
| 1935 | */ |
| 1936 | if (!buffer_uptodate(bh) || |
| 1937 | (offset >= i_size_read(inode))) |
| 1938 | set_buffer_new(bh); |
| 1939 | break; |
| 1940 | case IOMAP_DELALLOC: |
| 1941 | if (!buffer_uptodate(bh) || |
| 1942 | (offset >= i_size_read(inode))) |
| 1943 | set_buffer_new(bh); |
| 1944 | set_buffer_uptodate(bh); |
| 1945 | set_buffer_mapped(bh); |
| 1946 | set_buffer_delay(bh); |
| 1947 | break; |
| 1948 | case IOMAP_UNWRITTEN: |
| 1949 | /* |
Andreas Gruenbacher | 3d7b6b21 | 2018-06-19 15:10:55 -0700 | [diff] [blame] | 1950 | * For unwritten regions, we always need to ensure that regions |
| 1951 | * in the block we are not writing to are zeroed. Mark the |
| 1952 | * buffer as new to ensure this. |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1953 | */ |
| 1954 | set_buffer_new(bh); |
| 1955 | set_buffer_unwritten(bh); |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1956 | fallthrough; |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1957 | case IOMAP_MAPPED: |
Andreas Gruenbacher | 3d7b6b21 | 2018-06-19 15:10:55 -0700 | [diff] [blame] | 1958 | if ((iomap->flags & IOMAP_F_NEW) || |
| 1959 | offset >= i_size_read(inode)) |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1960 | set_buffer_new(bh); |
Andreas Gruenbacher | 19fe5f6 | 2017-10-01 17:55:54 -0400 | [diff] [blame] | 1961 | bh->b_blocknr = (iomap->addr + offset - iomap->offset) >> |
| 1962 | inode->i_blkbits; |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 1963 | set_buffer_mapped(bh); |
| 1964 | break; |
| 1965 | } |
| 1966 | } |
| 1967 | |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1968 | int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len, |
Christoph Hellwig | 6d49cc8 | 2021-08-10 18:33:05 -0700 | [diff] [blame] | 1969 | get_block_t *get_block, const struct iomap *iomap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1970 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1971 | unsigned from = pos & (PAGE_SIZE - 1); |
Christoph Hellwig | ebdec24 | 2010-10-06 10:47:23 +0200 | [diff] [blame] | 1972 | unsigned to = from + len; |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1973 | struct inode *inode = folio->mapping->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1974 | unsigned block_start, block_end; |
| 1975 | sector_t block; |
| 1976 | int err = 0; |
| 1977 | unsigned blocksize, bbits; |
| 1978 | struct buffer_head *bh, *head, *wait[2], **wait_bh=wait; |
| 1979 | |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1980 | BUG_ON(!folio_test_locked(folio)); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 1981 | BUG_ON(from > PAGE_SIZE); |
| 1982 | BUG_ON(to > PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1983 | BUG_ON(from > to); |
| 1984 | |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1985 | head = create_page_buffers(&folio->page, inode, 0); |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 1986 | blocksize = head->b_size; |
| 1987 | bbits = block_size_bits(blocksize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1988 | |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1989 | block = (sector_t)folio->index << (PAGE_SHIFT - bbits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1990 | |
| 1991 | for(bh = head, block_start = 0; bh != head || !block_start; |
| 1992 | block++, block_start=block_end, bh = bh->b_this_page) { |
| 1993 | block_end = block_start + blocksize; |
| 1994 | if (block_end <= from || block_start >= to) { |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 1995 | if (folio_test_uptodate(folio)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1996 | if (!buffer_uptodate(bh)) |
| 1997 | set_buffer_uptodate(bh); |
| 1998 | } |
| 1999 | continue; |
| 2000 | } |
| 2001 | if (buffer_new(bh)) |
| 2002 | clear_buffer_new(bh); |
| 2003 | if (!buffer_mapped(bh)) { |
Badari Pulavarty | b0cf232 | 2006-03-26 01:38:00 -0800 | [diff] [blame] | 2004 | WARN_ON(bh->b_size != blocksize); |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 2005 | if (get_block) { |
| 2006 | err = get_block(inode, block, bh, 1); |
| 2007 | if (err) |
| 2008 | break; |
| 2009 | } else { |
| 2010 | iomap_to_bh(inode, block, bh, iomap); |
| 2011 | } |
| 2012 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2013 | if (buffer_new(bh)) { |
Jan Kara | e64855c | 2016-11-04 18:08:15 +0100 | [diff] [blame] | 2014 | clean_bdev_bh_alias(bh); |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 2015 | if (folio_test_uptodate(folio)) { |
Nick Piggin | 637aff4 | 2007-10-16 01:25:00 -0700 | [diff] [blame] | 2016 | clear_buffer_new(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2017 | set_buffer_uptodate(bh); |
Nick Piggin | 637aff4 | 2007-10-16 01:25:00 -0700 | [diff] [blame] | 2018 | mark_buffer_dirty(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2019 | continue; |
| 2020 | } |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2021 | if (block_end > to || block_start < from) |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 2022 | folio_zero_segments(folio, |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2023 | to, block_end, |
| 2024 | block_start, from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2025 | continue; |
| 2026 | } |
| 2027 | } |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 2028 | if (folio_test_uptodate(folio)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2029 | if (!buffer_uptodate(bh)) |
| 2030 | set_buffer_uptodate(bh); |
| 2031 | continue; |
| 2032 | } |
| 2033 | if (!buffer_uptodate(bh) && !buffer_delay(bh) && |
David Chinner | 33a266d | 2007-02-12 00:51:41 -0800 | [diff] [blame] | 2034 | !buffer_unwritten(bh) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2035 | (block_start < from || block_end > to)) { |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 2036 | ll_rw_block(REQ_OP_READ, 0, 1, &bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | *wait_bh++=bh; |
| 2038 | } |
| 2039 | } |
| 2040 | /* |
| 2041 | * If we issued read requests - let them complete. |
| 2042 | */ |
| 2043 | while(wait_bh > wait) { |
| 2044 | wait_on_buffer(*--wait_bh); |
| 2045 | if (!buffer_uptodate(*wait_bh)) |
Nick Piggin | f3ddbdc | 2005-05-05 16:15:45 -0700 | [diff] [blame] | 2046 | err = -EIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | } |
Jan Kara | f9f07b6 | 2011-06-14 00:58:27 +0200 | [diff] [blame] | 2048 | if (unlikely(err)) |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 2049 | page_zero_new_buffers(&folio->page, from, to); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2050 | return err; |
| 2051 | } |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 2052 | |
| 2053 | int __block_write_begin(struct page *page, loff_t pos, unsigned len, |
| 2054 | get_block_t *get_block) |
| 2055 | { |
Matthew Wilcox (Oracle) | d1bd0b4 | 2021-11-03 14:05:47 -0400 | [diff] [blame] | 2056 | return __block_write_begin_int(page_folio(page), pos, len, get_block, |
| 2057 | NULL); |
Christoph Hellwig | ae259a9 | 2016-06-21 09:23:11 +1000 | [diff] [blame] | 2058 | } |
Christoph Hellwig | ebdec24 | 2010-10-06 10:47:23 +0200 | [diff] [blame] | 2059 | EXPORT_SYMBOL(__block_write_begin); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2060 | |
| 2061 | static int __block_commit_write(struct inode *inode, struct page *page, |
| 2062 | unsigned from, unsigned to) |
| 2063 | { |
| 2064 | unsigned block_start, block_end; |
| 2065 | int partial = 0; |
| 2066 | unsigned blocksize; |
| 2067 | struct buffer_head *bh, *head; |
| 2068 | |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2069 | bh = head = page_buffers(page); |
| 2070 | blocksize = bh->b_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2071 | |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2072 | block_start = 0; |
| 2073 | do { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2074 | block_end = block_start + blocksize; |
| 2075 | if (block_end <= from || block_start >= to) { |
| 2076 | if (!buffer_uptodate(bh)) |
| 2077 | partial = 1; |
| 2078 | } else { |
| 2079 | set_buffer_uptodate(bh); |
| 2080 | mark_buffer_dirty(bh); |
| 2081 | } |
Yang Guo | 4ebd3ae | 2021-02-24 12:02:48 -0800 | [diff] [blame] | 2082 | if (buffer_new(bh)) |
| 2083 | clear_buffer_new(bh); |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2084 | |
| 2085 | block_start = block_end; |
| 2086 | bh = bh->b_this_page; |
| 2087 | } while (bh != head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2088 | |
| 2089 | /* |
| 2090 | * If this is a partial write which happened to make all buffers |
| 2091 | * uptodate then we can optimize away a bogus readpage() for |
| 2092 | * the next read(). Here we 'discover' whether the page went |
| 2093 | * uptodate as a result of this (potentially partial) write. |
| 2094 | */ |
| 2095 | if (!partial) |
| 2096 | SetPageUptodate(page); |
| 2097 | return 0; |
| 2098 | } |
| 2099 | |
| 2100 | /* |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 2101 | * block_write_begin takes care of the basic task of block allocation and |
| 2102 | * bringing partial write blocks uptodate first. |
| 2103 | * |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 2104 | * The filesystem needs to handle block truncation upon failure. |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2105 | */ |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 2106 | int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, |
| 2107 | unsigned flags, struct page **pagep, get_block_t *get_block) |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2108 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2109 | pgoff_t index = pos >> PAGE_SHIFT; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2110 | struct page *page; |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2111 | int status; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2112 | |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2113 | page = grab_cache_page_write_begin(mapping, index, flags); |
| 2114 | if (!page) |
| 2115 | return -ENOMEM; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2116 | |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2117 | status = __block_write_begin(page, pos, len, get_block); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2118 | if (unlikely(status)) { |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2119 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2120 | put_page(page); |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2121 | page = NULL; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2122 | } |
| 2123 | |
Christoph Hellwig | 6e1db88 | 2010-06-04 11:29:57 +0200 | [diff] [blame] | 2124 | *pagep = page; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2125 | return status; |
| 2126 | } |
| 2127 | EXPORT_SYMBOL(block_write_begin); |
| 2128 | |
| 2129 | int block_write_end(struct file *file, struct address_space *mapping, |
| 2130 | loff_t pos, unsigned len, unsigned copied, |
| 2131 | struct page *page, void *fsdata) |
| 2132 | { |
| 2133 | struct inode *inode = mapping->host; |
| 2134 | unsigned start; |
| 2135 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2136 | start = pos & (PAGE_SIZE - 1); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2137 | |
| 2138 | if (unlikely(copied < len)) { |
| 2139 | /* |
| 2140 | * The buffers that were written will now be uptodate, so we |
| 2141 | * don't have to worry about a readpage reading them and |
| 2142 | * overwriting a partial write. However if we have encountered |
| 2143 | * a short write and only partially written into a buffer, it |
| 2144 | * will not be marked uptodate, so a readpage might come in and |
| 2145 | * destroy our partial write. |
| 2146 | * |
| 2147 | * Do the simplest thing, and just treat any short write to a |
| 2148 | * non uptodate page as a zero-length write, and force the |
| 2149 | * caller to redo the whole thing. |
| 2150 | */ |
| 2151 | if (!PageUptodate(page)) |
| 2152 | copied = 0; |
| 2153 | |
| 2154 | page_zero_new_buffers(page, start+copied, start+len); |
| 2155 | } |
| 2156 | flush_dcache_page(page); |
| 2157 | |
| 2158 | /* This could be a short (even 0-length) commit */ |
| 2159 | __block_commit_write(inode, page, start, start+copied); |
| 2160 | |
| 2161 | return copied; |
| 2162 | } |
| 2163 | EXPORT_SYMBOL(block_write_end); |
| 2164 | |
| 2165 | int generic_write_end(struct file *file, struct address_space *mapping, |
| 2166 | loff_t pos, unsigned len, unsigned copied, |
| 2167 | struct page *page, void *fsdata) |
| 2168 | { |
Christoph Hellwig | 8af54f2 | 2019-06-27 17:28:40 -0700 | [diff] [blame] | 2169 | struct inode *inode = mapping->host; |
| 2170 | loff_t old_size = inode->i_size; |
| 2171 | bool i_size_changed = false; |
| 2172 | |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2173 | copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); |
Christoph Hellwig | 8af54f2 | 2019-06-27 17:28:40 -0700 | [diff] [blame] | 2174 | |
| 2175 | /* |
| 2176 | * No need to use i_size_read() here, the i_size cannot change under us |
| 2177 | * because we hold i_rwsem. |
| 2178 | * |
| 2179 | * But it's important to update i_size while still holding page lock: |
| 2180 | * page writeout could otherwise come in and zero beyond i_size. |
| 2181 | */ |
| 2182 | if (pos + copied > inode->i_size) { |
| 2183 | i_size_write(inode, pos + copied); |
| 2184 | i_size_changed = true; |
| 2185 | } |
| 2186 | |
| 2187 | unlock_page(page); |
Andreas Gruenbacher | 7a77dad | 2019-04-30 08:45:34 -0700 | [diff] [blame] | 2188 | put_page(page); |
Christoph Hellwig | 8af54f2 | 2019-06-27 17:28:40 -0700 | [diff] [blame] | 2189 | |
| 2190 | if (old_size < pos) |
| 2191 | pagecache_isize_extended(inode, old_size, pos); |
| 2192 | /* |
| 2193 | * Don't mark the inode dirty under page lock. First, it unnecessarily |
| 2194 | * makes the holding time of page lock longer. Second, it forces lock |
| 2195 | * ordering of page lock and transaction start for journaling |
| 2196 | * filesystems. |
| 2197 | */ |
| 2198 | if (i_size_changed) |
| 2199 | mark_inode_dirty(inode); |
Andreas Gruenbacher | 26ddb1f | 2019-04-30 08:45:33 -0700 | [diff] [blame] | 2200 | return copied; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2201 | } |
| 2202 | EXPORT_SYMBOL(generic_write_end); |
| 2203 | |
| 2204 | /* |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2205 | * block_is_partially_uptodate checks whether buffers within a folio are |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2206 | * uptodate or not. |
| 2207 | * |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2208 | * Returns true if all buffers which correspond to the specified part |
| 2209 | * of the folio are uptodate. |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2210 | */ |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2211 | bool block_is_partially_uptodate(struct folio *folio, size_t from, size_t count) |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2212 | { |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2213 | unsigned block_start, block_end, blocksize; |
| 2214 | unsigned to; |
| 2215 | struct buffer_head *bh, *head; |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2216 | bool ret = true; |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2217 | |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2218 | head = folio_buffers(folio); |
| 2219 | if (!head) |
| 2220 | return false; |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2221 | blocksize = head->b_size; |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2222 | to = min_t(unsigned, folio_size(folio) - from, count); |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2223 | to = from + to; |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2224 | if (from < blocksize && to > folio_size(folio) - blocksize) |
| 2225 | return false; |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2226 | |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2227 | bh = head; |
| 2228 | block_start = 0; |
| 2229 | do { |
| 2230 | block_end = block_start + blocksize; |
| 2231 | if (block_end > from && block_start < to) { |
| 2232 | if (!buffer_uptodate(bh)) { |
Matthew Wilcox (Oracle) | 2e7e80f | 2022-02-09 20:21:27 +0000 | [diff] [blame] | 2233 | ret = false; |
Hisashi Hifumi | 8ab22b9 | 2008-07-28 15:46:36 -0700 | [diff] [blame] | 2234 | break; |
| 2235 | } |
| 2236 | if (block_end >= to) |
| 2237 | break; |
| 2238 | } |
| 2239 | block_start = block_end; |
| 2240 | bh = bh->b_this_page; |
| 2241 | } while (bh != head); |
| 2242 | |
| 2243 | return ret; |
| 2244 | } |
| 2245 | EXPORT_SYMBOL(block_is_partially_uptodate); |
| 2246 | |
| 2247 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2248 | * Generic "read page" function for block devices that have the normal |
| 2249 | * get_block functionality. This is most of the block device filesystems. |
| 2250 | * Reads the page asynchronously --- the unlock_buffer() and |
| 2251 | * set/clear_buffer_uptodate() functions propagate buffer state into the |
| 2252 | * page struct once IO has completed. |
| 2253 | */ |
| 2254 | int block_read_full_page(struct page *page, get_block_t *get_block) |
| 2255 | { |
| 2256 | struct inode *inode = page->mapping->host; |
| 2257 | sector_t iblock, lblock; |
| 2258 | struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2259 | unsigned int blocksize, bbits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2260 | int nr, i; |
| 2261 | int fully_mapped = 1; |
| 2262 | |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2263 | head = create_page_buffers(page, inode, 0); |
| 2264 | blocksize = head->b_size; |
| 2265 | bbits = block_size_bits(blocksize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2266 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2267 | iblock = (sector_t)page->index << (PAGE_SHIFT - bbits); |
Linus Torvalds | 45bce8f | 2012-11-29 10:21:43 -0800 | [diff] [blame] | 2268 | lblock = (i_size_read(inode)+blocksize-1) >> bbits; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2269 | bh = head; |
| 2270 | nr = 0; |
| 2271 | i = 0; |
| 2272 | |
| 2273 | do { |
| 2274 | if (buffer_uptodate(bh)) |
| 2275 | continue; |
| 2276 | |
| 2277 | if (!buffer_mapped(bh)) { |
Andrew Morton | c64610b | 2005-05-16 21:53:49 -0700 | [diff] [blame] | 2278 | int err = 0; |
| 2279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2280 | fully_mapped = 0; |
| 2281 | if (iblock < lblock) { |
Badari Pulavarty | b0cf232 | 2006-03-26 01:38:00 -0800 | [diff] [blame] | 2282 | WARN_ON(bh->b_size != blocksize); |
Andrew Morton | c64610b | 2005-05-16 21:53:49 -0700 | [diff] [blame] | 2283 | err = get_block(inode, iblock, bh, 0); |
| 2284 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2285 | SetPageError(page); |
| 2286 | } |
| 2287 | if (!buffer_mapped(bh)) { |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2288 | zero_user(page, i * blocksize, blocksize); |
Andrew Morton | c64610b | 2005-05-16 21:53:49 -0700 | [diff] [blame] | 2289 | if (!err) |
| 2290 | set_buffer_uptodate(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2291 | continue; |
| 2292 | } |
| 2293 | /* |
| 2294 | * get_block() might have updated the buffer |
| 2295 | * synchronously |
| 2296 | */ |
| 2297 | if (buffer_uptodate(bh)) |
| 2298 | continue; |
| 2299 | } |
| 2300 | arr[nr++] = bh; |
| 2301 | } while (i++, iblock++, (bh = bh->b_this_page) != head); |
| 2302 | |
| 2303 | if (fully_mapped) |
| 2304 | SetPageMappedToDisk(page); |
| 2305 | |
| 2306 | if (!nr) { |
| 2307 | /* |
| 2308 | * All buffers are uptodate - we can set the page uptodate |
| 2309 | * as well. But not if get_block() returned an error. |
| 2310 | */ |
| 2311 | if (!PageError(page)) |
| 2312 | SetPageUptodate(page); |
| 2313 | unlock_page(page); |
| 2314 | return 0; |
| 2315 | } |
| 2316 | |
| 2317 | /* Stage two: lock the buffers */ |
| 2318 | for (i = 0; i < nr; i++) { |
| 2319 | bh = arr[i]; |
| 2320 | lock_buffer(bh); |
| 2321 | mark_buffer_async_read(bh); |
| 2322 | } |
| 2323 | |
| 2324 | /* |
| 2325 | * Stage 3: start the IO. Check for uptodateness |
| 2326 | * inside the buffer lock in case another process reading |
| 2327 | * the underlying blockdev brought it uptodate (the sct fix). |
| 2328 | */ |
| 2329 | for (i = 0; i < nr; i++) { |
| 2330 | bh = arr[i]; |
| 2331 | if (buffer_uptodate(bh)) |
| 2332 | end_buffer_async_read(bh, 1); |
| 2333 | else |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 2334 | submit_bh(REQ_OP_READ, 0, bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | } |
| 2336 | return 0; |
| 2337 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2338 | EXPORT_SYMBOL(block_read_full_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2339 | |
| 2340 | /* utility function for filesystems that need to do work on expanding |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2341 | * truncates. Uses filesystem pagecache writes to allow the filesystem to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2342 | * deal with the hole. |
| 2343 | */ |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2344 | int generic_cont_expand_simple(struct inode *inode, loff_t size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2345 | { |
| 2346 | struct address_space *mapping = inode->i_mapping; |
| 2347 | struct page *page; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2348 | void *fsdata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2349 | int err; |
| 2350 | |
npiggin@suse.de | c08d3b0 | 2009-08-21 02:35:06 +1000 | [diff] [blame] | 2351 | err = inode_newsize_ok(inode, size); |
| 2352 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2353 | goto out; |
| 2354 | |
Matthew Wilcox (Oracle) | d7414ba | 2022-02-20 22:28:03 -0500 | [diff] [blame] | 2355 | err = pagecache_write_begin(NULL, mapping, size, 0, 0, &page, &fsdata); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2356 | if (err) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2357 | goto out; |
OGAWA Hirofumi | 05eb0b5 | 2006-01-08 01:02:13 -0800 | [diff] [blame] | 2358 | |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2359 | err = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata); |
| 2360 | BUG_ON(err > 0); |
OGAWA Hirofumi | 05eb0b5 | 2006-01-08 01:02:13 -0800 | [diff] [blame] | 2361 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2362 | out: |
| 2363 | return err; |
| 2364 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2365 | EXPORT_SYMBOL(generic_cont_expand_simple); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2366 | |
Adrian Bunk | f1e3af7 | 2008-04-29 00:59:01 -0700 | [diff] [blame] | 2367 | static int cont_expand_zero(struct file *file, struct address_space *mapping, |
| 2368 | loff_t pos, loff_t *bytes) |
OGAWA Hirofumi | 05eb0b5 | 2006-01-08 01:02:13 -0800 | [diff] [blame] | 2369 | { |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2370 | struct inode *inode = mapping->host; |
Fabian Frederick | 9340747 | 2017-02-27 14:28:32 -0800 | [diff] [blame] | 2371 | unsigned int blocksize = i_blocksize(inode); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2372 | struct page *page; |
| 2373 | void *fsdata; |
| 2374 | pgoff_t index, curidx; |
| 2375 | loff_t curpos; |
| 2376 | unsigned zerofrom, offset, len; |
| 2377 | int err = 0; |
OGAWA Hirofumi | 05eb0b5 | 2006-01-08 01:02:13 -0800 | [diff] [blame] | 2378 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2379 | index = pos >> PAGE_SHIFT; |
| 2380 | offset = pos & ~PAGE_MASK; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2381 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2382 | while (index > (curidx = (curpos = *bytes)>>PAGE_SHIFT)) { |
| 2383 | zerofrom = curpos & ~PAGE_MASK; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2384 | if (zerofrom & (blocksize-1)) { |
| 2385 | *bytes |= (blocksize-1); |
| 2386 | (*bytes)++; |
| 2387 | } |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2388 | len = PAGE_SIZE - zerofrom; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2389 | |
Tetsuo Handa | c718a97 | 2017-05-08 15:58:59 -0700 | [diff] [blame] | 2390 | err = pagecache_write_begin(file, mapping, curpos, len, 0, |
| 2391 | &page, &fsdata); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2392 | if (err) |
| 2393 | goto out; |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2394 | zero_user(page, zerofrom, len); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2395 | err = pagecache_write_end(file, mapping, curpos, len, len, |
| 2396 | page, fsdata); |
| 2397 | if (err < 0) |
| 2398 | goto out; |
| 2399 | BUG_ON(err != len); |
| 2400 | err = 0; |
OGAWA Hirofumi | 061e974 | 2008-04-28 02:16:28 -0700 | [diff] [blame] | 2401 | |
| 2402 | balance_dirty_pages_ratelimited(mapping); |
Mikulas Patocka | c2ca0fc | 2014-07-27 13:00:41 -0400 | [diff] [blame] | 2403 | |
Davidlohr Bueso | 08d405c | 2019-01-03 15:28:58 -0800 | [diff] [blame] | 2404 | if (fatal_signal_pending(current)) { |
Mikulas Patocka | c2ca0fc | 2014-07-27 13:00:41 -0400 | [diff] [blame] | 2405 | err = -EINTR; |
| 2406 | goto out; |
| 2407 | } |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2408 | } |
| 2409 | |
| 2410 | /* page covers the boundary, find the boundary offset */ |
| 2411 | if (index == curidx) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2412 | zerofrom = curpos & ~PAGE_MASK; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2413 | /* if we will expand the thing last block will be filled */ |
| 2414 | if (offset <= zerofrom) { |
| 2415 | goto out; |
| 2416 | } |
| 2417 | if (zerofrom & (blocksize-1)) { |
| 2418 | *bytes |= (blocksize-1); |
| 2419 | (*bytes)++; |
| 2420 | } |
| 2421 | len = offset - zerofrom; |
| 2422 | |
Tetsuo Handa | c718a97 | 2017-05-08 15:58:59 -0700 | [diff] [blame] | 2423 | err = pagecache_write_begin(file, mapping, curpos, len, 0, |
| 2424 | &page, &fsdata); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2425 | if (err) |
| 2426 | goto out; |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2427 | zero_user(page, zerofrom, len); |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2428 | err = pagecache_write_end(file, mapping, curpos, len, len, |
| 2429 | page, fsdata); |
| 2430 | if (err < 0) |
| 2431 | goto out; |
| 2432 | BUG_ON(err != len); |
| 2433 | err = 0; |
| 2434 | } |
| 2435 | out: |
| 2436 | return err; |
OGAWA Hirofumi | 05eb0b5 | 2006-01-08 01:02:13 -0800 | [diff] [blame] | 2437 | } |
| 2438 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2439 | /* |
| 2440 | * For moronic filesystems that do not allow holes in file. |
| 2441 | * We may have to extend the file. |
| 2442 | */ |
Christoph Hellwig | 282dc17 | 2010-06-04 11:29:55 +0200 | [diff] [blame] | 2443 | int cont_write_begin(struct file *file, struct address_space *mapping, |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2444 | loff_t pos, unsigned len, unsigned flags, |
| 2445 | struct page **pagep, void **fsdata, |
| 2446 | get_block_t *get_block, loff_t *bytes) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2447 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2448 | struct inode *inode = mapping->host; |
Fabian Frederick | 9340747 | 2017-02-27 14:28:32 -0800 | [diff] [blame] | 2449 | unsigned int blocksize = i_blocksize(inode); |
| 2450 | unsigned int zerofrom; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2451 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2452 | |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2453 | err = cont_expand_zero(file, mapping, pos, bytes); |
| 2454 | if (err) |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 2455 | return err; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2456 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2457 | zerofrom = *bytes & ~PAGE_MASK; |
Nick Piggin | 89e1078 | 2007-10-16 01:25:07 -0700 | [diff] [blame] | 2458 | if (pos+len > *bytes && zerofrom & (blocksize-1)) { |
| 2459 | *bytes |= (blocksize-1); |
| 2460 | (*bytes)++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2461 | } |
| 2462 | |
Christoph Hellwig | 155130a | 2010-06-04 11:29:58 +0200 | [diff] [blame] | 2463 | return block_write_begin(mapping, pos, len, flags, pagep, get_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2464 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2465 | EXPORT_SYMBOL(cont_write_begin); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2467 | int block_commit_write(struct page *page, unsigned from, unsigned to) |
| 2468 | { |
| 2469 | struct inode *inode = page->mapping->host; |
| 2470 | __block_commit_write(inode,page,from,to); |
| 2471 | return 0; |
| 2472 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2473 | EXPORT_SYMBOL(block_commit_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2474 | |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2475 | /* |
| 2476 | * block_page_mkwrite() is not allowed to change the file size as it gets |
| 2477 | * called from a page fault handler when a page is first dirtied. Hence we must |
| 2478 | * be careful to check for EOF conditions here. We set the page up correctly |
| 2479 | * for a written page which means we get ENOSPC checking when writing into |
| 2480 | * holes and correct delalloc and unwritten extent mapping on filesystems that |
| 2481 | * support these features. |
| 2482 | * |
| 2483 | * We are not allowed to take the i_mutex here so we have to play games to |
| 2484 | * protect against truncate races as the page could now be beyond EOF. Because |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 2485 | * truncate writes the inode size before removing pages, once we have the |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2486 | * page lock we can determine safely if the page is beyond EOF. If it is not |
| 2487 | * beyond EOF, then the page is guaranteed safe against truncation until we |
| 2488 | * unlock the page. |
Jan Kara | ea13a86 | 2011-05-24 00:23:35 +0200 | [diff] [blame] | 2489 | * |
Jan Kara | 14da920 | 2012-06-12 16:20:37 +0200 | [diff] [blame] | 2490 | * Direct callers of this function should protect against filesystem freezing |
Ross Zwisler | 5c50002 | 2015-10-13 16:51:02 -0600 | [diff] [blame] | 2491 | * using sb_start_pagefault() - sb_end_pagefault() functions. |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2492 | */ |
Ross Zwisler | 5c50002 | 2015-10-13 16:51:02 -0600 | [diff] [blame] | 2493 | int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, |
Jan Kara | 24da4fa | 2011-05-24 00:23:34 +0200 | [diff] [blame] | 2494 | get_block_t get_block) |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2495 | { |
Nick Piggin | c2ec175 | 2009-03-31 15:23:21 -0700 | [diff] [blame] | 2496 | struct page *page = vmf->page; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 2497 | struct inode *inode = file_inode(vma->vm_file); |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2498 | unsigned long end; |
| 2499 | loff_t size; |
Jan Kara | 24da4fa | 2011-05-24 00:23:34 +0200 | [diff] [blame] | 2500 | int ret; |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2501 | |
| 2502 | lock_page(page); |
| 2503 | size = i_size_read(inode); |
| 2504 | if ((page->mapping != inode->i_mapping) || |
Nick Piggin | 1833633 | 2007-07-20 00:31:45 -0700 | [diff] [blame] | 2505 | (page_offset(page) > size)) { |
Jan Kara | 24da4fa | 2011-05-24 00:23:34 +0200 | [diff] [blame] | 2506 | /* We overload EFAULT to mean page got truncated */ |
| 2507 | ret = -EFAULT; |
| 2508 | goto out_unlock; |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2509 | } |
| 2510 | |
| 2511 | /* page is wholly or partially inside EOF */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2512 | if (((page->index + 1) << PAGE_SHIFT) > size) |
| 2513 | end = size & ~PAGE_MASK; |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2514 | else |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2515 | end = PAGE_SIZE; |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2516 | |
Christoph Hellwig | ebdec24 | 2010-10-06 10:47:23 +0200 | [diff] [blame] | 2517 | ret = __block_write_begin(page, 0, end, get_block); |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2518 | if (!ret) |
| 2519 | ret = block_commit_write(page, 0, end); |
| 2520 | |
Jan Kara | 24da4fa | 2011-05-24 00:23:34 +0200 | [diff] [blame] | 2521 | if (unlikely(ret < 0)) |
| 2522 | goto out_unlock; |
Jan Kara | ea13a86 | 2011-05-24 00:23:35 +0200 | [diff] [blame] | 2523 | set_page_dirty(page); |
Darrick J. Wong | 1d1d1a7 | 2013-02-21 16:42:51 -0800 | [diff] [blame] | 2524 | wait_for_stable_page(page); |
Jan Kara | 24da4fa | 2011-05-24 00:23:34 +0200 | [diff] [blame] | 2525 | return 0; |
| 2526 | out_unlock: |
| 2527 | unlock_page(page); |
David Chinner | 5417169 | 2007-07-19 17:39:55 +1000 | [diff] [blame] | 2528 | return ret; |
| 2529 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2530 | EXPORT_SYMBOL(block_page_mkwrite); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2531 | |
| 2532 | /* |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2533 | * nobh_write_begin()'s prereads are special: the buffer_heads are freed |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2534 | * immediately, while under the page lock. So it needs a special end_io |
| 2535 | * handler which does not touch the bh after unlocking it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2536 | */ |
| 2537 | static void end_buffer_read_nobh(struct buffer_head *bh, int uptodate) |
| 2538 | { |
Dmitry Monakhov | 68671f3 | 2007-10-16 01:24:47 -0700 | [diff] [blame] | 2539 | __end_buffer_read_notouch(bh, uptodate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2540 | } |
| 2541 | |
| 2542 | /* |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2543 | * Attach the singly-linked list of buffers created by nobh_write_begin, to |
| 2544 | * the page (converting it to circular linked list and taking care of page |
| 2545 | * dirty races). |
| 2546 | */ |
| 2547 | static void attach_nobh_buffers(struct page *page, struct buffer_head *head) |
| 2548 | { |
| 2549 | struct buffer_head *bh; |
| 2550 | |
| 2551 | BUG_ON(!PageLocked(page)); |
| 2552 | |
| 2553 | spin_lock(&page->mapping->private_lock); |
| 2554 | bh = head; |
| 2555 | do { |
| 2556 | if (PageDirty(page)) |
| 2557 | set_buffer_dirty(bh); |
| 2558 | if (!bh->b_this_page) |
| 2559 | bh->b_this_page = head; |
| 2560 | bh = bh->b_this_page; |
| 2561 | } while (bh != head); |
Guoqing Jiang | 45dcfc2 | 2020-06-01 21:47:48 -0700 | [diff] [blame] | 2562 | attach_page_private(page, head); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2563 | spin_unlock(&page->mapping->private_lock); |
| 2564 | } |
| 2565 | |
| 2566 | /* |
Christoph Hellwig | ea0f04e | 2010-06-04 11:29:54 +0200 | [diff] [blame] | 2567 | * On entry, the page is fully not uptodate. |
| 2568 | * On exit the page is fully uptodate in the areas outside (from,to) |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 2569 | * The filesystem needs to handle block truncation upon failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2570 | */ |
Christoph Hellwig | ea0f04e | 2010-06-04 11:29:54 +0200 | [diff] [blame] | 2571 | int nobh_write_begin(struct address_space *mapping, |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2572 | loff_t pos, unsigned len, unsigned flags, |
| 2573 | struct page **pagep, void **fsdata, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2574 | get_block_t *get_block) |
| 2575 | { |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2576 | struct inode *inode = mapping->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2577 | const unsigned blkbits = inode->i_blkbits; |
| 2578 | const unsigned blocksize = 1 << blkbits; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2579 | struct buffer_head *head, *bh; |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2580 | struct page *page; |
| 2581 | pgoff_t index; |
| 2582 | unsigned from, to; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2583 | unsigned block_in_page; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2584 | unsigned block_start, block_end; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2585 | sector_t block_in_file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2586 | int nr_reads = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2587 | int ret = 0; |
| 2588 | int is_mapped_to_disk = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2589 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2590 | index = pos >> PAGE_SHIFT; |
| 2591 | from = pos & (PAGE_SIZE - 1); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2592 | to = from + len; |
| 2593 | |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 2594 | page = grab_cache_page_write_begin(mapping, index, flags); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2595 | if (!page) |
| 2596 | return -ENOMEM; |
| 2597 | *pagep = page; |
| 2598 | *fsdata = NULL; |
| 2599 | |
| 2600 | if (page_has_buffers(page)) { |
Namhyung Kim | 309f77a | 2010-10-25 15:01:12 +0900 | [diff] [blame] | 2601 | ret = __block_write_begin(page, pos, len, get_block); |
| 2602 | if (unlikely(ret)) |
| 2603 | goto out_release; |
| 2604 | return ret; |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2605 | } |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2606 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2607 | if (PageMappedToDisk(page)) |
| 2608 | return 0; |
| 2609 | |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2610 | /* |
| 2611 | * Allocate buffers so that we can keep track of state, and potentially |
| 2612 | * attach them to the page if an error occurs. In the common case of |
| 2613 | * no error, they will just be freed again without ever being attached |
| 2614 | * to the page (which is all OK, because we're under the page lock). |
| 2615 | * |
| 2616 | * Be careful: the buffer linked list is a NULL terminated one, rather |
| 2617 | * than the circular one we're used to. |
| 2618 | */ |
Jens Axboe | 640ab98 | 2017-09-27 05:40:16 -0600 | [diff] [blame] | 2619 | head = alloc_page_buffers(page, blocksize, false); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2620 | if (!head) { |
| 2621 | ret = -ENOMEM; |
| 2622 | goto out_release; |
| 2623 | } |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2624 | |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2625 | block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2626 | |
| 2627 | /* |
| 2628 | * We loop across all blocks in the page, whether or not they are |
| 2629 | * part of the affected region. This is so we can discover if the |
| 2630 | * page is fully mapped-to-disk. |
| 2631 | */ |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2632 | for (block_start = 0, block_in_page = 0, bh = head; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2633 | block_start < PAGE_SIZE; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2634 | block_in_page++, block_start += blocksize, bh = bh->b_this_page) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2635 | int create; |
| 2636 | |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2637 | block_end = block_start + blocksize; |
| 2638 | bh->b_state = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2639 | create = 1; |
| 2640 | if (block_start >= to) |
| 2641 | create = 0; |
| 2642 | ret = get_block(inode, block_in_file + block_in_page, |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2643 | bh, create); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2644 | if (ret) |
| 2645 | goto failed; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2646 | if (!buffer_mapped(bh)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2647 | is_mapped_to_disk = 0; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2648 | if (buffer_new(bh)) |
Jan Kara | e64855c | 2016-11-04 18:08:15 +0100 | [diff] [blame] | 2649 | clean_bdev_bh_alias(bh); |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2650 | if (PageUptodate(page)) { |
| 2651 | set_buffer_uptodate(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2652 | continue; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2653 | } |
| 2654 | if (buffer_new(bh) || !buffer_mapped(bh)) { |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2655 | zero_user_segments(page, block_start, from, |
| 2656 | to, block_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2657 | continue; |
| 2658 | } |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2659 | if (buffer_uptodate(bh)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2660 | continue; /* reiserfs does this */ |
| 2661 | if (block_start < from || block_end > to) { |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2662 | lock_buffer(bh); |
| 2663 | bh->b_end_io = end_buffer_read_nobh; |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 2664 | submit_bh(REQ_OP_READ, 0, bh); |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2665 | nr_reads++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2666 | } |
| 2667 | } |
| 2668 | |
| 2669 | if (nr_reads) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2670 | /* |
| 2671 | * The page is locked, so these buffers are protected from |
| 2672 | * any VM or truncate activity. Hence we don't need to care |
| 2673 | * for the buffer_head refcounts. |
| 2674 | */ |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2675 | for (bh = head; bh; bh = bh->b_this_page) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2676 | wait_on_buffer(bh); |
| 2677 | if (!buffer_uptodate(bh)) |
| 2678 | ret = -EIO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2679 | } |
| 2680 | if (ret) |
| 2681 | goto failed; |
| 2682 | } |
| 2683 | |
| 2684 | if (is_mapped_to_disk) |
| 2685 | SetPageMappedToDisk(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2687 | *fsdata = head; /* to be released by nobh_write_end */ |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2688 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2689 | return 0; |
| 2690 | |
| 2691 | failed: |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2692 | BUG_ON(!ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2693 | /* |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2694 | * Error recovery is a bit difficult. We need to zero out blocks that |
| 2695 | * were newly allocated, and dirty them to ensure they get written out. |
| 2696 | * Buffers need to be attached to the page at this point, otherwise |
| 2697 | * the handling of potential IO errors during writeout would be hard |
| 2698 | * (could try doing synchronous writeout, but what if that fails too?) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2699 | */ |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2700 | attach_nobh_buffers(page, head); |
| 2701 | page_zero_new_buffers(page, from, to); |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2702 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2703 | out_release: |
| 2704 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2705 | put_page(page); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2706 | *pagep = NULL; |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2707 | |
npiggin@suse.de | 7bb46a6 | 2010-05-27 01:05:33 +1000 | [diff] [blame] | 2708 | return ret; |
| 2709 | } |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2710 | EXPORT_SYMBOL(nobh_write_begin); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2711 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2712 | int nobh_write_end(struct file *file, struct address_space *mapping, |
| 2713 | loff_t pos, unsigned len, unsigned copied, |
| 2714 | struct page *page, void *fsdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2715 | { |
| 2716 | struct inode *inode = page->mapping->host; |
Nick Piggin | efdc313 | 2007-10-21 06:57:41 +0200 | [diff] [blame] | 2717 | struct buffer_head *head = fsdata; |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2718 | struct buffer_head *bh; |
Dmitri Monakhov | 5b41e74 | 2008-03-28 14:15:52 -0700 | [diff] [blame] | 2719 | BUG_ON(fsdata != NULL && page_has_buffers(page)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2720 | |
Dave Kleikamp | d4cf109 | 2009-02-06 14:59:26 -0600 | [diff] [blame] | 2721 | if (unlikely(copied < len) && head) |
Dmitri Monakhov | 5b41e74 | 2008-03-28 14:15:52 -0700 | [diff] [blame] | 2722 | attach_nobh_buffers(page, head); |
| 2723 | if (page_has_buffers(page)) |
| 2724 | return generic_write_end(file, mapping, pos, len, |
| 2725 | copied, page, fsdata); |
Nick Piggin | a4b0672 | 2007-10-16 01:24:48 -0700 | [diff] [blame] | 2726 | |
Nick Piggin | 22c8ca7 | 2007-02-20 13:58:09 -0800 | [diff] [blame] | 2727 | SetPageUptodate(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2728 | set_page_dirty(page); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2729 | if (pos+copied > inode->i_size) { |
| 2730 | i_size_write(inode, pos+copied); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2731 | mark_inode_dirty(inode); |
| 2732 | } |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2733 | |
| 2734 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2735 | put_page(page); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2736 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2737 | while (head) { |
| 2738 | bh = head; |
| 2739 | head = head->b_this_page; |
| 2740 | free_buffer_head(bh); |
| 2741 | } |
| 2742 | |
| 2743 | return copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2744 | } |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2745 | EXPORT_SYMBOL(nobh_write_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2746 | |
| 2747 | /* |
| 2748 | * nobh_writepage() - based on block_full_write_page() except |
| 2749 | * that it tries to operate without attaching bufferheads to |
| 2750 | * the page. |
| 2751 | */ |
| 2752 | int nobh_writepage(struct page *page, get_block_t *get_block, |
| 2753 | struct writeback_control *wbc) |
| 2754 | { |
| 2755 | struct inode * const inode = page->mapping->host; |
| 2756 | loff_t i_size = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2757 | const pgoff_t end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2758 | unsigned offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2759 | int ret; |
| 2760 | |
| 2761 | /* Is the page fully inside i_size? */ |
| 2762 | if (page->index < end_index) |
| 2763 | goto out; |
| 2764 | |
| 2765 | /* Is the page fully outside i_size? (truncate in progress) */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2766 | offset = i_size & (PAGE_SIZE-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2767 | if (page->index >= end_index+1 || !offset) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2768 | unlock_page(page); |
| 2769 | return 0; /* don't care */ |
| 2770 | } |
| 2771 | |
| 2772 | /* |
| 2773 | * The page straddles i_size. It must be zeroed out on each and every |
| 2774 | * writepage invocation because it may be mmapped. "A file is mapped |
| 2775 | * in multiples of the page size. For a file that is not a multiple of |
| 2776 | * the page size, the remaining memory is zeroed when mapped, and |
| 2777 | * writes to that region are not written out to the file." |
| 2778 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2779 | zero_user_segment(page, offset, PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2780 | out: |
| 2781 | ret = mpage_writepage(page, get_block, wbc); |
| 2782 | if (ret == -EAGAIN) |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 2783 | ret = __block_write_full_page(inode, page, get_block, wbc, |
| 2784 | end_buffer_async_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2785 | return ret; |
| 2786 | } |
| 2787 | EXPORT_SYMBOL(nobh_writepage); |
| 2788 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2789 | int nobh_truncate_page(struct address_space *mapping, |
| 2790 | loff_t from, get_block_t *get_block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2791 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2792 | pgoff_t index = from >> PAGE_SHIFT; |
| 2793 | unsigned offset = from & (PAGE_SIZE-1); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2794 | unsigned blocksize; |
| 2795 | sector_t iblock; |
| 2796 | unsigned length, pos; |
| 2797 | struct inode *inode = mapping->host; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2798 | struct page *page; |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2799 | struct buffer_head map_bh; |
| 2800 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2801 | |
Fabian Frederick | 9340747 | 2017-02-27 14:28:32 -0800 | [diff] [blame] | 2802 | blocksize = i_blocksize(inode); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2803 | length = offset & (blocksize - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2804 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2805 | /* Block boundary? Nothing to do */ |
| 2806 | if (!length) |
| 2807 | return 0; |
| 2808 | |
| 2809 | length = blocksize - length; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2810 | iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2811 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2812 | page = grab_cache_page(mapping, index); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2813 | err = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2814 | if (!page) |
| 2815 | goto out; |
| 2816 | |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2817 | if (page_has_buffers(page)) { |
| 2818 | has_buffers: |
| 2819 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2820 | put_page(page); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2821 | return block_truncate_page(mapping, from, get_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2822 | } |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2823 | |
| 2824 | /* Find the buffer that contains "offset" */ |
| 2825 | pos = blocksize; |
| 2826 | while (offset >= pos) { |
| 2827 | iblock++; |
| 2828 | pos += blocksize; |
| 2829 | } |
| 2830 | |
Theodore Ts'o | 460bcf5 | 2009-05-12 07:37:56 -0400 | [diff] [blame] | 2831 | map_bh.b_size = blocksize; |
| 2832 | map_bh.b_state = 0; |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2833 | err = get_block(inode, iblock, &map_bh, 0); |
| 2834 | if (err) |
| 2835 | goto unlock; |
| 2836 | /* unmapped? It's a hole - nothing to do */ |
| 2837 | if (!buffer_mapped(&map_bh)) |
| 2838 | goto unlock; |
| 2839 | |
| 2840 | /* Ok, it's mapped. Make sure it's up-to-date */ |
| 2841 | if (!PageUptodate(page)) { |
| 2842 | err = mapping->a_ops->readpage(NULL, page); |
| 2843 | if (err) { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2844 | put_page(page); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2845 | goto out; |
| 2846 | } |
| 2847 | lock_page(page); |
| 2848 | if (!PageUptodate(page)) { |
| 2849 | err = -EIO; |
| 2850 | goto unlock; |
| 2851 | } |
| 2852 | if (page_has_buffers(page)) |
| 2853 | goto has_buffers; |
| 2854 | } |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2855 | zero_user(page, offset, length); |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2856 | set_page_dirty(page); |
| 2857 | err = 0; |
| 2858 | |
| 2859 | unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2860 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2861 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2862 | out: |
Nick Piggin | 03158cd | 2007-10-16 01:25:25 -0700 | [diff] [blame] | 2863 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2864 | } |
| 2865 | EXPORT_SYMBOL(nobh_truncate_page); |
| 2866 | |
| 2867 | int block_truncate_page(struct address_space *mapping, |
| 2868 | loff_t from, get_block_t *get_block) |
| 2869 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2870 | pgoff_t index = from >> PAGE_SHIFT; |
| 2871 | unsigned offset = from & (PAGE_SIZE-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2872 | unsigned blocksize; |
Andrew Morton | 54b21a7 | 2006-01-08 01:03:05 -0800 | [diff] [blame] | 2873 | sector_t iblock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2874 | unsigned length, pos; |
| 2875 | struct inode *inode = mapping->host; |
| 2876 | struct page *page; |
| 2877 | struct buffer_head *bh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2878 | int err; |
| 2879 | |
Fabian Frederick | 9340747 | 2017-02-27 14:28:32 -0800 | [diff] [blame] | 2880 | blocksize = i_blocksize(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2881 | length = offset & (blocksize - 1); |
| 2882 | |
| 2883 | /* Block boundary? Nothing to do */ |
| 2884 | if (!length) |
| 2885 | return 0; |
| 2886 | |
| 2887 | length = blocksize - length; |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2888 | iblock = (sector_t)index << (PAGE_SHIFT - inode->i_blkbits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2889 | |
| 2890 | page = grab_cache_page(mapping, index); |
| 2891 | err = -ENOMEM; |
| 2892 | if (!page) |
| 2893 | goto out; |
| 2894 | |
| 2895 | if (!page_has_buffers(page)) |
| 2896 | create_empty_buffers(page, blocksize, 0); |
| 2897 | |
| 2898 | /* Find the buffer that contains "offset" */ |
| 2899 | bh = page_buffers(page); |
| 2900 | pos = blocksize; |
| 2901 | while (offset >= pos) { |
| 2902 | bh = bh->b_this_page; |
| 2903 | iblock++; |
| 2904 | pos += blocksize; |
| 2905 | } |
| 2906 | |
| 2907 | err = 0; |
| 2908 | if (!buffer_mapped(bh)) { |
Badari Pulavarty | b0cf232 | 2006-03-26 01:38:00 -0800 | [diff] [blame] | 2909 | WARN_ON(bh->b_size != blocksize); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2910 | err = get_block(inode, iblock, bh, 0); |
| 2911 | if (err) |
| 2912 | goto unlock; |
| 2913 | /* unmapped? It's a hole - nothing to do */ |
| 2914 | if (!buffer_mapped(bh)) |
| 2915 | goto unlock; |
| 2916 | } |
| 2917 | |
| 2918 | /* Ok, it's mapped. Make sure it's up-to-date */ |
| 2919 | if (PageUptodate(page)) |
| 2920 | set_buffer_uptodate(bh); |
| 2921 | |
David Chinner | 33a266d | 2007-02-12 00:51:41 -0800 | [diff] [blame] | 2922 | if (!buffer_uptodate(bh) && !buffer_delay(bh) && !buffer_unwritten(bh)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2923 | err = -EIO; |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 2924 | ll_rw_block(REQ_OP_READ, 0, 1, &bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2925 | wait_on_buffer(bh); |
| 2926 | /* Uhhuh. Read error. Complain and punt. */ |
| 2927 | if (!buffer_uptodate(bh)) |
| 2928 | goto unlock; |
| 2929 | } |
| 2930 | |
Christoph Lameter | eebd2aa | 2008-02-04 22:28:29 -0800 | [diff] [blame] | 2931 | zero_user(page, offset, length); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2932 | mark_buffer_dirty(bh); |
| 2933 | err = 0; |
| 2934 | |
| 2935 | unlock: |
| 2936 | unlock_page(page); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2937 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2938 | out: |
| 2939 | return err; |
| 2940 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2941 | EXPORT_SYMBOL(block_truncate_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2942 | |
| 2943 | /* |
| 2944 | * The generic ->writepage function for buffer-backed address_spaces |
| 2945 | */ |
Matthew Wilcox | 1b938c0 | 2014-06-04 16:07:43 -0700 | [diff] [blame] | 2946 | int block_write_full_page(struct page *page, get_block_t *get_block, |
| 2947 | struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2948 | { |
| 2949 | struct inode * const inode = page->mapping->host; |
| 2950 | loff_t i_size = i_size_read(inode); |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2951 | const pgoff_t end_index = i_size >> PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2952 | unsigned offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2953 | |
| 2954 | /* Is the page fully inside i_size? */ |
| 2955 | if (page->index < end_index) |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 2956 | return __block_write_full_page(inode, page, get_block, wbc, |
Matthew Wilcox | 1b938c0 | 2014-06-04 16:07:43 -0700 | [diff] [blame] | 2957 | end_buffer_async_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2958 | |
| 2959 | /* Is the page fully outside i_size? (truncate in progress) */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2960 | offset = i_size & (PAGE_SIZE-1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2961 | if (page->index >= end_index+1 || !offset) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2962 | unlock_page(page); |
| 2963 | return 0; /* don't care */ |
| 2964 | } |
| 2965 | |
| 2966 | /* |
| 2967 | * The page straddles i_size. It must be zeroed out on each and every |
Adam Buchbinder | 2a61aa4 | 2009-12-11 16:35:40 -0500 | [diff] [blame] | 2968 | * writepage invocation because it may be mmapped. "A file is mapped |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2969 | * in multiples of the page size. For a file that is not a multiple of |
| 2970 | * the page size, the remaining memory is zeroed when mapped, and |
| 2971 | * writes to that region are not written out to the file." |
| 2972 | */ |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 2973 | zero_user_segment(page, offset, PAGE_SIZE); |
Matthew Wilcox | 1b938c0 | 2014-06-04 16:07:43 -0700 | [diff] [blame] | 2974 | return __block_write_full_page(inode, page, get_block, wbc, |
| 2975 | end_buffer_async_write); |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 2976 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2977 | EXPORT_SYMBOL(block_write_full_page); |
Chris Mason | 35c80d5 | 2009-04-15 13:22:38 -0400 | [diff] [blame] | 2978 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2979 | sector_t generic_block_bmap(struct address_space *mapping, sector_t block, |
| 2980 | get_block_t *get_block) |
| 2981 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2982 | struct inode *inode = mapping->host; |
Alexander Potapenko | 2a527d6 | 2017-07-05 00:56:21 -0400 | [diff] [blame] | 2983 | struct buffer_head tmp = { |
| 2984 | .b_size = i_blocksize(inode), |
| 2985 | }; |
| 2986 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2987 | get_block(inode, block, &tmp, 0); |
| 2988 | return tmp.b_blocknr; |
| 2989 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 2990 | EXPORT_SYMBOL(generic_block_bmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2991 | |
Christoph Hellwig | 4246a0b | 2015-07-20 15:29:37 +0200 | [diff] [blame] | 2992 | static void end_bio_bh_io_sync(struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2993 | { |
| 2994 | struct buffer_head *bh = bio->bi_private; |
| 2995 | |
Jens Axboe | b7c44ed | 2015-07-24 12:37:59 -0600 | [diff] [blame] | 2996 | if (unlikely(bio_flagged(bio, BIO_QUIET))) |
Keith Mannthey | 08bafc0 | 2008-11-25 10:24:35 +0100 | [diff] [blame] | 2997 | set_bit(BH_Quiet, &bh->b_state); |
| 2998 | |
Christoph Hellwig | 4e4cbee | 2017-06-03 09:38:06 +0200 | [diff] [blame] | 2999 | bh->b_end_io(bh, !bio->bi_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3000 | bio_put(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3001 | } |
| 3002 | |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3003 | static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, |
Christoph Hellwig | c75e707 | 2022-03-04 18:55:56 +0100 | [diff] [blame] | 3004 | struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3005 | { |
| 3006 | struct bio *bio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3007 | |
| 3008 | BUG_ON(!buffer_locked(bh)); |
| 3009 | BUG_ON(!buffer_mapped(bh)); |
| 3010 | BUG_ON(!bh->b_end_io); |
Aneesh Kumar K.V | 8fb0e34 | 2009-05-12 16:22:37 -0400 | [diff] [blame] | 3011 | BUG_ON(buffer_delay(bh)); |
| 3012 | BUG_ON(buffer_unwritten(bh)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3013 | |
Jens Axboe | 48fd4f9 | 2008-08-22 10:00:36 +0200 | [diff] [blame] | 3014 | /* |
Jens Axboe | 48fd4f9 | 2008-08-22 10:00:36 +0200 | [diff] [blame] | 3015 | * Only clear out a write error when rewriting |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3016 | */ |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3017 | if (test_set_buffer_req(bh) && (op == REQ_OP_WRITE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3018 | clear_buffer_write_io_error(bh); |
| 3019 | |
Christoph Hellwig | 07888c66 | 2022-01-24 10:11:05 +0100 | [diff] [blame] | 3020 | if (buffer_meta(bh)) |
| 3021 | op_flags |= REQ_META; |
| 3022 | if (buffer_prio(bh)) |
| 3023 | op_flags |= REQ_PRIO; |
| 3024 | |
| 3025 | bio = bio_alloc(bh->b_bdev, 1, op | op_flags, GFP_NOIO); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3026 | |
Eric Biggers | 4f74d15 | 2020-07-02 01:56:07 +0000 | [diff] [blame] | 3027 | fscrypt_set_bio_crypt_ctx_bh(bio, bh, GFP_NOIO); |
| 3028 | |
Kent Overstreet | 4f024f3 | 2013-10-11 15:44:27 -0700 | [diff] [blame] | 3029 | bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3030 | |
Kent Overstreet | 6cf66b4 | 2014-12-22 12:48:42 +0100 | [diff] [blame] | 3031 | bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh)); |
| 3032 | BUG_ON(bio->bi_iter.bi_size != bh->b_size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3033 | |
| 3034 | bio->bi_end_io = end_bio_bh_io_sync; |
| 3035 | bio->bi_private = bh; |
| 3036 | |
Ming Lei | 83c9c54 | 2020-01-05 09:41:14 +0800 | [diff] [blame] | 3037 | /* Take care of bh's that straddle the end of the device */ |
| 3038 | guard_bio_eod(bio); |
| 3039 | |
Dennis Zhou | fd42df3 | 2018-12-05 12:10:34 -0500 | [diff] [blame] | 3040 | if (wbc) { |
| 3041 | wbc_init_bio(wbc, bio); |
Tejun Heo | 34e51a5 | 2019-06-27 13:39:49 -0700 | [diff] [blame] | 3042 | wbc_account_cgroup_owner(wbc, bh->b_page, bh->b_size); |
Dennis Zhou | fd42df3 | 2018-12-05 12:10:34 -0500 | [diff] [blame] | 3043 | } |
| 3044 | |
Mike Christie | 4e49ea4 | 2016-06-05 14:31:41 -0500 | [diff] [blame] | 3045 | submit_bio(bio); |
Julia Lawall | f6454b0 | 2015-05-26 21:59:53 +0200 | [diff] [blame] | 3046 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3047 | } |
Tejun Heo | bafc0db | 2015-06-02 08:37:23 -0600 | [diff] [blame] | 3048 | |
Eric Biggers | 020c2833 | 2017-03-25 21:02:18 -0700 | [diff] [blame] | 3049 | int submit_bh(int op, int op_flags, struct buffer_head *bh) |
Tejun Heo | bafc0db | 2015-06-02 08:37:23 -0600 | [diff] [blame] | 3050 | { |
Christoph Hellwig | c75e707 | 2022-03-04 18:55:56 +0100 | [diff] [blame] | 3051 | return submit_bh_wbc(op, op_flags, bh, NULL); |
Darrick J. Wong | 713685111 | 2013-04-29 15:07:25 -0700 | [diff] [blame] | 3052 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 3053 | EXPORT_SYMBOL(submit_bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3054 | |
| 3055 | /** |
| 3056 | * ll_rw_block: low-level access to block devices (DEPRECATED) |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 3057 | * @op: whether to %READ or %WRITE |
Christoph Hellwig | ef295ec | 2016-10-28 08:48:16 -0600 | [diff] [blame] | 3058 | * @op_flags: req_flag_bits |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3059 | * @nr: number of &struct buffer_heads in the array |
| 3060 | * @bhs: array of pointers to &struct buffer_head |
| 3061 | * |
Jan Kara | a766223 | 2005-09-06 15:19:10 -0700 | [diff] [blame] | 3062 | * ll_rw_block() takes an array of pointers to &struct buffer_heads, and |
Christoph Hellwig | 7024628 | 2016-07-19 11:28:41 +0200 | [diff] [blame] | 3063 | * requests an I/O operation on them, either a %REQ_OP_READ or a %REQ_OP_WRITE. |
| 3064 | * @op_flags contains flags modifying the detailed I/O behavior, most notably |
| 3065 | * %REQ_RAHEAD. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3066 | * |
| 3067 | * This function drops any buffer that it cannot get a lock on (with the |
Christoph Hellwig | 9cb569d | 2010-08-11 17:06:24 +0200 | [diff] [blame] | 3068 | * BH_Lock state bit), any buffer that appears to be clean when doing a write |
| 3069 | * request, and any buffer that appears to be up-to-date when doing read |
| 3070 | * request. Further it marks as clean buffers that are processed for |
| 3071 | * writing (the buffer cache won't assume that they are actually clean |
| 3072 | * until the buffer gets unlocked). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3073 | * |
| 3074 | * ll_rw_block sets b_end_io to simple completion handler that marks |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 3075 | * the buffer up-to-date (if appropriate), unlocks the buffer and wakes |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3076 | * any waiters. |
| 3077 | * |
| 3078 | * All of the buffers must be for the same device, and must also be a |
| 3079 | * multiple of the current approved size for the device. |
| 3080 | */ |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 3081 | void ll_rw_block(int op, int op_flags, int nr, struct buffer_head *bhs[]) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3082 | { |
| 3083 | int i; |
| 3084 | |
| 3085 | for (i = 0; i < nr; i++) { |
| 3086 | struct buffer_head *bh = bhs[i]; |
| 3087 | |
Christoph Hellwig | 9cb569d | 2010-08-11 17:06:24 +0200 | [diff] [blame] | 3088 | if (!trylock_buffer(bh)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3089 | continue; |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 3090 | if (op == WRITE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3091 | if (test_clear_buffer_dirty(bh)) { |
akpm@osdl.org | 76c3073 | 2005-04-16 15:24:07 -0700 | [diff] [blame] | 3092 | bh->b_end_io = end_buffer_write_sync; |
OGAWA Hirofumi | e60e5c5 | 2006-02-03 03:04:43 -0800 | [diff] [blame] | 3093 | get_bh(bh); |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 3094 | submit_bh(op, op_flags, bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3095 | continue; |
| 3096 | } |
| 3097 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3098 | if (!buffer_uptodate(bh)) { |
akpm@osdl.org | 76c3073 | 2005-04-16 15:24:07 -0700 | [diff] [blame] | 3099 | bh->b_end_io = end_buffer_read_sync; |
OGAWA Hirofumi | e60e5c5 | 2006-02-03 03:04:43 -0800 | [diff] [blame] | 3100 | get_bh(bh); |
Mike Christie | dfec8a1 | 2016-06-05 14:31:44 -0500 | [diff] [blame] | 3101 | submit_bh(op, op_flags, bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3102 | continue; |
| 3103 | } |
| 3104 | } |
| 3105 | unlock_buffer(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3106 | } |
| 3107 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 3108 | EXPORT_SYMBOL(ll_rw_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3109 | |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3110 | void write_dirty_buffer(struct buffer_head *bh, int op_flags) |
Christoph Hellwig | 9cb569d | 2010-08-11 17:06:24 +0200 | [diff] [blame] | 3111 | { |
| 3112 | lock_buffer(bh); |
| 3113 | if (!test_clear_buffer_dirty(bh)) { |
| 3114 | unlock_buffer(bh); |
| 3115 | return; |
| 3116 | } |
| 3117 | bh->b_end_io = end_buffer_write_sync; |
| 3118 | get_bh(bh); |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3119 | submit_bh(REQ_OP_WRITE, op_flags, bh); |
Christoph Hellwig | 9cb569d | 2010-08-11 17:06:24 +0200 | [diff] [blame] | 3120 | } |
| 3121 | EXPORT_SYMBOL(write_dirty_buffer); |
| 3122 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3123 | /* |
| 3124 | * For a data-integrity writeout, we need to wait upon any in-progress I/O |
| 3125 | * and then start new I/O and then wait upon it. The caller must have a ref on |
| 3126 | * the buffer_head. |
| 3127 | */ |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3128 | int __sync_dirty_buffer(struct buffer_head *bh, int op_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3129 | { |
| 3130 | int ret = 0; |
| 3131 | |
| 3132 | WARN_ON(atomic_read(&bh->b_count) < 1); |
| 3133 | lock_buffer(bh); |
| 3134 | if (test_clear_buffer_dirty(bh)) { |
Xianting Tian | 377254b | 2020-07-31 12:10:25 -0400 | [diff] [blame] | 3135 | /* |
| 3136 | * The bh should be mapped, but it might not be if the |
| 3137 | * device was hot-removed. Not much we can do but fail the I/O. |
| 3138 | */ |
| 3139 | if (!buffer_mapped(bh)) { |
| 3140 | unlock_buffer(bh); |
| 3141 | return -EIO; |
| 3142 | } |
| 3143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3144 | get_bh(bh); |
| 3145 | bh->b_end_io = end_buffer_write_sync; |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3146 | ret = submit_bh(REQ_OP_WRITE, op_flags, bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3147 | wait_on_buffer(bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3148 | if (!ret && !buffer_uptodate(bh)) |
| 3149 | ret = -EIO; |
| 3150 | } else { |
| 3151 | unlock_buffer(bh); |
| 3152 | } |
| 3153 | return ret; |
| 3154 | } |
Christoph Hellwig | 87e9951 | 2010-08-11 17:05:45 +0200 | [diff] [blame] | 3155 | EXPORT_SYMBOL(__sync_dirty_buffer); |
| 3156 | |
| 3157 | int sync_dirty_buffer(struct buffer_head *bh) |
| 3158 | { |
Christoph Hellwig | 70fd761 | 2016-11-01 07:40:10 -0600 | [diff] [blame] | 3159 | return __sync_dirty_buffer(bh, REQ_SYNC); |
Christoph Hellwig | 87e9951 | 2010-08-11 17:05:45 +0200 | [diff] [blame] | 3160 | } |
H Hartley Sweeten | 1fe72ea | 2009-09-22 16:43:51 -0700 | [diff] [blame] | 3161 | EXPORT_SYMBOL(sync_dirty_buffer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3162 | |
| 3163 | /* |
| 3164 | * try_to_free_buffers() checks if all the buffers on this particular page |
| 3165 | * are unused, and releases them if so. |
| 3166 | * |
| 3167 | * Exclusion against try_to_free_buffers may be obtained by either |
| 3168 | * locking the page or by holding its mapping's private_lock. |
| 3169 | * |
| 3170 | * If the page is dirty but all the buffers are clean then we need to |
| 3171 | * be sure to mark the page clean as well. This is because the page |
| 3172 | * may be against a block device, and a later reattachment of buffers |
| 3173 | * to a dirty page will set *all* buffers dirty. Which would corrupt |
| 3174 | * filesystem data on the same device. |
| 3175 | * |
| 3176 | * The same applies to regular filesystem pages: if all the buffers are |
| 3177 | * clean then we set the page clean and proceed. To do that, we require |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 3178 | * total exclusion from block_dirty_folio(). That is obtained with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3179 | * private_lock. |
| 3180 | * |
| 3181 | * try_to_free_buffers() is non-blocking. |
| 3182 | */ |
| 3183 | static inline int buffer_busy(struct buffer_head *bh) |
| 3184 | { |
| 3185 | return atomic_read(&bh->b_count) | |
| 3186 | (bh->b_state & ((1 << BH_Dirty) | (1 << BH_Lock))); |
| 3187 | } |
| 3188 | |
| 3189 | static int |
| 3190 | drop_buffers(struct page *page, struct buffer_head **buffers_to_free) |
| 3191 | { |
| 3192 | struct buffer_head *head = page_buffers(page); |
| 3193 | struct buffer_head *bh; |
| 3194 | |
| 3195 | bh = head; |
| 3196 | do { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3197 | if (buffer_busy(bh)) |
| 3198 | goto failed; |
| 3199 | bh = bh->b_this_page; |
| 3200 | } while (bh != head); |
| 3201 | |
| 3202 | do { |
| 3203 | struct buffer_head *next = bh->b_this_page; |
| 3204 | |
Jan Kara | 535ee2f | 2008-02-08 04:21:59 -0800 | [diff] [blame] | 3205 | if (bh->b_assoc_map) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3206 | __remove_assoc_queue(bh); |
| 3207 | bh = next; |
| 3208 | } while (bh != head); |
| 3209 | *buffers_to_free = head; |
Guoqing Jiang | 45dcfc2 | 2020-06-01 21:47:48 -0700 | [diff] [blame] | 3210 | detach_page_private(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3211 | return 1; |
| 3212 | failed: |
| 3213 | return 0; |
| 3214 | } |
| 3215 | |
| 3216 | int try_to_free_buffers(struct page *page) |
| 3217 | { |
| 3218 | struct address_space * const mapping = page->mapping; |
| 3219 | struct buffer_head *buffers_to_free = NULL; |
| 3220 | int ret = 0; |
| 3221 | |
| 3222 | BUG_ON(!PageLocked(page)); |
Linus Torvalds | ecdfc97 | 2007-01-26 12:47:06 -0800 | [diff] [blame] | 3223 | if (PageWriteback(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3224 | return 0; |
| 3225 | |
| 3226 | if (mapping == NULL) { /* can this still happen? */ |
| 3227 | ret = drop_buffers(page, &buffers_to_free); |
| 3228 | goto out; |
| 3229 | } |
| 3230 | |
| 3231 | spin_lock(&mapping->private_lock); |
| 3232 | ret = drop_buffers(page, &buffers_to_free); |
Linus Torvalds | ecdfc97 | 2007-01-26 12:47:06 -0800 | [diff] [blame] | 3233 | |
| 3234 | /* |
| 3235 | * If the filesystem writes its buffers by hand (eg ext3) |
| 3236 | * then we can have clean buffers against a dirty page. We |
| 3237 | * clean the page here; otherwise the VM will never notice |
| 3238 | * that the filesystem did any IO at all. |
| 3239 | * |
| 3240 | * Also, during truncate, discard_buffer will have marked all |
| 3241 | * the page's buffers clean. We discover that here and clean |
| 3242 | * the page also. |
Nick Piggin | 87df724 | 2007-01-30 14:36:27 +1100 | [diff] [blame] | 3243 | * |
| 3244 | * private_lock must be held over this entire operation in order |
Matthew Wilcox (Oracle) | e621900 | 2022-02-09 20:22:12 +0000 | [diff] [blame] | 3245 | * to synchronise against block_dirty_folio and prevent the |
Nick Piggin | 87df724 | 2007-01-30 14:36:27 +1100 | [diff] [blame] | 3246 | * dirty bit from being lost. |
Linus Torvalds | ecdfc97 | 2007-01-26 12:47:06 -0800 | [diff] [blame] | 3247 | */ |
Tejun Heo | 11f81be | 2015-05-22 17:13:15 -0400 | [diff] [blame] | 3248 | if (ret) |
| 3249 | cancel_dirty_page(page); |
Nick Piggin | 87df724 | 2007-01-30 14:36:27 +1100 | [diff] [blame] | 3250 | spin_unlock(&mapping->private_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3251 | out: |
| 3252 | if (buffers_to_free) { |
| 3253 | struct buffer_head *bh = buffers_to_free; |
| 3254 | |
| 3255 | do { |
| 3256 | struct buffer_head *next = bh->b_this_page; |
| 3257 | free_buffer_head(bh); |
| 3258 | bh = next; |
| 3259 | } while (bh != buffers_to_free); |
| 3260 | } |
| 3261 | return ret; |
| 3262 | } |
| 3263 | EXPORT_SYMBOL(try_to_free_buffers); |
| 3264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3265 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3266 | * Buffer-head allocation |
| 3267 | */ |
Shai Fultheim | a0a9b04 | 2012-05-15 12:29:52 +0300 | [diff] [blame] | 3268 | static struct kmem_cache *bh_cachep __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3269 | |
| 3270 | /* |
| 3271 | * Once the number of bh's in the machine exceeds this level, we start |
| 3272 | * stripping them in writeback. |
| 3273 | */ |
Zhang Yanfei | 43be594 | 2013-02-22 16:35:46 -0800 | [diff] [blame] | 3274 | static unsigned long max_buffer_heads; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3275 | |
| 3276 | int buffer_heads_over_limit; |
| 3277 | |
| 3278 | struct bh_accounting { |
| 3279 | int nr; /* Number of live bh's */ |
| 3280 | int ratelimit; /* Limit cacheline bouncing */ |
| 3281 | }; |
| 3282 | |
| 3283 | static DEFINE_PER_CPU(struct bh_accounting, bh_accounting) = {0, 0}; |
| 3284 | |
| 3285 | static void recalc_bh_state(void) |
| 3286 | { |
| 3287 | int i; |
| 3288 | int tot = 0; |
| 3289 | |
Christoph Lameter | ee1be86 | 2010-12-06 11:40:05 -0600 | [diff] [blame] | 3290 | if (__this_cpu_inc_return(bh_accounting.ratelimit) - 1 < 4096) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3291 | return; |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3292 | __this_cpu_write(bh_accounting.ratelimit, 0); |
Eric Dumazet | 8a14342 | 2006-03-24 03:18:10 -0800 | [diff] [blame] | 3293 | for_each_online_cpu(i) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3294 | tot += per_cpu(bh_accounting, i).nr; |
| 3295 | buffer_heads_over_limit = (tot > max_buffer_heads); |
| 3296 | } |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3297 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 3298 | struct buffer_head *alloc_buffer_head(gfp_t gfp_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3299 | { |
Richard Kennedy | 019b4d1 | 2010-03-10 15:20:33 -0800 | [diff] [blame] | 3300 | struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3301 | if (ret) { |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 3302 | INIT_LIST_HEAD(&ret->b_assoc_buffers); |
Thomas Gleixner | f1e67e3 | 2019-11-18 14:28:24 +0100 | [diff] [blame] | 3303 | spin_lock_init(&ret->b_uptodate_lock); |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3304 | preempt_disable(); |
| 3305 | __this_cpu_inc(bh_accounting.nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3306 | recalc_bh_state(); |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3307 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3308 | } |
| 3309 | return ret; |
| 3310 | } |
| 3311 | EXPORT_SYMBOL(alloc_buffer_head); |
| 3312 | |
| 3313 | void free_buffer_head(struct buffer_head *bh) |
| 3314 | { |
| 3315 | BUG_ON(!list_empty(&bh->b_assoc_buffers)); |
| 3316 | kmem_cache_free(bh_cachep, bh); |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3317 | preempt_disable(); |
| 3318 | __this_cpu_dec(bh_accounting.nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3319 | recalc_bh_state(); |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3320 | preempt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3321 | } |
| 3322 | EXPORT_SYMBOL(free_buffer_head); |
| 3323 | |
Sebastian Andrzej Siewior | fc4d24c | 2016-11-03 15:49:57 +0100 | [diff] [blame] | 3324 | static int buffer_exit_cpu_dead(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3325 | { |
| 3326 | int i; |
| 3327 | struct bh_lru *b = &per_cpu(bh_lrus, cpu); |
| 3328 | |
| 3329 | for (i = 0; i < BH_LRU_SIZE; i++) { |
| 3330 | brelse(b->bhs[i]); |
| 3331 | b->bhs[i] = NULL; |
| 3332 | } |
Christoph Lameter | c7b9251 | 2010-12-06 11:16:28 -0600 | [diff] [blame] | 3333 | this_cpu_add(bh_accounting.nr, per_cpu(bh_accounting, cpu).nr); |
Eric Dumazet | 8a14342 | 2006-03-24 03:18:10 -0800 | [diff] [blame] | 3334 | per_cpu(bh_accounting, cpu).nr = 0; |
Sebastian Andrzej Siewior | fc4d24c | 2016-11-03 15:49:57 +0100 | [diff] [blame] | 3335 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3336 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3337 | |
Aneesh Kumar K.V | 389d1b0 | 2008-01-28 23:58:26 -0500 | [diff] [blame] | 3338 | /** |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 3339 | * bh_uptodate_or_lock - Test whether the buffer is uptodate |
Aneesh Kumar K.V | 389d1b0 | 2008-01-28 23:58:26 -0500 | [diff] [blame] | 3340 | * @bh: struct buffer_head |
| 3341 | * |
| 3342 | * Return true if the buffer is up-to-date and false, |
| 3343 | * with the buffer locked, if not. |
| 3344 | */ |
| 3345 | int bh_uptodate_or_lock(struct buffer_head *bh) |
| 3346 | { |
| 3347 | if (!buffer_uptodate(bh)) { |
| 3348 | lock_buffer(bh); |
| 3349 | if (!buffer_uptodate(bh)) |
| 3350 | return 0; |
| 3351 | unlock_buffer(bh); |
| 3352 | } |
| 3353 | return 1; |
| 3354 | } |
| 3355 | EXPORT_SYMBOL(bh_uptodate_or_lock); |
| 3356 | |
| 3357 | /** |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 3358 | * bh_submit_read - Submit a locked buffer for reading |
Aneesh Kumar K.V | 389d1b0 | 2008-01-28 23:58:26 -0500 | [diff] [blame] | 3359 | * @bh: struct buffer_head |
| 3360 | * |
| 3361 | * Returns zero on success and -EIO on error. |
| 3362 | */ |
| 3363 | int bh_submit_read(struct buffer_head *bh) |
| 3364 | { |
| 3365 | BUG_ON(!buffer_locked(bh)); |
| 3366 | |
| 3367 | if (buffer_uptodate(bh)) { |
| 3368 | unlock_buffer(bh); |
| 3369 | return 0; |
| 3370 | } |
| 3371 | |
| 3372 | get_bh(bh); |
| 3373 | bh->b_end_io = end_buffer_read_sync; |
Mike Christie | 2a222ca | 2016-06-05 14:31:43 -0500 | [diff] [blame] | 3374 | submit_bh(REQ_OP_READ, 0, bh); |
Aneesh Kumar K.V | 389d1b0 | 2008-01-28 23:58:26 -0500 | [diff] [blame] | 3375 | wait_on_buffer(bh); |
| 3376 | if (buffer_uptodate(bh)) |
| 3377 | return 0; |
| 3378 | return -EIO; |
| 3379 | } |
| 3380 | EXPORT_SYMBOL(bh_submit_read); |
| 3381 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3382 | void __init buffer_init(void) |
| 3383 | { |
Zhang Yanfei | 43be594 | 2013-02-22 16:35:46 -0800 | [diff] [blame] | 3384 | unsigned long nrpages; |
Sebastian Andrzej Siewior | fc4d24c | 2016-11-03 15:49:57 +0100 | [diff] [blame] | 3385 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3386 | |
Christoph Lameter | b98938c | 2008-02-04 22:28:36 -0800 | [diff] [blame] | 3387 | bh_cachep = kmem_cache_create("buffer_head", |
| 3388 | sizeof(struct buffer_head), 0, |
| 3389 | (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| |
| 3390 | SLAB_MEM_SPREAD), |
Richard Kennedy | 019b4d1 | 2010-03-10 15:20:33 -0800 | [diff] [blame] | 3391 | NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3392 | |
| 3393 | /* |
| 3394 | * Limit the bh occupancy to 10% of ZONE_NORMAL |
| 3395 | */ |
| 3396 | nrpages = (nr_free_buffer_pages() * 10) / 100; |
| 3397 | max_buffer_heads = nrpages * (PAGE_SIZE / sizeof(struct buffer_head)); |
Sebastian Andrzej Siewior | fc4d24c | 2016-11-03 15:49:57 +0100 | [diff] [blame] | 3398 | ret = cpuhp_setup_state_nocalls(CPUHP_FS_BUFF_DEAD, "fs/buffer:dead", |
| 3399 | NULL, buffer_exit_cpu_dead); |
| 3400 | WARN_ON(ret < 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3401 | } |