blob: aed40966f3425a1318d7d3663c054b9c949589b5 [file] [log] [blame]
Theodore Ts'obd2d0212010-10-27 21:30:10 -04001/*
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
33static struct kmem_cache *io_page_cachep, *io_end_cachep;
34
Theodore Ts'o5dabfc72010-10-27 21:30:14 -040035int __init ext4_init_pageio(void)
Theodore Ts'obd2d0212010-10-27 21:30:10 -040036{
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);
Dan Carpenter13195182011-01-10 12:10:44 -050041 if (io_end_cachep == NULL) {
Theodore Ts'obd2d0212010-10-27 21:30:10 -040042 kmem_cache_destroy(io_page_cachep);
43 return -ENOMEM;
44 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -040045 return 0;
46}
47
Theodore Ts'o5dabfc72010-10-27 21:30:14 -040048void ext4_exit_pageio(void)
Theodore Ts'obd2d0212010-10-27 21:30:10 -040049{
50 kmem_cache_destroy(io_end_cachep);
51 kmem_cache_destroy(io_page_cachep);
52}
53
Theodore Ts'of7ad6d22010-11-08 13:43:33 -050054void ext4_ioend_wait(struct inode *inode)
55{
Eric Sandeene9e3bce2011-02-12 08:17:34 -050056 wait_queue_head_t *wq = ext4_ioend_wq(inode);
Theodore Ts'of7ad6d22010-11-08 13:43:33 -050057
58 wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0));
59}
60
Theodore Ts'o83668e72010-11-08 13:45:33 -050061static 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
Theodore Ts'obd2d0212010-10-27 21:30:10 -040070void ext4_free_io_end(ext4_io_end_t *io)
71{
72 int i;
Theodore Ts'of7ad6d22010-11-08 13:43:33 -050073 wait_queue_head_t *wq;
Theodore Ts'obd2d0212010-10-27 21:30:10 -040074
75 BUG_ON(!io);
76 if (io->page)
77 put_page(io->page);
Theodore Ts'o83668e72010-11-08 13:45:33 -050078 for (i = 0; i < io->num_io_pages; i++)
79 put_io_page(io->pages[i]);
Theodore Ts'obd2d0212010-10-27 21:30:10 -040080 io->num_io_pages = 0;
Eric Sandeene9e3bce2011-02-12 08:17:34 -050081 wq = ext4_ioend_wq(io->inode);
Theodore Ts'of7ad6d22010-11-08 13:43:33 -050082 if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count) &&
83 waitqueue_active(wq))
84 wake_up_all(wq);
Theodore Ts'obd2d0212010-10-27 21:30:10 -040085 kmem_cache_free(io_end_cachep, io);
86}
87
88/*
89 * check a range of space and convert unwritten extents to written.
Tao Mad73d5042011-10-30 18:26:08 -040090 *
91 * Called with inode->i_mutex; we depend on this when we manipulate
92 * io->flag, since we could otherwise race with ext4_flush_completed_IO()
Theodore Ts'obd2d0212010-10-27 21:30:10 -040093 */
94int ext4_end_io_nolock(ext4_io_end_t *io)
95{
96 struct inode *inode = io->inode;
97 loff_t offset = io->offset;
98 ssize_t size = io->size;
Eric Sandeene9e3bce2011-02-12 08:17:34 -050099 wait_queue_head_t *wq;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400100 int ret = 0;
101
102 ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
103 "list->prev 0x%p\n",
104 io, inode->i_ino, io->list.next, io->list.prev);
105
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400106 if (!(io->flag & EXT4_IO_END_UNWRITTEN))
107 return ret;
108
109 ret = ext4_convert_unwritten_extents(inode, offset, size);
110 if (ret < 0) {
111 printk(KERN_EMERG "%s: failed to convert unwritten "
112 "extents to written extents, error is %d "
113 "io is still on inode %lu aio dio list\n",
114 __func__, ret, inode->i_ino);
115 return ret;
116 }
117
118 if (io->iocb)
119 aio_complete(io->iocb, io->result, 0);
120 /* clear the DIO AIO unwritten flag */
Eric Sandeene9e3bce2011-02-12 08:17:34 -0500121 if (io->flag & EXT4_IO_END_UNWRITTEN) {
122 io->flag &= ~EXT4_IO_END_UNWRITTEN;
123 /* Wake up anyone waiting on unwritten extent conversion */
124 wq = ext4_ioend_wq(io->inode);
125 if (atomic_dec_and_test(&EXT4_I(inode)->i_aiodio_unwritten) &&
126 waitqueue_active(wq)) {
127 wake_up_all(wq);
128 }
129 }
130
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400131 return ret;
132}
133
134/*
135 * work on completed aio dio IO, to convert unwritten extents to extents
136 */
137static void ext4_end_io_work(struct work_struct *work)
138{
139 ext4_io_end_t *io = container_of(work, ext4_io_end_t, work);
140 struct inode *inode = io->inode;
141 struct ext4_inode_info *ei = EXT4_I(inode);
142 unsigned long flags;
143 int ret;
144
Tao Mad73d5042011-10-30 18:26:08 -0400145 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
146 if (list_empty(&io->list)) {
147 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
148 goto free;
149 }
150 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
151
Jiaying Zhang8c0bec22011-08-31 11:50:51 -0400152 if (!mutex_trylock(&inode->i_mutex)) {
153 /*
154 * Requeue the work instead of waiting so that the work
155 * items queued after this can be processed.
156 */
157 queue_work(EXT4_SB(inode->i_sb)->dio_unwritten_wq, &io->work);
158 /*
159 * To prevent the ext4-dio-unwritten thread from keeping
160 * requeueing end_io requests and occupying cpu for too long,
161 * yield the cpu if it sees an end_io request that has already
162 * been requeued.
163 */
164 if (io->flag & EXT4_IO_END_QUEUED)
165 yield();
166 io->flag |= EXT4_IO_END_QUEUED;
167 return;
168 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400169 ret = ext4_end_io_nolock(io);
170 if (ret < 0) {
171 mutex_unlock(&inode->i_mutex);
172 return;
173 }
174
175 spin_lock_irqsave(&ei->i_completed_io_lock, flags);
176 if (!list_empty(&io->list))
177 list_del_init(&io->list);
178 spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
179 mutex_unlock(&inode->i_mutex);
Tao Mad73d5042011-10-30 18:26:08 -0400180free:
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400181 ext4_free_io_end(io);
182}
183
184ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
185{
Jesper Juhlb17b35e2010-12-19 21:41:55 -0500186 ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400187 if (io) {
Theodore Ts'of7ad6d22010-11-08 13:43:33 -0500188 atomic_inc(&EXT4_I(inode)->i_ioend_count);
189 io->inode = inode;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400190 INIT_WORK(&io->work, ext4_end_io_work);
191 INIT_LIST_HEAD(&io->list);
192 }
193 return io;
194}
195
196/*
197 * Print an buffer I/O error compatible with the fs/buffer.c. This
198 * provides compatibility with dmesg scrapers that look for a specific
199 * buffer I/O error message. We really need a unified error reporting
200 * structure to userspace ala Digital Unix's uerf system, but it's
201 * probably not going to happen in my lifetime, due to LKML politics...
202 */
203static void buffer_io_error(struct buffer_head *bh)
204{
205 char b[BDEVNAME_SIZE];
206 printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n",
207 bdevname(bh->b_bdev, b),
208 (unsigned long long)bh->b_blocknr);
209}
210
211static void ext4_end_bio(struct bio *bio, int error)
212{
213 ext4_io_end_t *io_end = bio->bi_private;
214 struct workqueue_struct *wq;
215 struct inode *inode;
216 unsigned long flags;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400217 int i;
Curt Wohlgemuthd50bdd52011-02-07 12:46:14 -0500218 sector_t bi_sector = bio->bi_sector;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400219
220 BUG_ON(!io_end);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400221 bio->bi_private = NULL;
222 bio->bi_end_io = NULL;
223 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
224 error = 0;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400225 bio_put(bio);
226
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400227 for (i = 0; i < io_end->num_io_pages; i++) {
228 struct page *page = io_end->pages[i]->p_page;
229 struct buffer_head *bh, *head;
Curt Wohlgemuth39db00f2011-04-30 13:26:26 -0400230 loff_t offset;
231 loff_t io_end_offset;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400232
Curt Wohlgemuth39db00f2011-04-30 13:26:26 -0400233 if (error) {
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400234 SetPageError(page);
Curt Wohlgemuth39db00f2011-04-30 13:26:26 -0400235 set_bit(AS_EIO, &page->mapping->flags);
236 head = page_buffers(page);
237 BUG_ON(!head);
238
239 io_end_offset = io_end->offset + io_end->size;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400240
241 offset = (sector_t) page->index << PAGE_CACHE_SHIFT;
242 bh = head;
243 do {
244 if ((offset >= io_end->offset) &&
Curt Wohlgemuth39db00f2011-04-30 13:26:26 -0400245 (offset+bh->b_size <= io_end_offset))
246 buffer_io_error(bh);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400247
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400248 offset += bh->b_size;
249 bh = bh->b_this_page;
250 } while (bh != head);
251 }
252
Markus Trippelsdorf08da1192010-11-17 21:46:06 -0500253 put_io_page(io_end->pages[i]);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400254 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400255 io_end->num_io_pages = 0;
Theodore Ts'of7ad6d22010-11-08 13:43:33 -0500256 inode = io_end->inode;
257
258 if (error) {
259 io_end->flag |= EXT4_IO_END_ERROR;
260 ext4_warning(inode->i_sb, "I/O error writing to inode %lu "
261 "(offset %llu size %ld starting block %llu)",
262 inode->i_ino,
263 (unsigned long long) io_end->offset,
264 (long) io_end->size,
265 (unsigned long long)
Curt Wohlgemuthd50bdd52011-02-07 12:46:14 -0500266 bi_sector >> (inode->i_blkbits - 9));
Theodore Ts'of7ad6d22010-11-08 13:43:33 -0500267 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400268
Theodore Ts'ob6168442011-02-28 13:12:38 -0500269 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
270 ext4_free_io_end(io_end);
271 return;
272 }
273
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400274 /* Add the io_end to per-inode completed io list*/
275 spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags);
276 list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list);
277 spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags);
278
279 wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq;
280 /* queue the work to convert unwritten extents to written */
281 queue_work(wq, &io_end->work);
282}
283
284void ext4_io_submit(struct ext4_io_submit *io)
285{
286 struct bio *bio = io->io_bio;
287
288 if (bio) {
289 bio_get(io->io_bio);
290 submit_bio(io->io_op, io->io_bio);
291 BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP));
292 bio_put(io->io_bio);
293 }
Peter Huewe7dc57612011-02-21 21:01:42 -0500294 io->io_bio = NULL;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400295 io->io_op = 0;
Peter Huewe7dc57612011-02-21 21:01:42 -0500296 io->io_end = NULL;
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400297}
298
299static int io_submit_init(struct ext4_io_submit *io,
300 struct inode *inode,
301 struct writeback_control *wbc,
302 struct buffer_head *bh)
303{
304 ext4_io_end_t *io_end;
305 struct page *page = bh->b_page;
306 int nvecs = bio_get_nr_vecs(bh->b_bdev);
307 struct bio *bio;
308
309 io_end = ext4_init_io_end(inode, GFP_NOFS);
310 if (!io_end)
311 return -ENOMEM;
Theodore Ts'o275d3ba2011-06-29 21:44:45 -0400312 bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES));
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400313 bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
314 bio->bi_bdev = bh->b_bdev;
315 bio->bi_private = io->io_end = io_end;
316 bio->bi_end_io = ext4_end_bio;
317
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400318 io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh);
319
320 io->io_bio = bio;
Jens Axboe721a9602011-03-09 11:56:30 +0100321 io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400322 io->io_next_block = bh->b_blocknr;
323 return 0;
324}
325
326static int io_submit_add_bh(struct ext4_io_submit *io,
327 struct ext4_io_page *io_page,
328 struct inode *inode,
329 struct writeback_control *wbc,
330 struct buffer_head *bh)
331{
332 ext4_io_end_t *io_end;
333 int ret;
334
335 if (buffer_new(bh)) {
336 clear_buffer_new(bh);
337 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
338 }
339
340 if (!buffer_mapped(bh) || buffer_delay(bh)) {
341 if (!buffer_mapped(bh))
342 clear_buffer_dirty(bh);
343 if (io->io_bio)
344 ext4_io_submit(io);
345 return 0;
346 }
347
348 if (io->io_bio && bh->b_blocknr != io->io_next_block) {
349submit_and_retry:
350 ext4_io_submit(io);
351 }
352 if (io->io_bio == NULL) {
353 ret = io_submit_init(io, inode, wbc, bh);
354 if (ret)
355 return ret;
356 }
357 io_end = io->io_end;
358 if ((io_end->num_io_pages >= MAX_IO_PAGES) &&
359 (io_end->pages[io_end->num_io_pages-1] != io_page))
360 goto submit_and_retry;
Tao Ma32c80b32011-08-13 12:30:59 -0400361 if (buffer_uninit(bh) && !(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
362 io_end->flag |= EXT4_IO_END_UNWRITTEN;
363 atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
364 }
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400365 io->io_end->size += bh->b_size;
366 io->io_next_block++;
367 ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh));
368 if (ret != bh->b_size)
369 goto submit_and_retry;
370 if ((io_end->num_io_pages == 0) ||
371 (io_end->pages[io_end->num_io_pages-1] != io_page)) {
372 io_end->pages[io_end->num_io_pages++] = io_page;
Theodore Ts'o83668e72010-11-08 13:45:33 -0500373 atomic_inc(&io_page->p_count);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400374 }
375 return 0;
376}
377
378int ext4_bio_write_page(struct ext4_io_submit *io,
379 struct page *page,
380 int len,
381 struct writeback_control *wbc)
382{
383 struct inode *inode = page->mapping->host;
384 unsigned block_start, block_end, blocksize;
385 struct ext4_io_page *io_page;
386 struct buffer_head *bh, *head;
387 int ret = 0;
388
389 blocksize = 1 << inode->i_blkbits;
390
Curt Wohlgemuthd50bdd52011-02-07 12:46:14 -0500391 BUG_ON(!PageLocked(page));
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400392 BUG_ON(PageWriteback(page));
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400393
394 io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
395 if (!io_page) {
396 set_page_dirty(page);
397 unlock_page(page);
398 return -ENOMEM;
399 }
400 io_page->p_page = page;
Theodore Ts'o83668e72010-11-08 13:45:33 -0500401 atomic_set(&io_page->p_count, 1);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400402 get_page(page);
Theodore Ts'oa54aa762011-02-27 16:43:24 -0500403 set_page_writeback(page);
404 ClearPageError(page);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400405
406 for (bh = head = page_buffers(page), block_start = 0;
407 bh != head || !block_start;
408 block_start = block_end, bh = bh->b_this_page) {
Curt Wohlgemuthd50bdd52011-02-07 12:46:14 -0500409
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400410 block_end = block_start + blocksize;
411 if (block_start >= len) {
412 clear_buffer_dirty(bh);
413 set_buffer_uptodate(bh);
414 continue;
415 }
Curt Wohlgemuthd50bdd52011-02-07 12:46:14 -0500416 clear_buffer_dirty(bh);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400417 ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
418 if (ret) {
419 /*
420 * We only get here on ENOMEM. Not much else
421 * we can do but mark the page as dirty, and
422 * better luck next time.
423 */
424 set_page_dirty(page);
425 break;
426 }
427 }
428 unlock_page(page);
429 /*
430 * If the page was truncated before we could do the writeback,
431 * or we had a memory allocation error while trying to write
432 * the first buffer head, we won't have submitted any pages for
433 * I/O. In that case we need to make sure we've cleared the
434 * PageWriteback bit from the page to prevent the system from
435 * wedging later on.
436 */
Theodore Ts'o83668e72010-11-08 13:45:33 -0500437 put_io_page(io_page);
Theodore Ts'obd2d0212010-10-27 21:30:10 -0400438 return ret;
439}