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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/spinlock.h>
10#include <linux/completion.h>
11#include <linux/buffer_head.h>
12#include <linux/pagemap.h>
13#include <linux/pagevec.h>
14#include <linux/mpage.h>
15#include <linux/fs.h>
16#include <linux/writeback.h>
17#include <linux/swap.h>
18#include <linux/gfs2_ondisk.h>
19#include <linux/backing-dev.h>
20#include <linux/uio.h>
21#include <trace/events/writeback.h>
22#include <linux/sched/signal.h>
23
24#include "gfs2.h"
25#include "incore.h"
26#include "bmap.h"
27#include "glock.h"
28#include "inode.h"
29#include "log.h"
30#include "meta_io.h"
31#include "quota.h"
32#include "trans.h"
33#include "rgrp.h"
34#include "super.h"
35#include "util.h"
36#include "glops.h"
37#include "aops.h"
38
39
40void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
41 unsigned int from, unsigned int len)
42{
43 struct buffer_head *head = page_buffers(page);
44 unsigned int bsize = head->b_size;
45 struct buffer_head *bh;
46 unsigned int to = from + len;
47 unsigned int start, end;
48
49 for (bh = head, start = 0; bh != head || !start;
50 bh = bh->b_this_page, start = end) {
51 end = start + bsize;
52 if (end <= from)
53 continue;
54 if (start >= to)
55 break;
56 set_buffer_uptodate(bh);
57 gfs2_trans_add_data(ip->i_gl, bh);
58 }
59}
60
61/**
62 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
63 * @inode: The inode
64 * @lblock: The block number to look up
65 * @bh_result: The buffer head to return the result in
66 * @create: Non-zero if we may add block to the file
67 *
68 * Returns: errno
69 */
70
71static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
72 struct buffer_head *bh_result, int create)
73{
74 int error;
75
76 error = gfs2_block_map(inode, lblock, bh_result, 0);
77 if (error)
78 return error;
79 if (!buffer_mapped(bh_result))
80 return -ENODATA;
81 return 0;
82}
83
84/**
85 * gfs2_write_jdata_page - gfs2 jdata-specific version of block_write_full_page
86 * @page: The page to write
87 * @wbc: The writeback control
88 *
89 * This is the same as calling block_write_full_page, but it also
90 * writes pages outside of i_size
91 */
92static int gfs2_write_jdata_page(struct page *page,
93 struct writeback_control *wbc)
94{
95 struct inode * const inode = page->mapping->host;
96 loff_t i_size = i_size_read(inode);
97 const pgoff_t end_index = i_size >> PAGE_SHIFT;
98 unsigned offset;
99
100 /*
101 * The page straddles i_size. It must be zeroed out on each and every
102 * writepage invocation because it may be mmapped. "A file is mapped
103 * in multiples of the page size. For a file that is not a multiple of
104 * the page size, the remaining memory is zeroed when mapped, and
105 * writes to that region are not written out to the file."
106 */
107 offset = i_size & (PAGE_SIZE - 1);
108 if (page->index == end_index && offset)
109 zero_user_segment(page, offset, PAGE_SIZE);
110
111 return __block_write_full_page(inode, page, gfs2_get_block_noalloc, wbc,
112 end_buffer_async_write);
113}
114
115/**
116 * __gfs2_jdata_writepage - The core of jdata writepage
117 * @page: The page to write
118 * @wbc: The writeback control
119 *
120 * This is shared between writepage and writepages and implements the
121 * core of the writepage operation. If a transaction is required then
122 * PageChecked will have been set and the transaction will have
123 * already been started before this is called.
124 */
125
126static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
127{
128 struct inode *inode = page->mapping->host;
129 struct gfs2_inode *ip = GFS2_I(inode);
130 struct gfs2_sbd *sdp = GFS2_SB(inode);
131
132 if (PageChecked(page)) {
133 ClearPageChecked(page);
134 if (!page_has_buffers(page)) {
135 create_empty_buffers(page, inode->i_sb->s_blocksize,
136 BIT(BH_Dirty)|BIT(BH_Uptodate));
137 }
138 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
139 }
140 return gfs2_write_jdata_page(page, wbc);
141}
142
143/**
144 * gfs2_jdata_writepage - Write complete page
145 * @page: Page to write
146 * @wbc: The writeback control
147 *
148 * Returns: errno
149 *
150 */
151
152static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
153{
154 struct inode *inode = page->mapping->host;
155 struct gfs2_inode *ip = GFS2_I(inode);
156 struct gfs2_sbd *sdp = GFS2_SB(inode);
157
158 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
159 goto out;
160 if (PageChecked(page) || current->journal_info)
161 goto out_ignore;
162 return __gfs2_jdata_writepage(page, wbc);
163
164out_ignore:
165 redirty_page_for_writepage(wbc, page);
166out:
167 unlock_page(page);
168 return 0;
169}
170
171/**
172 * gfs2_writepages - Write a bunch of dirty pages back to disk
173 * @mapping: The mapping to write
174 * @wbc: Write-back control
175 *
176 * Used for both ordered and writeback modes.
177 */
178static int gfs2_writepages(struct address_space *mapping,
179 struct writeback_control *wbc)
180{
181 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
182 struct iomap_writepage_ctx wpc = { };
183 int ret;
184
185 /*
186 * Even if we didn't write any pages here, we might still be holding
187 * dirty pages in the ail. We forcibly flush the ail because we don't
188 * want balance_dirty_pages() to loop indefinitely trying to write out
189 * pages held in the ail that it can't find.
190 */
191 ret = iomap_writepages(mapping, wbc, &wpc, &gfs2_writeback_ops);
192 if (ret == 0)
193 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
194 return ret;
195}
196
197/**
198 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
199 * @mapping: The mapping
200 * @wbc: The writeback control
201 * @pvec: The vector of pages
202 * @nr_pages: The number of pages to write
203 * @done_index: Page index
204 *
205 * Returns: non-zero if loop should terminate, zero otherwise
206 */
207
208static int gfs2_write_jdata_pagevec(struct address_space *mapping,
209 struct writeback_control *wbc,
210 struct pagevec *pvec,
211 int nr_pages,
212 pgoff_t *done_index)
213{
214 struct inode *inode = mapping->host;
215 struct gfs2_sbd *sdp = GFS2_SB(inode);
216 unsigned nrblocks = nr_pages * (PAGE_SIZE >> inode->i_blkbits);
217 int i;
218 int ret;
219
220 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
221 if (ret < 0)
222 return ret;
223
224 for(i = 0; i < nr_pages; i++) {
225 struct page *page = pvec->pages[i];
226
227 *done_index = page->index;
228
229 lock_page(page);
230
231 if (unlikely(page->mapping != mapping)) {
232continue_unlock:
233 unlock_page(page);
234 continue;
235 }
236
237 if (!PageDirty(page)) {
238 /* someone wrote it for us */
239 goto continue_unlock;
240 }
241
242 if (PageWriteback(page)) {
243 if (wbc->sync_mode != WB_SYNC_NONE)
244 wait_on_page_writeback(page);
245 else
246 goto continue_unlock;
247 }
248
249 BUG_ON(PageWriteback(page));
250 if (!clear_page_dirty_for_io(page))
251 goto continue_unlock;
252
253 trace_wbc_writepage(wbc, inode_to_bdi(inode));
254
255 ret = __gfs2_jdata_writepage(page, wbc);
256 if (unlikely(ret)) {
257 if (ret == AOP_WRITEPAGE_ACTIVATE) {
258 unlock_page(page);
259 ret = 0;
260 } else {
261
262 /*
263 * done_index is set past this page,
264 * so media errors will not choke
265 * background writeout for the entire
266 * file. This has consequences for
267 * range_cyclic semantics (ie. it may
268 * not be suitable for data integrity
269 * writeout).
270 */
271 *done_index = page->index + 1;
272 ret = 1;
273 break;
274 }
275 }
276
277 /*
278 * We stop writing back only if we are not doing
279 * integrity sync. In case of integrity sync we have to
280 * keep going until we have written all the pages
281 * we tagged for writeback prior to entering this loop.
282 */
283 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
284 ret = 1;
285 break;
286 }
287
288 }
289 gfs2_trans_end(sdp);
290 return ret;
291}
292
293/**
294 * gfs2_write_cache_jdata - Like write_cache_pages but different
295 * @mapping: The mapping to write
296 * @wbc: The writeback control
297 *
298 * The reason that we use our own function here is that we need to
299 * start transactions before we grab page locks. This allows us
300 * to get the ordering right.
301 */
302
303static int gfs2_write_cache_jdata(struct address_space *mapping,
304 struct writeback_control *wbc)
305{
306 int ret = 0;
307 int done = 0;
308 struct pagevec pvec;
309 int nr_pages;
310 pgoff_t writeback_index;
311 pgoff_t index;
312 pgoff_t end;
313 pgoff_t done_index;
314 int cycled;
315 int range_whole = 0;
316 xa_mark_t tag;
317
318 pagevec_init(&pvec);
319 if (wbc->range_cyclic) {
320 writeback_index = mapping->writeback_index; /* prev offset */
321 index = writeback_index;
322 if (index == 0)
323 cycled = 1;
324 else
325 cycled = 0;
326 end = -1;
327 } else {
328 index = wbc->range_start >> PAGE_SHIFT;
329 end = wbc->range_end >> PAGE_SHIFT;
330 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
331 range_whole = 1;
332 cycled = 1; /* ignore range_cyclic tests */
333 }
334 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
335 tag = PAGECACHE_TAG_TOWRITE;
336 else
337 tag = PAGECACHE_TAG_DIRTY;
338
339retry:
340 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
341 tag_pages_for_writeback(mapping, index, end);
342 done_index = index;
343 while (!done && (index <= end)) {
344 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
345 tag);
346 if (nr_pages == 0)
347 break;
348
349 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
350 if (ret)
351 done = 1;
352 if (ret > 0)
353 ret = 0;
354 pagevec_release(&pvec);
355 cond_resched();
356 }
357
358 if (!cycled && !done) {
359 /*
360 * range_cyclic:
361 * We hit the last page and there is more work to be done: wrap
362 * back to the start of the file
363 */
364 cycled = 1;
365 index = 0;
366 end = writeback_index - 1;
367 goto retry;
368 }
369
370 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
371 mapping->writeback_index = done_index;
372
373 return ret;
374}
375
376
377/**
378 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
379 * @mapping: The mapping to write
380 * @wbc: The writeback control
381 *
382 */
383
384static int gfs2_jdata_writepages(struct address_space *mapping,
385 struct writeback_control *wbc)
386{
387 struct gfs2_inode *ip = GFS2_I(mapping->host);
388 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
389 int ret;
390
391 ret = gfs2_write_cache_jdata(mapping, wbc);
392 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
393 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
394 GFS2_LFC_JDATA_WPAGES);
395 ret = gfs2_write_cache_jdata(mapping, wbc);
396 }
397 return ret;
398}
399
400/**
401 * stuffed_readpage - Fill in a Linux page with stuffed file data
402 * @ip: the inode
403 * @page: the page
404 *
405 * Returns: errno
406 */
407static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
408{
409 struct buffer_head *dibh;
410 u64 dsize = i_size_read(&ip->i_inode);
411 void *kaddr;
412 int error;
413
414 /*
415 * Due to the order of unstuffing files and ->fault(), we can be
416 * asked for a zero page in the case of a stuffed file being extended,
417 * so we need to supply one here. It doesn't happen often.
418 */
419 if (unlikely(page->index)) {
420 zero_user(page, 0, PAGE_SIZE);
421 SetPageUptodate(page);
422 return 0;
423 }
424
425 error = gfs2_meta_inode_buffer(ip, &dibh);
426 if (error)
427 return error;
428
429 kaddr = kmap_atomic(page);
430 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
431 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
432 kunmap_atomic(kaddr);
433 flush_dcache_page(page);
434 brelse(dibh);
435 SetPageUptodate(page);
436
437 return 0;
438}
439
440/**
441 * gfs2_read_folio - read a folio from a file
442 * @file: The file to read
443 * @folio: The folio in the file
444 */
445static int gfs2_read_folio(struct file *file, struct folio *folio)
446{
447 struct inode *inode = folio->mapping->host;
448 struct gfs2_inode *ip = GFS2_I(inode);
449 struct gfs2_sbd *sdp = GFS2_SB(inode);
450 int error;
451
452 if (!gfs2_is_jdata(ip) ||
453 (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
454 error = iomap_read_folio(folio, &gfs2_iomap_ops);
455 } else if (gfs2_is_stuffed(ip)) {
456 error = stuffed_readpage(ip, &folio->page);
457 folio_unlock(folio);
458 } else {
459 error = mpage_read_folio(folio, gfs2_block_map);
460 }
461
462 if (unlikely(gfs2_withdrawn(sdp)))
463 return -EIO;
464
465 return error;
466}
467
468/**
469 * gfs2_internal_read - read an internal file
470 * @ip: The gfs2 inode
471 * @buf: The buffer to fill
472 * @pos: The file position
473 * @size: The amount to read
474 *
475 */
476
477int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
478 unsigned size)
479{
480 struct address_space *mapping = ip->i_inode.i_mapping;
481 unsigned long index = *pos >> PAGE_SHIFT;
482 unsigned offset = *pos & (PAGE_SIZE - 1);
483 unsigned copied = 0;
484 unsigned amt;
485 struct page *page;
486 void *p;
487
488 do {
489 amt = size - copied;
490 if (offset + size > PAGE_SIZE)
491 amt = PAGE_SIZE - offset;
492 page = read_cache_page(mapping, index, gfs2_read_folio, NULL);
493 if (IS_ERR(page))
494 return PTR_ERR(page);
495 p = kmap_atomic(page);
496 memcpy(buf + copied, p + offset, amt);
497 kunmap_atomic(p);
498 put_page(page);
499 copied += amt;
500 index++;
501 offset = 0;
502 } while(copied < size);
503 (*pos) += size;
504 return size;
505}
506
507/**
508 * gfs2_readahead - Read a bunch of pages at once
509 * @rac: Read-ahead control structure
510 *
511 * Some notes:
512 * 1. This is only for readahead, so we can simply ignore any things
513 * which are slightly inconvenient (such as locking conflicts between
514 * the page lock and the glock) and return having done no I/O. Its
515 * obviously not something we'd want to do on too regular a basis.
516 * Any I/O we ignore at this time will be done via readpage later.
517 * 2. We don't handle stuffed files here we let readpage do the honours.
518 * 3. mpage_readahead() does most of the heavy lifting in the common case.
519 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
520 */
521
522static void gfs2_readahead(struct readahead_control *rac)
523{
524 struct inode *inode = rac->mapping->host;
525 struct gfs2_inode *ip = GFS2_I(inode);
526
527 if (gfs2_is_stuffed(ip))
528 ;
529 else if (gfs2_is_jdata(ip))
530 mpage_readahead(rac, gfs2_block_map);
531 else
532 iomap_readahead(rac, &gfs2_iomap_ops);
533}
534
535/**
536 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
537 * @inode: the rindex inode
538 */
539void adjust_fs_space(struct inode *inode)
540{
541 struct gfs2_sbd *sdp = GFS2_SB(inode);
542 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
543 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
544 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
545 struct buffer_head *m_bh;
546 u64 fs_total, new_free;
547
548 if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
549 return;
550
551 /* Total up the file system space, according to the latest rindex. */
552 fs_total = gfs2_ri_total(sdp);
553 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
554 goto out;
555
556 spin_lock(&sdp->sd_statfs_spin);
557 gfs2_statfs_change_in(m_sc, m_bh->b_data +
558 sizeof(struct gfs2_dinode));
559 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
560 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
561 else
562 new_free = 0;
563 spin_unlock(&sdp->sd_statfs_spin);
564 fs_warn(sdp, "File system extended by %llu blocks.\n",
565 (unsigned long long)new_free);
566 gfs2_statfs_change(sdp, new_free, new_free, 0);
567
568 update_statfs(sdp, m_bh);
569 brelse(m_bh);
570out:
571 sdp->sd_rindex_uptodate = 0;
572 gfs2_trans_end(sdp);
573}
574
575static bool jdata_dirty_folio(struct address_space *mapping,
576 struct folio *folio)
577{
578 if (current->journal_info)
579 folio_set_checked(folio);
580 return block_dirty_folio(mapping, folio);
581}
582
583/**
584 * gfs2_bmap - Block map function
585 * @mapping: Address space info
586 * @lblock: The block to map
587 *
588 * Returns: The disk address for the block or 0 on hole or error
589 */
590
591static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
592{
593 struct gfs2_inode *ip = GFS2_I(mapping->host);
594 struct gfs2_holder i_gh;
595 sector_t dblock = 0;
596 int error;
597
598 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
599 if (error)
600 return 0;
601
602 if (!gfs2_is_stuffed(ip))
603 dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
604
605 gfs2_glock_dq_uninit(&i_gh);
606
607 return dblock;
608}
609
610static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
611{
612 struct gfs2_bufdata *bd;
613
614 lock_buffer(bh);
615 gfs2_log_lock(sdp);
616 clear_buffer_dirty(bh);
617 bd = bh->b_private;
618 if (bd) {
619 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
620 list_del_init(&bd->bd_list);
621 else {
622 spin_lock(&sdp->sd_ail_lock);
623 gfs2_remove_from_journal(bh, REMOVE_JDATA);
624 spin_unlock(&sdp->sd_ail_lock);
625 }
626 }
627 bh->b_bdev = NULL;
628 clear_buffer_mapped(bh);
629 clear_buffer_req(bh);
630 clear_buffer_new(bh);
631 gfs2_log_unlock(sdp);
632 unlock_buffer(bh);
633}
634
635static void gfs2_invalidate_folio(struct folio *folio, size_t offset,
636 size_t length)
637{
638 struct gfs2_sbd *sdp = GFS2_SB(folio->mapping->host);
639 size_t stop = offset + length;
640 int partial_page = (offset || length < folio_size(folio));
641 struct buffer_head *bh, *head;
642 unsigned long pos = 0;
643
644 BUG_ON(!folio_test_locked(folio));
645 if (!partial_page)
646 folio_clear_checked(folio);
647 head = folio_buffers(folio);
648 if (!head)
649 goto out;
650
651 bh = head;
652 do {
653 if (pos + bh->b_size > stop)
654 return;
655
656 if (offset <= pos)
657 gfs2_discard(sdp, bh);
658 pos += bh->b_size;
659 bh = bh->b_this_page;
660 } while (bh != head);
661out:
662 if (!partial_page)
663 filemap_release_folio(folio, 0);
664}
665
666/**
667 * gfs2_release_folio - free the metadata associated with a folio
668 * @folio: the folio that's being released
669 * @gfp_mask: passed from Linux VFS, ignored by us
670 *
671 * Calls try_to_free_buffers() to free the buffers and put the folio if the
672 * buffers can be released.
673 *
674 * Returns: true if the folio was put or else false
675 */
676
677bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask)
678{
679 struct address_space *mapping = folio->mapping;
680 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
681 struct buffer_head *bh, *head;
682 struct gfs2_bufdata *bd;
683
684 head = folio_buffers(folio);
685 if (!head)
686 return false;
687
688 /*
689 * mm accommodates an old ext3 case where clean folios might
690 * not have had the dirty bit cleared. Thus, it can send actual
691 * dirty folios to ->release_folio() via shrink_active_list().
692 *
693 * As a workaround, we skip folios that contain dirty buffers
694 * below. Once ->release_folio isn't called on dirty folios
695 * anymore, we can warn on dirty buffers like we used to here
696 * again.
697 */
698
699 gfs2_log_lock(sdp);
700 bh = head;
701 do {
702 if (atomic_read(&bh->b_count))
703 goto cannot_release;
704 bd = bh->b_private;
705 if (bd && bd->bd_tr)
706 goto cannot_release;
707 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
708 goto cannot_release;
709 bh = bh->b_this_page;
710 } while (bh != head);
711
712 bh = head;
713 do {
714 bd = bh->b_private;
715 if (bd) {
716 gfs2_assert_warn(sdp, bd->bd_bh == bh);
717 bd->bd_bh = NULL;
718 bh->b_private = NULL;
719 /*
720 * The bd may still be queued as a revoke, in which
721 * case we must not dequeue nor free it.
722 */
723 if (!bd->bd_blkno && !list_empty(&bd->bd_list))
724 list_del_init(&bd->bd_list);
725 if (list_empty(&bd->bd_list))
726 kmem_cache_free(gfs2_bufdata_cachep, bd);
727 }
728
729 bh = bh->b_this_page;
730 } while (bh != head);
731 gfs2_log_unlock(sdp);
732
733 return try_to_free_buffers(folio);
734
735cannot_release:
736 gfs2_log_unlock(sdp);
737 return false;
738}
739
740static const struct address_space_operations gfs2_aops = {
741 .writepages = gfs2_writepages,
742 .read_folio = gfs2_read_folio,
743 .readahead = gfs2_readahead,
744 .dirty_folio = filemap_dirty_folio,
745 .release_folio = iomap_release_folio,
746 .invalidate_folio = iomap_invalidate_folio,
747 .bmap = gfs2_bmap,
748 .direct_IO = noop_direct_IO,
749 .migrate_folio = filemap_migrate_folio,
750 .is_partially_uptodate = iomap_is_partially_uptodate,
751 .error_remove_page = generic_error_remove_page,
752};
753
754static const struct address_space_operations gfs2_jdata_aops = {
755 .writepage = gfs2_jdata_writepage,
756 .writepages = gfs2_jdata_writepages,
757 .read_folio = gfs2_read_folio,
758 .readahead = gfs2_readahead,
759 .dirty_folio = jdata_dirty_folio,
760 .bmap = gfs2_bmap,
761 .invalidate_folio = gfs2_invalidate_folio,
762 .release_folio = gfs2_release_folio,
763 .is_partially_uptodate = block_is_partially_uptodate,
764 .error_remove_page = generic_error_remove_page,
765};
766
767void gfs2_set_aops(struct inode *inode)
768{
769 if (gfs2_is_jdata(GFS2_I(inode)))
770 inode->i_mapping->a_ops = &gfs2_jdata_aops;
771 else
772 inode->i_mapping->a_ops = &gfs2_aops;
773}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
4 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/spinlock.h>
10#include <linux/completion.h>
11#include <linux/buffer_head.h>
12#include <linux/pagemap.h>
13#include <linux/pagevec.h>
14#include <linux/mpage.h>
15#include <linux/fs.h>
16#include <linux/writeback.h>
17#include <linux/swap.h>
18#include <linux/gfs2_ondisk.h>
19#include <linux/backing-dev.h>
20#include <linux/uio.h>
21#include <trace/events/writeback.h>
22#include <linux/sched/signal.h>
23
24#include "gfs2.h"
25#include "incore.h"
26#include "bmap.h"
27#include "glock.h"
28#include "inode.h"
29#include "log.h"
30#include "meta_io.h"
31#include "quota.h"
32#include "trans.h"
33#include "rgrp.h"
34#include "super.h"
35#include "util.h"
36#include "glops.h"
37#include "aops.h"
38
39
40void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
41 unsigned int from, unsigned int len)
42{
43 struct buffer_head *head = page_buffers(page);
44 unsigned int bsize = head->b_size;
45 struct buffer_head *bh;
46 unsigned int to = from + len;
47 unsigned int start, end;
48
49 for (bh = head, start = 0; bh != head || !start;
50 bh = bh->b_this_page, start = end) {
51 end = start + bsize;
52 if (end <= from)
53 continue;
54 if (start >= to)
55 break;
56 set_buffer_uptodate(bh);
57 gfs2_trans_add_data(ip->i_gl, bh);
58 }
59}
60
61/**
62 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
63 * @inode: The inode
64 * @lblock: The block number to look up
65 * @bh_result: The buffer head to return the result in
66 * @create: Non-zero if we may add block to the file
67 *
68 * Returns: errno
69 */
70
71static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
72 struct buffer_head *bh_result, int create)
73{
74 int error;
75
76 error = gfs2_block_map(inode, lblock, bh_result, 0);
77 if (error)
78 return error;
79 if (!buffer_mapped(bh_result))
80 return -EIO;
81 return 0;
82}
83
84/**
85 * gfs2_writepage - Write page for writeback mappings
86 * @page: The page
87 * @wbc: The writeback control
88 */
89static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
90{
91 struct inode *inode = page->mapping->host;
92 struct gfs2_inode *ip = GFS2_I(inode);
93 struct gfs2_sbd *sdp = GFS2_SB(inode);
94 loff_t i_size = i_size_read(inode);
95 pgoff_t end_index = i_size >> PAGE_SHIFT;
96 unsigned offset;
97
98 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
99 goto out;
100 if (current->journal_info)
101 goto redirty;
102 /* Is the page fully outside i_size? (truncate in progress) */
103 offset = i_size & (PAGE_SIZE-1);
104 if (page->index > end_index || (page->index == end_index && !offset)) {
105 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
106 goto out;
107 }
108
109 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
110
111redirty:
112 redirty_page_for_writepage(wbc, page);
113out:
114 unlock_page(page);
115 return 0;
116}
117
118/* This is the same as calling block_write_full_page, but it also
119 * writes pages outside of i_size
120 */
121static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
122 struct writeback_control *wbc)
123{
124 struct inode * const inode = page->mapping->host;
125 loff_t i_size = i_size_read(inode);
126 const pgoff_t end_index = i_size >> PAGE_SHIFT;
127 unsigned offset;
128
129 /*
130 * The page straddles i_size. It must be zeroed out on each and every
131 * writepage invocation because it may be mmapped. "A file is mapped
132 * in multiples of the page size. For a file that is not a multiple of
133 * the page size, the remaining memory is zeroed when mapped, and
134 * writes to that region are not written out to the file."
135 */
136 offset = i_size & (PAGE_SIZE-1);
137 if (page->index == end_index && offset)
138 zero_user_segment(page, offset, PAGE_SIZE);
139
140 return __block_write_full_page(inode, page, get_block, wbc,
141 end_buffer_async_write);
142}
143
144/**
145 * __gfs2_jdata_writepage - The core of jdata writepage
146 * @page: The page to write
147 * @wbc: The writeback control
148 *
149 * This is shared between writepage and writepages and implements the
150 * core of the writepage operation. If a transaction is required then
151 * PageChecked will have been set and the transaction will have
152 * already been started before this is called.
153 */
154
155static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
156{
157 struct inode *inode = page->mapping->host;
158 struct gfs2_inode *ip = GFS2_I(inode);
159 struct gfs2_sbd *sdp = GFS2_SB(inode);
160
161 if (PageChecked(page)) {
162 ClearPageChecked(page);
163 if (!page_has_buffers(page)) {
164 create_empty_buffers(page, inode->i_sb->s_blocksize,
165 BIT(BH_Dirty)|BIT(BH_Uptodate));
166 }
167 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
168 }
169 return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
170}
171
172/**
173 * gfs2_jdata_writepage - Write complete page
174 * @page: Page to write
175 * @wbc: The writeback control
176 *
177 * Returns: errno
178 *
179 */
180
181static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
182{
183 struct inode *inode = page->mapping->host;
184 struct gfs2_inode *ip = GFS2_I(inode);
185 struct gfs2_sbd *sdp = GFS2_SB(inode);
186 int ret;
187
188 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
189 goto out;
190 if (PageChecked(page) || current->journal_info)
191 goto out_ignore;
192 ret = __gfs2_jdata_writepage(page, wbc);
193 return ret;
194
195out_ignore:
196 redirty_page_for_writepage(wbc, page);
197out:
198 unlock_page(page);
199 return 0;
200}
201
202/**
203 * gfs2_writepages - Write a bunch of dirty pages back to disk
204 * @mapping: The mapping to write
205 * @wbc: Write-back control
206 *
207 * Used for both ordered and writeback modes.
208 */
209static int gfs2_writepages(struct address_space *mapping,
210 struct writeback_control *wbc)
211{
212 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
213 int ret = mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
214
215 /*
216 * Even if we didn't write any pages here, we might still be holding
217 * dirty pages in the ail. We forcibly flush the ail because we don't
218 * want balance_dirty_pages() to loop indefinitely trying to write out
219 * pages held in the ail that it can't find.
220 */
221 if (ret == 0)
222 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
223
224 return ret;
225}
226
227/**
228 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
229 * @mapping: The mapping
230 * @wbc: The writeback control
231 * @pvec: The vector of pages
232 * @nr_pages: The number of pages to write
233 * @done_index: Page index
234 *
235 * Returns: non-zero if loop should terminate, zero otherwise
236 */
237
238static int gfs2_write_jdata_pagevec(struct address_space *mapping,
239 struct writeback_control *wbc,
240 struct pagevec *pvec,
241 int nr_pages,
242 pgoff_t *done_index)
243{
244 struct inode *inode = mapping->host;
245 struct gfs2_sbd *sdp = GFS2_SB(inode);
246 unsigned nrblocks = nr_pages * (PAGE_SIZE >> inode->i_blkbits);
247 int i;
248 int ret;
249
250 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
251 if (ret < 0)
252 return ret;
253
254 for(i = 0; i < nr_pages; i++) {
255 struct page *page = pvec->pages[i];
256
257 *done_index = page->index;
258
259 lock_page(page);
260
261 if (unlikely(page->mapping != mapping)) {
262continue_unlock:
263 unlock_page(page);
264 continue;
265 }
266
267 if (!PageDirty(page)) {
268 /* someone wrote it for us */
269 goto continue_unlock;
270 }
271
272 if (PageWriteback(page)) {
273 if (wbc->sync_mode != WB_SYNC_NONE)
274 wait_on_page_writeback(page);
275 else
276 goto continue_unlock;
277 }
278
279 BUG_ON(PageWriteback(page));
280 if (!clear_page_dirty_for_io(page))
281 goto continue_unlock;
282
283 trace_wbc_writepage(wbc, inode_to_bdi(inode));
284
285 ret = __gfs2_jdata_writepage(page, wbc);
286 if (unlikely(ret)) {
287 if (ret == AOP_WRITEPAGE_ACTIVATE) {
288 unlock_page(page);
289 ret = 0;
290 } else {
291
292 /*
293 * done_index is set past this page,
294 * so media errors will not choke
295 * background writeout for the entire
296 * file. This has consequences for
297 * range_cyclic semantics (ie. it may
298 * not be suitable for data integrity
299 * writeout).
300 */
301 *done_index = page->index + 1;
302 ret = 1;
303 break;
304 }
305 }
306
307 /*
308 * We stop writing back only if we are not doing
309 * integrity sync. In case of integrity sync we have to
310 * keep going until we have written all the pages
311 * we tagged for writeback prior to entering this loop.
312 */
313 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
314 ret = 1;
315 break;
316 }
317
318 }
319 gfs2_trans_end(sdp);
320 return ret;
321}
322
323/**
324 * gfs2_write_cache_jdata - Like write_cache_pages but different
325 * @mapping: The mapping to write
326 * @wbc: The writeback control
327 *
328 * The reason that we use our own function here is that we need to
329 * start transactions before we grab page locks. This allows us
330 * to get the ordering right.
331 */
332
333static int gfs2_write_cache_jdata(struct address_space *mapping,
334 struct writeback_control *wbc)
335{
336 int ret = 0;
337 int done = 0;
338 struct pagevec pvec;
339 int nr_pages;
340 pgoff_t uninitialized_var(writeback_index);
341 pgoff_t index;
342 pgoff_t end;
343 pgoff_t done_index;
344 int cycled;
345 int range_whole = 0;
346 xa_mark_t tag;
347
348 pagevec_init(&pvec);
349 if (wbc->range_cyclic) {
350 writeback_index = mapping->writeback_index; /* prev offset */
351 index = writeback_index;
352 if (index == 0)
353 cycled = 1;
354 else
355 cycled = 0;
356 end = -1;
357 } else {
358 index = wbc->range_start >> PAGE_SHIFT;
359 end = wbc->range_end >> PAGE_SHIFT;
360 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
361 range_whole = 1;
362 cycled = 1; /* ignore range_cyclic tests */
363 }
364 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
365 tag = PAGECACHE_TAG_TOWRITE;
366 else
367 tag = PAGECACHE_TAG_DIRTY;
368
369retry:
370 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
371 tag_pages_for_writeback(mapping, index, end);
372 done_index = index;
373 while (!done && (index <= end)) {
374 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
375 tag);
376 if (nr_pages == 0)
377 break;
378
379 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
380 if (ret)
381 done = 1;
382 if (ret > 0)
383 ret = 0;
384 pagevec_release(&pvec);
385 cond_resched();
386 }
387
388 if (!cycled && !done) {
389 /*
390 * range_cyclic:
391 * We hit the last page and there is more work to be done: wrap
392 * back to the start of the file
393 */
394 cycled = 1;
395 index = 0;
396 end = writeback_index - 1;
397 goto retry;
398 }
399
400 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
401 mapping->writeback_index = done_index;
402
403 return ret;
404}
405
406
407/**
408 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
409 * @mapping: The mapping to write
410 * @wbc: The writeback control
411 *
412 */
413
414static int gfs2_jdata_writepages(struct address_space *mapping,
415 struct writeback_control *wbc)
416{
417 struct gfs2_inode *ip = GFS2_I(mapping->host);
418 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
419 int ret;
420
421 ret = gfs2_write_cache_jdata(mapping, wbc);
422 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
423 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
424 GFS2_LFC_JDATA_WPAGES);
425 ret = gfs2_write_cache_jdata(mapping, wbc);
426 }
427 return ret;
428}
429
430/**
431 * stuffed_readpage - Fill in a Linux page with stuffed file data
432 * @ip: the inode
433 * @page: the page
434 *
435 * Returns: errno
436 */
437static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
438{
439 struct buffer_head *dibh;
440 u64 dsize = i_size_read(&ip->i_inode);
441 void *kaddr;
442 int error;
443
444 /*
445 * Due to the order of unstuffing files and ->fault(), we can be
446 * asked for a zero page in the case of a stuffed file being extended,
447 * so we need to supply one here. It doesn't happen often.
448 */
449 if (unlikely(page->index)) {
450 zero_user(page, 0, PAGE_SIZE);
451 SetPageUptodate(page);
452 return 0;
453 }
454
455 error = gfs2_meta_inode_buffer(ip, &dibh);
456 if (error)
457 return error;
458
459 kaddr = kmap_atomic(page);
460 if (dsize > gfs2_max_stuffed_size(ip))
461 dsize = gfs2_max_stuffed_size(ip);
462 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
463 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
464 kunmap_atomic(kaddr);
465 flush_dcache_page(page);
466 brelse(dibh);
467 SetPageUptodate(page);
468
469 return 0;
470}
471
472
473/**
474 * __gfs2_readpage - readpage
475 * @file: The file to read a page for
476 * @page: The page to read
477 *
478 * This is the core of gfs2's readpage. It's used by the internal file
479 * reading code as in that case we already hold the glock. Also it's
480 * called by gfs2_readpage() once the required lock has been granted.
481 */
482
483static int __gfs2_readpage(void *file, struct page *page)
484{
485 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
486 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
487
488 int error;
489
490 if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
491 !page_has_buffers(page)) {
492 error = iomap_readpage(page, &gfs2_iomap_ops);
493 } else if (gfs2_is_stuffed(ip)) {
494 error = stuffed_readpage(ip, page);
495 unlock_page(page);
496 } else {
497 error = mpage_readpage(page, gfs2_block_map);
498 }
499
500 if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags)))
501 return -EIO;
502
503 return error;
504}
505
506/**
507 * gfs2_readpage - read a page of a file
508 * @file: The file to read
509 * @page: The page of the file
510 *
511 * This deals with the locking required. We have to unlock and
512 * relock the page in order to get the locking in the right
513 * order.
514 */
515
516static int gfs2_readpage(struct file *file, struct page *page)
517{
518 struct address_space *mapping = page->mapping;
519 struct gfs2_inode *ip = GFS2_I(mapping->host);
520 struct gfs2_holder gh;
521 int error;
522
523 unlock_page(page);
524 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
525 error = gfs2_glock_nq(&gh);
526 if (unlikely(error))
527 goto out;
528 error = AOP_TRUNCATED_PAGE;
529 lock_page(page);
530 if (page->mapping == mapping && !PageUptodate(page))
531 error = __gfs2_readpage(file, page);
532 else
533 unlock_page(page);
534 gfs2_glock_dq(&gh);
535out:
536 gfs2_holder_uninit(&gh);
537 if (error && error != AOP_TRUNCATED_PAGE)
538 lock_page(page);
539 return error;
540}
541
542/**
543 * gfs2_internal_read - read an internal file
544 * @ip: The gfs2 inode
545 * @buf: The buffer to fill
546 * @pos: The file position
547 * @size: The amount to read
548 *
549 */
550
551int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
552 unsigned size)
553{
554 struct address_space *mapping = ip->i_inode.i_mapping;
555 unsigned long index = *pos >> PAGE_SHIFT;
556 unsigned offset = *pos & (PAGE_SIZE - 1);
557 unsigned copied = 0;
558 unsigned amt;
559 struct page *page;
560 void *p;
561
562 do {
563 amt = size - copied;
564 if (offset + size > PAGE_SIZE)
565 amt = PAGE_SIZE - offset;
566 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
567 if (IS_ERR(page))
568 return PTR_ERR(page);
569 p = kmap_atomic(page);
570 memcpy(buf + copied, p + offset, amt);
571 kunmap_atomic(p);
572 put_page(page);
573 copied += amt;
574 index++;
575 offset = 0;
576 } while(copied < size);
577 (*pos) += size;
578 return size;
579}
580
581/**
582 * gfs2_readpages - Read a bunch of pages at once
583 * @file: The file to read from
584 * @mapping: Address space info
585 * @pages: List of pages to read
586 * @nr_pages: Number of pages to read
587 *
588 * Some notes:
589 * 1. This is only for readahead, so we can simply ignore any things
590 * which are slightly inconvenient (such as locking conflicts between
591 * the page lock and the glock) and return having done no I/O. Its
592 * obviously not something we'd want to do on too regular a basis.
593 * Any I/O we ignore at this time will be done via readpage later.
594 * 2. We don't handle stuffed files here we let readpage do the honours.
595 * 3. mpage_readpages() does most of the heavy lifting in the common case.
596 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
597 */
598
599static int gfs2_readpages(struct file *file, struct address_space *mapping,
600 struct list_head *pages, unsigned nr_pages)
601{
602 struct inode *inode = mapping->host;
603 struct gfs2_inode *ip = GFS2_I(inode);
604 struct gfs2_sbd *sdp = GFS2_SB(inode);
605 struct gfs2_holder gh;
606 int ret;
607
608 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
609 ret = gfs2_glock_nq(&gh);
610 if (unlikely(ret))
611 goto out_uninit;
612 if (!gfs2_is_stuffed(ip))
613 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
614 gfs2_glock_dq(&gh);
615out_uninit:
616 gfs2_holder_uninit(&gh);
617 if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags)))
618 ret = -EIO;
619 return ret;
620}
621
622/**
623 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
624 * @inode: the rindex inode
625 */
626void adjust_fs_space(struct inode *inode)
627{
628 struct gfs2_sbd *sdp = GFS2_SB(inode);
629 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
630 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
631 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
632 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
633 struct buffer_head *m_bh, *l_bh;
634 u64 fs_total, new_free;
635
636 if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
637 return;
638
639 /* Total up the file system space, according to the latest rindex. */
640 fs_total = gfs2_ri_total(sdp);
641 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
642 goto out;
643
644 spin_lock(&sdp->sd_statfs_spin);
645 gfs2_statfs_change_in(m_sc, m_bh->b_data +
646 sizeof(struct gfs2_dinode));
647 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
648 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
649 else
650 new_free = 0;
651 spin_unlock(&sdp->sd_statfs_spin);
652 fs_warn(sdp, "File system extended by %llu blocks.\n",
653 (unsigned long long)new_free);
654 gfs2_statfs_change(sdp, new_free, new_free, 0);
655
656 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
657 goto out2;
658 update_statfs(sdp, m_bh, l_bh);
659 brelse(l_bh);
660out2:
661 brelse(m_bh);
662out:
663 sdp->sd_rindex_uptodate = 0;
664 gfs2_trans_end(sdp);
665}
666
667/**
668 * jdata_set_page_dirty - Page dirtying function
669 * @page: The page to dirty
670 *
671 * Returns: 1 if it dirtyed the page, or 0 otherwise
672 */
673
674static int jdata_set_page_dirty(struct page *page)
675{
676 SetPageChecked(page);
677 return __set_page_dirty_buffers(page);
678}
679
680/**
681 * gfs2_bmap - Block map function
682 * @mapping: Address space info
683 * @lblock: The block to map
684 *
685 * Returns: The disk address for the block or 0 on hole or error
686 */
687
688static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
689{
690 struct gfs2_inode *ip = GFS2_I(mapping->host);
691 struct gfs2_holder i_gh;
692 sector_t dblock = 0;
693 int error;
694
695 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
696 if (error)
697 return 0;
698
699 if (!gfs2_is_stuffed(ip))
700 dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
701
702 gfs2_glock_dq_uninit(&i_gh);
703
704 return dblock;
705}
706
707static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
708{
709 struct gfs2_bufdata *bd;
710
711 lock_buffer(bh);
712 gfs2_log_lock(sdp);
713 clear_buffer_dirty(bh);
714 bd = bh->b_private;
715 if (bd) {
716 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
717 list_del_init(&bd->bd_list);
718 else
719 gfs2_remove_from_journal(bh, REMOVE_JDATA);
720 }
721 bh->b_bdev = NULL;
722 clear_buffer_mapped(bh);
723 clear_buffer_req(bh);
724 clear_buffer_new(bh);
725 gfs2_log_unlock(sdp);
726 unlock_buffer(bh);
727}
728
729static void gfs2_invalidatepage(struct page *page, unsigned int offset,
730 unsigned int length)
731{
732 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
733 unsigned int stop = offset + length;
734 int partial_page = (offset || length < PAGE_SIZE);
735 struct buffer_head *bh, *head;
736 unsigned long pos = 0;
737
738 BUG_ON(!PageLocked(page));
739 if (!partial_page)
740 ClearPageChecked(page);
741 if (!page_has_buffers(page))
742 goto out;
743
744 bh = head = page_buffers(page);
745 do {
746 if (pos + bh->b_size > stop)
747 return;
748
749 if (offset <= pos)
750 gfs2_discard(sdp, bh);
751 pos += bh->b_size;
752 bh = bh->b_this_page;
753 } while (bh != head);
754out:
755 if (!partial_page)
756 try_to_release_page(page, 0);
757}
758
759/**
760 * gfs2_releasepage - free the metadata associated with a page
761 * @page: the page that's being released
762 * @gfp_mask: passed from Linux VFS, ignored by us
763 *
764 * Calls try_to_free_buffers() to free the buffers and put the page if the
765 * buffers can be released.
766 *
767 * Returns: 1 if the page was put or else 0
768 */
769
770int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
771{
772 struct address_space *mapping = page->mapping;
773 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
774 struct buffer_head *bh, *head;
775 struct gfs2_bufdata *bd;
776
777 if (!page_has_buffers(page))
778 return 0;
779
780 /*
781 * From xfs_vm_releasepage: mm accommodates an old ext3 case where
782 * clean pages might not have had the dirty bit cleared. Thus, it can
783 * send actual dirty pages to ->releasepage() via shrink_active_list().
784 *
785 * As a workaround, we skip pages that contain dirty buffers below.
786 * Once ->releasepage isn't called on dirty pages anymore, we can warn
787 * on dirty buffers like we used to here again.
788 */
789
790 gfs2_log_lock(sdp);
791 spin_lock(&sdp->sd_ail_lock);
792 head = bh = page_buffers(page);
793 do {
794 if (atomic_read(&bh->b_count))
795 goto cannot_release;
796 bd = bh->b_private;
797 if (bd && bd->bd_tr)
798 goto cannot_release;
799 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
800 goto cannot_release;
801 bh = bh->b_this_page;
802 } while(bh != head);
803 spin_unlock(&sdp->sd_ail_lock);
804
805 head = bh = page_buffers(page);
806 do {
807 bd = bh->b_private;
808 if (bd) {
809 gfs2_assert_warn(sdp, bd->bd_bh == bh);
810 if (!list_empty(&bd->bd_list))
811 list_del_init(&bd->bd_list);
812 bd->bd_bh = NULL;
813 bh->b_private = NULL;
814 kmem_cache_free(gfs2_bufdata_cachep, bd);
815 }
816
817 bh = bh->b_this_page;
818 } while (bh != head);
819 gfs2_log_unlock(sdp);
820
821 return try_to_free_buffers(page);
822
823cannot_release:
824 spin_unlock(&sdp->sd_ail_lock);
825 gfs2_log_unlock(sdp);
826 return 0;
827}
828
829static const struct address_space_operations gfs2_aops = {
830 .writepage = gfs2_writepage,
831 .writepages = gfs2_writepages,
832 .readpage = gfs2_readpage,
833 .readpages = gfs2_readpages,
834 .bmap = gfs2_bmap,
835 .invalidatepage = gfs2_invalidatepage,
836 .releasepage = gfs2_releasepage,
837 .direct_IO = noop_direct_IO,
838 .migratepage = buffer_migrate_page,
839 .is_partially_uptodate = block_is_partially_uptodate,
840 .error_remove_page = generic_error_remove_page,
841};
842
843static const struct address_space_operations gfs2_jdata_aops = {
844 .writepage = gfs2_jdata_writepage,
845 .writepages = gfs2_jdata_writepages,
846 .readpage = gfs2_readpage,
847 .readpages = gfs2_readpages,
848 .set_page_dirty = jdata_set_page_dirty,
849 .bmap = gfs2_bmap,
850 .invalidatepage = gfs2_invalidatepage,
851 .releasepage = gfs2_releasepage,
852 .is_partially_uptodate = block_is_partially_uptodate,
853 .error_remove_page = generic_error_remove_page,
854};
855
856void gfs2_set_aops(struct inode *inode)
857{
858 if (gfs2_is_jdata(GFS2_I(inode)))
859 inode->i_mapping->a_ops = &gfs2_jdata_aops;
860 else
861 inode->i_mapping->a_ops = &gfs2_aops;
862}