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); | |
2c30c71b | 68 | struct bio_vec *bvec; |
b0857d30 | 69 | |
2c30c71b | 70 | bio_for_each_segment_all(bvec, bio, i) { |
b0857d30 JK |
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 | kmem_cache_free(io_end_cachep, io_end); |
127 | } | |
128 | ||
129 | static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) | |
130 | { | |
131 | struct inode *inode = io_end->inode; | |
82e54229 | 132 | |
97a851ed JK |
133 | io_end->flag &= ~EXT4_IO_END_UNWRITTEN; |
134 | /* Wake up anyone waiting on unwritten extent conversion */ | |
135 | if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) | |
136 | wake_up_all(ext4_ioend_wq(inode)); | |
bd2d0210 TT |
137 | } |
138 | ||
a115f749 JK |
139 | /* |
140 | * Check a range of space and convert unwritten extents to written. Note that | |
141 | * we are protected from truncate touching same part of extent tree by the | |
142 | * fact that truncate code waits for all DIO to finish (thus exclusion from | |
143 | * direct IO is achieved) and also waits for PageWriteback bits. Thus we | |
144 | * cannot get to ext4_ext_truncate() before all IOs overlapping that range are | |
145 | * completed (happens from ext4_free_ioend()). | |
146 | */ | |
28a535f9 | 147 | static int ext4_end_io(ext4_io_end_t *io) |
bd2d0210 TT |
148 | { |
149 | struct inode *inode = io->inode; | |
150 | loff_t offset = io->offset; | |
151 | ssize_t size = io->size; | |
6b523df4 | 152 | handle_t *handle = io->handle; |
bd2d0210 TT |
153 | int ret = 0; |
154 | ||
155 | ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," | |
156 | "list->prev 0x%p\n", | |
157 | io, inode->i_ino, io->list.next, io->list.prev); | |
158 | ||
6b523df4 JK |
159 | io->handle = NULL; /* Following call will use up the handle */ |
160 | ret = ext4_convert_unwritten_extents(handle, inode, offset, size); | |
bd2d0210 | 161 | if (ret < 0) { |
b82e384c TT |
162 | ext4_msg(inode->i_sb, KERN_EMERG, |
163 | "failed to convert unwritten extents to written " | |
164 | "extents -- potential data loss! " | |
165 | "(inode %lu, offset %llu, size %zd, error %d)", | |
166 | inode->i_ino, offset, size, ret); | |
bd2d0210 | 167 | } |
97a851ed JK |
168 | ext4_clear_io_unwritten_flag(io); |
169 | ext4_release_io_end(io); | |
bd2d0210 TT |
170 | return ret; |
171 | } | |
172 | ||
2e8fa54e | 173 | static void dump_completed_IO(struct inode *inode, struct list_head *head) |
28a535f9 DM |
174 | { |
175 | #ifdef EXT4FS_DEBUG | |
176 | struct list_head *cur, *before, *after; | |
177 | ext4_io_end_t *io, *io0, *io1; | |
28a535f9 | 178 | |
2e8fa54e | 179 | if (list_empty(head)) |
28a535f9 | 180 | return; |
28a535f9 | 181 | |
2e8fa54e JK |
182 | ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); |
183 | list_for_each_entry(io, head, list) { | |
28a535f9 DM |
184 | cur = &io->list; |
185 | before = cur->prev; | |
186 | io0 = container_of(before, ext4_io_end_t, list); | |
187 | after = cur->next; | |
188 | io1 = container_of(after, ext4_io_end_t, list); | |
189 | ||
190 | ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", | |
191 | io, inode->i_ino, io0, io1); | |
192 | } | |
193 | #endif | |
194 | } | |
195 | ||
196 | /* Add the io_end to per-inode completed end_io list. */ | |
97a851ed | 197 | static void ext4_add_complete_io(ext4_io_end_t *io_end) |
bd2d0210 | 198 | { |
28a535f9 | 199 | struct ext4_inode_info *ei = EXT4_I(io_end->inode); |
78371a45 | 200 | struct ext4_sb_info *sbi = EXT4_SB(io_end->inode->i_sb); |
28a535f9 DM |
201 | struct workqueue_struct *wq; |
202 | unsigned long flags; | |
203 | ||
7b7a8665 CH |
204 | /* Only reserved conversions from writeback should enter here */ |
205 | WARN_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); | |
78371a45 | 206 | WARN_ON(!io_end->handle && sbi->s_journal); |
d73d5046 | 207 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
78371a45 | 208 | wq = sbi->rsv_conversion_wq; |
7b7a8665 CH |
209 | if (list_empty(&ei->i_rsv_conversion_list)) |
210 | queue_work(wq, &ei->i_rsv_conversion_work); | |
211 | list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); | |
28a535f9 DM |
212 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
213 | } | |
d73d5046 | 214 | |
2e8fa54e JK |
215 | static int ext4_do_flush_completed_IO(struct inode *inode, |
216 | struct list_head *head) | |
28a535f9 DM |
217 | { |
218 | ext4_io_end_t *io; | |
002bd7fa | 219 | struct list_head unwritten; |
28a535f9 DM |
220 | unsigned long flags; |
221 | struct ext4_inode_info *ei = EXT4_I(inode); | |
222 | int err, ret = 0; | |
223 | ||
28a535f9 | 224 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
2e8fa54e JK |
225 | dump_completed_IO(inode, head); |
226 | list_replace_init(head, &unwritten); | |
28a535f9 DM |
227 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
228 | ||
229 | while (!list_empty(&unwritten)) { | |
230 | io = list_entry(unwritten.next, ext4_io_end_t, list); | |
231 | BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); | |
232 | list_del_init(&io->list); | |
233 | ||
234 | err = ext4_end_io(io); | |
235 | if (unlikely(!ret && err)) | |
236 | ret = err; | |
28a535f9 DM |
237 | } |
238 | return ret; | |
239 | } | |
240 | ||
241 | /* | |
2e8fa54e | 242 | * work on completed IO, to convert unwritten extents to extents |
28a535f9 | 243 | */ |
2e8fa54e JK |
244 | void ext4_end_io_rsv_work(struct work_struct *work) |
245 | { | |
246 | struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, | |
247 | i_rsv_conversion_work); | |
248 | ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); | |
249 | } | |
250 | ||
bd2d0210 TT |
251 | ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) |
252 | { | |
b17b35ec | 253 | ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); |
bd2d0210 | 254 | if (io) { |
f7ad6d2e TT |
255 | atomic_inc(&EXT4_I(inode)->i_ioend_count); |
256 | io->inode = inode; | |
bd2d0210 | 257 | INIT_LIST_HEAD(&io->list); |
97a851ed | 258 | atomic_set(&io->count, 1); |
bd2d0210 TT |
259 | } |
260 | return io; | |
261 | } | |
262 | ||
97a851ed JK |
263 | void ext4_put_io_end_defer(ext4_io_end_t *io_end) |
264 | { | |
265 | if (atomic_dec_and_test(&io_end->count)) { | |
266 | if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { | |
267 | ext4_release_io_end(io_end); | |
268 | return; | |
269 | } | |
270 | ext4_add_complete_io(io_end); | |
271 | } | |
272 | } | |
273 | ||
274 | int ext4_put_io_end(ext4_io_end_t *io_end) | |
275 | { | |
276 | int err = 0; | |
277 | ||
278 | if (atomic_dec_and_test(&io_end->count)) { | |
279 | if (io_end->flag & EXT4_IO_END_UNWRITTEN) { | |
6b523df4 JK |
280 | err = ext4_convert_unwritten_extents(io_end->handle, |
281 | io_end->inode, io_end->offset, | |
282 | io_end->size); | |
283 | io_end->handle = NULL; | |
97a851ed JK |
284 | ext4_clear_io_unwritten_flag(io_end); |
285 | } | |
286 | ext4_release_io_end(io_end); | |
287 | } | |
288 | return err; | |
289 | } | |
290 | ||
291 | ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) | |
292 | { | |
293 | atomic_inc(&io_end->count); | |
294 | return io_end; | |
295 | } | |
296 | ||
822dbba3 | 297 | /* BIO completion function for page writeback */ |
bd2d0210 TT |
298 | static void ext4_end_bio(struct bio *bio, int error) |
299 | { | |
300 | ext4_io_end_t *io_end = bio->bi_private; | |
d50bdd5a | 301 | sector_t bi_sector = bio->bi_sector; |
bd2d0210 TT |
302 | |
303 | BUG_ON(!io_end); | |
bd2d0210 TT |
304 | bio->bi_end_io = NULL; |
305 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
306 | error = 0; | |
0058f965 | 307 | |
f7ad6d2e | 308 | if (error) { |
b0857d30 JK |
309 | struct inode *inode = io_end->inode; |
310 | ||
f7ad6d2e TT |
311 | ext4_warning(inode->i_sb, "I/O error writing to inode %lu " |
312 | "(offset %llu size %ld starting block %llu)", | |
313 | inode->i_ino, | |
314 | (unsigned long long) io_end->offset, | |
315 | (long) io_end->size, | |
316 | (unsigned long long) | |
d50bdd5a | 317 | bi_sector >> (inode->i_blkbits - 9)); |
f7ad6d2e | 318 | } |
822dbba3 JK |
319 | |
320 | if (io_end->flag & EXT4_IO_END_UNWRITTEN) { | |
321 | /* | |
322 | * Link bio into list hanging from io_end. We have to do it | |
323 | * atomically as bio completions can be racing against each | |
324 | * other. | |
325 | */ | |
326 | bio->bi_private = xchg(&io_end->bio, bio); | |
327 | ext4_put_io_end_defer(io_end); | |
328 | } else { | |
329 | /* | |
330 | * Drop io_end reference early. Inode can get freed once | |
331 | * we finish the bio. | |
332 | */ | |
333 | ext4_put_io_end_defer(io_end); | |
334 | ext4_finish_bio(bio); | |
335 | bio_put(bio); | |
336 | } | |
bd2d0210 TT |
337 | } |
338 | ||
339 | void ext4_io_submit(struct ext4_io_submit *io) | |
340 | { | |
341 | struct bio *bio = io->io_bio; | |
342 | ||
343 | if (bio) { | |
344 | bio_get(io->io_bio); | |
345 | submit_bio(io->io_op, io->io_bio); | |
346 | BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); | |
347 | bio_put(io->io_bio); | |
348 | } | |
7dc57615 | 349 | io->io_bio = NULL; |
97a851ed JK |
350 | } |
351 | ||
352 | void ext4_io_submit_init(struct ext4_io_submit *io, | |
353 | struct writeback_control *wbc) | |
354 | { | |
355 | io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); | |
356 | io->io_bio = NULL; | |
7dc57615 | 357 | io->io_end = NULL; |
bd2d0210 TT |
358 | } |
359 | ||
97a851ed JK |
360 | static int io_submit_init_bio(struct ext4_io_submit *io, |
361 | struct buffer_head *bh) | |
bd2d0210 | 362 | { |
bd2d0210 TT |
363 | int nvecs = bio_get_nr_vecs(bh->b_bdev); |
364 | struct bio *bio; | |
365 | ||
275d3ba6 | 366 | bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); |
a1d8d9a7 TT |
367 | if (!bio) |
368 | return -ENOMEM; | |
bd2d0210 TT |
369 | bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
370 | bio->bi_bdev = bh->b_bdev; | |
bd2d0210 | 371 | bio->bi_end_io = ext4_end_bio; |
97a851ed | 372 | bio->bi_private = ext4_get_io_end(io->io_end); |
bd2d0210 | 373 | io->io_bio = bio; |
bd2d0210 TT |
374 | io->io_next_block = bh->b_blocknr; |
375 | return 0; | |
376 | } | |
377 | ||
378 | static int io_submit_add_bh(struct ext4_io_submit *io, | |
bd2d0210 | 379 | struct inode *inode, |
bd2d0210 TT |
380 | struct buffer_head *bh) |
381 | { | |
bd2d0210 TT |
382 | int ret; |
383 | ||
bd2d0210 TT |
384 | if (io->io_bio && bh->b_blocknr != io->io_next_block) { |
385 | submit_and_retry: | |
386 | ext4_io_submit(io); | |
387 | } | |
388 | if (io->io_bio == NULL) { | |
97a851ed | 389 | ret = io_submit_init_bio(io, bh); |
bd2d0210 TT |
390 | if (ret) |
391 | return ret; | |
392 | } | |
97a851ed JK |
393 | ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); |
394 | if (ret != bh->b_size) | |
395 | goto submit_and_retry; | |
bd2d0210 | 396 | io->io_next_block++; |
bd2d0210 TT |
397 | return 0; |
398 | } | |
399 | ||
400 | int ext4_bio_write_page(struct ext4_io_submit *io, | |
401 | struct page *page, | |
402 | int len, | |
403 | struct writeback_control *wbc) | |
404 | { | |
405 | struct inode *inode = page->mapping->host; | |
0058f965 | 406 | unsigned block_start, blocksize; |
bd2d0210 TT |
407 | struct buffer_head *bh, *head; |
408 | int ret = 0; | |
0058f965 | 409 | int nr_submitted = 0; |
bd2d0210 TT |
410 | |
411 | blocksize = 1 << inode->i_blkbits; | |
412 | ||
d50bdd5a | 413 | BUG_ON(!PageLocked(page)); |
bd2d0210 | 414 | BUG_ON(PageWriteback(page)); |
bd2d0210 | 415 | |
a54aa761 TT |
416 | set_page_writeback(page); |
417 | ClearPageError(page); | |
bd2d0210 | 418 | |
0058f965 JK |
419 | /* |
420 | * In the first loop we prepare and mark buffers to submit. We have to | |
421 | * mark all buffers in the page before submitting so that | |
422 | * end_page_writeback() cannot be called from ext4_bio_end_io() when IO | |
423 | * on the first buffer finishes and we are still working on submitting | |
424 | * the second buffer. | |
425 | */ | |
426 | bh = head = page_buffers(page); | |
427 | do { | |
428 | block_start = bh_offset(bh); | |
bd2d0210 | 429 | if (block_start >= len) { |
5a0dc736 YY |
430 | /* |
431 | * Comments copied from block_write_full_page_endio: | |
432 | * | |
433 | * The page straddles i_size. It must be zeroed out on | |
434 | * each and every writepage invocation because it may | |
435 | * be mmapped. "A file is mapped in multiples of the | |
436 | * page size. For a file that is not a multiple of | |
437 | * the page size, the remaining memory is zeroed when | |
438 | * mapped, and writes to that region are not written | |
439 | * out to the file." | |
440 | */ | |
0058f965 JK |
441 | zero_user_segment(page, block_start, |
442 | block_start + blocksize); | |
bd2d0210 TT |
443 | clear_buffer_dirty(bh); |
444 | set_buffer_uptodate(bh); | |
445 | continue; | |
446 | } | |
8a850c3f JK |
447 | if (!buffer_dirty(bh) || buffer_delay(bh) || |
448 | !buffer_mapped(bh) || buffer_unwritten(bh)) { | |
449 | /* A hole? We can safely clear the dirty bit */ | |
450 | if (!buffer_mapped(bh)) | |
451 | clear_buffer_dirty(bh); | |
452 | if (io->io_bio) | |
453 | ext4_io_submit(io); | |
454 | continue; | |
455 | } | |
0058f965 JK |
456 | if (buffer_new(bh)) { |
457 | clear_buffer_new(bh); | |
458 | unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); | |
459 | } | |
460 | set_buffer_async_write(bh); | |
461 | } while ((bh = bh->b_this_page) != head); | |
462 | ||
463 | /* Now submit buffers to write */ | |
464 | bh = head = page_buffers(page); | |
465 | do { | |
466 | if (!buffer_async_write(bh)) | |
467 | continue; | |
97a851ed | 468 | ret = io_submit_add_bh(io, inode, bh); |
bd2d0210 TT |
469 | if (ret) { |
470 | /* | |
471 | * We only get here on ENOMEM. Not much else | |
472 | * we can do but mark the page as dirty, and | |
473 | * better luck next time. | |
474 | */ | |
1ae48a63 | 475 | redirty_page_for_writepage(wbc, page); |
bd2d0210 TT |
476 | break; |
477 | } | |
0058f965 | 478 | nr_submitted++; |
1ae48a63 | 479 | clear_buffer_dirty(bh); |
0058f965 JK |
480 | } while ((bh = bh->b_this_page) != head); |
481 | ||
482 | /* Error stopped previous loop? Clean up buffers... */ | |
483 | if (ret) { | |
484 | do { | |
485 | clear_buffer_async_write(bh); | |
486 | bh = bh->b_this_page; | |
487 | } while (bh != head); | |
bd2d0210 TT |
488 | } |
489 | unlock_page(page); | |
0058f965 JK |
490 | /* Nothing submitted - we have to end page writeback */ |
491 | if (!nr_submitted) | |
492 | end_page_writeback(page); | |
bd2d0210 TT |
493 | return ret; |
494 | } |