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Commit | Line | Data |
---|---|---|
bd2d0210 TT |
1 | /* |
2 | * linux/fs/ext4/page-io.c | |
3 | * | |
4 | * This contains the new page_io functions for ext4 | |
5 | * | |
6 | * Written by Theodore Ts'o, 2010. | |
7 | */ | |
8 | ||
bd2d0210 TT |
9 | #include <linux/fs.h> |
10 | #include <linux/time.h> | |
11 | #include <linux/jbd2.h> | |
12 | #include <linux/highuid.h> | |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/quotaops.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/buffer_head.h> | |
17 | #include <linux/writeback.h> | |
18 | #include <linux/pagevec.h> | |
19 | #include <linux/mpage.h> | |
20 | #include <linux/namei.h> | |
a27bb332 | 21 | #include <linux/aio.h> |
bd2d0210 TT |
22 | #include <linux/uio.h> |
23 | #include <linux/bio.h> | |
24 | #include <linux/workqueue.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/slab.h> | |
1ae48a63 | 27 | #include <linux/mm.h> |
e8974c39 | 28 | #include <linux/ratelimit.h> |
bd2d0210 TT |
29 | |
30 | #include "ext4_jbd2.h" | |
31 | #include "xattr.h" | |
32 | #include "acl.h" | |
bd2d0210 | 33 | |
0058f965 | 34 | static struct kmem_cache *io_end_cachep; |
bd2d0210 | 35 | |
5dabfc78 | 36 | int __init ext4_init_pageio(void) |
bd2d0210 | 37 | { |
bd2d0210 | 38 | io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); |
0058f965 | 39 | if (io_end_cachep == NULL) |
bd2d0210 | 40 | return -ENOMEM; |
bd2d0210 TT |
41 | return 0; |
42 | } | |
43 | ||
5dabfc78 | 44 | void ext4_exit_pageio(void) |
bd2d0210 TT |
45 | { |
46 | kmem_cache_destroy(io_end_cachep); | |
bd2d0210 TT |
47 | } |
48 | ||
b0857d30 JK |
49 | /* |
50 | * Print an buffer I/O error compatible with the fs/buffer.c. This | |
51 | * provides compatibility with dmesg scrapers that look for a specific | |
52 | * buffer I/O error message. We really need a unified error reporting | |
53 | * structure to userspace ala Digital Unix's uerf system, but it's | |
54 | * probably not going to happen in my lifetime, due to LKML politics... | |
55 | */ | |
56 | static void buffer_io_error(struct buffer_head *bh) | |
57 | { | |
58 | char b[BDEVNAME_SIZE]; | |
e8974c39 | 59 | printk_ratelimited(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n", |
b0857d30 JK |
60 | bdevname(bh->b_bdev, b), |
61 | (unsigned long long)bh->b_blocknr); | |
62 | } | |
63 | ||
64 | static void ext4_finish_bio(struct bio *bio) | |
65 | { | |
66 | int i; | |
67 | int error = !test_bit(BIO_UPTODATE, &bio->bi_flags); | |
68 | ||
69 | for (i = 0; i < bio->bi_vcnt; i++) { | |
70 | struct bio_vec *bvec = &bio->bi_io_vec[i]; | |
71 | struct page *page = bvec->bv_page; | |
72 | struct buffer_head *bh, *head; | |
73 | unsigned bio_start = bvec->bv_offset; | |
74 | unsigned bio_end = bio_start + bvec->bv_len; | |
75 | unsigned under_io = 0; | |
76 | unsigned long flags; | |
77 | ||
78 | if (!page) | |
79 | continue; | |
80 | ||
81 | if (error) { | |
82 | SetPageError(page); | |
83 | set_bit(AS_EIO, &page->mapping->flags); | |
84 | } | |
85 | bh = head = page_buffers(page); | |
86 | /* | |
87 | * We check all buffers in the page under BH_Uptodate_Lock | |
88 | * to avoid races with other end io clearing async_write flags | |
89 | */ | |
90 | local_irq_save(flags); | |
91 | bit_spin_lock(BH_Uptodate_Lock, &head->b_state); | |
92 | do { | |
93 | if (bh_offset(bh) < bio_start || | |
94 | bh_offset(bh) + bh->b_size > bio_end) { | |
95 | if (buffer_async_write(bh)) | |
96 | under_io++; | |
97 | continue; | |
98 | } | |
99 | clear_buffer_async_write(bh); | |
100 | if (error) | |
101 | buffer_io_error(bh); | |
102 | } while ((bh = bh->b_this_page) != head); | |
103 | bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); | |
104 | local_irq_restore(flags); | |
105 | if (!under_io) | |
106 | end_page_writeback(page); | |
107 | } | |
108 | } | |
109 | ||
97a851ed | 110 | static void ext4_release_io_end(ext4_io_end_t *io_end) |
bd2d0210 | 111 | { |
b0857d30 JK |
112 | struct bio *bio, *next_bio; |
113 | ||
97a851ed JK |
114 | BUG_ON(!list_empty(&io_end->list)); |
115 | BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); | |
6b523df4 | 116 | WARN_ON(io_end->handle); |
97a851ed JK |
117 | |
118 | if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count)) | |
119 | wake_up_all(ext4_ioend_wq(io_end->inode)); | |
b0857d30 JK |
120 | |
121 | for (bio = io_end->bio; bio; bio = next_bio) { | |
122 | next_bio = bio->bi_private; | |
123 | ext4_finish_bio(bio); | |
124 | bio_put(bio); | |
125 | } | |
97a851ed JK |
126 | if (io_end->flag & EXT4_IO_END_DIRECT) |
127 | inode_dio_done(io_end->inode); | |
128 | if (io_end->iocb) | |
129 | aio_complete(io_end->iocb, io_end->result, 0); | |
130 | kmem_cache_free(io_end_cachep, io_end); | |
131 | } | |
132 | ||
133 | static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) | |
134 | { | |
135 | struct inode *inode = io_end->inode; | |
82e54229 | 136 | |
97a851ed JK |
137 | io_end->flag &= ~EXT4_IO_END_UNWRITTEN; |
138 | /* Wake up anyone waiting on unwritten extent conversion */ | |
139 | if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) | |
140 | wake_up_all(ext4_ioend_wq(inode)); | |
bd2d0210 TT |
141 | } |
142 | ||
a115f749 JK |
143 | /* |
144 | * Check a range of space and convert unwritten extents to written. Note that | |
145 | * we are protected from truncate touching same part of extent tree by the | |
146 | * fact that truncate code waits for all DIO to finish (thus exclusion from | |
147 | * direct IO is achieved) and also waits for PageWriteback bits. Thus we | |
148 | * cannot get to ext4_ext_truncate() before all IOs overlapping that range are | |
149 | * completed (happens from ext4_free_ioend()). | |
150 | */ | |
28a535f9 | 151 | static int ext4_end_io(ext4_io_end_t *io) |
bd2d0210 TT |
152 | { |
153 | struct inode *inode = io->inode; | |
154 | loff_t offset = io->offset; | |
155 | ssize_t size = io->size; | |
6b523df4 | 156 | handle_t *handle = io->handle; |
bd2d0210 TT |
157 | int ret = 0; |
158 | ||
159 | ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," | |
160 | "list->prev 0x%p\n", | |
161 | io, inode->i_ino, io->list.next, io->list.prev); | |
162 | ||
6b523df4 JK |
163 | io->handle = NULL; /* Following call will use up the handle */ |
164 | ret = ext4_convert_unwritten_extents(handle, inode, offset, size); | |
bd2d0210 | 165 | if (ret < 0) { |
b82e384c TT |
166 | ext4_msg(inode->i_sb, KERN_EMERG, |
167 | "failed to convert unwritten extents to written " | |
168 | "extents -- potential data loss! " | |
169 | "(inode %lu, offset %llu, size %zd, error %d)", | |
170 | inode->i_ino, offset, size, ret); | |
bd2d0210 | 171 | } |
97a851ed JK |
172 | ext4_clear_io_unwritten_flag(io); |
173 | ext4_release_io_end(io); | |
bd2d0210 TT |
174 | return ret; |
175 | } | |
176 | ||
2e8fa54e | 177 | static void dump_completed_IO(struct inode *inode, struct list_head *head) |
28a535f9 DM |
178 | { |
179 | #ifdef EXT4FS_DEBUG | |
180 | struct list_head *cur, *before, *after; | |
181 | ext4_io_end_t *io, *io0, *io1; | |
28a535f9 | 182 | |
2e8fa54e | 183 | if (list_empty(head)) |
28a535f9 | 184 | return; |
28a535f9 | 185 | |
2e8fa54e JK |
186 | ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); |
187 | list_for_each_entry(io, head, list) { | |
28a535f9 DM |
188 | cur = &io->list; |
189 | before = cur->prev; | |
190 | io0 = container_of(before, ext4_io_end_t, list); | |
191 | after = cur->next; | |
192 | io1 = container_of(after, ext4_io_end_t, list); | |
193 | ||
194 | ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", | |
195 | io, inode->i_ino, io0, io1); | |
196 | } | |
197 | #endif | |
198 | } | |
199 | ||
200 | /* Add the io_end to per-inode completed end_io list. */ | |
97a851ed | 201 | static void ext4_add_complete_io(ext4_io_end_t *io_end) |
bd2d0210 | 202 | { |
28a535f9 DM |
203 | struct ext4_inode_info *ei = EXT4_I(io_end->inode); |
204 | struct workqueue_struct *wq; | |
205 | unsigned long flags; | |
206 | ||
207 | BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); | |
d73d5046 | 208 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
2e8fa54e JK |
209 | if (io_end->handle) { |
210 | wq = EXT4_SB(io_end->inode->i_sb)->rsv_conversion_wq; | |
211 | if (list_empty(&ei->i_rsv_conversion_list)) | |
212 | queue_work(wq, &ei->i_rsv_conversion_work); | |
213 | list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); | |
214 | } else { | |
215 | wq = EXT4_SB(io_end->inode->i_sb)->unrsv_conversion_wq; | |
216 | if (list_empty(&ei->i_unrsv_conversion_list)) | |
217 | queue_work(wq, &ei->i_unrsv_conversion_work); | |
218 | list_add_tail(&io_end->list, &ei->i_unrsv_conversion_list); | |
219 | } | |
28a535f9 DM |
220 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
221 | } | |
d73d5046 | 222 | |
2e8fa54e JK |
223 | static int ext4_do_flush_completed_IO(struct inode *inode, |
224 | struct list_head *head) | |
28a535f9 DM |
225 | { |
226 | ext4_io_end_t *io; | |
002bd7fa | 227 | struct list_head unwritten; |
28a535f9 DM |
228 | unsigned long flags; |
229 | struct ext4_inode_info *ei = EXT4_I(inode); | |
230 | int err, ret = 0; | |
231 | ||
28a535f9 | 232 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
2e8fa54e JK |
233 | dump_completed_IO(inode, head); |
234 | list_replace_init(head, &unwritten); | |
28a535f9 DM |
235 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
236 | ||
237 | while (!list_empty(&unwritten)) { | |
238 | io = list_entry(unwritten.next, ext4_io_end_t, list); | |
239 | BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); | |
240 | list_del_init(&io->list); | |
241 | ||
242 | err = ext4_end_io(io); | |
243 | if (unlikely(!ret && err)) | |
244 | ret = err; | |
28a535f9 DM |
245 | } |
246 | return ret; | |
247 | } | |
248 | ||
249 | /* | |
2e8fa54e | 250 | * work on completed IO, to convert unwritten extents to extents |
28a535f9 | 251 | */ |
2e8fa54e JK |
252 | void ext4_end_io_rsv_work(struct work_struct *work) |
253 | { | |
254 | struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, | |
255 | i_rsv_conversion_work); | |
256 | ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); | |
257 | } | |
258 | ||
259 | void ext4_end_io_unrsv_work(struct work_struct *work) | |
28a535f9 | 260 | { |
84c17543 | 261 | struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, |
2e8fa54e JK |
262 | i_unrsv_conversion_work); |
263 | ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_unrsv_conversion_list); | |
28a535f9 DM |
264 | } |
265 | ||
bd2d0210 TT |
266 | ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) |
267 | { | |
b17b35ec | 268 | ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); |
bd2d0210 | 269 | if (io) { |
f7ad6d2e TT |
270 | atomic_inc(&EXT4_I(inode)->i_ioend_count); |
271 | io->inode = inode; | |
bd2d0210 | 272 | INIT_LIST_HEAD(&io->list); |
97a851ed | 273 | atomic_set(&io->count, 1); |
bd2d0210 TT |
274 | } |
275 | return io; | |
276 | } | |
277 | ||
97a851ed JK |
278 | void ext4_put_io_end_defer(ext4_io_end_t *io_end) |
279 | { | |
280 | if (atomic_dec_and_test(&io_end->count)) { | |
281 | if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { | |
282 | ext4_release_io_end(io_end); | |
283 | return; | |
284 | } | |
285 | ext4_add_complete_io(io_end); | |
286 | } | |
287 | } | |
288 | ||
289 | int ext4_put_io_end(ext4_io_end_t *io_end) | |
290 | { | |
291 | int err = 0; | |
292 | ||
293 | if (atomic_dec_and_test(&io_end->count)) { | |
294 | if (io_end->flag & EXT4_IO_END_UNWRITTEN) { | |
6b523df4 JK |
295 | err = ext4_convert_unwritten_extents(io_end->handle, |
296 | io_end->inode, io_end->offset, | |
297 | io_end->size); | |
298 | io_end->handle = NULL; | |
97a851ed JK |
299 | ext4_clear_io_unwritten_flag(io_end); |
300 | } | |
301 | ext4_release_io_end(io_end); | |
302 | } | |
303 | return err; | |
304 | } | |
305 | ||
306 | ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) | |
307 | { | |
308 | atomic_inc(&io_end->count); | |
309 | return io_end; | |
310 | } | |
311 | ||
822dbba3 | 312 | /* BIO completion function for page writeback */ |
bd2d0210 TT |
313 | static void ext4_end_bio(struct bio *bio, int error) |
314 | { | |
315 | ext4_io_end_t *io_end = bio->bi_private; | |
d50bdd5a | 316 | sector_t bi_sector = bio->bi_sector; |
bd2d0210 TT |
317 | |
318 | BUG_ON(!io_end); | |
bd2d0210 TT |
319 | bio->bi_end_io = NULL; |
320 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
321 | error = 0; | |
0058f965 | 322 | |
f7ad6d2e | 323 | if (error) { |
b0857d30 JK |
324 | struct inode *inode = io_end->inode; |
325 | ||
f7ad6d2e TT |
326 | ext4_warning(inode->i_sb, "I/O error writing to inode %lu " |
327 | "(offset %llu size %ld starting block %llu)", | |
328 | inode->i_ino, | |
329 | (unsigned long long) io_end->offset, | |
330 | (long) io_end->size, | |
331 | (unsigned long long) | |
d50bdd5a | 332 | bi_sector >> (inode->i_blkbits - 9)); |
f7ad6d2e | 333 | } |
822dbba3 JK |
334 | |
335 | if (io_end->flag & EXT4_IO_END_UNWRITTEN) { | |
336 | /* | |
337 | * Link bio into list hanging from io_end. We have to do it | |
338 | * atomically as bio completions can be racing against each | |
339 | * other. | |
340 | */ | |
341 | bio->bi_private = xchg(&io_end->bio, bio); | |
342 | ext4_put_io_end_defer(io_end); | |
343 | } else { | |
344 | /* | |
345 | * Drop io_end reference early. Inode can get freed once | |
346 | * we finish the bio. | |
347 | */ | |
348 | ext4_put_io_end_defer(io_end); | |
349 | ext4_finish_bio(bio); | |
350 | bio_put(bio); | |
351 | } | |
bd2d0210 TT |
352 | } |
353 | ||
354 | void ext4_io_submit(struct ext4_io_submit *io) | |
355 | { | |
356 | struct bio *bio = io->io_bio; | |
357 | ||
358 | if (bio) { | |
359 | bio_get(io->io_bio); | |
360 | submit_bio(io->io_op, io->io_bio); | |
361 | BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); | |
362 | bio_put(io->io_bio); | |
363 | } | |
7dc57615 | 364 | io->io_bio = NULL; |
97a851ed JK |
365 | } |
366 | ||
367 | void ext4_io_submit_init(struct ext4_io_submit *io, | |
368 | struct writeback_control *wbc) | |
369 | { | |
370 | io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); | |
371 | io->io_bio = NULL; | |
7dc57615 | 372 | io->io_end = NULL; |
bd2d0210 TT |
373 | } |
374 | ||
97a851ed JK |
375 | static int io_submit_init_bio(struct ext4_io_submit *io, |
376 | struct buffer_head *bh) | |
bd2d0210 | 377 | { |
bd2d0210 TT |
378 | int nvecs = bio_get_nr_vecs(bh->b_bdev); |
379 | struct bio *bio; | |
380 | ||
275d3ba6 | 381 | bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); |
a1d8d9a7 TT |
382 | if (!bio) |
383 | return -ENOMEM; | |
bd2d0210 TT |
384 | bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
385 | bio->bi_bdev = bh->b_bdev; | |
bd2d0210 | 386 | bio->bi_end_io = ext4_end_bio; |
97a851ed | 387 | bio->bi_private = ext4_get_io_end(io->io_end); |
bd2d0210 | 388 | io->io_bio = bio; |
bd2d0210 TT |
389 | io->io_next_block = bh->b_blocknr; |
390 | return 0; | |
391 | } | |
392 | ||
393 | static int io_submit_add_bh(struct ext4_io_submit *io, | |
bd2d0210 | 394 | struct inode *inode, |
bd2d0210 TT |
395 | struct buffer_head *bh) |
396 | { | |
bd2d0210 TT |
397 | int ret; |
398 | ||
bd2d0210 TT |
399 | if (io->io_bio && bh->b_blocknr != io->io_next_block) { |
400 | submit_and_retry: | |
401 | ext4_io_submit(io); | |
402 | } | |
403 | if (io->io_bio == NULL) { | |
97a851ed | 404 | ret = io_submit_init_bio(io, bh); |
bd2d0210 TT |
405 | if (ret) |
406 | return ret; | |
407 | } | |
97a851ed JK |
408 | ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); |
409 | if (ret != bh->b_size) | |
410 | goto submit_and_retry; | |
bd2d0210 | 411 | io->io_next_block++; |
bd2d0210 TT |
412 | return 0; |
413 | } | |
414 | ||
415 | int ext4_bio_write_page(struct ext4_io_submit *io, | |
416 | struct page *page, | |
417 | int len, | |
418 | struct writeback_control *wbc) | |
419 | { | |
420 | struct inode *inode = page->mapping->host; | |
0058f965 | 421 | unsigned block_start, blocksize; |
bd2d0210 TT |
422 | struct buffer_head *bh, *head; |
423 | int ret = 0; | |
0058f965 | 424 | int nr_submitted = 0; |
bd2d0210 TT |
425 | |
426 | blocksize = 1 << inode->i_blkbits; | |
427 | ||
d50bdd5a | 428 | BUG_ON(!PageLocked(page)); |
bd2d0210 | 429 | BUG_ON(PageWriteback(page)); |
bd2d0210 | 430 | |
a54aa761 TT |
431 | set_page_writeback(page); |
432 | ClearPageError(page); | |
bd2d0210 | 433 | |
0058f965 JK |
434 | /* |
435 | * In the first loop we prepare and mark buffers to submit. We have to | |
436 | * mark all buffers in the page before submitting so that | |
437 | * end_page_writeback() cannot be called from ext4_bio_end_io() when IO | |
438 | * on the first buffer finishes and we are still working on submitting | |
439 | * the second buffer. | |
440 | */ | |
441 | bh = head = page_buffers(page); | |
442 | do { | |
443 | block_start = bh_offset(bh); | |
bd2d0210 | 444 | if (block_start >= len) { |
5a0dc736 YY |
445 | /* |
446 | * Comments copied from block_write_full_page_endio: | |
447 | * | |
448 | * The page straddles i_size. It must be zeroed out on | |
449 | * each and every writepage invocation because it may | |
450 | * be mmapped. "A file is mapped in multiples of the | |
451 | * page size. For a file that is not a multiple of | |
452 | * the page size, the remaining memory is zeroed when | |
453 | * mapped, and writes to that region are not written | |
454 | * out to the file." | |
455 | */ | |
0058f965 JK |
456 | zero_user_segment(page, block_start, |
457 | block_start + blocksize); | |
bd2d0210 TT |
458 | clear_buffer_dirty(bh); |
459 | set_buffer_uptodate(bh); | |
460 | continue; | |
461 | } | |
8a850c3f JK |
462 | if (!buffer_dirty(bh) || buffer_delay(bh) || |
463 | !buffer_mapped(bh) || buffer_unwritten(bh)) { | |
464 | /* A hole? We can safely clear the dirty bit */ | |
465 | if (!buffer_mapped(bh)) | |
466 | clear_buffer_dirty(bh); | |
467 | if (io->io_bio) | |
468 | ext4_io_submit(io); | |
469 | continue; | |
470 | } | |
0058f965 JK |
471 | if (buffer_new(bh)) { |
472 | clear_buffer_new(bh); | |
473 | unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); | |
474 | } | |
475 | set_buffer_async_write(bh); | |
476 | } while ((bh = bh->b_this_page) != head); | |
477 | ||
478 | /* Now submit buffers to write */ | |
479 | bh = head = page_buffers(page); | |
480 | do { | |
481 | if (!buffer_async_write(bh)) | |
482 | continue; | |
97a851ed | 483 | ret = io_submit_add_bh(io, inode, bh); |
bd2d0210 TT |
484 | if (ret) { |
485 | /* | |
486 | * We only get here on ENOMEM. Not much else | |
487 | * we can do but mark the page as dirty, and | |
488 | * better luck next time. | |
489 | */ | |
1ae48a63 | 490 | redirty_page_for_writepage(wbc, page); |
bd2d0210 TT |
491 | break; |
492 | } | |
0058f965 | 493 | nr_submitted++; |
1ae48a63 | 494 | clear_buffer_dirty(bh); |
0058f965 JK |
495 | } while ((bh = bh->b_this_page) != head); |
496 | ||
497 | /* Error stopped previous loop? Clean up buffers... */ | |
498 | if (ret) { | |
499 | do { | |
500 | clear_buffer_async_write(bh); | |
501 | bh = bh->b_this_page; | |
502 | } while (bh != head); | |
bd2d0210 TT |
503 | } |
504 | unlock_page(page); | |
0058f965 JK |
505 | /* Nothing submitted - we have to end page writeback */ |
506 | if (!nr_submitted) | |
507 | end_page_writeback(page); | |
bd2d0210 TT |
508 | return ret; |
509 | } |