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Commit | Line | Data |
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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> | |
21 | #include <linux/uio.h> | |
22 | #include <linux/bio.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #include "ext4_jbd2.h" | |
28 | #include "xattr.h" | |
29 | #include "acl.h" | |
bd2d0210 TT |
30 | |
31 | static struct kmem_cache *io_page_cachep, *io_end_cachep; | |
32 | ||
5dabfc78 | 33 | int __init ext4_init_pageio(void) |
bd2d0210 TT |
34 | { |
35 | io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT); | |
36 | if (io_page_cachep == NULL) | |
37 | return -ENOMEM; | |
38 | io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); | |
13195184 | 39 | if (io_end_cachep == NULL) { |
bd2d0210 TT |
40 | kmem_cache_destroy(io_page_cachep); |
41 | return -ENOMEM; | |
42 | } | |
bd2d0210 TT |
43 | return 0; |
44 | } | |
45 | ||
5dabfc78 | 46 | void ext4_exit_pageio(void) |
bd2d0210 TT |
47 | { |
48 | kmem_cache_destroy(io_end_cachep); | |
49 | kmem_cache_destroy(io_page_cachep); | |
50 | } | |
51 | ||
f7ad6d2e TT |
52 | void ext4_ioend_wait(struct inode *inode) |
53 | { | |
e9e3bcec | 54 | wait_queue_head_t *wq = ext4_ioend_wq(inode); |
f7ad6d2e TT |
55 | |
56 | wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0)); | |
57 | } | |
58 | ||
83668e71 TT |
59 | static void put_io_page(struct ext4_io_page *io_page) |
60 | { | |
61 | if (atomic_dec_and_test(&io_page->p_count)) { | |
6268b325 | 62 | end_page_writeback(io_page->p_page); |
83668e71 TT |
63 | put_page(io_page->p_page); |
64 | kmem_cache_free(io_page_cachep, io_page); | |
65 | } | |
66 | } | |
67 | ||
bd2d0210 TT |
68 | void ext4_free_io_end(ext4_io_end_t *io) |
69 | { | |
70 | int i; | |
71 | ||
72 | BUG_ON(!io); | |
28a535f9 | 73 | BUG_ON(!list_empty(&io->list)); |
82e54229 DM |
74 | BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN); |
75 | ||
bd2d0210 TT |
76 | if (io->page) |
77 | put_page(io->page); | |
83668e71 TT |
78 | for (i = 0; i < io->num_io_pages; i++) |
79 | put_io_page(io->pages[i]); | |
bd2d0210 | 80 | io->num_io_pages = 0; |
4e298021 TT |
81 | if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count)) |
82 | wake_up_all(ext4_ioend_wq(io->inode)); | |
bd2d0210 TT |
83 | kmem_cache_free(io_end_cachep, io); |
84 | } | |
85 | ||
28a535f9 DM |
86 | /* check a range of space and convert unwritten extents to written. */ |
87 | static int ext4_end_io(ext4_io_end_t *io) | |
bd2d0210 TT |
88 | { |
89 | struct inode *inode = io->inode; | |
90 | loff_t offset = io->offset; | |
91 | ssize_t size = io->size; | |
92 | int ret = 0; | |
93 | ||
94 | ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," | |
95 | "list->prev 0x%p\n", | |
96 | io, inode->i_ino, io->list.next, io->list.prev); | |
97 | ||
bd2d0210 TT |
98 | ret = ext4_convert_unwritten_extents(inode, offset, size); |
99 | if (ret < 0) { | |
b82e384c TT |
100 | ext4_msg(inode->i_sb, KERN_EMERG, |
101 | "failed to convert unwritten extents to written " | |
102 | "extents -- potential data loss! " | |
103 | "(inode %lu, offset %llu, size %zd, error %d)", | |
104 | inode->i_ino, offset, size, ret); | |
bd2d0210 | 105 | } |
bd2d0210 TT |
106 | if (io->iocb) |
107 | aio_complete(io->iocb, io->result, 0); | |
e9e3bcec | 108 | |
266991b1 JM |
109 | if (io->flag & EXT4_IO_END_DIRECT) |
110 | inode_dio_done(inode); | |
b82e384c | 111 | /* Wake up anyone waiting on unwritten extent conversion */ |
e27f41e1 | 112 | if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) |
8d8c1825 | 113 | wake_up_all(ext4_ioend_wq(inode)); |
bd2d0210 TT |
114 | return ret; |
115 | } | |
116 | ||
28a535f9 DM |
117 | static void dump_completed_IO(struct inode *inode) |
118 | { | |
119 | #ifdef EXT4FS_DEBUG | |
120 | struct list_head *cur, *before, *after; | |
121 | ext4_io_end_t *io, *io0, *io1; | |
122 | unsigned long flags; | |
123 | ||
124 | if (list_empty(&EXT4_I(inode)->i_completed_io_list)) { | |
125 | ext4_debug("inode %lu completed_io list is empty\n", | |
126 | inode->i_ino); | |
127 | return; | |
128 | } | |
129 | ||
130 | ext4_debug("Dump inode %lu completed_io list\n", inode->i_ino); | |
131 | list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list) { | |
132 | cur = &io->list; | |
133 | before = cur->prev; | |
134 | io0 = container_of(before, ext4_io_end_t, list); | |
135 | after = cur->next; | |
136 | io1 = container_of(after, ext4_io_end_t, list); | |
137 | ||
138 | ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", | |
139 | io, inode->i_ino, io0, io1); | |
140 | } | |
141 | #endif | |
142 | } | |
143 | ||
144 | /* Add the io_end to per-inode completed end_io list. */ | |
145 | void ext4_add_complete_io(ext4_io_end_t *io_end) | |
bd2d0210 | 146 | { |
28a535f9 DM |
147 | struct ext4_inode_info *ei = EXT4_I(io_end->inode); |
148 | struct workqueue_struct *wq; | |
149 | unsigned long flags; | |
150 | ||
151 | BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); | |
152 | wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq; | |
bd2d0210 | 153 | |
d73d5046 | 154 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
28a535f9 DM |
155 | if (list_empty(&ei->i_completed_io_list)) { |
156 | io_end->flag |= EXT4_IO_END_QUEUED; | |
157 | queue_work(wq, &io_end->work); | |
d73d5046 | 158 | } |
28a535f9 DM |
159 | list_add_tail(&io_end->list, &ei->i_completed_io_list); |
160 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); | |
161 | } | |
d73d5046 | 162 | |
28a535f9 DM |
163 | static int ext4_do_flush_completed_IO(struct inode *inode, |
164 | ext4_io_end_t *work_io) | |
165 | { | |
166 | ext4_io_end_t *io; | |
167 | struct list_head unwritten, complete, to_free; | |
168 | unsigned long flags; | |
169 | struct ext4_inode_info *ei = EXT4_I(inode); | |
170 | int err, ret = 0; | |
171 | ||
172 | INIT_LIST_HEAD(&complete); | |
173 | INIT_LIST_HEAD(&to_free); | |
174 | ||
175 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); | |
176 | dump_completed_IO(inode); | |
177 | list_replace_init(&ei->i_completed_io_list, &unwritten); | |
178 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); | |
179 | ||
180 | while (!list_empty(&unwritten)) { | |
181 | io = list_entry(unwritten.next, ext4_io_end_t, list); | |
182 | BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); | |
183 | list_del_init(&io->list); | |
184 | ||
185 | err = ext4_end_io(io); | |
186 | if (unlikely(!ret && err)) | |
187 | ret = err; | |
188 | ||
189 | list_add_tail(&io->list, &complete); | |
190 | } | |
28a535f9 DM |
191 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
192 | while (!list_empty(&complete)) { | |
193 | io = list_entry(complete.next, ext4_io_end_t, list); | |
194 | io->flag &= ~EXT4_IO_END_UNWRITTEN; | |
195 | /* end_io context can not be destroyed now because it still | |
196 | * used by queued worker. Worker thread will destroy it later */ | |
197 | if (io->flag & EXT4_IO_END_QUEUED) | |
198 | list_del_init(&io->list); | |
199 | else | |
200 | list_move(&io->list, &to_free); | |
201 | } | |
202 | /* If we are called from worker context, it is time to clear queued | |
203 | * flag, and destroy it's end_io if it was converted already */ | |
204 | if (work_io) { | |
205 | work_io->flag &= ~EXT4_IO_END_QUEUED; | |
206 | if (!(work_io->flag & EXT4_IO_END_UNWRITTEN)) | |
207 | list_add_tail(&work_io->list, &to_free); | |
8c0bec21 | 208 | } |
bd2d0210 | 209 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
28a535f9 DM |
210 | |
211 | while (!list_empty(&to_free)) { | |
212 | io = list_entry(to_free.next, ext4_io_end_t, list); | |
213 | list_del_init(&io->list); | |
214 | ext4_free_io_end(io); | |
215 | } | |
216 | return ret; | |
217 | } | |
218 | ||
219 | /* | |
220 | * work on completed aio dio IO, to convert unwritten extents to extents | |
221 | */ | |
222 | static void ext4_end_io_work(struct work_struct *work) | |
223 | { | |
224 | ext4_io_end_t *io = container_of(work, ext4_io_end_t, work); | |
225 | ext4_do_flush_completed_IO(io->inode, io); | |
226 | } | |
227 | ||
c278531d | 228 | int ext4_flush_unwritten_io(struct inode *inode) |
28a535f9 | 229 | { |
c278531d DM |
230 | int ret; |
231 | WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex) && | |
232 | !(inode->i_state & I_FREEING)); | |
233 | ret = ext4_do_flush_completed_IO(inode, NULL); | |
234 | ext4_unwritten_wait(inode); | |
235 | return ret; | |
bd2d0210 TT |
236 | } |
237 | ||
238 | ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) | |
239 | { | |
b17b35ec | 240 | ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); |
bd2d0210 | 241 | if (io) { |
f7ad6d2e TT |
242 | atomic_inc(&EXT4_I(inode)->i_ioend_count); |
243 | io->inode = inode; | |
bd2d0210 TT |
244 | INIT_WORK(&io->work, ext4_end_io_work); |
245 | INIT_LIST_HEAD(&io->list); | |
246 | } | |
247 | return io; | |
248 | } | |
249 | ||
250 | /* | |
251 | * Print an buffer I/O error compatible with the fs/buffer.c. This | |
252 | * provides compatibility with dmesg scrapers that look for a specific | |
253 | * buffer I/O error message. We really need a unified error reporting | |
254 | * structure to userspace ala Digital Unix's uerf system, but it's | |
255 | * probably not going to happen in my lifetime, due to LKML politics... | |
256 | */ | |
257 | static void buffer_io_error(struct buffer_head *bh) | |
258 | { | |
259 | char b[BDEVNAME_SIZE]; | |
260 | printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n", | |
261 | bdevname(bh->b_bdev, b), | |
262 | (unsigned long long)bh->b_blocknr); | |
263 | } | |
264 | ||
265 | static void ext4_end_bio(struct bio *bio, int error) | |
266 | { | |
267 | ext4_io_end_t *io_end = bio->bi_private; | |
bd2d0210 | 268 | struct inode *inode; |
bd2d0210 | 269 | int i; |
d50bdd5a | 270 | sector_t bi_sector = bio->bi_sector; |
bd2d0210 TT |
271 | |
272 | BUG_ON(!io_end); | |
bd2d0210 TT |
273 | bio->bi_private = NULL; |
274 | bio->bi_end_io = NULL; | |
275 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
276 | error = 0; | |
bd2d0210 TT |
277 | bio_put(bio); |
278 | ||
bd2d0210 TT |
279 | for (i = 0; i < io_end->num_io_pages; i++) { |
280 | struct page *page = io_end->pages[i]->p_page; | |
281 | struct buffer_head *bh, *head; | |
39db00f1 CW |
282 | loff_t offset; |
283 | loff_t io_end_offset; | |
bd2d0210 | 284 | |
39db00f1 | 285 | if (error) { |
bd2d0210 | 286 | SetPageError(page); |
39db00f1 CW |
287 | set_bit(AS_EIO, &page->mapping->flags); |
288 | head = page_buffers(page); | |
289 | BUG_ON(!head); | |
290 | ||
291 | io_end_offset = io_end->offset + io_end->size; | |
bd2d0210 TT |
292 | |
293 | offset = (sector_t) page->index << PAGE_CACHE_SHIFT; | |
294 | bh = head; | |
295 | do { | |
296 | if ((offset >= io_end->offset) && | |
39db00f1 CW |
297 | (offset+bh->b_size <= io_end_offset)) |
298 | buffer_io_error(bh); | |
299 | ||
bd2d0210 TT |
300 | offset += bh->b_size; |
301 | bh = bh->b_this_page; | |
302 | } while (bh != head); | |
303 | } | |
304 | ||
6268b325 | 305 | put_io_page(io_end->pages[i]); |
bd2d0210 | 306 | } |
6268b325 | 307 | io_end->num_io_pages = 0; |
f7ad6d2e TT |
308 | inode = io_end->inode; |
309 | ||
310 | if (error) { | |
311 | io_end->flag |= EXT4_IO_END_ERROR; | |
312 | ext4_warning(inode->i_sb, "I/O error writing to inode %lu " | |
313 | "(offset %llu size %ld starting block %llu)", | |
314 | inode->i_ino, | |
315 | (unsigned long long) io_end->offset, | |
316 | (long) io_end->size, | |
317 | (unsigned long long) | |
d50bdd5a | 318 | bi_sector >> (inode->i_blkbits - 9)); |
f7ad6d2e | 319 | } |
bd2d0210 | 320 | |
b6168443 TT |
321 | if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { |
322 | ext4_free_io_end(io_end); | |
323 | return; | |
324 | } | |
325 | ||
28a535f9 | 326 | ext4_add_complete_io(io_end); |
bd2d0210 TT |
327 | } |
328 | ||
329 | void ext4_io_submit(struct ext4_io_submit *io) | |
330 | { | |
331 | struct bio *bio = io->io_bio; | |
332 | ||
333 | if (bio) { | |
334 | bio_get(io->io_bio); | |
335 | submit_bio(io->io_op, io->io_bio); | |
336 | BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); | |
337 | bio_put(io->io_bio); | |
338 | } | |
7dc57615 | 339 | io->io_bio = NULL; |
bd2d0210 | 340 | io->io_op = 0; |
7dc57615 | 341 | io->io_end = NULL; |
bd2d0210 TT |
342 | } |
343 | ||
344 | static int io_submit_init(struct ext4_io_submit *io, | |
345 | struct inode *inode, | |
346 | struct writeback_control *wbc, | |
347 | struct buffer_head *bh) | |
348 | { | |
349 | ext4_io_end_t *io_end; | |
350 | struct page *page = bh->b_page; | |
351 | int nvecs = bio_get_nr_vecs(bh->b_bdev); | |
352 | struct bio *bio; | |
353 | ||
354 | io_end = ext4_init_io_end(inode, GFP_NOFS); | |
355 | if (!io_end) | |
356 | return -ENOMEM; | |
275d3ba6 | 357 | bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); |
bd2d0210 TT |
358 | bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
359 | bio->bi_bdev = bh->b_bdev; | |
360 | bio->bi_private = io->io_end = io_end; | |
361 | bio->bi_end_io = ext4_end_bio; | |
362 | ||
bd2d0210 TT |
363 | io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh); |
364 | ||
365 | io->io_bio = bio; | |
721a9602 | 366 | io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); |
bd2d0210 TT |
367 | io->io_next_block = bh->b_blocknr; |
368 | return 0; | |
369 | } | |
370 | ||
371 | static int io_submit_add_bh(struct ext4_io_submit *io, | |
372 | struct ext4_io_page *io_page, | |
373 | struct inode *inode, | |
374 | struct writeback_control *wbc, | |
375 | struct buffer_head *bh) | |
376 | { | |
377 | ext4_io_end_t *io_end; | |
378 | int ret; | |
379 | ||
380 | if (buffer_new(bh)) { | |
381 | clear_buffer_new(bh); | |
382 | unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); | |
383 | } | |
384 | ||
385 | if (!buffer_mapped(bh) || buffer_delay(bh)) { | |
386 | if (!buffer_mapped(bh)) | |
387 | clear_buffer_dirty(bh); | |
388 | if (io->io_bio) | |
389 | ext4_io_submit(io); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | if (io->io_bio && bh->b_blocknr != io->io_next_block) { | |
394 | submit_and_retry: | |
395 | ext4_io_submit(io); | |
396 | } | |
397 | if (io->io_bio == NULL) { | |
398 | ret = io_submit_init(io, inode, wbc, bh); | |
399 | if (ret) | |
400 | return ret; | |
401 | } | |
402 | io_end = io->io_end; | |
403 | if ((io_end->num_io_pages >= MAX_IO_PAGES) && | |
404 | (io_end->pages[io_end->num_io_pages-1] != io_page)) | |
405 | goto submit_and_retry; | |
0edeb71d TM |
406 | if (buffer_uninit(bh)) |
407 | ext4_set_io_unwritten_flag(inode, io_end); | |
bd2d0210 TT |
408 | io->io_end->size += bh->b_size; |
409 | io->io_next_block++; | |
410 | ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); | |
411 | if (ret != bh->b_size) | |
412 | goto submit_and_retry; | |
413 | if ((io_end->num_io_pages == 0) || | |
414 | (io_end->pages[io_end->num_io_pages-1] != io_page)) { | |
415 | io_end->pages[io_end->num_io_pages++] = io_page; | |
83668e71 | 416 | atomic_inc(&io_page->p_count); |
bd2d0210 TT |
417 | } |
418 | return 0; | |
419 | } | |
420 | ||
421 | int ext4_bio_write_page(struct ext4_io_submit *io, | |
422 | struct page *page, | |
423 | int len, | |
424 | struct writeback_control *wbc) | |
425 | { | |
426 | struct inode *inode = page->mapping->host; | |
427 | unsigned block_start, block_end, blocksize; | |
428 | struct ext4_io_page *io_page; | |
429 | struct buffer_head *bh, *head; | |
430 | int ret = 0; | |
431 | ||
432 | blocksize = 1 << inode->i_blkbits; | |
433 | ||
d50bdd5a | 434 | BUG_ON(!PageLocked(page)); |
bd2d0210 | 435 | BUG_ON(PageWriteback(page)); |
bd2d0210 TT |
436 | |
437 | io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS); | |
438 | if (!io_page) { | |
439 | set_page_dirty(page); | |
440 | unlock_page(page); | |
441 | return -ENOMEM; | |
442 | } | |
443 | io_page->p_page = page; | |
83668e71 | 444 | atomic_set(&io_page->p_count, 1); |
bd2d0210 | 445 | get_page(page); |
a54aa761 TT |
446 | set_page_writeback(page); |
447 | ClearPageError(page); | |
bd2d0210 TT |
448 | |
449 | for (bh = head = page_buffers(page), block_start = 0; | |
450 | bh != head || !block_start; | |
451 | block_start = block_end, bh = bh->b_this_page) { | |
d50bdd5a | 452 | |
bd2d0210 TT |
453 | block_end = block_start + blocksize; |
454 | if (block_start >= len) { | |
5a0dc736 YY |
455 | /* |
456 | * Comments copied from block_write_full_page_endio: | |
457 | * | |
458 | * The page straddles i_size. It must be zeroed out on | |
459 | * each and every writepage invocation because it may | |
460 | * be mmapped. "A file is mapped in multiples of the | |
461 | * page size. For a file that is not a multiple of | |
462 | * the page size, the remaining memory is zeroed when | |
463 | * mapped, and writes to that region are not written | |
464 | * out to the file." | |
465 | */ | |
466 | zero_user_segment(page, block_start, block_end); | |
bd2d0210 TT |
467 | clear_buffer_dirty(bh); |
468 | set_buffer_uptodate(bh); | |
469 | continue; | |
470 | } | |
d50bdd5a | 471 | clear_buffer_dirty(bh); |
bd2d0210 TT |
472 | ret = io_submit_add_bh(io, io_page, inode, wbc, bh); |
473 | if (ret) { | |
474 | /* | |
475 | * We only get here on ENOMEM. Not much else | |
476 | * we can do but mark the page as dirty, and | |
477 | * better luck next time. | |
478 | */ | |
479 | set_page_dirty(page); | |
480 | break; | |
481 | } | |
482 | } | |
483 | unlock_page(page); | |
484 | /* | |
485 | * If the page was truncated before we could do the writeback, | |
486 | * or we had a memory allocation error while trying to write | |
487 | * the first buffer head, we won't have submitted any pages for | |
488 | * I/O. In that case we need to make sure we've cleared the | |
489 | * PageWriteback bit from the page to prevent the system from | |
490 | * wedging later on. | |
491 | */ | |
83668e71 | 492 | put_io_page(io_page); |
bd2d0210 TT |
493 | return ret; |
494 | } |