]>
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 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/fs.h> | |
11 | #include <linux/time.h> | |
12 | #include <linux/jbd2.h> | |
13 | #include <linux/highuid.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/quotaops.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/buffer_head.h> | |
18 | #include <linux/writeback.h> | |
19 | #include <linux/pagevec.h> | |
20 | #include <linux/mpage.h> | |
21 | #include <linux/namei.h> | |
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> | |
27 | ||
28 | #include "ext4_jbd2.h" | |
29 | #include "xattr.h" | |
30 | #include "acl.h" | |
31 | #include "ext4_extents.h" | |
32 | ||
33 | static struct kmem_cache *io_page_cachep, *io_end_cachep; | |
34 | ||
5dabfc78 | 35 | int __init ext4_init_pageio(void) |
bd2d0210 TT |
36 | { |
37 | io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT); | |
38 | if (io_page_cachep == NULL) | |
39 | return -ENOMEM; | |
40 | io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); | |
13195184 | 41 | if (io_end_cachep == NULL) { |
bd2d0210 TT |
42 | kmem_cache_destroy(io_page_cachep); |
43 | return -ENOMEM; | |
44 | } | |
bd2d0210 TT |
45 | return 0; |
46 | } | |
47 | ||
5dabfc78 | 48 | void ext4_exit_pageio(void) |
bd2d0210 TT |
49 | { |
50 | kmem_cache_destroy(io_end_cachep); | |
51 | kmem_cache_destroy(io_page_cachep); | |
52 | } | |
53 | ||
f7ad6d2e TT |
54 | void ext4_ioend_wait(struct inode *inode) |
55 | { | |
e9e3bcec | 56 | wait_queue_head_t *wq = ext4_ioend_wq(inode); |
f7ad6d2e TT |
57 | |
58 | wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0)); | |
59 | } | |
60 | ||
83668e71 TT |
61 | static void put_io_page(struct ext4_io_page *io_page) |
62 | { | |
63 | if (atomic_dec_and_test(&io_page->p_count)) { | |
64 | end_page_writeback(io_page->p_page); | |
65 | put_page(io_page->p_page); | |
66 | kmem_cache_free(io_page_cachep, io_page); | |
67 | } | |
68 | } | |
69 | ||
bd2d0210 TT |
70 | void ext4_free_io_end(ext4_io_end_t *io) |
71 | { | |
72 | int i; | |
73 | ||
74 | BUG_ON(!io); | |
75 | if (io->page) | |
76 | put_page(io->page); | |
83668e71 TT |
77 | for (i = 0; i < io->num_io_pages; i++) |
78 | put_io_page(io->pages[i]); | |
bd2d0210 | 79 | io->num_io_pages = 0; |
4e298021 TT |
80 | if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count)) |
81 | wake_up_all(ext4_ioend_wq(io->inode)); | |
bd2d0210 TT |
82 | kmem_cache_free(io_end_cachep, io); |
83 | } | |
84 | ||
85 | /* | |
86 | * check a range of space and convert unwritten extents to written. | |
d73d5046 TM |
87 | * |
88 | * Called with inode->i_mutex; we depend on this when we manipulate | |
89 | * io->flag, since we could otherwise race with ext4_flush_completed_IO() | |
bd2d0210 TT |
90 | */ |
91 | int ext4_end_io_nolock(ext4_io_end_t *io) | |
92 | { | |
93 | struct inode *inode = io->inode; | |
94 | loff_t offset = io->offset; | |
95 | ssize_t size = io->size; | |
96 | int ret = 0; | |
97 | ||
98 | ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," | |
99 | "list->prev 0x%p\n", | |
100 | io, inode->i_ino, io->list.next, io->list.prev); | |
101 | ||
bd2d0210 TT |
102 | ret = ext4_convert_unwritten_extents(inode, offset, size); |
103 | if (ret < 0) { | |
b82e384c TT |
104 | ext4_msg(inode->i_sb, KERN_EMERG, |
105 | "failed to convert unwritten extents to written " | |
106 | "extents -- potential data loss! " | |
107 | "(inode %lu, offset %llu, size %zd, error %d)", | |
108 | inode->i_ino, offset, size, ret); | |
bd2d0210 TT |
109 | } |
110 | ||
111 | if (io->iocb) | |
112 | aio_complete(io->iocb, io->result, 0); | |
e9e3bcec | 113 | |
b82e384c TT |
114 | /* Wake up anyone waiting on unwritten extent conversion */ |
115 | if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten)) | |
116 | wake_up_all(ext4_ioend_wq(io->inode)); | |
bd2d0210 TT |
117 | return ret; |
118 | } | |
119 | ||
120 | /* | |
121 | * work on completed aio dio IO, to convert unwritten extents to extents | |
122 | */ | |
123 | static void ext4_end_io_work(struct work_struct *work) | |
124 | { | |
125 | ext4_io_end_t *io = container_of(work, ext4_io_end_t, work); | |
126 | struct inode *inode = io->inode; | |
127 | struct ext4_inode_info *ei = EXT4_I(inode); | |
128 | unsigned long flags; | |
bd2d0210 | 129 | |
d73d5046 TM |
130 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
131 | if (list_empty(&io->list)) { | |
132 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); | |
133 | goto free; | |
134 | } | |
d73d5046 | 135 | |
8c0bec21 | 136 | if (!mutex_trylock(&inode->i_mutex)) { |
b82e384c | 137 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
8c0bec21 JZ |
138 | /* |
139 | * Requeue the work instead of waiting so that the work | |
140 | * items queued after this can be processed. | |
141 | */ | |
142 | queue_work(EXT4_SB(inode->i_sb)->dio_unwritten_wq, &io->work); | |
143 | /* | |
144 | * To prevent the ext4-dio-unwritten thread from keeping | |
145 | * requeueing end_io requests and occupying cpu for too long, | |
146 | * yield the cpu if it sees an end_io request that has already | |
147 | * been requeued. | |
148 | */ | |
149 | if (io->flag & EXT4_IO_END_QUEUED) | |
150 | yield(); | |
151 | io->flag |= EXT4_IO_END_QUEUED; | |
152 | return; | |
153 | } | |
b82e384c | 154 | list_del_init(&io->list); |
bd2d0210 | 155 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
b82e384c | 156 | (void) ext4_end_io_nolock(io); |
bd2d0210 | 157 | mutex_unlock(&inode->i_mutex); |
d73d5046 | 158 | free: |
bd2d0210 TT |
159 | ext4_free_io_end(io); |
160 | } | |
161 | ||
162 | ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) | |
163 | { | |
b17b35ec | 164 | ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); |
bd2d0210 | 165 | if (io) { |
f7ad6d2e TT |
166 | atomic_inc(&EXT4_I(inode)->i_ioend_count); |
167 | io->inode = inode; | |
bd2d0210 TT |
168 | INIT_WORK(&io->work, ext4_end_io_work); |
169 | INIT_LIST_HEAD(&io->list); | |
170 | } | |
171 | return io; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Print an buffer I/O error compatible with the fs/buffer.c. This | |
176 | * provides compatibility with dmesg scrapers that look for a specific | |
177 | * buffer I/O error message. We really need a unified error reporting | |
178 | * structure to userspace ala Digital Unix's uerf system, but it's | |
179 | * probably not going to happen in my lifetime, due to LKML politics... | |
180 | */ | |
181 | static void buffer_io_error(struct buffer_head *bh) | |
182 | { | |
183 | char b[BDEVNAME_SIZE]; | |
184 | printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n", | |
185 | bdevname(bh->b_bdev, b), | |
186 | (unsigned long long)bh->b_blocknr); | |
187 | } | |
188 | ||
189 | static void ext4_end_bio(struct bio *bio, int error) | |
190 | { | |
191 | ext4_io_end_t *io_end = bio->bi_private; | |
192 | struct workqueue_struct *wq; | |
193 | struct inode *inode; | |
194 | unsigned long flags; | |
bd2d0210 | 195 | int i; |
d50bdd5a | 196 | sector_t bi_sector = bio->bi_sector; |
bd2d0210 TT |
197 | |
198 | BUG_ON(!io_end); | |
bd2d0210 TT |
199 | bio->bi_private = NULL; |
200 | bio->bi_end_io = NULL; | |
201 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
202 | error = 0; | |
bd2d0210 TT |
203 | bio_put(bio); |
204 | ||
bd2d0210 TT |
205 | for (i = 0; i < io_end->num_io_pages; i++) { |
206 | struct page *page = io_end->pages[i]->p_page; | |
207 | struct buffer_head *bh, *head; | |
39db00f1 CW |
208 | loff_t offset; |
209 | loff_t io_end_offset; | |
bd2d0210 | 210 | |
39db00f1 | 211 | if (error) { |
bd2d0210 | 212 | SetPageError(page); |
39db00f1 CW |
213 | set_bit(AS_EIO, &page->mapping->flags); |
214 | head = page_buffers(page); | |
215 | BUG_ON(!head); | |
216 | ||
217 | io_end_offset = io_end->offset + io_end->size; | |
bd2d0210 TT |
218 | |
219 | offset = (sector_t) page->index << PAGE_CACHE_SHIFT; | |
220 | bh = head; | |
221 | do { | |
222 | if ((offset >= io_end->offset) && | |
39db00f1 CW |
223 | (offset+bh->b_size <= io_end_offset)) |
224 | buffer_io_error(bh); | |
225 | ||
bd2d0210 TT |
226 | offset += bh->b_size; |
227 | bh = bh->b_this_page; | |
228 | } while (bh != head); | |
229 | } | |
230 | ||
08da1193 | 231 | put_io_page(io_end->pages[i]); |
bd2d0210 | 232 | } |
bd2d0210 | 233 | io_end->num_io_pages = 0; |
f7ad6d2e TT |
234 | inode = io_end->inode; |
235 | ||
236 | if (error) { | |
237 | io_end->flag |= EXT4_IO_END_ERROR; | |
238 | ext4_warning(inode->i_sb, "I/O error writing to inode %lu " | |
239 | "(offset %llu size %ld starting block %llu)", | |
240 | inode->i_ino, | |
241 | (unsigned long long) io_end->offset, | |
242 | (long) io_end->size, | |
243 | (unsigned long long) | |
d50bdd5a | 244 | bi_sector >> (inode->i_blkbits - 9)); |
f7ad6d2e | 245 | } |
bd2d0210 | 246 | |
b6168443 TT |
247 | if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { |
248 | ext4_free_io_end(io_end); | |
249 | return; | |
250 | } | |
251 | ||
bd2d0210 TT |
252 | /* Add the io_end to per-inode completed io list*/ |
253 | spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); | |
254 | list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list); | |
255 | spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags); | |
256 | ||
257 | wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq; | |
258 | /* queue the work to convert unwritten extents to written */ | |
259 | queue_work(wq, &io_end->work); | |
260 | } | |
261 | ||
262 | void ext4_io_submit(struct ext4_io_submit *io) | |
263 | { | |
264 | struct bio *bio = io->io_bio; | |
265 | ||
266 | if (bio) { | |
267 | bio_get(io->io_bio); | |
268 | submit_bio(io->io_op, io->io_bio); | |
269 | BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); | |
270 | bio_put(io->io_bio); | |
271 | } | |
7dc57615 | 272 | io->io_bio = NULL; |
bd2d0210 | 273 | io->io_op = 0; |
7dc57615 | 274 | io->io_end = NULL; |
bd2d0210 TT |
275 | } |
276 | ||
277 | static int io_submit_init(struct ext4_io_submit *io, | |
278 | struct inode *inode, | |
279 | struct writeback_control *wbc, | |
280 | struct buffer_head *bh) | |
281 | { | |
282 | ext4_io_end_t *io_end; | |
283 | struct page *page = bh->b_page; | |
284 | int nvecs = bio_get_nr_vecs(bh->b_bdev); | |
285 | struct bio *bio; | |
286 | ||
287 | io_end = ext4_init_io_end(inode, GFP_NOFS); | |
288 | if (!io_end) | |
289 | return -ENOMEM; | |
275d3ba6 | 290 | bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); |
bd2d0210 TT |
291 | bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); |
292 | bio->bi_bdev = bh->b_bdev; | |
293 | bio->bi_private = io->io_end = io_end; | |
294 | bio->bi_end_io = ext4_end_bio; | |
295 | ||
bd2d0210 TT |
296 | io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh); |
297 | ||
298 | io->io_bio = bio; | |
721a9602 | 299 | io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); |
bd2d0210 TT |
300 | io->io_next_block = bh->b_blocknr; |
301 | return 0; | |
302 | } | |
303 | ||
304 | static int io_submit_add_bh(struct ext4_io_submit *io, | |
305 | struct ext4_io_page *io_page, | |
306 | struct inode *inode, | |
307 | struct writeback_control *wbc, | |
308 | struct buffer_head *bh) | |
309 | { | |
310 | ext4_io_end_t *io_end; | |
311 | int ret; | |
312 | ||
313 | if (buffer_new(bh)) { | |
314 | clear_buffer_new(bh); | |
315 | unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); | |
316 | } | |
317 | ||
318 | if (!buffer_mapped(bh) || buffer_delay(bh)) { | |
319 | if (!buffer_mapped(bh)) | |
320 | clear_buffer_dirty(bh); | |
321 | if (io->io_bio) | |
322 | ext4_io_submit(io); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | if (io->io_bio && bh->b_blocknr != io->io_next_block) { | |
327 | submit_and_retry: | |
328 | ext4_io_submit(io); | |
329 | } | |
330 | if (io->io_bio == NULL) { | |
331 | ret = io_submit_init(io, inode, wbc, bh); | |
332 | if (ret) | |
333 | return ret; | |
334 | } | |
335 | io_end = io->io_end; | |
336 | if ((io_end->num_io_pages >= MAX_IO_PAGES) && | |
337 | (io_end->pages[io_end->num_io_pages-1] != io_page)) | |
338 | goto submit_and_retry; | |
0edeb71d TM |
339 | if (buffer_uninit(bh)) |
340 | ext4_set_io_unwritten_flag(inode, io_end); | |
bd2d0210 TT |
341 | io->io_end->size += bh->b_size; |
342 | io->io_next_block++; | |
343 | ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); | |
344 | if (ret != bh->b_size) | |
345 | goto submit_and_retry; | |
346 | if ((io_end->num_io_pages == 0) || | |
347 | (io_end->pages[io_end->num_io_pages-1] != io_page)) { | |
348 | io_end->pages[io_end->num_io_pages++] = io_page; | |
83668e71 | 349 | atomic_inc(&io_page->p_count); |
bd2d0210 TT |
350 | } |
351 | return 0; | |
352 | } | |
353 | ||
354 | int ext4_bio_write_page(struct ext4_io_submit *io, | |
355 | struct page *page, | |
356 | int len, | |
357 | struct writeback_control *wbc) | |
358 | { | |
359 | struct inode *inode = page->mapping->host; | |
360 | unsigned block_start, block_end, blocksize; | |
361 | struct ext4_io_page *io_page; | |
362 | struct buffer_head *bh, *head; | |
363 | int ret = 0; | |
364 | ||
365 | blocksize = 1 << inode->i_blkbits; | |
366 | ||
d50bdd5a | 367 | BUG_ON(!PageLocked(page)); |
bd2d0210 | 368 | BUG_ON(PageWriteback(page)); |
bd2d0210 TT |
369 | |
370 | io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS); | |
371 | if (!io_page) { | |
372 | set_page_dirty(page); | |
373 | unlock_page(page); | |
374 | return -ENOMEM; | |
375 | } | |
376 | io_page->p_page = page; | |
83668e71 | 377 | atomic_set(&io_page->p_count, 1); |
bd2d0210 | 378 | get_page(page); |
a54aa761 TT |
379 | set_page_writeback(page); |
380 | ClearPageError(page); | |
bd2d0210 TT |
381 | |
382 | for (bh = head = page_buffers(page), block_start = 0; | |
383 | bh != head || !block_start; | |
384 | block_start = block_end, bh = bh->b_this_page) { | |
d50bdd5a | 385 | |
bd2d0210 TT |
386 | block_end = block_start + blocksize; |
387 | if (block_start >= len) { | |
388 | clear_buffer_dirty(bh); | |
389 | set_buffer_uptodate(bh); | |
390 | continue; | |
391 | } | |
d50bdd5a | 392 | clear_buffer_dirty(bh); |
bd2d0210 TT |
393 | ret = io_submit_add_bh(io, io_page, inode, wbc, bh); |
394 | if (ret) { | |
395 | /* | |
396 | * We only get here on ENOMEM. Not much else | |
397 | * we can do but mark the page as dirty, and | |
398 | * better luck next time. | |
399 | */ | |
400 | set_page_dirty(page); | |
401 | break; | |
402 | } | |
403 | } | |
404 | unlock_page(page); | |
405 | /* | |
406 | * If the page was truncated before we could do the writeback, | |
407 | * or we had a memory allocation error while trying to write | |
408 | * the first buffer head, we won't have submitted any pages for | |
409 | * I/O. In that case we need to make sure we've cleared the | |
410 | * PageWriteback bit from the page to prevent the system from | |
411 | * wedging later on. | |
412 | */ | |
83668e71 | 413 | put_io_page(io_page); |
bd2d0210 TT |
414 | return ret; |
415 | } |