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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/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/pagemap.h>
16#include <linux/pagevec.h>
17#include <linux/mpage.h>
18#include <linux/fs.h>
19#include <linux/writeback.h>
20#include <linux/swap.h>
21#include <linux/gfs2_ondisk.h>
22#include <linux/backing-dev.h>
23#include <linux/uio.h>
24#include <trace/events/writeback.h>
25
26#include "gfs2.h"
27#include "incore.h"
28#include "bmap.h"
29#include "glock.h"
30#include "inode.h"
31#include "log.h"
32#include "meta_io.h"
33#include "quota.h"
34#include "trans.h"
35#include "rgrp.h"
36#include "super.h"
37#include "util.h"
38#include "glops.h"
39
40
41static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
42 unsigned int from, unsigned int to)
43{
44 struct buffer_head *head = page_buffers(page);
45 unsigned int bsize = head->b_size;
46 struct buffer_head *bh;
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 || start >= to)
53 continue;
54 if (gfs2_is_jdata(ip))
55 set_buffer_uptodate(bh);
56 gfs2_trans_add_data(ip->i_gl, bh);
57 }
58}
59
60/**
61 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
62 * @inode: The inode
63 * @lblock: The block number to look up
64 * @bh_result: The buffer head to return the result in
65 * @create: Non-zero if we may add block to the file
66 *
67 * Returns: errno
68 */
69
70static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
71 struct buffer_head *bh_result, int create)
72{
73 int error;
74
75 error = gfs2_block_map(inode, lblock, bh_result, 0);
76 if (error)
77 return error;
78 if (!buffer_mapped(bh_result))
79 return -EIO;
80 return 0;
81}
82
83static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
84 struct buffer_head *bh_result, int create)
85{
86 return gfs2_block_map(inode, lblock, bh_result, 0);
87}
88
89/**
90 * gfs2_writepage_common - Common bits of writepage
91 * @page: The page to be written
92 * @wbc: The writeback control
93 *
94 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
95 */
96
97static int gfs2_writepage_common(struct page *page,
98 struct writeback_control *wbc)
99{
100 struct inode *inode = page->mapping->host;
101 struct gfs2_inode *ip = GFS2_I(inode);
102 struct gfs2_sbd *sdp = GFS2_SB(inode);
103 loff_t i_size = i_size_read(inode);
104 pgoff_t end_index = i_size >> PAGE_SHIFT;
105 unsigned offset;
106
107 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
108 goto out;
109 if (current->journal_info)
110 goto redirty;
111 /* Is the page fully outside i_size? (truncate in progress) */
112 offset = i_size & (PAGE_SIZE-1);
113 if (page->index > end_index || (page->index == end_index && !offset)) {
114 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
115 goto out;
116 }
117 return 1;
118redirty:
119 redirty_page_for_writepage(wbc, page);
120out:
121 unlock_page(page);
122 return 0;
123}
124
125/**
126 * gfs2_writepage - Write page for writeback mappings
127 * @page: The page
128 * @wbc: The writeback control
129 *
130 */
131
132static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
133{
134 int ret;
135
136 ret = gfs2_writepage_common(page, wbc);
137 if (ret <= 0)
138 return ret;
139
140 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
141}
142
143/**
144 * __gfs2_jdata_writepage - The core of jdata writepage
145 * @page: The page to write
146 * @wbc: The writeback control
147 *
148 * This is shared between writepage and writepages and implements the
149 * core of the writepage operation. If a transaction is required then
150 * PageChecked will have been set and the transaction will have
151 * already been started before this is called.
152 */
153
154static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
155{
156 struct inode *inode = page->mapping->host;
157 struct gfs2_inode *ip = GFS2_I(inode);
158 struct gfs2_sbd *sdp = GFS2_SB(inode);
159
160 if (PageChecked(page)) {
161 ClearPageChecked(page);
162 if (!page_has_buffers(page)) {
163 create_empty_buffers(page, inode->i_sb->s_blocksize,
164 (1 << BH_Dirty)|(1 << BH_Uptodate));
165 }
166 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
167 }
168 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
169}
170
171/**
172 * gfs2_jdata_writepage - Write complete page
173 * @page: Page to write
174 * @wbc: The writeback control
175 *
176 * Returns: errno
177 *
178 */
179
180static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
181{
182 struct inode *inode = page->mapping->host;
183 struct gfs2_sbd *sdp = GFS2_SB(inode);
184 int ret;
185 int done_trans = 0;
186
187 if (PageChecked(page)) {
188 if (wbc->sync_mode != WB_SYNC_ALL)
189 goto out_ignore;
190 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
191 if (ret)
192 goto out_ignore;
193 done_trans = 1;
194 }
195 ret = gfs2_writepage_common(page, wbc);
196 if (ret > 0)
197 ret = __gfs2_jdata_writepage(page, wbc);
198 if (done_trans)
199 gfs2_trans_end(sdp);
200 return ret;
201
202out_ignore:
203 redirty_page_for_writepage(wbc, page);
204 unlock_page(page);
205 return 0;
206}
207
208/**
209 * gfs2_writepages - Write a bunch of dirty pages back to disk
210 * @mapping: The mapping to write
211 * @wbc: Write-back control
212 *
213 * Used for both ordered and writeback modes.
214 */
215static int gfs2_writepages(struct address_space *mapping,
216 struct writeback_control *wbc)
217{
218 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
219}
220
221/**
222 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
223 * @mapping: The mapping
224 * @wbc: The writeback control
225 * @pvec: The vector of pages
226 * @nr_pages: The number of pages to write
227 * @end: End position
228 * @done_index: Page index
229 *
230 * Returns: non-zero if loop should terminate, zero otherwise
231 */
232
233static int gfs2_write_jdata_pagevec(struct address_space *mapping,
234 struct writeback_control *wbc,
235 struct pagevec *pvec,
236 int nr_pages, pgoff_t end,
237 pgoff_t *done_index)
238{
239 struct inode *inode = mapping->host;
240 struct gfs2_sbd *sdp = GFS2_SB(inode);
241 unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
242 int i;
243 int ret;
244
245 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
246 if (ret < 0)
247 return ret;
248
249 for(i = 0; i < nr_pages; i++) {
250 struct page *page = pvec->pages[i];
251
252 /*
253 * At this point, the page may be truncated or
254 * invalidated (changing page->mapping to NULL), or
255 * even swizzled back from swapper_space to tmpfs file
256 * mapping. However, page->index will not change
257 * because we have a reference on the page.
258 */
259 if (page->index > end) {
260 /*
261 * can't be range_cyclic (1st pass) because
262 * end == -1 in that case.
263 */
264 ret = 1;
265 break;
266 }
267
268 *done_index = page->index;
269
270 lock_page(page);
271
272 if (unlikely(page->mapping != mapping)) {
273continue_unlock:
274 unlock_page(page);
275 continue;
276 }
277
278 if (!PageDirty(page)) {
279 /* someone wrote it for us */
280 goto continue_unlock;
281 }
282
283 if (PageWriteback(page)) {
284 if (wbc->sync_mode != WB_SYNC_NONE)
285 wait_on_page_writeback(page);
286 else
287 goto continue_unlock;
288 }
289
290 BUG_ON(PageWriteback(page));
291 if (!clear_page_dirty_for_io(page))
292 goto continue_unlock;
293
294 trace_wbc_writepage(wbc, inode_to_bdi(inode));
295
296 ret = __gfs2_jdata_writepage(page, wbc);
297 if (unlikely(ret)) {
298 if (ret == AOP_WRITEPAGE_ACTIVATE) {
299 unlock_page(page);
300 ret = 0;
301 } else {
302
303 /*
304 * done_index is set past this page,
305 * so media errors will not choke
306 * background writeout for the entire
307 * file. This has consequences for
308 * range_cyclic semantics (ie. it may
309 * not be suitable for data integrity
310 * writeout).
311 */
312 *done_index = page->index + 1;
313 ret = 1;
314 break;
315 }
316 }
317
318 /*
319 * We stop writing back only if we are not doing
320 * integrity sync. In case of integrity sync we have to
321 * keep going until we have written all the pages
322 * we tagged for writeback prior to entering this loop.
323 */
324 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
325 ret = 1;
326 break;
327 }
328
329 }
330 gfs2_trans_end(sdp);
331 return ret;
332}
333
334/**
335 * gfs2_write_cache_jdata - Like write_cache_pages but different
336 * @mapping: The mapping to write
337 * @wbc: The writeback control
338 *
339 * The reason that we use our own function here is that we need to
340 * start transactions before we grab page locks. This allows us
341 * to get the ordering right.
342 */
343
344static int gfs2_write_cache_jdata(struct address_space *mapping,
345 struct writeback_control *wbc)
346{
347 int ret = 0;
348 int done = 0;
349 struct pagevec pvec;
350 int nr_pages;
351 pgoff_t uninitialized_var(writeback_index);
352 pgoff_t index;
353 pgoff_t end;
354 pgoff_t done_index;
355 int cycled;
356 int range_whole = 0;
357 int tag;
358
359 pagevec_init(&pvec, 0);
360 if (wbc->range_cyclic) {
361 writeback_index = mapping->writeback_index; /* prev offset */
362 index = writeback_index;
363 if (index == 0)
364 cycled = 1;
365 else
366 cycled = 0;
367 end = -1;
368 } else {
369 index = wbc->range_start >> PAGE_SHIFT;
370 end = wbc->range_end >> PAGE_SHIFT;
371 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
372 range_whole = 1;
373 cycled = 1; /* ignore range_cyclic tests */
374 }
375 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
376 tag = PAGECACHE_TAG_TOWRITE;
377 else
378 tag = PAGECACHE_TAG_DIRTY;
379
380retry:
381 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
382 tag_pages_for_writeback(mapping, index, end);
383 done_index = index;
384 while (!done && (index <= end)) {
385 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
386 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
387 if (nr_pages == 0)
388 break;
389
390 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end, &done_index);
391 if (ret)
392 done = 1;
393 if (ret > 0)
394 ret = 0;
395 pagevec_release(&pvec);
396 cond_resched();
397 }
398
399 if (!cycled && !done) {
400 /*
401 * range_cyclic:
402 * We hit the last page and there is more work to be done: wrap
403 * back to the start of the file
404 */
405 cycled = 1;
406 index = 0;
407 end = writeback_index - 1;
408 goto retry;
409 }
410
411 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
412 mapping->writeback_index = done_index;
413
414 return ret;
415}
416
417
418/**
419 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
420 * @mapping: The mapping to write
421 * @wbc: The writeback control
422 *
423 */
424
425static int gfs2_jdata_writepages(struct address_space *mapping,
426 struct writeback_control *wbc)
427{
428 struct gfs2_inode *ip = GFS2_I(mapping->host);
429 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
430 int ret;
431
432 ret = gfs2_write_cache_jdata(mapping, wbc);
433 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
434 gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
435 ret = gfs2_write_cache_jdata(mapping, wbc);
436 }
437 return ret;
438}
439
440/**
441 * stuffed_readpage - Fill in a Linux page with stuffed file data
442 * @ip: the inode
443 * @page: the page
444 *
445 * Returns: errno
446 */
447
448static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
449{
450 struct buffer_head *dibh;
451 u64 dsize = i_size_read(&ip->i_inode);
452 void *kaddr;
453 int error;
454
455 /*
456 * Due to the order of unstuffing files and ->fault(), we can be
457 * asked for a zero page in the case of a stuffed file being extended,
458 * so we need to supply one here. It doesn't happen often.
459 */
460 if (unlikely(page->index)) {
461 zero_user(page, 0, PAGE_SIZE);
462 SetPageUptodate(page);
463 return 0;
464 }
465
466 error = gfs2_meta_inode_buffer(ip, &dibh);
467 if (error)
468 return error;
469
470 kaddr = kmap_atomic(page);
471 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
472 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
473 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
474 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
475 kunmap_atomic(kaddr);
476 flush_dcache_page(page);
477 brelse(dibh);
478 SetPageUptodate(page);
479
480 return 0;
481}
482
483
484/**
485 * __gfs2_readpage - readpage
486 * @file: The file to read a page for
487 * @page: The page to read
488 *
489 * This is the core of gfs2's readpage. Its used by the internal file
490 * reading code as in that case we already hold the glock. Also its
491 * called by gfs2_readpage() once the required lock has been granted.
492 *
493 */
494
495static int __gfs2_readpage(void *file, struct page *page)
496{
497 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
498 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
499 int error;
500
501 if (gfs2_is_stuffed(ip)) {
502 error = stuffed_readpage(ip, page);
503 unlock_page(page);
504 } else {
505 error = mpage_readpage(page, gfs2_block_map);
506 }
507
508 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
509 return -EIO;
510
511 return error;
512}
513
514/**
515 * gfs2_readpage - read a page of a file
516 * @file: The file to read
517 * @page: The page of the file
518 *
519 * This deals with the locking required. We have to unlock and
520 * relock the page in order to get the locking in the right
521 * order.
522 */
523
524static int gfs2_readpage(struct file *file, struct page *page)
525{
526 struct address_space *mapping = page->mapping;
527 struct gfs2_inode *ip = GFS2_I(mapping->host);
528 struct gfs2_holder gh;
529 int error;
530
531 unlock_page(page);
532 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
533 error = gfs2_glock_nq(&gh);
534 if (unlikely(error))
535 goto out;
536 error = AOP_TRUNCATED_PAGE;
537 lock_page(page);
538 if (page->mapping == mapping && !PageUptodate(page))
539 error = __gfs2_readpage(file, page);
540 else
541 unlock_page(page);
542 gfs2_glock_dq(&gh);
543out:
544 gfs2_holder_uninit(&gh);
545 if (error && error != AOP_TRUNCATED_PAGE)
546 lock_page(page);
547 return error;
548}
549
550/**
551 * gfs2_internal_read - read an internal file
552 * @ip: The gfs2 inode
553 * @buf: The buffer to fill
554 * @pos: The file position
555 * @size: The amount to read
556 *
557 */
558
559int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
560 unsigned size)
561{
562 struct address_space *mapping = ip->i_inode.i_mapping;
563 unsigned long index = *pos / PAGE_SIZE;
564 unsigned offset = *pos & (PAGE_SIZE - 1);
565 unsigned copied = 0;
566 unsigned amt;
567 struct page *page;
568 void *p;
569
570 do {
571 amt = size - copied;
572 if (offset + size > PAGE_SIZE)
573 amt = PAGE_SIZE - offset;
574 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
575 if (IS_ERR(page))
576 return PTR_ERR(page);
577 p = kmap_atomic(page);
578 memcpy(buf + copied, p + offset, amt);
579 kunmap_atomic(p);
580 put_page(page);
581 copied += amt;
582 index++;
583 offset = 0;
584 } while(copied < size);
585 (*pos) += size;
586 return size;
587}
588
589/**
590 * gfs2_readpages - Read a bunch of pages at once
591 * @file: The file to read from
592 * @mapping: Address space info
593 * @pages: List of pages to read
594 * @nr_pages: Number of pages to read
595 *
596 * Some notes:
597 * 1. This is only for readahead, so we can simply ignore any things
598 * which are slightly inconvenient (such as locking conflicts between
599 * the page lock and the glock) and return having done no I/O. Its
600 * obviously not something we'd want to do on too regular a basis.
601 * Any I/O we ignore at this time will be done via readpage later.
602 * 2. We don't handle stuffed files here we let readpage do the honours.
603 * 3. mpage_readpages() does most of the heavy lifting in the common case.
604 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
605 */
606
607static int gfs2_readpages(struct file *file, struct address_space *mapping,
608 struct list_head *pages, unsigned nr_pages)
609{
610 struct inode *inode = mapping->host;
611 struct gfs2_inode *ip = GFS2_I(inode);
612 struct gfs2_sbd *sdp = GFS2_SB(inode);
613 struct gfs2_holder gh;
614 int ret;
615
616 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
617 ret = gfs2_glock_nq(&gh);
618 if (unlikely(ret))
619 goto out_uninit;
620 if (!gfs2_is_stuffed(ip))
621 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
622 gfs2_glock_dq(&gh);
623out_uninit:
624 gfs2_holder_uninit(&gh);
625 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
626 ret = -EIO;
627 return ret;
628}
629
630/**
631 * gfs2_write_begin - Begin to write to a file
632 * @file: The file to write to
633 * @mapping: The mapping in which to write
634 * @pos: The file offset at which to start writing
635 * @len: Length of the write
636 * @flags: Various flags
637 * @pagep: Pointer to return the page
638 * @fsdata: Pointer to return fs data (unused by GFS2)
639 *
640 * Returns: errno
641 */
642
643static int gfs2_write_begin(struct file *file, struct address_space *mapping,
644 loff_t pos, unsigned len, unsigned flags,
645 struct page **pagep, void **fsdata)
646{
647 struct gfs2_inode *ip = GFS2_I(mapping->host);
648 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
649 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
650 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
651 unsigned requested = 0;
652 int alloc_required;
653 int error = 0;
654 pgoff_t index = pos >> PAGE_SHIFT;
655 unsigned from = pos & (PAGE_SIZE - 1);
656 struct page *page;
657
658 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
659 error = gfs2_glock_nq(&ip->i_gh);
660 if (unlikely(error))
661 goto out_uninit;
662 if (&ip->i_inode == sdp->sd_rindex) {
663 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
664 GL_NOCACHE, &m_ip->i_gh);
665 if (unlikely(error)) {
666 gfs2_glock_dq(&ip->i_gh);
667 goto out_uninit;
668 }
669 }
670
671 alloc_required = gfs2_write_alloc_required(ip, pos, len);
672
673 if (alloc_required || gfs2_is_jdata(ip))
674 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
675
676 if (alloc_required) {
677 struct gfs2_alloc_parms ap = { .aflags = 0, };
678 requested = data_blocks + ind_blocks;
679 ap.target = requested;
680 error = gfs2_quota_lock_check(ip, &ap);
681 if (error)
682 goto out_unlock;
683
684 error = gfs2_inplace_reserve(ip, &ap);
685 if (error)
686 goto out_qunlock;
687 }
688
689 rblocks = RES_DINODE + ind_blocks;
690 if (gfs2_is_jdata(ip))
691 rblocks += data_blocks ? data_blocks : 1;
692 if (ind_blocks || data_blocks)
693 rblocks += RES_STATFS + RES_QUOTA;
694 if (&ip->i_inode == sdp->sd_rindex)
695 rblocks += 2 * RES_STATFS;
696 if (alloc_required)
697 rblocks += gfs2_rg_blocks(ip, requested);
698
699 error = gfs2_trans_begin(sdp, rblocks,
700 PAGE_SIZE/sdp->sd_sb.sb_bsize);
701 if (error)
702 goto out_trans_fail;
703
704 error = -ENOMEM;
705 flags |= AOP_FLAG_NOFS;
706 page = grab_cache_page_write_begin(mapping, index, flags);
707 *pagep = page;
708 if (unlikely(!page))
709 goto out_endtrans;
710
711 if (gfs2_is_stuffed(ip)) {
712 error = 0;
713 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
714 error = gfs2_unstuff_dinode(ip, page);
715 if (error == 0)
716 goto prepare_write;
717 } else if (!PageUptodate(page)) {
718 error = stuffed_readpage(ip, page);
719 }
720 goto out;
721 }
722
723prepare_write:
724 error = __block_write_begin(page, from, len, gfs2_block_map);
725out:
726 if (error == 0)
727 return 0;
728
729 unlock_page(page);
730 put_page(page);
731
732 gfs2_trans_end(sdp);
733 if (pos + len > ip->i_inode.i_size)
734 gfs2_trim_blocks(&ip->i_inode);
735 goto out_trans_fail;
736
737out_endtrans:
738 gfs2_trans_end(sdp);
739out_trans_fail:
740 if (alloc_required) {
741 gfs2_inplace_release(ip);
742out_qunlock:
743 gfs2_quota_unlock(ip);
744 }
745out_unlock:
746 if (&ip->i_inode == sdp->sd_rindex) {
747 gfs2_glock_dq(&m_ip->i_gh);
748 gfs2_holder_uninit(&m_ip->i_gh);
749 }
750 gfs2_glock_dq(&ip->i_gh);
751out_uninit:
752 gfs2_holder_uninit(&ip->i_gh);
753 return error;
754}
755
756/**
757 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
758 * @inode: the rindex inode
759 */
760static void adjust_fs_space(struct inode *inode)
761{
762 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
763 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
764 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
765 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
766 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
767 struct buffer_head *m_bh, *l_bh;
768 u64 fs_total, new_free;
769
770 /* Total up the file system space, according to the latest rindex. */
771 fs_total = gfs2_ri_total(sdp);
772 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
773 return;
774
775 spin_lock(&sdp->sd_statfs_spin);
776 gfs2_statfs_change_in(m_sc, m_bh->b_data +
777 sizeof(struct gfs2_dinode));
778 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
779 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
780 else
781 new_free = 0;
782 spin_unlock(&sdp->sd_statfs_spin);
783 fs_warn(sdp, "File system extended by %llu blocks.\n",
784 (unsigned long long)new_free);
785 gfs2_statfs_change(sdp, new_free, new_free, 0);
786
787 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
788 goto out;
789 update_statfs(sdp, m_bh, l_bh);
790 brelse(l_bh);
791out:
792 brelse(m_bh);
793}
794
795/**
796 * gfs2_stuffed_write_end - Write end for stuffed files
797 * @inode: The inode
798 * @dibh: The buffer_head containing the on-disk inode
799 * @pos: The file position
800 * @len: The length of the write
801 * @copied: How much was actually copied by the VFS
802 * @page: The page
803 *
804 * This copies the data from the page into the inode block after
805 * the inode data structure itself.
806 *
807 * Returns: errno
808 */
809static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
810 loff_t pos, unsigned len, unsigned copied,
811 struct page *page)
812{
813 struct gfs2_inode *ip = GFS2_I(inode);
814 struct gfs2_sbd *sdp = GFS2_SB(inode);
815 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
816 u64 to = pos + copied;
817 void *kaddr;
818 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
819
820 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
821 kaddr = kmap_atomic(page);
822 memcpy(buf + pos, kaddr + pos, copied);
823 memset(kaddr + pos + copied, 0, len - copied);
824 flush_dcache_page(page);
825 kunmap_atomic(kaddr);
826
827 if (!PageUptodate(page))
828 SetPageUptodate(page);
829 unlock_page(page);
830 put_page(page);
831
832 if (copied) {
833 if (inode->i_size < to)
834 i_size_write(inode, to);
835 mark_inode_dirty(inode);
836 }
837
838 if (inode == sdp->sd_rindex) {
839 adjust_fs_space(inode);
840 sdp->sd_rindex_uptodate = 0;
841 }
842
843 brelse(dibh);
844 gfs2_trans_end(sdp);
845 if (inode == sdp->sd_rindex) {
846 gfs2_glock_dq(&m_ip->i_gh);
847 gfs2_holder_uninit(&m_ip->i_gh);
848 }
849 gfs2_glock_dq(&ip->i_gh);
850 gfs2_holder_uninit(&ip->i_gh);
851 return copied;
852}
853
854/**
855 * gfs2_write_end
856 * @file: The file to write to
857 * @mapping: The address space to write to
858 * @pos: The file position
859 * @len: The length of the data
860 * @copied: How much was actually copied by the VFS
861 * @page: The page that has been written
862 * @fsdata: The fsdata (unused in GFS2)
863 *
864 * The main write_end function for GFS2. We have a separate one for
865 * stuffed files as they are slightly different, otherwise we just
866 * put our locking around the VFS provided functions.
867 *
868 * Returns: errno
869 */
870
871static int gfs2_write_end(struct file *file, struct address_space *mapping,
872 loff_t pos, unsigned len, unsigned copied,
873 struct page *page, void *fsdata)
874{
875 struct inode *inode = page->mapping->host;
876 struct gfs2_inode *ip = GFS2_I(inode);
877 struct gfs2_sbd *sdp = GFS2_SB(inode);
878 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
879 struct buffer_head *dibh;
880 unsigned int from = pos & (PAGE_SIZE - 1);
881 unsigned int to = from + len;
882 int ret;
883 struct gfs2_trans *tr = current->journal_info;
884 BUG_ON(!tr);
885
886 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
887
888 ret = gfs2_meta_inode_buffer(ip, &dibh);
889 if (unlikely(ret)) {
890 unlock_page(page);
891 put_page(page);
892 goto failed;
893 }
894
895 if (gfs2_is_stuffed(ip))
896 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
897
898 if (!gfs2_is_writeback(ip))
899 gfs2_page_add_databufs(ip, page, from, to);
900
901 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
902 if (tr->tr_num_buf_new)
903 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
904 else
905 gfs2_trans_add_meta(ip->i_gl, dibh);
906
907
908 if (inode == sdp->sd_rindex) {
909 adjust_fs_space(inode);
910 sdp->sd_rindex_uptodate = 0;
911 }
912
913 brelse(dibh);
914failed:
915 gfs2_trans_end(sdp);
916 gfs2_inplace_release(ip);
917 if (ip->i_qadata && ip->i_qadata->qa_qd_num)
918 gfs2_quota_unlock(ip);
919 if (inode == sdp->sd_rindex) {
920 gfs2_glock_dq(&m_ip->i_gh);
921 gfs2_holder_uninit(&m_ip->i_gh);
922 }
923 gfs2_glock_dq(&ip->i_gh);
924 gfs2_holder_uninit(&ip->i_gh);
925 return ret;
926}
927
928/**
929 * gfs2_set_page_dirty - Page dirtying function
930 * @page: The page to dirty
931 *
932 * Returns: 1 if it dirtyed the page, or 0 otherwise
933 */
934
935static int gfs2_set_page_dirty(struct page *page)
936{
937 SetPageChecked(page);
938 return __set_page_dirty_buffers(page);
939}
940
941/**
942 * gfs2_bmap - Block map function
943 * @mapping: Address space info
944 * @lblock: The block to map
945 *
946 * Returns: The disk address for the block or 0 on hole or error
947 */
948
949static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
950{
951 struct gfs2_inode *ip = GFS2_I(mapping->host);
952 struct gfs2_holder i_gh;
953 sector_t dblock = 0;
954 int error;
955
956 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
957 if (error)
958 return 0;
959
960 if (!gfs2_is_stuffed(ip))
961 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
962
963 gfs2_glock_dq_uninit(&i_gh);
964
965 return dblock;
966}
967
968static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
969{
970 struct gfs2_bufdata *bd;
971
972 lock_buffer(bh);
973 gfs2_log_lock(sdp);
974 clear_buffer_dirty(bh);
975 bd = bh->b_private;
976 if (bd) {
977 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
978 list_del_init(&bd->bd_list);
979 else
980 gfs2_remove_from_journal(bh, current->journal_info, 0);
981 }
982 bh->b_bdev = NULL;
983 clear_buffer_mapped(bh);
984 clear_buffer_req(bh);
985 clear_buffer_new(bh);
986 gfs2_log_unlock(sdp);
987 unlock_buffer(bh);
988}
989
990static void gfs2_invalidatepage(struct page *page, unsigned int offset,
991 unsigned int length)
992{
993 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
994 unsigned int stop = offset + length;
995 int partial_page = (offset || length < PAGE_SIZE);
996 struct buffer_head *bh, *head;
997 unsigned long pos = 0;
998
999 BUG_ON(!PageLocked(page));
1000 if (!partial_page)
1001 ClearPageChecked(page);
1002 if (!page_has_buffers(page))
1003 goto out;
1004
1005 bh = head = page_buffers(page);
1006 do {
1007 if (pos + bh->b_size > stop)
1008 return;
1009
1010 if (offset <= pos)
1011 gfs2_discard(sdp, bh);
1012 pos += bh->b_size;
1013 bh = bh->b_this_page;
1014 } while (bh != head);
1015out:
1016 if (!partial_page)
1017 try_to_release_page(page, 0);
1018}
1019
1020/**
1021 * gfs2_ok_for_dio - check that dio is valid on this file
1022 * @ip: The inode
1023 * @offset: The offset at which we are reading or writing
1024 *
1025 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
1026 * 1 (to accept the i/o request)
1027 */
1028static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset)
1029{
1030 /*
1031 * Should we return an error here? I can't see that O_DIRECT for
1032 * a stuffed file makes any sense. For now we'll silently fall
1033 * back to buffered I/O
1034 */
1035 if (gfs2_is_stuffed(ip))
1036 return 0;
1037
1038 if (offset >= i_size_read(&ip->i_inode))
1039 return 0;
1040 return 1;
1041}
1042
1043
1044
1045static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1046 loff_t offset)
1047{
1048 struct file *file = iocb->ki_filp;
1049 struct inode *inode = file->f_mapping->host;
1050 struct address_space *mapping = inode->i_mapping;
1051 struct gfs2_inode *ip = GFS2_I(inode);
1052 struct gfs2_holder gh;
1053 int rv;
1054
1055 /*
1056 * Deferred lock, even if its a write, since we do no allocation
1057 * on this path. All we need change is atime, and this lock mode
1058 * ensures that other nodes have flushed their buffered read caches
1059 * (i.e. their page cache entries for this inode). We do not,
1060 * unfortunately have the option of only flushing a range like
1061 * the VFS does.
1062 */
1063 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1064 rv = gfs2_glock_nq(&gh);
1065 if (rv)
1066 return rv;
1067 rv = gfs2_ok_for_dio(ip, offset);
1068 if (rv != 1)
1069 goto out; /* dio not valid, fall back to buffered i/o */
1070
1071 /*
1072 * Now since we are holding a deferred (CW) lock at this point, you
1073 * might be wondering why this is ever needed. There is a case however
1074 * where we've granted a deferred local lock against a cached exclusive
1075 * glock. That is ok provided all granted local locks are deferred, but
1076 * it also means that it is possible to encounter pages which are
1077 * cached and possibly also mapped. So here we check for that and sort
1078 * them out ahead of the dio. The glock state machine will take care of
1079 * everything else.
1080 *
1081 * If in fact the cached glock state (gl->gl_state) is deferred (CW) in
1082 * the first place, mapping->nr_pages will always be zero.
1083 */
1084 if (mapping->nrpages) {
1085 loff_t lstart = offset & ~(PAGE_SIZE - 1);
1086 loff_t len = iov_iter_count(iter);
1087 loff_t end = PAGE_ALIGN(offset + len) - 1;
1088
1089 rv = 0;
1090 if (len == 0)
1091 goto out;
1092 if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
1093 unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
1094 rv = filemap_write_and_wait_range(mapping, lstart, end);
1095 if (rv)
1096 goto out;
1097 if (iov_iter_rw(iter) == WRITE)
1098 truncate_inode_pages_range(mapping, lstart, end);
1099 }
1100
1101 rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
1102 offset, gfs2_get_block_direct, NULL, NULL, 0);
1103out:
1104 gfs2_glock_dq(&gh);
1105 gfs2_holder_uninit(&gh);
1106 return rv;
1107}
1108
1109/**
1110 * gfs2_releasepage - free the metadata associated with a page
1111 * @page: the page that's being released
1112 * @gfp_mask: passed from Linux VFS, ignored by us
1113 *
1114 * Call try_to_free_buffers() if the buffers in this page can be
1115 * released.
1116 *
1117 * Returns: 0
1118 */
1119
1120int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1121{
1122 struct address_space *mapping = page->mapping;
1123 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1124 struct buffer_head *bh, *head;
1125 struct gfs2_bufdata *bd;
1126
1127 if (!page_has_buffers(page))
1128 return 0;
1129
1130 gfs2_log_lock(sdp);
1131 spin_lock(&sdp->sd_ail_lock);
1132 head = bh = page_buffers(page);
1133 do {
1134 if (atomic_read(&bh->b_count))
1135 goto cannot_release;
1136 bd = bh->b_private;
1137 if (bd && bd->bd_tr)
1138 goto cannot_release;
1139 if (buffer_pinned(bh) || buffer_dirty(bh))
1140 goto not_possible;
1141 bh = bh->b_this_page;
1142 } while(bh != head);
1143 spin_unlock(&sdp->sd_ail_lock);
1144
1145 head = bh = page_buffers(page);
1146 do {
1147 bd = bh->b_private;
1148 if (bd) {
1149 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1150 if (!list_empty(&bd->bd_list))
1151 list_del_init(&bd->bd_list);
1152 bd->bd_bh = NULL;
1153 bh->b_private = NULL;
1154 kmem_cache_free(gfs2_bufdata_cachep, bd);
1155 }
1156
1157 bh = bh->b_this_page;
1158 } while (bh != head);
1159 gfs2_log_unlock(sdp);
1160
1161 return try_to_free_buffers(page);
1162
1163not_possible: /* Should never happen */
1164 WARN_ON(buffer_dirty(bh));
1165 WARN_ON(buffer_pinned(bh));
1166cannot_release:
1167 spin_unlock(&sdp->sd_ail_lock);
1168 gfs2_log_unlock(sdp);
1169 return 0;
1170}
1171
1172static const struct address_space_operations gfs2_writeback_aops = {
1173 .writepage = gfs2_writepage,
1174 .writepages = gfs2_writepages,
1175 .readpage = gfs2_readpage,
1176 .readpages = gfs2_readpages,
1177 .write_begin = gfs2_write_begin,
1178 .write_end = gfs2_write_end,
1179 .bmap = gfs2_bmap,
1180 .invalidatepage = gfs2_invalidatepage,
1181 .releasepage = gfs2_releasepage,
1182 .direct_IO = gfs2_direct_IO,
1183 .migratepage = buffer_migrate_page,
1184 .is_partially_uptodate = block_is_partially_uptodate,
1185 .error_remove_page = generic_error_remove_page,
1186};
1187
1188static const struct address_space_operations gfs2_ordered_aops = {
1189 .writepage = gfs2_writepage,
1190 .writepages = gfs2_writepages,
1191 .readpage = gfs2_readpage,
1192 .readpages = gfs2_readpages,
1193 .write_begin = gfs2_write_begin,
1194 .write_end = gfs2_write_end,
1195 .set_page_dirty = gfs2_set_page_dirty,
1196 .bmap = gfs2_bmap,
1197 .invalidatepage = gfs2_invalidatepage,
1198 .releasepage = gfs2_releasepage,
1199 .direct_IO = gfs2_direct_IO,
1200 .migratepage = buffer_migrate_page,
1201 .is_partially_uptodate = block_is_partially_uptodate,
1202 .error_remove_page = generic_error_remove_page,
1203};
1204
1205static const struct address_space_operations gfs2_jdata_aops = {
1206 .writepage = gfs2_jdata_writepage,
1207 .writepages = gfs2_jdata_writepages,
1208 .readpage = gfs2_readpage,
1209 .readpages = gfs2_readpages,
1210 .write_begin = gfs2_write_begin,
1211 .write_end = gfs2_write_end,
1212 .set_page_dirty = gfs2_set_page_dirty,
1213 .bmap = gfs2_bmap,
1214 .invalidatepage = gfs2_invalidatepage,
1215 .releasepage = gfs2_releasepage,
1216 .is_partially_uptodate = block_is_partially_uptodate,
1217 .error_remove_page = generic_error_remove_page,
1218};
1219
1220void gfs2_set_aops(struct inode *inode)
1221{
1222 struct gfs2_inode *ip = GFS2_I(inode);
1223
1224 if (gfs2_is_writeback(ip))
1225 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1226 else if (gfs2_is_ordered(ip))
1227 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1228 else if (gfs2_is_jdata(ip))
1229 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1230 else
1231 BUG();
1232}
1233