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1 | /* | |
2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. | |
3 | * All Rights Reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it would be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | #include "xfs.h" | |
19 | #include "xfs_shared.h" | |
20 | #include "xfs_format.h" | |
21 | #include "xfs_log_format.h" | |
22 | #include "xfs_trans_resv.h" | |
23 | #include "xfs_mount.h" | |
24 | #include "xfs_inode.h" | |
25 | #include "xfs_trans.h" | |
26 | #include "xfs_inode_item.h" | |
27 | #include "xfs_alloc.h" | |
28 | #include "xfs_error.h" | |
29 | #include "xfs_iomap.h" | |
30 | #include "xfs_trace.h" | |
31 | #include "xfs_bmap.h" | |
32 | #include "xfs_bmap_util.h" | |
33 | #include "xfs_bmap_btree.h" | |
34 | #include <linux/gfp.h> | |
35 | #include <linux/mpage.h> | |
36 | #include <linux/pagevec.h> | |
37 | #include <linux/writeback.h> | |
38 | ||
39 | void | |
40 | xfs_count_page_state( | |
41 | struct page *page, | |
42 | int *delalloc, | |
43 | int *unwritten) | |
44 | { | |
45 | struct buffer_head *bh, *head; | |
46 | ||
47 | *delalloc = *unwritten = 0; | |
48 | ||
49 | bh = head = page_buffers(page); | |
50 | do { | |
51 | if (buffer_unwritten(bh)) | |
52 | (*unwritten) = 1; | |
53 | else if (buffer_delay(bh)) | |
54 | (*delalloc) = 1; | |
55 | } while ((bh = bh->b_this_page) != head); | |
56 | } | |
57 | ||
58 | STATIC struct block_device * | |
59 | xfs_find_bdev_for_inode( | |
60 | struct inode *inode) | |
61 | { | |
62 | struct xfs_inode *ip = XFS_I(inode); | |
63 | struct xfs_mount *mp = ip->i_mount; | |
64 | ||
65 | if (XFS_IS_REALTIME_INODE(ip)) | |
66 | return mp->m_rtdev_targp->bt_bdev; | |
67 | else | |
68 | return mp->m_ddev_targp->bt_bdev; | |
69 | } | |
70 | ||
71 | /* | |
72 | * We're now finished for good with this ioend structure. | |
73 | * Update the page state via the associated buffer_heads, | |
74 | * release holds on the inode and bio, and finally free | |
75 | * up memory. Do not use the ioend after this. | |
76 | */ | |
77 | STATIC void | |
78 | xfs_destroy_ioend( | |
79 | xfs_ioend_t *ioend) | |
80 | { | |
81 | struct buffer_head *bh, *next; | |
82 | ||
83 | for (bh = ioend->io_buffer_head; bh; bh = next) { | |
84 | next = bh->b_private; | |
85 | bh->b_end_io(bh, !ioend->io_error); | |
86 | } | |
87 | ||
88 | mempool_free(ioend, xfs_ioend_pool); | |
89 | } | |
90 | ||
91 | /* | |
92 | * Fast and loose check if this write could update the on-disk inode size. | |
93 | */ | |
94 | static inline bool xfs_ioend_is_append(struct xfs_ioend *ioend) | |
95 | { | |
96 | return ioend->io_offset + ioend->io_size > | |
97 | XFS_I(ioend->io_inode)->i_d.di_size; | |
98 | } | |
99 | ||
100 | STATIC int | |
101 | xfs_setfilesize_trans_alloc( | |
102 | struct xfs_ioend *ioend) | |
103 | { | |
104 | struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount; | |
105 | struct xfs_trans *tp; | |
106 | int error; | |
107 | ||
108 | tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS); | |
109 | ||
110 | error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0); | |
111 | if (error) { | |
112 | xfs_trans_cancel(tp); | |
113 | return error; | |
114 | } | |
115 | ||
116 | ioend->io_append_trans = tp; | |
117 | ||
118 | /* | |
119 | * We may pass freeze protection with a transaction. So tell lockdep | |
120 | * we released it. | |
121 | */ | |
122 | __sb_writers_release(ioend->io_inode->i_sb, SB_FREEZE_FS); | |
123 | /* | |
124 | * We hand off the transaction to the completion thread now, so | |
125 | * clear the flag here. | |
126 | */ | |
127 | current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | /* | |
132 | * Update on-disk file size now that data has been written to disk. | |
133 | */ | |
134 | STATIC int | |
135 | xfs_setfilesize( | |
136 | struct xfs_inode *ip, | |
137 | struct xfs_trans *tp, | |
138 | xfs_off_t offset, | |
139 | size_t size) | |
140 | { | |
141 | xfs_fsize_t isize; | |
142 | ||
143 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
144 | isize = xfs_new_eof(ip, offset + size); | |
145 | if (!isize) { | |
146 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
147 | xfs_trans_cancel(tp); | |
148 | return 0; | |
149 | } | |
150 | ||
151 | trace_xfs_setfilesize(ip, offset, size); | |
152 | ||
153 | ip->i_d.di_size = isize; | |
154 | xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); | |
155 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
156 | ||
157 | return xfs_trans_commit(tp); | |
158 | } | |
159 | ||
160 | STATIC int | |
161 | xfs_setfilesize_ioend( | |
162 | struct xfs_ioend *ioend) | |
163 | { | |
164 | struct xfs_inode *ip = XFS_I(ioend->io_inode); | |
165 | struct xfs_trans *tp = ioend->io_append_trans; | |
166 | ||
167 | /* | |
168 | * The transaction may have been allocated in the I/O submission thread, | |
169 | * thus we need to mark ourselves as being in a transaction manually. | |
170 | * Similarly for freeze protection. | |
171 | */ | |
172 | current_set_flags_nested(&tp->t_pflags, PF_FSTRANS); | |
173 | __sb_writers_acquired(VFS_I(ip)->i_sb, SB_FREEZE_FS); | |
174 | ||
175 | return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size); | |
176 | } | |
177 | ||
178 | /* | |
179 | * Schedule IO completion handling on the final put of an ioend. | |
180 | * | |
181 | * If there is no work to do we might as well call it a day and free the | |
182 | * ioend right now. | |
183 | */ | |
184 | STATIC void | |
185 | xfs_finish_ioend( | |
186 | struct xfs_ioend *ioend) | |
187 | { | |
188 | if (atomic_dec_and_test(&ioend->io_remaining)) { | |
189 | struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount; | |
190 | ||
191 | if (ioend->io_type == XFS_IO_UNWRITTEN) | |
192 | queue_work(mp->m_unwritten_workqueue, &ioend->io_work); | |
193 | else if (ioend->io_append_trans) | |
194 | queue_work(mp->m_data_workqueue, &ioend->io_work); | |
195 | else | |
196 | xfs_destroy_ioend(ioend); | |
197 | } | |
198 | } | |
199 | ||
200 | /* | |
201 | * IO write completion. | |
202 | */ | |
203 | STATIC void | |
204 | xfs_end_io( | |
205 | struct work_struct *work) | |
206 | { | |
207 | xfs_ioend_t *ioend = container_of(work, xfs_ioend_t, io_work); | |
208 | struct xfs_inode *ip = XFS_I(ioend->io_inode); | |
209 | int error = 0; | |
210 | ||
211 | if (XFS_FORCED_SHUTDOWN(ip->i_mount)) { | |
212 | ioend->io_error = -EIO; | |
213 | goto done; | |
214 | } | |
215 | if (ioend->io_error) | |
216 | goto done; | |
217 | ||
218 | /* | |
219 | * For unwritten extents we need to issue transactions to convert a | |
220 | * range to normal written extens after the data I/O has finished. | |
221 | */ | |
222 | if (ioend->io_type == XFS_IO_UNWRITTEN) { | |
223 | error = xfs_iomap_write_unwritten(ip, ioend->io_offset, | |
224 | ioend->io_size); | |
225 | } else if (ioend->io_append_trans) { | |
226 | error = xfs_setfilesize_ioend(ioend); | |
227 | } else { | |
228 | ASSERT(!xfs_ioend_is_append(ioend)); | |
229 | } | |
230 | ||
231 | done: | |
232 | if (error) | |
233 | ioend->io_error = error; | |
234 | xfs_destroy_ioend(ioend); | |
235 | } | |
236 | ||
237 | /* | |
238 | * Allocate and initialise an IO completion structure. | |
239 | * We need to track unwritten extent write completion here initially. | |
240 | * We'll need to extend this for updating the ondisk inode size later | |
241 | * (vs. incore size). | |
242 | */ | |
243 | STATIC xfs_ioend_t * | |
244 | xfs_alloc_ioend( | |
245 | struct inode *inode, | |
246 | unsigned int type) | |
247 | { | |
248 | xfs_ioend_t *ioend; | |
249 | ||
250 | ioend = mempool_alloc(xfs_ioend_pool, GFP_NOFS); | |
251 | ||
252 | /* | |
253 | * Set the count to 1 initially, which will prevent an I/O | |
254 | * completion callback from happening before we have started | |
255 | * all the I/O from calling the completion routine too early. | |
256 | */ | |
257 | atomic_set(&ioend->io_remaining, 1); | |
258 | ioend->io_error = 0; | |
259 | ioend->io_list = NULL; | |
260 | ioend->io_type = type; | |
261 | ioend->io_inode = inode; | |
262 | ioend->io_buffer_head = NULL; | |
263 | ioend->io_buffer_tail = NULL; | |
264 | ioend->io_offset = 0; | |
265 | ioend->io_size = 0; | |
266 | ioend->io_append_trans = NULL; | |
267 | ||
268 | INIT_WORK(&ioend->io_work, xfs_end_io); | |
269 | return ioend; | |
270 | } | |
271 | ||
272 | STATIC int | |
273 | xfs_map_blocks( | |
274 | struct inode *inode, | |
275 | loff_t offset, | |
276 | struct xfs_bmbt_irec *imap, | |
277 | int type, | |
278 | int nonblocking) | |
279 | { | |
280 | struct xfs_inode *ip = XFS_I(inode); | |
281 | struct xfs_mount *mp = ip->i_mount; | |
282 | ssize_t count = 1 << inode->i_blkbits; | |
283 | xfs_fileoff_t offset_fsb, end_fsb; | |
284 | int error = 0; | |
285 | int bmapi_flags = XFS_BMAPI_ENTIRE; | |
286 | int nimaps = 1; | |
287 | ||
288 | if (XFS_FORCED_SHUTDOWN(mp)) | |
289 | return -EIO; | |
290 | ||
291 | if (type == XFS_IO_UNWRITTEN) | |
292 | bmapi_flags |= XFS_BMAPI_IGSTATE; | |
293 | ||
294 | if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) { | |
295 | if (nonblocking) | |
296 | return -EAGAIN; | |
297 | xfs_ilock(ip, XFS_ILOCK_SHARED); | |
298 | } | |
299 | ||
300 | ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE || | |
301 | (ip->i_df.if_flags & XFS_IFEXTENTS)); | |
302 | ASSERT(offset <= mp->m_super->s_maxbytes); | |
303 | ||
304 | if (offset + count > mp->m_super->s_maxbytes) | |
305 | count = mp->m_super->s_maxbytes - offset; | |
306 | end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); | |
307 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
308 | error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, | |
309 | imap, &nimaps, bmapi_flags); | |
310 | xfs_iunlock(ip, XFS_ILOCK_SHARED); | |
311 | ||
312 | if (error) | |
313 | return error; | |
314 | ||
315 | if (type == XFS_IO_DELALLOC && | |
316 | (!nimaps || isnullstartblock(imap->br_startblock))) { | |
317 | error = xfs_iomap_write_allocate(ip, offset, imap); | |
318 | if (!error) | |
319 | trace_xfs_map_blocks_alloc(ip, offset, count, type, imap); | |
320 | return error; | |
321 | } | |
322 | ||
323 | #ifdef DEBUG | |
324 | if (type == XFS_IO_UNWRITTEN) { | |
325 | ASSERT(nimaps); | |
326 | ASSERT(imap->br_startblock != HOLESTARTBLOCK); | |
327 | ASSERT(imap->br_startblock != DELAYSTARTBLOCK); | |
328 | } | |
329 | #endif | |
330 | if (nimaps) | |
331 | trace_xfs_map_blocks_found(ip, offset, count, type, imap); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | STATIC int | |
336 | xfs_imap_valid( | |
337 | struct inode *inode, | |
338 | struct xfs_bmbt_irec *imap, | |
339 | xfs_off_t offset) | |
340 | { | |
341 | offset >>= inode->i_blkbits; | |
342 | ||
343 | return offset >= imap->br_startoff && | |
344 | offset < imap->br_startoff + imap->br_blockcount; | |
345 | } | |
346 | ||
347 | /* | |
348 | * BIO completion handler for buffered IO. | |
349 | */ | |
350 | STATIC void | |
351 | xfs_end_bio( | |
352 | struct bio *bio) | |
353 | { | |
354 | xfs_ioend_t *ioend = bio->bi_private; | |
355 | ||
356 | if (!ioend->io_error) | |
357 | ioend->io_error = bio->bi_error; | |
358 | ||
359 | /* Toss bio and pass work off to an xfsdatad thread */ | |
360 | bio->bi_private = NULL; | |
361 | bio->bi_end_io = NULL; | |
362 | bio_put(bio); | |
363 | ||
364 | xfs_finish_ioend(ioend); | |
365 | } | |
366 | ||
367 | STATIC void | |
368 | xfs_submit_ioend_bio( | |
369 | struct writeback_control *wbc, | |
370 | xfs_ioend_t *ioend, | |
371 | struct bio *bio) | |
372 | { | |
373 | atomic_inc(&ioend->io_remaining); | |
374 | bio->bi_private = ioend; | |
375 | bio->bi_end_io = xfs_end_bio; | |
376 | submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE, bio); | |
377 | } | |
378 | ||
379 | STATIC struct bio * | |
380 | xfs_alloc_ioend_bio( | |
381 | struct buffer_head *bh) | |
382 | { | |
383 | struct bio *bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); | |
384 | ||
385 | ASSERT(bio->bi_private == NULL); | |
386 | bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); | |
387 | bio->bi_bdev = bh->b_bdev; | |
388 | return bio; | |
389 | } | |
390 | ||
391 | STATIC void | |
392 | xfs_start_buffer_writeback( | |
393 | struct buffer_head *bh) | |
394 | { | |
395 | ASSERT(buffer_mapped(bh)); | |
396 | ASSERT(buffer_locked(bh)); | |
397 | ASSERT(!buffer_delay(bh)); | |
398 | ASSERT(!buffer_unwritten(bh)); | |
399 | ||
400 | mark_buffer_async_write(bh); | |
401 | set_buffer_uptodate(bh); | |
402 | clear_buffer_dirty(bh); | |
403 | } | |
404 | ||
405 | STATIC void | |
406 | xfs_start_page_writeback( | |
407 | struct page *page, | |
408 | int clear_dirty, | |
409 | int buffers) | |
410 | { | |
411 | ASSERT(PageLocked(page)); | |
412 | ASSERT(!PageWriteback(page)); | |
413 | ||
414 | /* | |
415 | * if the page was not fully cleaned, we need to ensure that the higher | |
416 | * layers come back to it correctly. That means we need to keep the page | |
417 | * dirty, and for WB_SYNC_ALL writeback we need to ensure the | |
418 | * PAGECACHE_TAG_TOWRITE index mark is not removed so another attempt to | |
419 | * write this page in this writeback sweep will be made. | |
420 | */ | |
421 | if (clear_dirty) { | |
422 | clear_page_dirty_for_io(page); | |
423 | set_page_writeback(page); | |
424 | } else | |
425 | set_page_writeback_keepwrite(page); | |
426 | ||
427 | unlock_page(page); | |
428 | ||
429 | /* If no buffers on the page are to be written, finish it here */ | |
430 | if (!buffers) | |
431 | end_page_writeback(page); | |
432 | } | |
433 | ||
434 | static inline int xfs_bio_add_buffer(struct bio *bio, struct buffer_head *bh) | |
435 | { | |
436 | return bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh)); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Submit all of the bios for all of the ioends we have saved up, covering the | |
441 | * initial writepage page and also any probed pages. | |
442 | * | |
443 | * Because we may have multiple ioends spanning a page, we need to start | |
444 | * writeback on all the buffers before we submit them for I/O. If we mark the | |
445 | * buffers as we got, then we can end up with a page that only has buffers | |
446 | * marked async write and I/O complete on can occur before we mark the other | |
447 | * buffers async write. | |
448 | * | |
449 | * The end result of this is that we trip a bug in end_page_writeback() because | |
450 | * we call it twice for the one page as the code in end_buffer_async_write() | |
451 | * assumes that all buffers on the page are started at the same time. | |
452 | * | |
453 | * The fix is two passes across the ioend list - one to start writeback on the | |
454 | * buffer_heads, and then submit them for I/O on the second pass. | |
455 | * | |
456 | * If @fail is non-zero, it means that we have a situation where some part of | |
457 | * the submission process has failed after we have marked paged for writeback | |
458 | * and unlocked them. In this situation, we need to fail the ioend chain rather | |
459 | * than submit it to IO. This typically only happens on a filesystem shutdown. | |
460 | */ | |
461 | STATIC void | |
462 | xfs_submit_ioend( | |
463 | struct writeback_control *wbc, | |
464 | xfs_ioend_t *ioend, | |
465 | int fail) | |
466 | { | |
467 | xfs_ioend_t *head = ioend; | |
468 | xfs_ioend_t *next; | |
469 | struct buffer_head *bh; | |
470 | struct bio *bio; | |
471 | sector_t lastblock = 0; | |
472 | ||
473 | /* Pass 1 - start writeback */ | |
474 | do { | |
475 | next = ioend->io_list; | |
476 | for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) | |
477 | xfs_start_buffer_writeback(bh); | |
478 | } while ((ioend = next) != NULL); | |
479 | ||
480 | /* Pass 2 - submit I/O */ | |
481 | ioend = head; | |
482 | do { | |
483 | next = ioend->io_list; | |
484 | bio = NULL; | |
485 | ||
486 | /* | |
487 | * If we are failing the IO now, just mark the ioend with an | |
488 | * error and finish it. This will run IO completion immediately | |
489 | * as there is only one reference to the ioend at this point in | |
490 | * time. | |
491 | */ | |
492 | if (fail) { | |
493 | ioend->io_error = fail; | |
494 | xfs_finish_ioend(ioend); | |
495 | continue; | |
496 | } | |
497 | ||
498 | for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) { | |
499 | ||
500 | if (!bio) { | |
501 | retry: | |
502 | bio = xfs_alloc_ioend_bio(bh); | |
503 | } else if (bh->b_blocknr != lastblock + 1) { | |
504 | xfs_submit_ioend_bio(wbc, ioend, bio); | |
505 | goto retry; | |
506 | } | |
507 | ||
508 | if (xfs_bio_add_buffer(bio, bh) != bh->b_size) { | |
509 | xfs_submit_ioend_bio(wbc, ioend, bio); | |
510 | goto retry; | |
511 | } | |
512 | ||
513 | lastblock = bh->b_blocknr; | |
514 | } | |
515 | if (bio) | |
516 | xfs_submit_ioend_bio(wbc, ioend, bio); | |
517 | xfs_finish_ioend(ioend); | |
518 | } while ((ioend = next) != NULL); | |
519 | } | |
520 | ||
521 | /* | |
522 | * Cancel submission of all buffer_heads so far in this endio. | |
523 | * Toss the endio too. Only ever called for the initial page | |
524 | * in a writepage request, so only ever one page. | |
525 | */ | |
526 | STATIC void | |
527 | xfs_cancel_ioend( | |
528 | xfs_ioend_t *ioend) | |
529 | { | |
530 | xfs_ioend_t *next; | |
531 | struct buffer_head *bh, *next_bh; | |
532 | ||
533 | do { | |
534 | next = ioend->io_list; | |
535 | bh = ioend->io_buffer_head; | |
536 | do { | |
537 | next_bh = bh->b_private; | |
538 | clear_buffer_async_write(bh); | |
539 | /* | |
540 | * The unwritten flag is cleared when added to the | |
541 | * ioend. We're not submitting for I/O so mark the | |
542 | * buffer unwritten again for next time around. | |
543 | */ | |
544 | if (ioend->io_type == XFS_IO_UNWRITTEN) | |
545 | set_buffer_unwritten(bh); | |
546 | unlock_buffer(bh); | |
547 | } while ((bh = next_bh) != NULL); | |
548 | ||
549 | mempool_free(ioend, xfs_ioend_pool); | |
550 | } while ((ioend = next) != NULL); | |
551 | } | |
552 | ||
553 | /* | |
554 | * Test to see if we've been building up a completion structure for | |
555 | * earlier buffers -- if so, we try to append to this ioend if we | |
556 | * can, otherwise we finish off any current ioend and start another. | |
557 | * Return true if we've finished the given ioend. | |
558 | */ | |
559 | STATIC void | |
560 | xfs_add_to_ioend( | |
561 | struct inode *inode, | |
562 | struct buffer_head *bh, | |
563 | xfs_off_t offset, | |
564 | unsigned int type, | |
565 | xfs_ioend_t **result, | |
566 | int need_ioend) | |
567 | { | |
568 | xfs_ioend_t *ioend = *result; | |
569 | ||
570 | if (!ioend || need_ioend || type != ioend->io_type) { | |
571 | xfs_ioend_t *previous = *result; | |
572 | ||
573 | ioend = xfs_alloc_ioend(inode, type); | |
574 | ioend->io_offset = offset; | |
575 | ioend->io_buffer_head = bh; | |
576 | ioend->io_buffer_tail = bh; | |
577 | if (previous) | |
578 | previous->io_list = ioend; | |
579 | *result = ioend; | |
580 | } else { | |
581 | ioend->io_buffer_tail->b_private = bh; | |
582 | ioend->io_buffer_tail = bh; | |
583 | } | |
584 | ||
585 | bh->b_private = NULL; | |
586 | ioend->io_size += bh->b_size; | |
587 | } | |
588 | ||
589 | STATIC void | |
590 | xfs_map_buffer( | |
591 | struct inode *inode, | |
592 | struct buffer_head *bh, | |
593 | struct xfs_bmbt_irec *imap, | |
594 | xfs_off_t offset) | |
595 | { | |
596 | sector_t bn; | |
597 | struct xfs_mount *m = XFS_I(inode)->i_mount; | |
598 | xfs_off_t iomap_offset = XFS_FSB_TO_B(m, imap->br_startoff); | |
599 | xfs_daddr_t iomap_bn = xfs_fsb_to_db(XFS_I(inode), imap->br_startblock); | |
600 | ||
601 | ASSERT(imap->br_startblock != HOLESTARTBLOCK); | |
602 | ASSERT(imap->br_startblock != DELAYSTARTBLOCK); | |
603 | ||
604 | bn = (iomap_bn >> (inode->i_blkbits - BBSHIFT)) + | |
605 | ((offset - iomap_offset) >> inode->i_blkbits); | |
606 | ||
607 | ASSERT(bn || XFS_IS_REALTIME_INODE(XFS_I(inode))); | |
608 | ||
609 | bh->b_blocknr = bn; | |
610 | set_buffer_mapped(bh); | |
611 | } | |
612 | ||
613 | STATIC void | |
614 | xfs_map_at_offset( | |
615 | struct inode *inode, | |
616 | struct buffer_head *bh, | |
617 | struct xfs_bmbt_irec *imap, | |
618 | xfs_off_t offset) | |
619 | { | |
620 | ASSERT(imap->br_startblock != HOLESTARTBLOCK); | |
621 | ASSERT(imap->br_startblock != DELAYSTARTBLOCK); | |
622 | ||
623 | xfs_map_buffer(inode, bh, imap, offset); | |
624 | set_buffer_mapped(bh); | |
625 | clear_buffer_delay(bh); | |
626 | clear_buffer_unwritten(bh); | |
627 | } | |
628 | ||
629 | /* | |
630 | * Test if a given page contains at least one buffer of a given @type. | |
631 | * If @check_all_buffers is true, then we walk all the buffers in the page to | |
632 | * try to find one of the type passed in. If it is not set, then the caller only | |
633 | * needs to check the first buffer on the page for a match. | |
634 | */ | |
635 | STATIC bool | |
636 | xfs_check_page_type( | |
637 | struct page *page, | |
638 | unsigned int type, | |
639 | bool check_all_buffers) | |
640 | { | |
641 | struct buffer_head *bh; | |
642 | struct buffer_head *head; | |
643 | ||
644 | if (PageWriteback(page)) | |
645 | return false; | |
646 | if (!page->mapping) | |
647 | return false; | |
648 | if (!page_has_buffers(page)) | |
649 | return false; | |
650 | ||
651 | bh = head = page_buffers(page); | |
652 | do { | |
653 | if (buffer_unwritten(bh)) { | |
654 | if (type == XFS_IO_UNWRITTEN) | |
655 | return true; | |
656 | } else if (buffer_delay(bh)) { | |
657 | if (type == XFS_IO_DELALLOC) | |
658 | return true; | |
659 | } else if (buffer_dirty(bh) && buffer_mapped(bh)) { | |
660 | if (type == XFS_IO_OVERWRITE) | |
661 | return true; | |
662 | } | |
663 | ||
664 | /* If we are only checking the first buffer, we are done now. */ | |
665 | if (!check_all_buffers) | |
666 | break; | |
667 | } while ((bh = bh->b_this_page) != head); | |
668 | ||
669 | return false; | |
670 | } | |
671 | ||
672 | /* | |
673 | * Allocate & map buffers for page given the extent map. Write it out. | |
674 | * except for the original page of a writepage, this is called on | |
675 | * delalloc/unwritten pages only, for the original page it is possible | |
676 | * that the page has no mapping at all. | |
677 | */ | |
678 | STATIC int | |
679 | xfs_convert_page( | |
680 | struct inode *inode, | |
681 | struct page *page, | |
682 | loff_t tindex, | |
683 | struct xfs_bmbt_irec *imap, | |
684 | xfs_ioend_t **ioendp, | |
685 | struct writeback_control *wbc) | |
686 | { | |
687 | struct buffer_head *bh, *head; | |
688 | xfs_off_t end_offset; | |
689 | unsigned long p_offset; | |
690 | unsigned int type; | |
691 | int len, page_dirty; | |
692 | int count = 0, done = 0, uptodate = 1; | |
693 | xfs_off_t offset = page_offset(page); | |
694 | ||
695 | if (page->index != tindex) | |
696 | goto fail; | |
697 | if (!trylock_page(page)) | |
698 | goto fail; | |
699 | if (PageWriteback(page)) | |
700 | goto fail_unlock_page; | |
701 | if (page->mapping != inode->i_mapping) | |
702 | goto fail_unlock_page; | |
703 | if (!xfs_check_page_type(page, (*ioendp)->io_type, false)) | |
704 | goto fail_unlock_page; | |
705 | ||
706 | /* | |
707 | * page_dirty is initially a count of buffers on the page before | |
708 | * EOF and is decremented as we move each into a cleanable state. | |
709 | * | |
710 | * Derivation: | |
711 | * | |
712 | * End offset is the highest offset that this page should represent. | |
713 | * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1)) | |
714 | * will evaluate non-zero and be less than PAGE_CACHE_SIZE and | |
715 | * hence give us the correct page_dirty count. On any other page, | |
716 | * it will be zero and in that case we need page_dirty to be the | |
717 | * count of buffers on the page. | |
718 | */ | |
719 | end_offset = min_t(unsigned long long, | |
720 | (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT, | |
721 | i_size_read(inode)); | |
722 | ||
723 | /* | |
724 | * If the current map does not span the entire page we are about to try | |
725 | * to write, then give up. The only way we can write a page that spans | |
726 | * multiple mappings in a single writeback iteration is via the | |
727 | * xfs_vm_writepage() function. Data integrity writeback requires the | |
728 | * entire page to be written in a single attempt, otherwise the part of | |
729 | * the page we don't write here doesn't get written as part of the data | |
730 | * integrity sync. | |
731 | * | |
732 | * For normal writeback, we also don't attempt to write partial pages | |
733 | * here as it simply means that write_cache_pages() will see it under | |
734 | * writeback and ignore the page until some point in the future, at | |
735 | * which time this will be the only page in the file that needs | |
736 | * writeback. Hence for more optimal IO patterns, we should always | |
737 | * avoid partial page writeback due to multiple mappings on a page here. | |
738 | */ | |
739 | if (!xfs_imap_valid(inode, imap, end_offset)) | |
740 | goto fail_unlock_page; | |
741 | ||
742 | len = 1 << inode->i_blkbits; | |
743 | p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1), | |
744 | PAGE_CACHE_SIZE); | |
745 | p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE; | |
746 | page_dirty = p_offset / len; | |
747 | ||
748 | /* | |
749 | * The moment we find a buffer that doesn't match our current type | |
750 | * specification or can't be written, abort the loop and start | |
751 | * writeback. As per the above xfs_imap_valid() check, only | |
752 | * xfs_vm_writepage() can handle partial page writeback fully - we are | |
753 | * limited here to the buffers that are contiguous with the current | |
754 | * ioend, and hence a buffer we can't write breaks that contiguity and | |
755 | * we have to defer the rest of the IO to xfs_vm_writepage(). | |
756 | */ | |
757 | bh = head = page_buffers(page); | |
758 | do { | |
759 | if (offset >= end_offset) | |
760 | break; | |
761 | if (!buffer_uptodate(bh)) | |
762 | uptodate = 0; | |
763 | if (!(PageUptodate(page) || buffer_uptodate(bh))) { | |
764 | done = 1; | |
765 | break; | |
766 | } | |
767 | ||
768 | if (buffer_unwritten(bh) || buffer_delay(bh) || | |
769 | buffer_mapped(bh)) { | |
770 | if (buffer_unwritten(bh)) | |
771 | type = XFS_IO_UNWRITTEN; | |
772 | else if (buffer_delay(bh)) | |
773 | type = XFS_IO_DELALLOC; | |
774 | else | |
775 | type = XFS_IO_OVERWRITE; | |
776 | ||
777 | /* | |
778 | * imap should always be valid because of the above | |
779 | * partial page end_offset check on the imap. | |
780 | */ | |
781 | ASSERT(xfs_imap_valid(inode, imap, offset)); | |
782 | ||
783 | lock_buffer(bh); | |
784 | if (type != XFS_IO_OVERWRITE) | |
785 | xfs_map_at_offset(inode, bh, imap, offset); | |
786 | xfs_add_to_ioend(inode, bh, offset, type, | |
787 | ioendp, done); | |
788 | ||
789 | page_dirty--; | |
790 | count++; | |
791 | } else { | |
792 | done = 1; | |
793 | break; | |
794 | } | |
795 | } while (offset += len, (bh = bh->b_this_page) != head); | |
796 | ||
797 | if (uptodate && bh == head) | |
798 | SetPageUptodate(page); | |
799 | ||
800 | if (count) { | |
801 | if (--wbc->nr_to_write <= 0 && | |
802 | wbc->sync_mode == WB_SYNC_NONE) | |
803 | done = 1; | |
804 | } | |
805 | xfs_start_page_writeback(page, !page_dirty, count); | |
806 | ||
807 | return done; | |
808 | fail_unlock_page: | |
809 | unlock_page(page); | |
810 | fail: | |
811 | return 1; | |
812 | } | |
813 | ||
814 | /* | |
815 | * Convert & write out a cluster of pages in the same extent as defined | |
816 | * by mp and following the start page. | |
817 | */ | |
818 | STATIC void | |
819 | xfs_cluster_write( | |
820 | struct inode *inode, | |
821 | pgoff_t tindex, | |
822 | struct xfs_bmbt_irec *imap, | |
823 | xfs_ioend_t **ioendp, | |
824 | struct writeback_control *wbc, | |
825 | pgoff_t tlast) | |
826 | { | |
827 | struct pagevec pvec; | |
828 | int done = 0, i; | |
829 | ||
830 | pagevec_init(&pvec, 0); | |
831 | while (!done && tindex <= tlast) { | |
832 | unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1); | |
833 | ||
834 | if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len)) | |
835 | break; | |
836 | ||
837 | for (i = 0; i < pagevec_count(&pvec); i++) { | |
838 | done = xfs_convert_page(inode, pvec.pages[i], tindex++, | |
839 | imap, ioendp, wbc); | |
840 | if (done) | |
841 | break; | |
842 | } | |
843 | ||
844 | pagevec_release(&pvec); | |
845 | cond_resched(); | |
846 | } | |
847 | } | |
848 | ||
849 | STATIC void | |
850 | xfs_vm_invalidatepage( | |
851 | struct page *page, | |
852 | unsigned int offset, | |
853 | unsigned int length) | |
854 | { | |
855 | trace_xfs_invalidatepage(page->mapping->host, page, offset, | |
856 | length); | |
857 | block_invalidatepage(page, offset, length); | |
858 | } | |
859 | ||
860 | /* | |
861 | * If the page has delalloc buffers on it, we need to punch them out before we | |
862 | * invalidate the page. If we don't, we leave a stale delalloc mapping on the | |
863 | * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read | |
864 | * is done on that same region - the delalloc extent is returned when none is | |
865 | * supposed to be there. | |
866 | * | |
867 | * We prevent this by truncating away the delalloc regions on the page before | |
868 | * invalidating it. Because they are delalloc, we can do this without needing a | |
869 | * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this | |
870 | * truncation without a transaction as there is no space left for block | |
871 | * reservation (typically why we see a ENOSPC in writeback). | |
872 | * | |
873 | * This is not a performance critical path, so for now just do the punching a | |
874 | * buffer head at a time. | |
875 | */ | |
876 | STATIC void | |
877 | xfs_aops_discard_page( | |
878 | struct page *page) | |
879 | { | |
880 | struct inode *inode = page->mapping->host; | |
881 | struct xfs_inode *ip = XFS_I(inode); | |
882 | struct buffer_head *bh, *head; | |
883 | loff_t offset = page_offset(page); | |
884 | ||
885 | if (!xfs_check_page_type(page, XFS_IO_DELALLOC, true)) | |
886 | goto out_invalidate; | |
887 | ||
888 | if (XFS_FORCED_SHUTDOWN(ip->i_mount)) | |
889 | goto out_invalidate; | |
890 | ||
891 | xfs_alert(ip->i_mount, | |
892 | "page discard on page %p, inode 0x%llx, offset %llu.", | |
893 | page, ip->i_ino, offset); | |
894 | ||
895 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
896 | bh = head = page_buffers(page); | |
897 | do { | |
898 | int error; | |
899 | xfs_fileoff_t start_fsb; | |
900 | ||
901 | if (!buffer_delay(bh)) | |
902 | goto next_buffer; | |
903 | ||
904 | start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
905 | error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1); | |
906 | if (error) { | |
907 | /* something screwed, just bail */ | |
908 | if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) { | |
909 | xfs_alert(ip->i_mount, | |
910 | "page discard unable to remove delalloc mapping."); | |
911 | } | |
912 | break; | |
913 | } | |
914 | next_buffer: | |
915 | offset += 1 << inode->i_blkbits; | |
916 | ||
917 | } while ((bh = bh->b_this_page) != head); | |
918 | ||
919 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
920 | out_invalidate: | |
921 | xfs_vm_invalidatepage(page, 0, PAGE_CACHE_SIZE); | |
922 | return; | |
923 | } | |
924 | ||
925 | /* | |
926 | * Write out a dirty page. | |
927 | * | |
928 | * For delalloc space on the page we need to allocate space and flush it. | |
929 | * For unwritten space on the page we need to start the conversion to | |
930 | * regular allocated space. | |
931 | * For any other dirty buffer heads on the page we should flush them. | |
932 | */ | |
933 | STATIC int | |
934 | xfs_vm_writepage( | |
935 | struct page *page, | |
936 | struct writeback_control *wbc) | |
937 | { | |
938 | struct inode *inode = page->mapping->host; | |
939 | struct buffer_head *bh, *head; | |
940 | struct xfs_bmbt_irec imap; | |
941 | xfs_ioend_t *ioend = NULL, *iohead = NULL; | |
942 | loff_t offset; | |
943 | unsigned int type; | |
944 | __uint64_t end_offset; | |
945 | pgoff_t end_index, last_index; | |
946 | ssize_t len; | |
947 | int err, imap_valid = 0, uptodate = 1; | |
948 | int count = 0; | |
949 | int nonblocking = 0; | |
950 | ||
951 | trace_xfs_writepage(inode, page, 0, 0); | |
952 | ||
953 | ASSERT(page_has_buffers(page)); | |
954 | ||
955 | /* | |
956 | * Refuse to write the page out if we are called from reclaim context. | |
957 | * | |
958 | * This avoids stack overflows when called from deeply used stacks in | |
959 | * random callers for direct reclaim or memcg reclaim. We explicitly | |
960 | * allow reclaim from kswapd as the stack usage there is relatively low. | |
961 | * | |
962 | * This should never happen except in the case of a VM regression so | |
963 | * warn about it. | |
964 | */ | |
965 | if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == | |
966 | PF_MEMALLOC)) | |
967 | goto redirty; | |
968 | ||
969 | /* | |
970 | * Given that we do not allow direct reclaim to call us, we should | |
971 | * never be called while in a filesystem transaction. | |
972 | */ | |
973 | if (WARN_ON_ONCE(current->flags & PF_FSTRANS)) | |
974 | goto redirty; | |
975 | ||
976 | /* Is this page beyond the end of the file? */ | |
977 | offset = i_size_read(inode); | |
978 | end_index = offset >> PAGE_CACHE_SHIFT; | |
979 | last_index = (offset - 1) >> PAGE_CACHE_SHIFT; | |
980 | ||
981 | /* | |
982 | * The page index is less than the end_index, adjust the end_offset | |
983 | * to the highest offset that this page should represent. | |
984 | * ----------------------------------------------------- | |
985 | * | file mapping | <EOF> | | |
986 | * ----------------------------------------------------- | |
987 | * | Page ... | Page N-2 | Page N-1 | Page N | | | |
988 | * ^--------------------------------^----------|-------- | |
989 | * | desired writeback range | see else | | |
990 | * ---------------------------------^------------------| | |
991 | */ | |
992 | if (page->index < end_index) | |
993 | end_offset = (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT; | |
994 | else { | |
995 | /* | |
996 | * Check whether the page to write out is beyond or straddles | |
997 | * i_size or not. | |
998 | * ------------------------------------------------------- | |
999 | * | file mapping | <EOF> | | |
1000 | * ------------------------------------------------------- | |
1001 | * | Page ... | Page N-2 | Page N-1 | Page N | Beyond | | |
1002 | * ^--------------------------------^-----------|--------- | |
1003 | * | | Straddles | | |
1004 | * ---------------------------------^-----------|--------| | |
1005 | */ | |
1006 | unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1); | |
1007 | ||
1008 | /* | |
1009 | * Skip the page if it is fully outside i_size, e.g. due to a | |
1010 | * truncate operation that is in progress. We must redirty the | |
1011 | * page so that reclaim stops reclaiming it. Otherwise | |
1012 | * xfs_vm_releasepage() is called on it and gets confused. | |
1013 | * | |
1014 | * Note that the end_index is unsigned long, it would overflow | |
1015 | * if the given offset is greater than 16TB on 32-bit system | |
1016 | * and if we do check the page is fully outside i_size or not | |
1017 | * via "if (page->index >= end_index + 1)" as "end_index + 1" | |
1018 | * will be evaluated to 0. Hence this page will be redirtied | |
1019 | * and be written out repeatedly which would result in an | |
1020 | * infinite loop, the user program that perform this operation | |
1021 | * will hang. Instead, we can verify this situation by checking | |
1022 | * if the page to write is totally beyond the i_size or if it's | |
1023 | * offset is just equal to the EOF. | |
1024 | */ | |
1025 | if (page->index > end_index || | |
1026 | (page->index == end_index && offset_into_page == 0)) | |
1027 | goto redirty; | |
1028 | ||
1029 | /* | |
1030 | * The page straddles i_size. It must be zeroed out on each | |
1031 | * and every writepage invocation because it may be mmapped. | |
1032 | * "A file is mapped in multiples of the page size. For a file | |
1033 | * that is not a multiple of the page size, the remaining | |
1034 | * memory is zeroed when mapped, and writes to that region are | |
1035 | * not written out to the file." | |
1036 | */ | |
1037 | zero_user_segment(page, offset_into_page, PAGE_CACHE_SIZE); | |
1038 | ||
1039 | /* Adjust the end_offset to the end of file */ | |
1040 | end_offset = offset; | |
1041 | } | |
1042 | ||
1043 | len = 1 << inode->i_blkbits; | |
1044 | ||
1045 | bh = head = page_buffers(page); | |
1046 | offset = page_offset(page); | |
1047 | type = XFS_IO_OVERWRITE; | |
1048 | ||
1049 | if (wbc->sync_mode == WB_SYNC_NONE) | |
1050 | nonblocking = 1; | |
1051 | ||
1052 | do { | |
1053 | int new_ioend = 0; | |
1054 | ||
1055 | if (offset >= end_offset) | |
1056 | break; | |
1057 | if (!buffer_uptodate(bh)) | |
1058 | uptodate = 0; | |
1059 | ||
1060 | /* | |
1061 | * set_page_dirty dirties all buffers in a page, independent | |
1062 | * of their state. The dirty state however is entirely | |
1063 | * meaningless for holes (!mapped && uptodate), so skip | |
1064 | * buffers covering holes here. | |
1065 | */ | |
1066 | if (!buffer_mapped(bh) && buffer_uptodate(bh)) { | |
1067 | imap_valid = 0; | |
1068 | continue; | |
1069 | } | |
1070 | ||
1071 | if (buffer_unwritten(bh)) { | |
1072 | if (type != XFS_IO_UNWRITTEN) { | |
1073 | type = XFS_IO_UNWRITTEN; | |
1074 | imap_valid = 0; | |
1075 | } | |
1076 | } else if (buffer_delay(bh)) { | |
1077 | if (type != XFS_IO_DELALLOC) { | |
1078 | type = XFS_IO_DELALLOC; | |
1079 | imap_valid = 0; | |
1080 | } | |
1081 | } else if (buffer_uptodate(bh)) { | |
1082 | if (type != XFS_IO_OVERWRITE) { | |
1083 | type = XFS_IO_OVERWRITE; | |
1084 | imap_valid = 0; | |
1085 | } | |
1086 | } else { | |
1087 | if (PageUptodate(page)) | |
1088 | ASSERT(buffer_mapped(bh)); | |
1089 | /* | |
1090 | * This buffer is not uptodate and will not be | |
1091 | * written to disk. Ensure that we will put any | |
1092 | * subsequent writeable buffers into a new | |
1093 | * ioend. | |
1094 | */ | |
1095 | imap_valid = 0; | |
1096 | continue; | |
1097 | } | |
1098 | ||
1099 | if (imap_valid) | |
1100 | imap_valid = xfs_imap_valid(inode, &imap, offset); | |
1101 | if (!imap_valid) { | |
1102 | /* | |
1103 | * If we didn't have a valid mapping then we need to | |
1104 | * put the new mapping into a separate ioend structure. | |
1105 | * This ensures non-contiguous extents always have | |
1106 | * separate ioends, which is particularly important | |
1107 | * for unwritten extent conversion at I/O completion | |
1108 | * time. | |
1109 | */ | |
1110 | new_ioend = 1; | |
1111 | err = xfs_map_blocks(inode, offset, &imap, type, | |
1112 | nonblocking); | |
1113 | if (err) | |
1114 | goto error; | |
1115 | imap_valid = xfs_imap_valid(inode, &imap, offset); | |
1116 | } | |
1117 | if (imap_valid) { | |
1118 | lock_buffer(bh); | |
1119 | if (type != XFS_IO_OVERWRITE) | |
1120 | xfs_map_at_offset(inode, bh, &imap, offset); | |
1121 | xfs_add_to_ioend(inode, bh, offset, type, &ioend, | |
1122 | new_ioend); | |
1123 | count++; | |
1124 | } | |
1125 | ||
1126 | if (!iohead) | |
1127 | iohead = ioend; | |
1128 | ||
1129 | } while (offset += len, ((bh = bh->b_this_page) != head)); | |
1130 | ||
1131 | if (uptodate && bh == head) | |
1132 | SetPageUptodate(page); | |
1133 | ||
1134 | xfs_start_page_writeback(page, 1, count); | |
1135 | ||
1136 | /* if there is no IO to be submitted for this page, we are done */ | |
1137 | if (!ioend) | |
1138 | return 0; | |
1139 | ||
1140 | ASSERT(iohead); | |
1141 | ||
1142 | /* | |
1143 | * Any errors from this point onwards need tobe reported through the IO | |
1144 | * completion path as we have marked the initial page as under writeback | |
1145 | * and unlocked it. | |
1146 | */ | |
1147 | if (imap_valid) { | |
1148 | xfs_off_t end_index; | |
1149 | ||
1150 | end_index = imap.br_startoff + imap.br_blockcount; | |
1151 | ||
1152 | /* to bytes */ | |
1153 | end_index <<= inode->i_blkbits; | |
1154 | ||
1155 | /* to pages */ | |
1156 | end_index = (end_index - 1) >> PAGE_CACHE_SHIFT; | |
1157 | ||
1158 | /* check against file size */ | |
1159 | if (end_index > last_index) | |
1160 | end_index = last_index; | |
1161 | ||
1162 | xfs_cluster_write(inode, page->index + 1, &imap, &ioend, | |
1163 | wbc, end_index); | |
1164 | } | |
1165 | ||
1166 | ||
1167 | /* | |
1168 | * Reserve log space if we might write beyond the on-disk inode size. | |
1169 | */ | |
1170 | err = 0; | |
1171 | if (ioend->io_type != XFS_IO_UNWRITTEN && xfs_ioend_is_append(ioend)) | |
1172 | err = xfs_setfilesize_trans_alloc(ioend); | |
1173 | ||
1174 | xfs_submit_ioend(wbc, iohead, err); | |
1175 | ||
1176 | return 0; | |
1177 | ||
1178 | error: | |
1179 | if (iohead) | |
1180 | xfs_cancel_ioend(iohead); | |
1181 | ||
1182 | if (err == -EAGAIN) | |
1183 | goto redirty; | |
1184 | ||
1185 | xfs_aops_discard_page(page); | |
1186 | ClearPageUptodate(page); | |
1187 | unlock_page(page); | |
1188 | return err; | |
1189 | ||
1190 | redirty: | |
1191 | redirty_page_for_writepage(wbc, page); | |
1192 | unlock_page(page); | |
1193 | return 0; | |
1194 | } | |
1195 | ||
1196 | STATIC int | |
1197 | xfs_vm_writepages( | |
1198 | struct address_space *mapping, | |
1199 | struct writeback_control *wbc) | |
1200 | { | |
1201 | xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED); | |
1202 | return generic_writepages(mapping, wbc); | |
1203 | } | |
1204 | ||
1205 | /* | |
1206 | * Called to move a page into cleanable state - and from there | |
1207 | * to be released. The page should already be clean. We always | |
1208 | * have buffer heads in this call. | |
1209 | * | |
1210 | * Returns 1 if the page is ok to release, 0 otherwise. | |
1211 | */ | |
1212 | STATIC int | |
1213 | xfs_vm_releasepage( | |
1214 | struct page *page, | |
1215 | gfp_t gfp_mask) | |
1216 | { | |
1217 | int delalloc, unwritten; | |
1218 | ||
1219 | trace_xfs_releasepage(page->mapping->host, page, 0, 0); | |
1220 | ||
1221 | xfs_count_page_state(page, &delalloc, &unwritten); | |
1222 | ||
1223 | if (WARN_ON_ONCE(delalloc)) | |
1224 | return 0; | |
1225 | if (WARN_ON_ONCE(unwritten)) | |
1226 | return 0; | |
1227 | ||
1228 | return try_to_free_buffers(page); | |
1229 | } | |
1230 | ||
1231 | /* | |
1232 | * When we map a DIO buffer, we may need to attach an ioend that describes the | |
1233 | * type of write IO we are doing. This passes to the completion function the | |
1234 | * operations it needs to perform. If the mapping is for an overwrite wholly | |
1235 | * within the EOF then we don't need an ioend and so we don't allocate one. | |
1236 | * This avoids the unnecessary overhead of allocating and freeing ioends for | |
1237 | * workloads that don't require transactions on IO completion. | |
1238 | * | |
1239 | * If we get multiple mappings in a single IO, we might be mapping different | |
1240 | * types. But because the direct IO can only have a single private pointer, we | |
1241 | * need to ensure that: | |
1242 | * | |
1243 | * a) i) the ioend spans the entire region of unwritten mappings; or | |
1244 | * ii) the ioend spans all the mappings that cross or are beyond EOF; and | |
1245 | * b) if it contains unwritten extents, it is *permanently* marked as such | |
1246 | * | |
1247 | * We could do this by chaining ioends like buffered IO does, but we only | |
1248 | * actually get one IO completion callback from the direct IO, and that spans | |
1249 | * the entire IO regardless of how many mappings and IOs are needed to complete | |
1250 | * the DIO. There is only going to be one reference to the ioend and its life | |
1251 | * cycle is constrained by the DIO completion code. hence we don't need | |
1252 | * reference counting here. | |
1253 | */ | |
1254 | static void | |
1255 | xfs_map_direct( | |
1256 | struct inode *inode, | |
1257 | struct buffer_head *bh_result, | |
1258 | struct xfs_bmbt_irec *imap, | |
1259 | xfs_off_t offset) | |
1260 | { | |
1261 | struct xfs_ioend *ioend; | |
1262 | xfs_off_t size = bh_result->b_size; | |
1263 | int type; | |
1264 | ||
1265 | if (ISUNWRITTEN(imap)) | |
1266 | type = XFS_IO_UNWRITTEN; | |
1267 | else | |
1268 | type = XFS_IO_OVERWRITE; | |
1269 | ||
1270 | trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap); | |
1271 | ||
1272 | if (bh_result->b_private) { | |
1273 | ioend = bh_result->b_private; | |
1274 | ASSERT(ioend->io_size > 0); | |
1275 | ASSERT(offset >= ioend->io_offset); | |
1276 | if (offset + size > ioend->io_offset + ioend->io_size) | |
1277 | ioend->io_size = offset - ioend->io_offset + size; | |
1278 | ||
1279 | if (type == XFS_IO_UNWRITTEN && type != ioend->io_type) | |
1280 | ioend->io_type = XFS_IO_UNWRITTEN; | |
1281 | ||
1282 | trace_xfs_gbmap_direct_update(XFS_I(inode), ioend->io_offset, | |
1283 | ioend->io_size, ioend->io_type, | |
1284 | imap); | |
1285 | } else if (type == XFS_IO_UNWRITTEN || | |
1286 | offset + size > i_size_read(inode)) { | |
1287 | ioend = xfs_alloc_ioend(inode, type); | |
1288 | ioend->io_offset = offset; | |
1289 | ioend->io_size = size; | |
1290 | ||
1291 | bh_result->b_private = ioend; | |
1292 | set_buffer_defer_completion(bh_result); | |
1293 | ||
1294 | trace_xfs_gbmap_direct_new(XFS_I(inode), offset, size, type, | |
1295 | imap); | |
1296 | } else { | |
1297 | trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type, | |
1298 | imap); | |
1299 | } | |
1300 | } | |
1301 | ||
1302 | /* | |
1303 | * If this is O_DIRECT or the mpage code calling tell them how large the mapping | |
1304 | * is, so that we can avoid repeated get_blocks calls. | |
1305 | * | |
1306 | * If the mapping spans EOF, then we have to break the mapping up as the mapping | |
1307 | * for blocks beyond EOF must be marked new so that sub block regions can be | |
1308 | * correctly zeroed. We can't do this for mappings within EOF unless the mapping | |
1309 | * was just allocated or is unwritten, otherwise the callers would overwrite | |
1310 | * existing data with zeros. Hence we have to split the mapping into a range up | |
1311 | * to and including EOF, and a second mapping for beyond EOF. | |
1312 | */ | |
1313 | static void | |
1314 | xfs_map_trim_size( | |
1315 | struct inode *inode, | |
1316 | sector_t iblock, | |
1317 | struct buffer_head *bh_result, | |
1318 | struct xfs_bmbt_irec *imap, | |
1319 | xfs_off_t offset, | |
1320 | ssize_t size) | |
1321 | { | |
1322 | xfs_off_t mapping_size; | |
1323 | ||
1324 | mapping_size = imap->br_startoff + imap->br_blockcount - iblock; | |
1325 | mapping_size <<= inode->i_blkbits; | |
1326 | ||
1327 | ASSERT(mapping_size > 0); | |
1328 | if (mapping_size > size) | |
1329 | mapping_size = size; | |
1330 | if (offset < i_size_read(inode) && | |
1331 | offset + mapping_size >= i_size_read(inode)) { | |
1332 | /* limit mapping to block that spans EOF */ | |
1333 | mapping_size = roundup_64(i_size_read(inode) - offset, | |
1334 | 1 << inode->i_blkbits); | |
1335 | } | |
1336 | if (mapping_size > LONG_MAX) | |
1337 | mapping_size = LONG_MAX; | |
1338 | ||
1339 | bh_result->b_size = mapping_size; | |
1340 | } | |
1341 | ||
1342 | STATIC int | |
1343 | __xfs_get_blocks( | |
1344 | struct inode *inode, | |
1345 | sector_t iblock, | |
1346 | struct buffer_head *bh_result, | |
1347 | int create, | |
1348 | bool direct) | |
1349 | { | |
1350 | struct xfs_inode *ip = XFS_I(inode); | |
1351 | struct xfs_mount *mp = ip->i_mount; | |
1352 | xfs_fileoff_t offset_fsb, end_fsb; | |
1353 | int error = 0; | |
1354 | int lockmode = 0; | |
1355 | struct xfs_bmbt_irec imap; | |
1356 | int nimaps = 1; | |
1357 | xfs_off_t offset; | |
1358 | ssize_t size; | |
1359 | int new = 0; | |
1360 | ||
1361 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1362 | return -EIO; | |
1363 | ||
1364 | offset = (xfs_off_t)iblock << inode->i_blkbits; | |
1365 | ASSERT(bh_result->b_size >= (1 << inode->i_blkbits)); | |
1366 | size = bh_result->b_size; | |
1367 | ||
1368 | if (!create && direct && offset >= i_size_read(inode)) | |
1369 | return 0; | |
1370 | ||
1371 | /* | |
1372 | * Direct I/O is usually done on preallocated files, so try getting | |
1373 | * a block mapping without an exclusive lock first. For buffered | |
1374 | * writes we already have the exclusive iolock anyway, so avoiding | |
1375 | * a lock roundtrip here by taking the ilock exclusive from the | |
1376 | * beginning is a useful micro optimization. | |
1377 | */ | |
1378 | if (create && !direct) { | |
1379 | lockmode = XFS_ILOCK_EXCL; | |
1380 | xfs_ilock(ip, lockmode); | |
1381 | } else { | |
1382 | lockmode = xfs_ilock_data_map_shared(ip); | |
1383 | } | |
1384 | ||
1385 | ASSERT(offset <= mp->m_super->s_maxbytes); | |
1386 | if (offset + size > mp->m_super->s_maxbytes) | |
1387 | size = mp->m_super->s_maxbytes - offset; | |
1388 | end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size); | |
1389 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
1390 | ||
1391 | error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, | |
1392 | &imap, &nimaps, XFS_BMAPI_ENTIRE); | |
1393 | if (error) | |
1394 | goto out_unlock; | |
1395 | ||
1396 | if (create && | |
1397 | (!nimaps || | |
1398 | (imap.br_startblock == HOLESTARTBLOCK || | |
1399 | imap.br_startblock == DELAYSTARTBLOCK))) { | |
1400 | if (direct || xfs_get_extsz_hint(ip)) { | |
1401 | /* | |
1402 | * Drop the ilock in preparation for starting the block | |
1403 | * allocation transaction. It will be retaken | |
1404 | * exclusively inside xfs_iomap_write_direct for the | |
1405 | * actual allocation. | |
1406 | */ | |
1407 | xfs_iunlock(ip, lockmode); | |
1408 | error = xfs_iomap_write_direct(ip, offset, size, | |
1409 | &imap, nimaps); | |
1410 | if (error) | |
1411 | return error; | |
1412 | new = 1; | |
1413 | ||
1414 | } else { | |
1415 | /* | |
1416 | * Delalloc reservations do not require a transaction, | |
1417 | * we can go on without dropping the lock here. If we | |
1418 | * are allocating a new delalloc block, make sure that | |
1419 | * we set the new flag so that we mark the buffer new so | |
1420 | * that we know that it is newly allocated if the write | |
1421 | * fails. | |
1422 | */ | |
1423 | if (nimaps && imap.br_startblock == HOLESTARTBLOCK) | |
1424 | new = 1; | |
1425 | error = xfs_iomap_write_delay(ip, offset, size, &imap); | |
1426 | if (error) | |
1427 | goto out_unlock; | |
1428 | ||
1429 | xfs_iunlock(ip, lockmode); | |
1430 | } | |
1431 | trace_xfs_get_blocks_alloc(ip, offset, size, | |
1432 | ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN | |
1433 | : XFS_IO_DELALLOC, &imap); | |
1434 | } else if (nimaps) { | |
1435 | trace_xfs_get_blocks_found(ip, offset, size, | |
1436 | ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN | |
1437 | : XFS_IO_OVERWRITE, &imap); | |
1438 | xfs_iunlock(ip, lockmode); | |
1439 | } else { | |
1440 | trace_xfs_get_blocks_notfound(ip, offset, size); | |
1441 | goto out_unlock; | |
1442 | } | |
1443 | ||
1444 | /* trim mapping down to size requested */ | |
1445 | if (direct || size > (1 << inode->i_blkbits)) | |
1446 | xfs_map_trim_size(inode, iblock, bh_result, | |
1447 | &imap, offset, size); | |
1448 | ||
1449 | /* | |
1450 | * For unwritten extents do not report a disk address in the buffered | |
1451 | * read case (treat as if we're reading into a hole). | |
1452 | */ | |
1453 | if (imap.br_startblock != HOLESTARTBLOCK && | |
1454 | imap.br_startblock != DELAYSTARTBLOCK && | |
1455 | (create || !ISUNWRITTEN(&imap))) { | |
1456 | xfs_map_buffer(inode, bh_result, &imap, offset); | |
1457 | if (ISUNWRITTEN(&imap)) | |
1458 | set_buffer_unwritten(bh_result); | |
1459 | /* direct IO needs special help */ | |
1460 | if (create && direct) | |
1461 | xfs_map_direct(inode, bh_result, &imap, offset); | |
1462 | } | |
1463 | ||
1464 | /* | |
1465 | * If this is a realtime file, data may be on a different device. | |
1466 | * to that pointed to from the buffer_head b_bdev currently. | |
1467 | */ | |
1468 | bh_result->b_bdev = xfs_find_bdev_for_inode(inode); | |
1469 | ||
1470 | /* | |
1471 | * If we previously allocated a block out beyond eof and we are now | |
1472 | * coming back to use it then we will need to flag it as new even if it | |
1473 | * has a disk address. | |
1474 | * | |
1475 | * With sub-block writes into unwritten extents we also need to mark | |
1476 | * the buffer as new so that the unwritten parts of the buffer gets | |
1477 | * correctly zeroed. | |
1478 | */ | |
1479 | if (create && | |
1480 | ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) || | |
1481 | (offset >= i_size_read(inode)) || | |
1482 | (new || ISUNWRITTEN(&imap)))) | |
1483 | set_buffer_new(bh_result); | |
1484 | ||
1485 | if (imap.br_startblock == DELAYSTARTBLOCK) { | |
1486 | BUG_ON(direct); | |
1487 | if (create) { | |
1488 | set_buffer_uptodate(bh_result); | |
1489 | set_buffer_mapped(bh_result); | |
1490 | set_buffer_delay(bh_result); | |
1491 | } | |
1492 | } | |
1493 | ||
1494 | return 0; | |
1495 | ||
1496 | out_unlock: | |
1497 | xfs_iunlock(ip, lockmode); | |
1498 | return error; | |
1499 | } | |
1500 | ||
1501 | int | |
1502 | xfs_get_blocks( | |
1503 | struct inode *inode, | |
1504 | sector_t iblock, | |
1505 | struct buffer_head *bh_result, | |
1506 | int create) | |
1507 | { | |
1508 | return __xfs_get_blocks(inode, iblock, bh_result, create, false); | |
1509 | } | |
1510 | ||
1511 | int | |
1512 | xfs_get_blocks_direct( | |
1513 | struct inode *inode, | |
1514 | sector_t iblock, | |
1515 | struct buffer_head *bh_result, | |
1516 | int create) | |
1517 | { | |
1518 | return __xfs_get_blocks(inode, iblock, bh_result, create, true); | |
1519 | } | |
1520 | ||
1521 | static void | |
1522 | __xfs_end_io_direct_write( | |
1523 | struct inode *inode, | |
1524 | struct xfs_ioend *ioend, | |
1525 | loff_t offset, | |
1526 | ssize_t size) | |
1527 | { | |
1528 | struct xfs_mount *mp = XFS_I(inode)->i_mount; | |
1529 | ||
1530 | if (XFS_FORCED_SHUTDOWN(mp) || ioend->io_error) | |
1531 | goto out_end_io; | |
1532 | ||
1533 | /* | |
1534 | * dio completion end_io functions are only called on writes if more | |
1535 | * than 0 bytes was written. | |
1536 | */ | |
1537 | ASSERT(size > 0); | |
1538 | ||
1539 | /* | |
1540 | * The ioend only maps whole blocks, while the IO may be sector aligned. | |
1541 | * Hence the ioend offset/size may not match the IO offset/size exactly. | |
1542 | * Because we don't map overwrites within EOF into the ioend, the offset | |
1543 | * may not match, but only if the endio spans EOF. Either way, write | |
1544 | * the IO sizes into the ioend so that completion processing does the | |
1545 | * right thing. | |
1546 | */ | |
1547 | ASSERT(offset + size <= ioend->io_offset + ioend->io_size); | |
1548 | ioend->io_size = size; | |
1549 | ioend->io_offset = offset; | |
1550 | ||
1551 | /* | |
1552 | * The ioend tells us whether we are doing unwritten extent conversion | |
1553 | * or an append transaction that updates the on-disk file size. These | |
1554 | * cases are the only cases where we should *potentially* be needing | |
1555 | * to update the VFS inode size. | |
1556 | * | |
1557 | * We need to update the in-core inode size here so that we don't end up | |
1558 | * with the on-disk inode size being outside the in-core inode size. We | |
1559 | * have no other method of updating EOF for AIO, so always do it here | |
1560 | * if necessary. | |
1561 | * | |
1562 | * We need to lock the test/set EOF update as we can be racing with | |
1563 | * other IO completions here to update the EOF. Failing to serialise | |
1564 | * here can result in EOF moving backwards and Bad Things Happen when | |
1565 | * that occurs. | |
1566 | */ | |
1567 | spin_lock(&XFS_I(inode)->i_flags_lock); | |
1568 | if (offset + size > i_size_read(inode)) | |
1569 | i_size_write(inode, offset + size); | |
1570 | spin_unlock(&XFS_I(inode)->i_flags_lock); | |
1571 | ||
1572 | /* | |
1573 | * If we are doing an append IO that needs to update the EOF on disk, | |
1574 | * do the transaction reserve now so we can use common end io | |
1575 | * processing. Stashing the error (if there is one) in the ioend will | |
1576 | * result in the ioend processing passing on the error if it is | |
1577 | * possible as we can't return it from here. | |
1578 | */ | |
1579 | if (ioend->io_type == XFS_IO_OVERWRITE) | |
1580 | ioend->io_error = xfs_setfilesize_trans_alloc(ioend); | |
1581 | ||
1582 | out_end_io: | |
1583 | xfs_end_io(&ioend->io_work); | |
1584 | return; | |
1585 | } | |
1586 | ||
1587 | /* | |
1588 | * Complete a direct I/O write request. | |
1589 | * | |
1590 | * The ioend structure is passed from __xfs_get_blocks() to tell us what to do. | |
1591 | * If no ioend exists (i.e. @private == NULL) then the write IO is an overwrite | |
1592 | * wholly within the EOF and so there is nothing for us to do. Note that in this | |
1593 | * case the completion can be called in interrupt context, whereas if we have an | |
1594 | * ioend we will always be called in task context (i.e. from a workqueue). | |
1595 | */ | |
1596 | STATIC void | |
1597 | xfs_end_io_direct_write( | |
1598 | struct kiocb *iocb, | |
1599 | loff_t offset, | |
1600 | ssize_t size, | |
1601 | void *private) | |
1602 | { | |
1603 | struct inode *inode = file_inode(iocb->ki_filp); | |
1604 | struct xfs_ioend *ioend = private; | |
1605 | ||
1606 | trace_xfs_gbmap_direct_endio(XFS_I(inode), offset, size, | |
1607 | ioend ? ioend->io_type : 0, NULL); | |
1608 | ||
1609 | if (!ioend) { | |
1610 | ASSERT(offset + size <= i_size_read(inode)); | |
1611 | return; | |
1612 | } | |
1613 | ||
1614 | __xfs_end_io_direct_write(inode, ioend, offset, size); | |
1615 | } | |
1616 | ||
1617 | /* | |
1618 | * For DAX we need a mapping buffer callback for unwritten extent conversion | |
1619 | * when page faults allocate blocks and then zero them. Note that in this | |
1620 | * case the mapping indicated by the ioend may extend beyond EOF. We most | |
1621 | * definitely do not want to extend EOF here, so we trim back the ioend size to | |
1622 | * EOF. | |
1623 | */ | |
1624 | #ifdef CONFIG_FS_DAX | |
1625 | void | |
1626 | xfs_end_io_dax_write( | |
1627 | struct buffer_head *bh, | |
1628 | int uptodate) | |
1629 | { | |
1630 | struct xfs_ioend *ioend = bh->b_private; | |
1631 | struct inode *inode = ioend->io_inode; | |
1632 | ssize_t size = ioend->io_size; | |
1633 | ||
1634 | ASSERT(IS_DAX(ioend->io_inode)); | |
1635 | ||
1636 | /* if there was an error zeroing, then don't convert it */ | |
1637 | if (!uptodate) | |
1638 | ioend->io_error = -EIO; | |
1639 | ||
1640 | /* | |
1641 | * Trim update to EOF, so we don't extend EOF during unwritten extent | |
1642 | * conversion of partial EOF blocks. | |
1643 | */ | |
1644 | spin_lock(&XFS_I(inode)->i_flags_lock); | |
1645 | if (ioend->io_offset + size > i_size_read(inode)) | |
1646 | size = i_size_read(inode) - ioend->io_offset; | |
1647 | spin_unlock(&XFS_I(inode)->i_flags_lock); | |
1648 | ||
1649 | __xfs_end_io_direct_write(inode, ioend, ioend->io_offset, size); | |
1650 | ||
1651 | } | |
1652 | #else | |
1653 | void xfs_end_io_dax_write(struct buffer_head *bh, int uptodate) { } | |
1654 | #endif | |
1655 | ||
1656 | static inline ssize_t | |
1657 | xfs_vm_do_dio( | |
1658 | struct inode *inode, | |
1659 | struct kiocb *iocb, | |
1660 | struct iov_iter *iter, | |
1661 | loff_t offset, | |
1662 | void (*endio)(struct kiocb *iocb, | |
1663 | loff_t offset, | |
1664 | ssize_t size, | |
1665 | void *private), | |
1666 | int flags) | |
1667 | { | |
1668 | struct block_device *bdev; | |
1669 | ||
1670 | if (IS_DAX(inode)) | |
1671 | return dax_do_io(iocb, inode, iter, offset, | |
1672 | xfs_get_blocks_direct, endio, 0); | |
1673 | ||
1674 | bdev = xfs_find_bdev_for_inode(inode); | |
1675 | return __blockdev_direct_IO(iocb, inode, bdev, iter, offset, | |
1676 | xfs_get_blocks_direct, endio, NULL, flags); | |
1677 | } | |
1678 | ||
1679 | STATIC ssize_t | |
1680 | xfs_vm_direct_IO( | |
1681 | struct kiocb *iocb, | |
1682 | struct iov_iter *iter, | |
1683 | loff_t offset) | |
1684 | { | |
1685 | struct inode *inode = iocb->ki_filp->f_mapping->host; | |
1686 | ||
1687 | if (iov_iter_rw(iter) == WRITE) | |
1688 | return xfs_vm_do_dio(inode, iocb, iter, offset, | |
1689 | xfs_end_io_direct_write, DIO_ASYNC_EXTEND); | |
1690 | return xfs_vm_do_dio(inode, iocb, iter, offset, NULL, 0); | |
1691 | } | |
1692 | ||
1693 | /* | |
1694 | * Punch out the delalloc blocks we have already allocated. | |
1695 | * | |
1696 | * Don't bother with xfs_setattr given that nothing can have made it to disk yet | |
1697 | * as the page is still locked at this point. | |
1698 | */ | |
1699 | STATIC void | |
1700 | xfs_vm_kill_delalloc_range( | |
1701 | struct inode *inode, | |
1702 | loff_t start, | |
1703 | loff_t end) | |
1704 | { | |
1705 | struct xfs_inode *ip = XFS_I(inode); | |
1706 | xfs_fileoff_t start_fsb; | |
1707 | xfs_fileoff_t end_fsb; | |
1708 | int error; | |
1709 | ||
1710 | start_fsb = XFS_B_TO_FSB(ip->i_mount, start); | |
1711 | end_fsb = XFS_B_TO_FSB(ip->i_mount, end); | |
1712 | if (end_fsb <= start_fsb) | |
1713 | return; | |
1714 | ||
1715 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1716 | error = xfs_bmap_punch_delalloc_range(ip, start_fsb, | |
1717 | end_fsb - start_fsb); | |
1718 | if (error) { | |
1719 | /* something screwed, just bail */ | |
1720 | if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) { | |
1721 | xfs_alert(ip->i_mount, | |
1722 | "xfs_vm_write_failed: unable to clean up ino %lld", | |
1723 | ip->i_ino); | |
1724 | } | |
1725 | } | |
1726 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1727 | } | |
1728 | ||
1729 | STATIC void | |
1730 | xfs_vm_write_failed( | |
1731 | struct inode *inode, | |
1732 | struct page *page, | |
1733 | loff_t pos, | |
1734 | unsigned len) | |
1735 | { | |
1736 | loff_t block_offset; | |
1737 | loff_t block_start; | |
1738 | loff_t block_end; | |
1739 | loff_t from = pos & (PAGE_CACHE_SIZE - 1); | |
1740 | loff_t to = from + len; | |
1741 | struct buffer_head *bh, *head; | |
1742 | ||
1743 | /* | |
1744 | * The request pos offset might be 32 or 64 bit, this is all fine | |
1745 | * on 64-bit platform. However, for 64-bit pos request on 32-bit | |
1746 | * platform, the high 32-bit will be masked off if we evaluate the | |
1747 | * block_offset via (pos & PAGE_MASK) because the PAGE_MASK is | |
1748 | * 0xfffff000 as an unsigned long, hence the result is incorrect | |
1749 | * which could cause the following ASSERT failed in most cases. | |
1750 | * In order to avoid this, we can evaluate the block_offset of the | |
1751 | * start of the page by using shifts rather than masks the mismatch | |
1752 | * problem. | |
1753 | */ | |
1754 | block_offset = (pos >> PAGE_CACHE_SHIFT) << PAGE_CACHE_SHIFT; | |
1755 | ||
1756 | ASSERT(block_offset + from == pos); | |
1757 | ||
1758 | head = page_buffers(page); | |
1759 | block_start = 0; | |
1760 | for (bh = head; bh != head || !block_start; | |
1761 | bh = bh->b_this_page, block_start = block_end, | |
1762 | block_offset += bh->b_size) { | |
1763 | block_end = block_start + bh->b_size; | |
1764 | ||
1765 | /* skip buffers before the write */ | |
1766 | if (block_end <= from) | |
1767 | continue; | |
1768 | ||
1769 | /* if the buffer is after the write, we're done */ | |
1770 | if (block_start >= to) | |
1771 | break; | |
1772 | ||
1773 | if (!buffer_delay(bh)) | |
1774 | continue; | |
1775 | ||
1776 | if (!buffer_new(bh) && block_offset < i_size_read(inode)) | |
1777 | continue; | |
1778 | ||
1779 | xfs_vm_kill_delalloc_range(inode, block_offset, | |
1780 | block_offset + bh->b_size); | |
1781 | ||
1782 | /* | |
1783 | * This buffer does not contain data anymore. make sure anyone | |
1784 | * who finds it knows that for certain. | |
1785 | */ | |
1786 | clear_buffer_delay(bh); | |
1787 | clear_buffer_uptodate(bh); | |
1788 | clear_buffer_mapped(bh); | |
1789 | clear_buffer_new(bh); | |
1790 | clear_buffer_dirty(bh); | |
1791 | } | |
1792 | ||
1793 | } | |
1794 | ||
1795 | /* | |
1796 | * This used to call block_write_begin(), but it unlocks and releases the page | |
1797 | * on error, and we need that page to be able to punch stale delalloc blocks out | |
1798 | * on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at | |
1799 | * the appropriate point. | |
1800 | */ | |
1801 | STATIC int | |
1802 | xfs_vm_write_begin( | |
1803 | struct file *file, | |
1804 | struct address_space *mapping, | |
1805 | loff_t pos, | |
1806 | unsigned len, | |
1807 | unsigned flags, | |
1808 | struct page **pagep, | |
1809 | void **fsdata) | |
1810 | { | |
1811 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
1812 | struct page *page; | |
1813 | int status; | |
1814 | ||
1815 | ASSERT(len <= PAGE_CACHE_SIZE); | |
1816 | ||
1817 | page = grab_cache_page_write_begin(mapping, index, flags); | |
1818 | if (!page) | |
1819 | return -ENOMEM; | |
1820 | ||
1821 | status = __block_write_begin(page, pos, len, xfs_get_blocks); | |
1822 | if (unlikely(status)) { | |
1823 | struct inode *inode = mapping->host; | |
1824 | size_t isize = i_size_read(inode); | |
1825 | ||
1826 | xfs_vm_write_failed(inode, page, pos, len); | |
1827 | unlock_page(page); | |
1828 | ||
1829 | /* | |
1830 | * If the write is beyond EOF, we only want to kill blocks | |
1831 | * allocated in this write, not blocks that were previously | |
1832 | * written successfully. | |
1833 | */ | |
1834 | if (pos + len > isize) { | |
1835 | ssize_t start = max_t(ssize_t, pos, isize); | |
1836 | ||
1837 | truncate_pagecache_range(inode, start, pos + len); | |
1838 | } | |
1839 | ||
1840 | page_cache_release(page); | |
1841 | page = NULL; | |
1842 | } | |
1843 | ||
1844 | *pagep = page; | |
1845 | return status; | |
1846 | } | |
1847 | ||
1848 | /* | |
1849 | * On failure, we only need to kill delalloc blocks beyond EOF in the range of | |
1850 | * this specific write because they will never be written. Previous writes | |
1851 | * beyond EOF where block allocation succeeded do not need to be trashed, so | |
1852 | * only new blocks from this write should be trashed. For blocks within | |
1853 | * EOF, generic_write_end() zeros them so they are safe to leave alone and be | |
1854 | * written with all the other valid data. | |
1855 | */ | |
1856 | STATIC int | |
1857 | xfs_vm_write_end( | |
1858 | struct file *file, | |
1859 | struct address_space *mapping, | |
1860 | loff_t pos, | |
1861 | unsigned len, | |
1862 | unsigned copied, | |
1863 | struct page *page, | |
1864 | void *fsdata) | |
1865 | { | |
1866 | int ret; | |
1867 | ||
1868 | ASSERT(len <= PAGE_CACHE_SIZE); | |
1869 | ||
1870 | ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); | |
1871 | if (unlikely(ret < len)) { | |
1872 | struct inode *inode = mapping->host; | |
1873 | size_t isize = i_size_read(inode); | |
1874 | loff_t to = pos + len; | |
1875 | ||
1876 | if (to > isize) { | |
1877 | /* only kill blocks in this write beyond EOF */ | |
1878 | if (pos > isize) | |
1879 | isize = pos; | |
1880 | xfs_vm_kill_delalloc_range(inode, isize, to); | |
1881 | truncate_pagecache_range(inode, isize, to); | |
1882 | } | |
1883 | } | |
1884 | return ret; | |
1885 | } | |
1886 | ||
1887 | STATIC sector_t | |
1888 | xfs_vm_bmap( | |
1889 | struct address_space *mapping, | |
1890 | sector_t block) | |
1891 | { | |
1892 | struct inode *inode = (struct inode *)mapping->host; | |
1893 | struct xfs_inode *ip = XFS_I(inode); | |
1894 | ||
1895 | trace_xfs_vm_bmap(XFS_I(inode)); | |
1896 | xfs_ilock(ip, XFS_IOLOCK_SHARED); | |
1897 | filemap_write_and_wait(mapping); | |
1898 | xfs_iunlock(ip, XFS_IOLOCK_SHARED); | |
1899 | return generic_block_bmap(mapping, block, xfs_get_blocks); | |
1900 | } | |
1901 | ||
1902 | STATIC int | |
1903 | xfs_vm_readpage( | |
1904 | struct file *unused, | |
1905 | struct page *page) | |
1906 | { | |
1907 | return mpage_readpage(page, xfs_get_blocks); | |
1908 | } | |
1909 | ||
1910 | STATIC int | |
1911 | xfs_vm_readpages( | |
1912 | struct file *unused, | |
1913 | struct address_space *mapping, | |
1914 | struct list_head *pages, | |
1915 | unsigned nr_pages) | |
1916 | { | |
1917 | return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks); | |
1918 | } | |
1919 | ||
1920 | /* | |
1921 | * This is basically a copy of __set_page_dirty_buffers() with one | |
1922 | * small tweak: buffers beyond EOF do not get marked dirty. If we mark them | |
1923 | * dirty, we'll never be able to clean them because we don't write buffers | |
1924 | * beyond EOF, and that means we can't invalidate pages that span EOF | |
1925 | * that have been marked dirty. Further, the dirty state can leak into | |
1926 | * the file interior if the file is extended, resulting in all sorts of | |
1927 | * bad things happening as the state does not match the underlying data. | |
1928 | * | |
1929 | * XXX: this really indicates that bufferheads in XFS need to die. Warts like | |
1930 | * this only exist because of bufferheads and how the generic code manages them. | |
1931 | */ | |
1932 | STATIC int | |
1933 | xfs_vm_set_page_dirty( | |
1934 | struct page *page) | |
1935 | { | |
1936 | struct address_space *mapping = page->mapping; | |
1937 | struct inode *inode = mapping->host; | |
1938 | loff_t end_offset; | |
1939 | loff_t offset; | |
1940 | int newly_dirty; | |
1941 | struct mem_cgroup *memcg; | |
1942 | ||
1943 | if (unlikely(!mapping)) | |
1944 | return !TestSetPageDirty(page); | |
1945 | ||
1946 | end_offset = i_size_read(inode); | |
1947 | offset = page_offset(page); | |
1948 | ||
1949 | spin_lock(&mapping->private_lock); | |
1950 | if (page_has_buffers(page)) { | |
1951 | struct buffer_head *head = page_buffers(page); | |
1952 | struct buffer_head *bh = head; | |
1953 | ||
1954 | do { | |
1955 | if (offset < end_offset) | |
1956 | set_buffer_dirty(bh); | |
1957 | bh = bh->b_this_page; | |
1958 | offset += 1 << inode->i_blkbits; | |
1959 | } while (bh != head); | |
1960 | } | |
1961 | /* | |
1962 | * Use mem_group_begin_page_stat() to keep PageDirty synchronized with | |
1963 | * per-memcg dirty page counters. | |
1964 | */ | |
1965 | memcg = mem_cgroup_begin_page_stat(page); | |
1966 | newly_dirty = !TestSetPageDirty(page); | |
1967 | spin_unlock(&mapping->private_lock); | |
1968 | ||
1969 | if (newly_dirty) { | |
1970 | /* sigh - __set_page_dirty() is static, so copy it here, too */ | |
1971 | unsigned long flags; | |
1972 | ||
1973 | spin_lock_irqsave(&mapping->tree_lock, flags); | |
1974 | if (page->mapping) { /* Race with truncate? */ | |
1975 | WARN_ON_ONCE(!PageUptodate(page)); | |
1976 | account_page_dirtied(page, mapping, memcg); | |
1977 | radix_tree_tag_set(&mapping->page_tree, | |
1978 | page_index(page), PAGECACHE_TAG_DIRTY); | |
1979 | } | |
1980 | spin_unlock_irqrestore(&mapping->tree_lock, flags); | |
1981 | } | |
1982 | mem_cgroup_end_page_stat(memcg); | |
1983 | if (newly_dirty) | |
1984 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); | |
1985 | return newly_dirty; | |
1986 | } | |
1987 | ||
1988 | const struct address_space_operations xfs_address_space_operations = { | |
1989 | .readpage = xfs_vm_readpage, | |
1990 | .readpages = xfs_vm_readpages, | |
1991 | .writepage = xfs_vm_writepage, | |
1992 | .writepages = xfs_vm_writepages, | |
1993 | .set_page_dirty = xfs_vm_set_page_dirty, | |
1994 | .releasepage = xfs_vm_releasepage, | |
1995 | .invalidatepage = xfs_vm_invalidatepage, | |
1996 | .write_begin = xfs_vm_write_begin, | |
1997 | .write_end = xfs_vm_write_end, | |
1998 | .bmap = xfs_vm_bmap, | |
1999 | .direct_IO = xfs_vm_direct_IO, | |
2000 | .migratepage = buffer_migrate_page, | |
2001 | .is_partially_uptodate = block_is_partially_uptodate, | |
2002 | .error_remove_page = generic_error_remove_page, | |
2003 | }; |