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v6.2
  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}
v6.9.4
  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_trans_add_databufs(struct gfs2_inode *ip, struct folio *folio,
 41			     size_t from, size_t len)
 42{
 43	struct buffer_head *head = folio_buffers(folio);
 44	unsigned int bsize = head->b_size;
 45	struct buffer_head *bh;
 46	size_t to = from + len;
 47	size_t 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_folio - gfs2 jdata-specific version of block_write_full_folio
 86 * @folio: The folio to write
 87 * @wbc: The writeback control
 88 *
 89 * This is the same as calling block_write_full_folio, but it also
 90 * writes pages outside of i_size
 91 */
 92static int gfs2_write_jdata_folio(struct folio *folio,
 93				 struct writeback_control *wbc)
 94{
 95	struct inode * const inode = folio->mapping->host;
 96	loff_t i_size = i_size_read(inode);
 
 
 97
 98	/*
 99	 * The folio straddles i_size.  It must be zeroed out on each and every
100	 * writepage invocation because it may be mmapped.  "A file is mapped
101	 * in multiples of the page size.  For a file that is not a multiple of
102	 * the page size, the remaining memory is zeroed when mapped, and
103	 * writes to that region are not written out to the file."
104	 */
105	if (folio_pos(folio) < i_size &&
106	    i_size < folio_pos(folio) + folio_size(folio))
107		folio_zero_segment(folio, offset_in_folio(folio, i_size),
108				folio_size(folio));
109
110	return __block_write_full_folio(inode, folio, gfs2_get_block_noalloc,
111			wbc);
112}
113
114/**
115 * __gfs2_jdata_write_folio - The core of jdata writepage
116 * @folio: The folio to write
117 * @wbc: The writeback control
118 *
119 * This is shared between writepage and writepages and implements the
120 * core of the writepage operation. If a transaction is required then
121 * the checked flag will have been set and the transaction will have
122 * already been started before this is called.
123 */
124static int __gfs2_jdata_write_folio(struct folio *folio,
125		struct writeback_control *wbc)
126{
127	struct inode *inode = folio->mapping->host;
128	struct gfs2_inode *ip = GFS2_I(inode);
 
129
130	if (folio_test_checked(folio)) {
131		folio_clear_checked(folio);
132		if (!folio_buffers(folio)) {
133			create_empty_buffers(folio,
134					inode->i_sb->s_blocksize,
135					BIT(BH_Dirty)|BIT(BH_Uptodate));
136		}
137		gfs2_trans_add_databufs(ip, folio, 0, folio_size(folio));
138	}
139	return gfs2_write_jdata_folio(folio, wbc);
140}
141
142/**
143 * gfs2_jdata_writepage - Write complete page
144 * @page: Page to write
145 * @wbc: The writeback control
146 *
147 * Returns: errno
148 *
149 */
150
151static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
152{
153	struct folio *folio = page_folio(page);
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, ip->i_gl->gl_state == LM_ST_EXCLUSIVE))
159		goto out;
160	if (folio_test_checked(folio) || current->journal_info)
161		goto out_ignore;
162	return __gfs2_jdata_write_folio(folio, wbc);
163
164out_ignore:
165	folio_redirty_for_writepage(wbc, folio);
166out:
167	folio_unlock(folio);
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 enough 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 && wbc->nr_to_write > 0)
193		set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
194	return ret;
195}
196
197/**
198 * gfs2_write_jdata_batch - Write back a folio batch's worth of folios
199 * @mapping: The mapping
200 * @wbc: The writeback control
201 * @fbatch: The batch of folios
 
202 * @done_index: Page index
203 *
204 * Returns: non-zero if loop should terminate, zero otherwise
205 */
206
207static int gfs2_write_jdata_batch(struct address_space *mapping,
208				    struct writeback_control *wbc,
209				    struct folio_batch *fbatch,
 
210				    pgoff_t *done_index)
211{
212	struct inode *inode = mapping->host;
213	struct gfs2_sbd *sdp = GFS2_SB(inode);
214	unsigned nrblocks;
215	int i;
216	int ret;
217	size_t size = 0;
218	int nr_folios = folio_batch_count(fbatch);
219
220	for (i = 0; i < nr_folios; i++)
221		size += folio_size(fbatch->folios[i]);
222	nrblocks = size >> inode->i_blkbits;
223
224	ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
225	if (ret < 0)
226		return ret;
227
228	for (i = 0; i < nr_folios; i++) {
229		struct folio *folio = fbatch->folios[i];
230
231		*done_index = folio->index;
232
233		folio_lock(folio);
234
235		if (unlikely(folio->mapping != mapping)) {
236continue_unlock:
237			folio_unlock(folio);
238			continue;
239		}
240
241		if (!folio_test_dirty(folio)) {
242			/* someone wrote it for us */
243			goto continue_unlock;
244		}
245
246		if (folio_test_writeback(folio)) {
247			if (wbc->sync_mode != WB_SYNC_NONE)
248				folio_wait_writeback(folio);
249			else
250				goto continue_unlock;
251		}
252
253		BUG_ON(folio_test_writeback(folio));
254		if (!folio_clear_dirty_for_io(folio))
255			goto continue_unlock;
256
257		trace_wbc_writepage(wbc, inode_to_bdi(inode));
258
259		ret = __gfs2_jdata_write_folio(folio, wbc);
260		if (unlikely(ret)) {
261			if (ret == AOP_WRITEPAGE_ACTIVATE) {
262				folio_unlock(folio);
263				ret = 0;
264			} else {
265
266				/*
267				 * done_index is set past this page,
268				 * so media errors will not choke
269				 * background writeout for the entire
270				 * file. This has consequences for
271				 * range_cyclic semantics (ie. it may
272				 * not be suitable for data integrity
273				 * writeout).
274				 */
275				*done_index = folio_next_index(folio);
276				ret = 1;
277				break;
278			}
279		}
280
281		/*
282		 * We stop writing back only if we are not doing
283		 * integrity sync. In case of integrity sync we have to
284		 * keep going until we have written all the pages
285		 * we tagged for writeback prior to entering this loop.
286		 */
287		if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
288			ret = 1;
289			break;
290		}
291
292	}
293	gfs2_trans_end(sdp);
294	return ret;
295}
296
297/**
298 * gfs2_write_cache_jdata - Like write_cache_pages but different
299 * @mapping: The mapping to write
300 * @wbc: The writeback control
301 *
302 * The reason that we use our own function here is that we need to
303 * start transactions before we grab page locks. This allows us
304 * to get the ordering right.
305 */
306
307static int gfs2_write_cache_jdata(struct address_space *mapping,
308				  struct writeback_control *wbc)
309{
310	int ret = 0;
311	int done = 0;
312	struct folio_batch fbatch;
313	int nr_folios;
314	pgoff_t writeback_index;
315	pgoff_t index;
316	pgoff_t end;
317	pgoff_t done_index;
318	int cycled;
319	int range_whole = 0;
320	xa_mark_t tag;
321
322	folio_batch_init(&fbatch);
323	if (wbc->range_cyclic) {
324		writeback_index = mapping->writeback_index; /* prev offset */
325		index = writeback_index;
326		if (index == 0)
327			cycled = 1;
328		else
329			cycled = 0;
330		end = -1;
331	} else {
332		index = wbc->range_start >> PAGE_SHIFT;
333		end = wbc->range_end >> PAGE_SHIFT;
334		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
335			range_whole = 1;
336		cycled = 1; /* ignore range_cyclic tests */
337	}
338	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
339		tag = PAGECACHE_TAG_TOWRITE;
340	else
341		tag = PAGECACHE_TAG_DIRTY;
342
343retry:
344	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
345		tag_pages_for_writeback(mapping, index, end);
346	done_index = index;
347	while (!done && (index <= end)) {
348		nr_folios = filemap_get_folios_tag(mapping, &index, end,
349				tag, &fbatch);
350		if (nr_folios == 0)
351			break;
352
353		ret = gfs2_write_jdata_batch(mapping, wbc, &fbatch,
354				&done_index);
355		if (ret)
356			done = 1;
357		if (ret > 0)
358			ret = 0;
359		folio_batch_release(&fbatch);
360		cond_resched();
361	}
362
363	if (!cycled && !done) {
364		/*
365		 * range_cyclic:
366		 * We hit the last page and there is more work to be done: wrap
367		 * back to the start of the file
368		 */
369		cycled = 1;
370		index = 0;
371		end = writeback_index - 1;
372		goto retry;
373	}
374
375	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
376		mapping->writeback_index = done_index;
377
378	return ret;
379}
380
381
382/**
383 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
384 * @mapping: The mapping to write
385 * @wbc: The writeback control
386 * 
387 */
388
389static int gfs2_jdata_writepages(struct address_space *mapping,
390				 struct writeback_control *wbc)
391{
392	struct gfs2_inode *ip = GFS2_I(mapping->host);
393	struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
394	int ret;
395
396	ret = gfs2_write_cache_jdata(mapping, wbc);
397	if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
398		gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
399			       GFS2_LFC_JDATA_WPAGES);
400		ret = gfs2_write_cache_jdata(mapping, wbc);
401	}
402	return ret;
403}
404
405/**
406 * stuffed_read_folio - Fill in a Linux folio with stuffed file data
407 * @ip: the inode
408 * @folio: the folio
409 *
410 * Returns: errno
411 */
412static int stuffed_read_folio(struct gfs2_inode *ip, struct folio *folio)
413{
414	struct buffer_head *dibh = NULL;
415	size_t dsize = i_size_read(&ip->i_inode);
416	void *from = NULL;
417	int error = 0;
418
419	/*
420	 * Due to the order of unstuffing files and ->fault(), we can be
421	 * asked for a zero folio in the case of a stuffed file being extended,
422	 * so we need to supply one here. It doesn't happen often.
423	 */
424	if (unlikely(folio->index)) {
425		dsize = 0;
426	} else {
427		error = gfs2_meta_inode_buffer(ip, &dibh);
428		if (error)
429			goto out;
430		from = dibh->b_data + sizeof(struct gfs2_dinode);
431	}
432
433	folio_fill_tail(folio, 0, from, dsize);
 
 
 
 
 
 
 
 
434	brelse(dibh);
435out:
436	folio_end_read(folio, error == 0);
437
438	return error;
439}
440
441/**
442 * gfs2_read_folio - read a folio from a file
443 * @file: The file to read
444 * @folio: The folio in the file
445 */
446static int gfs2_read_folio(struct file *file, struct folio *folio)
447{
448	struct inode *inode = folio->mapping->host;
449	struct gfs2_inode *ip = GFS2_I(inode);
450	struct gfs2_sbd *sdp = GFS2_SB(inode);
451	int error;
452
453	if (!gfs2_is_jdata(ip) ||
454	    (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
455		error = iomap_read_folio(folio, &gfs2_iomap_ops);
456	} else if (gfs2_is_stuffed(ip)) {
457		error = stuffed_read_folio(ip, folio);
 
458	} else {
459		error = mpage_read_folio(folio, gfs2_block_map);
460	}
461
462	if (gfs2_withdrawing_or_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
477ssize_t gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
478			   size_t size)
479{
480	struct address_space *mapping = ip->i_inode.i_mapping;
481	unsigned long index = *pos >> PAGE_SHIFT;
482	size_t copied = 0;
 
 
 
 
483
484	do {
485		size_t offset, chunk;
486		struct folio *folio;
487
488		folio = read_cache_folio(mapping, index, gfs2_read_folio, NULL);
489		if (IS_ERR(folio)) {
490			if (PTR_ERR(folio) == -EINTR)
491				continue;
492			return PTR_ERR(folio);
493		}
494		offset = *pos + copied - folio_pos(folio);
495		chunk = min(size - copied, folio_size(folio) - offset);
496		memcpy_from_folio(buf + copied, folio, offset, chunk);
497		index = folio_next_index(folio);
498		folio_put(folio);
499		copied += chunk;
500	} while(copied < size);
501	(*pos) += size;
502	return size;
503}
504
505/**
506 * gfs2_readahead - Read a bunch of pages at once
507 * @rac: Read-ahead control structure
508 *
509 * Some notes:
510 * 1. This is only for readahead, so we can simply ignore any things
511 *    which are slightly inconvenient (such as locking conflicts between
512 *    the page lock and the glock) and return having done no I/O. Its
513 *    obviously not something we'd want to do on too regular a basis.
514 *    Any I/O we ignore at this time will be done via readpage later.
515 * 2. We don't handle stuffed files here we let readpage do the honours.
516 * 3. mpage_readahead() does most of the heavy lifting in the common case.
517 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
518 */
519
520static void gfs2_readahead(struct readahead_control *rac)
521{
522	struct inode *inode = rac->mapping->host;
523	struct gfs2_inode *ip = GFS2_I(inode);
524
525	if (gfs2_is_stuffed(ip))
526		;
527	else if (gfs2_is_jdata(ip))
528		mpage_readahead(rac, gfs2_block_map);
529	else
530		iomap_readahead(rac, &gfs2_iomap_ops);
531}
532
533/**
534 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
535 * @inode: the rindex inode
536 */
537void adjust_fs_space(struct inode *inode)
538{
539	struct gfs2_sbd *sdp = GFS2_SB(inode);
540	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
541	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
542	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
543	struct buffer_head *m_bh;
544	u64 fs_total, new_free;
545
546	if (gfs2_trans_begin(sdp, 2 * RES_STATFS, 0) != 0)
547		return;
548
549	/* Total up the file system space, according to the latest rindex. */
550	fs_total = gfs2_ri_total(sdp);
551	if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
552		goto out;
553
554	spin_lock(&sdp->sd_statfs_spin);
555	gfs2_statfs_change_in(m_sc, m_bh->b_data +
556			      sizeof(struct gfs2_dinode));
557	if (fs_total > (m_sc->sc_total + l_sc->sc_total))
558		new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
559	else
560		new_free = 0;
561	spin_unlock(&sdp->sd_statfs_spin);
562	fs_warn(sdp, "File system extended by %llu blocks.\n",
563		(unsigned long long)new_free);
564	gfs2_statfs_change(sdp, new_free, new_free, 0);
565
566	update_statfs(sdp, m_bh);
567	brelse(m_bh);
568out:
569	sdp->sd_rindex_uptodate = 0;
570	gfs2_trans_end(sdp);
571}
572
573static bool jdata_dirty_folio(struct address_space *mapping,
574		struct folio *folio)
575{
576	if (current->journal_info)
577		folio_set_checked(folio);
578	return block_dirty_folio(mapping, folio);
579}
580
581/**
582 * gfs2_bmap - Block map function
583 * @mapping: Address space info
584 * @lblock: The block to map
585 *
586 * Returns: The disk address for the block or 0 on hole or error
587 */
588
589static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
590{
591	struct gfs2_inode *ip = GFS2_I(mapping->host);
592	struct gfs2_holder i_gh;
593	sector_t dblock = 0;
594	int error;
595
596	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
597	if (error)
598		return 0;
599
600	if (!gfs2_is_stuffed(ip))
601		dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
602
603	gfs2_glock_dq_uninit(&i_gh);
604
605	return dblock;
606}
607
608static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
609{
610	struct gfs2_bufdata *bd;
611
612	lock_buffer(bh);
613	gfs2_log_lock(sdp);
614	clear_buffer_dirty(bh);
615	bd = bh->b_private;
616	if (bd) {
617		if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
618			list_del_init(&bd->bd_list);
619		else {
620			spin_lock(&sdp->sd_ail_lock);
621			gfs2_remove_from_journal(bh, REMOVE_JDATA);
622			spin_unlock(&sdp->sd_ail_lock);
623		}
624	}
625	bh->b_bdev = NULL;
626	clear_buffer_mapped(bh);
627	clear_buffer_req(bh);
628	clear_buffer_new(bh);
629	gfs2_log_unlock(sdp);
630	unlock_buffer(bh);
631}
632
633static void gfs2_invalidate_folio(struct folio *folio, size_t offset,
634				size_t length)
635{
636	struct gfs2_sbd *sdp = GFS2_SB(folio->mapping->host);
637	size_t stop = offset + length;
638	int partial_page = (offset || length < folio_size(folio));
639	struct buffer_head *bh, *head;
640	unsigned long pos = 0;
641
642	BUG_ON(!folio_test_locked(folio));
643	if (!partial_page)
644		folio_clear_checked(folio);
645	head = folio_buffers(folio);
646	if (!head)
647		goto out;
648
649	bh = head;
650	do {
651		if (pos + bh->b_size > stop)
652			return;
653
654		if (offset <= pos)
655			gfs2_discard(sdp, bh);
656		pos += bh->b_size;
657		bh = bh->b_this_page;
658	} while (bh != head);
659out:
660	if (!partial_page)
661		filemap_release_folio(folio, 0);
662}
663
664/**
665 * gfs2_release_folio - free the metadata associated with a folio
666 * @folio: the folio that's being released
667 * @gfp_mask: passed from Linux VFS, ignored by us
668 *
669 * Calls try_to_free_buffers() to free the buffers and put the folio if the
670 * buffers can be released.
671 *
672 * Returns: true if the folio was put or else false
673 */
674
675bool gfs2_release_folio(struct folio *folio, gfp_t gfp_mask)
676{
677	struct address_space *mapping = folio->mapping;
678	struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
679	struct buffer_head *bh, *head;
680	struct gfs2_bufdata *bd;
681
682	head = folio_buffers(folio);
683	if (!head)
684		return false;
685
686	/*
687	 * mm accommodates an old ext3 case where clean folios might
688	 * not have had the dirty bit cleared.	Thus, it can send actual
689	 * dirty folios to ->release_folio() via shrink_active_list().
690	 *
691	 * As a workaround, we skip folios that contain dirty buffers
692	 * below.  Once ->release_folio isn't called on dirty folios
693	 * anymore, we can warn on dirty buffers like we used to here
694	 * again.
695	 */
696
697	gfs2_log_lock(sdp);
698	bh = head;
699	do {
700		if (atomic_read(&bh->b_count))
701			goto cannot_release;
702		bd = bh->b_private;
703		if (bd && bd->bd_tr)
704			goto cannot_release;
705		if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
706			goto cannot_release;
707		bh = bh->b_this_page;
708	} while (bh != head);
709
710	bh = head;
711	do {
712		bd = bh->b_private;
713		if (bd) {
714			gfs2_assert_warn(sdp, bd->bd_bh == bh);
715			bd->bd_bh = NULL;
716			bh->b_private = NULL;
717			/*
718			 * The bd may still be queued as a revoke, in which
719			 * case we must not dequeue nor free it.
720			 */
721			if (!bd->bd_blkno && !list_empty(&bd->bd_list))
722				list_del_init(&bd->bd_list);
723			if (list_empty(&bd->bd_list))
724				kmem_cache_free(gfs2_bufdata_cachep, bd);
725		}
726
727		bh = bh->b_this_page;
728	} while (bh != head);
729	gfs2_log_unlock(sdp);
730
731	return try_to_free_buffers(folio);
732
733cannot_release:
734	gfs2_log_unlock(sdp);
735	return false;
736}
737
738static const struct address_space_operations gfs2_aops = {
739	.writepages = gfs2_writepages,
740	.read_folio = gfs2_read_folio,
741	.readahead = gfs2_readahead,
742	.dirty_folio = iomap_dirty_folio,
743	.release_folio = iomap_release_folio,
744	.invalidate_folio = iomap_invalidate_folio,
745	.bmap = gfs2_bmap,
 
746	.migrate_folio = filemap_migrate_folio,
747	.is_partially_uptodate = iomap_is_partially_uptodate,
748	.error_remove_folio = generic_error_remove_folio,
749};
750
751static const struct address_space_operations gfs2_jdata_aops = {
752	.writepage = gfs2_jdata_writepage,
753	.writepages = gfs2_jdata_writepages,
754	.read_folio = gfs2_read_folio,
755	.readahead = gfs2_readahead,
756	.dirty_folio = jdata_dirty_folio,
757	.bmap = gfs2_bmap,
758	.invalidate_folio = gfs2_invalidate_folio,
759	.release_folio = gfs2_release_folio,
760	.is_partially_uptodate = block_is_partially_uptodate,
761	.error_remove_folio = generic_error_remove_folio,
762};
763
764void gfs2_set_aops(struct inode *inode)
765{
766	if (gfs2_is_jdata(GFS2_I(inode)))
767		inode->i_mapping->a_ops = &gfs2_jdata_aops;
768	else
769		inode->i_mapping->a_ops = &gfs2_aops;
770}