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v6.9.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *   Copyright (C) International Business Machines Corp., 2000-2005
  4 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
  5 */
  6
 
  7#include <linux/fs.h>
  8#include <linux/mm.h>
  9#include <linux/module.h>
 10#include <linux/bio.h>
 11#include <linux/slab.h>
 12#include <linux/init.h>
 13#include <linux/buffer_head.h>
 14#include <linux/mempool.h>
 15#include <linux/seq_file.h>
 16#include <linux/writeback.h>
 17#include "jfs_incore.h"
 18#include "jfs_superblock.h"
 19#include "jfs_filsys.h"
 20#include "jfs_metapage.h"
 21#include "jfs_txnmgr.h"
 22#include "jfs_debug.h"
 23
 24#ifdef CONFIG_JFS_STATISTICS
 25static struct {
 26	uint	pagealloc;	/* # of page allocations */
 27	uint	pagefree;	/* # of page frees */
 28	uint	lockwait;	/* # of sleeping lock_metapage() calls */
 29} mpStat;
 30#endif
 31
 32#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
 33#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag)
 34
 35static inline void unlock_metapage(struct metapage *mp)
 36{
 37	clear_bit_unlock(META_locked, &mp->flag);
 38	wake_up(&mp->wait);
 39}
 40
 41static inline void __lock_metapage(struct metapage *mp)
 42{
 43	DECLARE_WAITQUEUE(wait, current);
 44	INCREMENT(mpStat.lockwait);
 45	add_wait_queue_exclusive(&mp->wait, &wait);
 46	do {
 47		set_current_state(TASK_UNINTERRUPTIBLE);
 48		if (metapage_locked(mp)) {
 49			unlock_page(mp->page);
 50			io_schedule();
 51			lock_page(mp->page);
 52		}
 53	} while (trylock_metapage(mp));
 54	__set_current_state(TASK_RUNNING);
 55	remove_wait_queue(&mp->wait, &wait);
 56}
 57
 58/*
 59 * Must have mp->page locked
 60 */
 61static inline void lock_metapage(struct metapage *mp)
 62{
 63	if (trylock_metapage(mp))
 64		__lock_metapage(mp);
 65}
 66
 67#define METAPOOL_MIN_PAGES 32
 68static struct kmem_cache *metapage_cache;
 69static mempool_t *metapage_mempool;
 70
 71#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)
 72
 73#if MPS_PER_PAGE > 1
 74
 75struct meta_anchor {
 76	int mp_count;
 77	atomic_t io_count;
 
 78	struct metapage *mp[MPS_PER_PAGE];
 79};
 80#define mp_anchor(page) ((struct meta_anchor *)page_private(page))
 81
 82static inline struct metapage *page_to_mp(struct page *page, int offset)
 83{
 84	if (!PagePrivate(page))
 
 
 85		return NULL;
 86	return mp_anchor(page)->mp[offset >> L2PSIZE];
 87}
 88
 89static inline int insert_metapage(struct page *page, struct metapage *mp)
 90{
 91	struct meta_anchor *a;
 92	int index;
 93	int l2mp_blocks;	/* log2 blocks per metapage */
 94
 95	if (PagePrivate(page))
 96		a = mp_anchor(page);
 97	else {
 98		a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
 99		if (!a)
100			return -ENOMEM;
101		set_page_private(page, (unsigned long)a);
102		SetPagePrivate(page);
103		kmap(page);
104	}
105
106	if (mp) {
107		l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
108		index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
109		a->mp_count++;
110		a->mp[index] = mp;
111	}
112
113	return 0;
114}
115
116static inline void remove_metapage(struct page *page, struct metapage *mp)
117{
118	struct meta_anchor *a = mp_anchor(page);
119	int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
120	int index;
121
122	index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
123
124	BUG_ON(a->mp[index] != mp);
125
126	a->mp[index] = NULL;
127	if (--a->mp_count == 0) {
128		kfree(a);
129		set_page_private(page, 0);
130		ClearPagePrivate(page);
131		kunmap(page);
132	}
133}
134
135static inline void inc_io(struct page *page)
136{
137	atomic_inc(&mp_anchor(page)->io_count);
 
 
138}
139
140static inline void dec_io(struct page *page, void (*handler) (struct page *))
 
141{
142	if (atomic_dec_and_test(&mp_anchor(page)->io_count))
143		handler(page);
 
 
 
 
 
144}
145
146#else
147static inline struct metapage *page_to_mp(struct page *page, int offset)
148{
149	return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
150}
151
152static inline int insert_metapage(struct page *page, struct metapage *mp)
153{
154	if (mp) {
155		set_page_private(page, (unsigned long)mp);
156		SetPagePrivate(page);
157		kmap(page);
158	}
159	return 0;
160}
161
162static inline void remove_metapage(struct page *page, struct metapage *mp)
163{
164	set_page_private(page, 0);
165	ClearPagePrivate(page);
166	kunmap(page);
167}
168
169#define inc_io(page) do {} while(0)
170#define dec_io(page, handler) handler(page)
171
172#endif
173
174static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
175{
176	struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask);
177
178	if (mp) {
179		mp->lid = 0;
180		mp->lsn = 0;
181		mp->data = NULL;
182		mp->clsn = 0;
183		mp->log = NULL;
184		init_waitqueue_head(&mp->wait);
185	}
186	return mp;
187}
188
189static inline void free_metapage(struct metapage *mp)
190{
191	mempool_free(mp, metapage_mempool);
192}
193
194int __init metapage_init(void)
195{
196	/*
197	 * Allocate the metapage structures
198	 */
199	metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
200					   0, 0, NULL);
201	if (metapage_cache == NULL)
202		return -ENOMEM;
203
204	metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
205						    metapage_cache);
206
207	if (metapage_mempool == NULL) {
208		kmem_cache_destroy(metapage_cache);
209		return -ENOMEM;
210	}
211
212	return 0;
213}
214
215void metapage_exit(void)
216{
217	mempool_destroy(metapage_mempool);
218	kmem_cache_destroy(metapage_cache);
219}
220
221static inline void drop_metapage(struct page *page, struct metapage *mp)
222{
223	if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
224	    test_bit(META_io, &mp->flag))
225		return;
226	remove_metapage(page, mp);
227	INCREMENT(mpStat.pagefree);
228	free_metapage(mp);
229}
230
231/*
232 * Metapage address space operations
233 */
234
235static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
236				    int *len)
237{
238	int rc = 0;
239	int xflag;
240	s64 xaddr;
241	sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
242			       inode->i_blkbits;
243
244	if (lblock >= file_blocks)
245		return 0;
246	if (lblock + *len > file_blocks)
247		*len = file_blocks - lblock;
248
249	if (inode->i_ino) {
250		rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
251		if ((rc == 0) && *len)
252			lblock = (sector_t)xaddr;
253		else
254			lblock = 0;
255	} /* else no mapping */
256
257	return lblock;
258}
259
260static void last_read_complete(struct page *page)
261{
262	if (!PageError(page))
263		SetPageUptodate(page);
264	unlock_page(page);
 
 
265}
266
267static void metapage_read_end_io(struct bio *bio)
268{
269	struct page *page = bio->bi_private;
270
271	if (bio->bi_status) {
272		printk(KERN_ERR "metapage_read_end_io: I/O error\n");
273		SetPageError(page);
274	}
275
276	dec_io(page, last_read_complete);
277	bio_put(bio);
278}
279
280static void remove_from_logsync(struct metapage *mp)
281{
282	struct jfs_log *log = mp->log;
283	unsigned long flags;
284/*
285 * This can race.  Recheck that log hasn't been set to null, and after
286 * acquiring logsync lock, recheck lsn
287 */
288	if (!log)
289		return;
290
291	LOGSYNC_LOCK(log, flags);
292	if (mp->lsn) {
293		mp->log = NULL;
294		mp->lsn = 0;
295		mp->clsn = 0;
296		log->count--;
297		list_del(&mp->synclist);
298	}
299	LOGSYNC_UNLOCK(log, flags);
300}
301
302static void last_write_complete(struct page *page)
303{
304	struct metapage *mp;
305	unsigned int offset;
306
 
 
 
 
 
 
307	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
308		mp = page_to_mp(page, offset);
309		if (mp && test_bit(META_io, &mp->flag)) {
310			if (mp->lsn)
311				remove_from_logsync(mp);
312			clear_bit(META_io, &mp->flag);
313		}
314		/*
315		 * I'd like to call drop_metapage here, but I don't think it's
316		 * safe unless I have the page locked
317		 */
318	}
319	end_page_writeback(page);
320}
321
322static void metapage_write_end_io(struct bio *bio)
323{
324	struct page *page = bio->bi_private;
325
326	BUG_ON(!PagePrivate(page));
327
328	if (bio->bi_status) {
329		printk(KERN_ERR "metapage_write_end_io: I/O error\n");
330		SetPageError(page);
331	}
332	dec_io(page, last_write_complete);
333	bio_put(bio);
334}
335
336static int metapage_writepage(struct page *page, struct writeback_control *wbc)
 
337{
338	struct bio *bio = NULL;
339	int block_offset;	/* block offset of mp within page */
340	struct inode *inode = page->mapping->host;
341	int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
342	int len;
343	int xlen;
344	struct metapage *mp;
345	int redirty = 0;
346	sector_t lblock;
347	int nr_underway = 0;
348	sector_t pblock;
349	sector_t next_block = 0;
350	sector_t page_start;
351	unsigned long bio_bytes = 0;
352	unsigned long bio_offset = 0;
353	int offset;
354	int bad_blocks = 0;
355
356	page_start = (sector_t)page->index <<
357		     (PAGE_SHIFT - inode->i_blkbits);
358	BUG_ON(!PageLocked(page));
359	BUG_ON(PageWriteback(page));
360	set_page_writeback(page);
361
362	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
363		mp = page_to_mp(page, offset);
364
365		if (!mp || !test_bit(META_dirty, &mp->flag))
366			continue;
367
368		if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
369			redirty = 1;
370			/*
371			 * Make sure this page isn't blocked indefinitely.
372			 * If the journal isn't undergoing I/O, push it
373			 */
374			if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
375				jfs_flush_journal(mp->log, 0);
376			continue;
377		}
378
379		clear_bit(META_dirty, &mp->flag);
380		set_bit(META_io, &mp->flag);
381		block_offset = offset >> inode->i_blkbits;
382		lblock = page_start + block_offset;
383		if (bio) {
384			if (xlen && lblock == next_block) {
385				/* Contiguous, in memory & on disk */
386				len = min(xlen, blocks_per_mp);
387				xlen -= len;
388				bio_bytes += len << inode->i_blkbits;
389				continue;
390			}
391			/* Not contiguous */
392			if (bio_add_page(bio, page, bio_bytes, bio_offset) <
393			    bio_bytes)
394				goto add_failed;
395			/*
396			 * Increment counter before submitting i/o to keep
397			 * count from hitting zero before we're through
398			 */
399			inc_io(page);
400			if (!bio->bi_iter.bi_size)
401				goto dump_bio;
402			submit_bio(bio);
403			nr_underway++;
404			bio = NULL;
405		} else
406			inc_io(page);
407		xlen = (PAGE_SIZE - offset) >> inode->i_blkbits;
408		pblock = metapage_get_blocks(inode, lblock, &xlen);
409		if (!pblock) {
410			printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
411			/*
412			 * We already called inc_io(), but can't cancel it
413			 * with dec_io() until we're done with the page
414			 */
415			bad_blocks++;
416			continue;
417		}
418		len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
419
420		bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOFS);
421		bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
422		bio->bi_end_io = metapage_write_end_io;
423		bio->bi_private = page;
424
425		/* Don't call bio_add_page yet, we may add to this vec */
426		bio_offset = offset;
427		bio_bytes = len << inode->i_blkbits;
428
429		xlen -= len;
430		next_block = lblock + len;
431	}
432	if (bio) {
433		if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
434				goto add_failed;
435		if (!bio->bi_iter.bi_size)
436			goto dump_bio;
437
438		submit_bio(bio);
439		nr_underway++;
440	}
441	if (redirty)
442		redirty_page_for_writepage(wbc, page);
443
444	unlock_page(page);
445
446	if (bad_blocks)
447		goto err_out;
448
449	if (nr_underway == 0)
450		end_page_writeback(page);
451
452	return 0;
453add_failed:
454	/* We should never reach here, since we're only adding one vec */
455	printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
456	goto skip;
457dump_bio:
458	print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
459		       4, bio, sizeof(*bio), 0);
460skip:
461	bio_put(bio);
462	unlock_page(page);
463	dec_io(page, last_write_complete);
464err_out:
465	while (bad_blocks--)
466		dec_io(page, last_write_complete);
467	return -EIO;
468}
469
 
 
 
 
 
 
 
 
 
 
 
 
 
470static int metapage_read_folio(struct file *fp, struct folio *folio)
471{
472	struct page *page = &folio->page;
473	struct inode *inode = page->mapping->host;
474	struct bio *bio = NULL;
475	int block_offset;
476	int blocks_per_page = i_blocks_per_page(inode, page);
477	sector_t page_start;	/* address of page in fs blocks */
478	sector_t pblock;
479	int xlen;
480	unsigned int len;
481	int offset;
482
483	BUG_ON(!PageLocked(page));
484	page_start = (sector_t)page->index <<
485		     (PAGE_SHIFT - inode->i_blkbits);
486
487	block_offset = 0;
488	while (block_offset < blocks_per_page) {
489		xlen = blocks_per_page - block_offset;
490		pblock = metapage_get_blocks(inode, page_start + block_offset,
491					     &xlen);
492		if (pblock) {
493			if (!PagePrivate(page))
494				insert_metapage(page, NULL);
495			inc_io(page);
496			if (bio)
497				submit_bio(bio);
498
499			bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_READ,
500					GFP_NOFS);
501			bio->bi_iter.bi_sector =
502				pblock << (inode->i_blkbits - 9);
503			bio->bi_end_io = metapage_read_end_io;
504			bio->bi_private = page;
505			len = xlen << inode->i_blkbits;
506			offset = block_offset << inode->i_blkbits;
507			if (bio_add_page(bio, page, len, offset) < len)
508				goto add_failed;
509			block_offset += xlen;
510		} else
511			block_offset++;
512	}
513	if (bio)
514		submit_bio(bio);
515	else
516		unlock_page(page);
517
518	return 0;
519
520add_failed:
521	printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
522	bio_put(bio);
523	dec_io(page, last_read_complete);
524	return -EIO;
525}
526
527static bool metapage_release_folio(struct folio *folio, gfp_t gfp_mask)
528{
529	struct metapage *mp;
530	bool ret = true;
531	int offset;
532
533	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
534		mp = page_to_mp(&folio->page, offset);
535
536		if (!mp)
537			continue;
538
539		jfs_info("metapage_release_folio: mp = 0x%p", mp);
540		if (mp->count || mp->nohomeok ||
541		    test_bit(META_dirty, &mp->flag)) {
542			jfs_info("count = %ld, nohomeok = %d", mp->count,
543				 mp->nohomeok);
544			ret = false;
545			continue;
546		}
547		if (mp->lsn)
548			remove_from_logsync(mp);
549		remove_metapage(&folio->page, mp);
550		INCREMENT(mpStat.pagefree);
551		free_metapage(mp);
552	}
553	return ret;
554}
555
556static void metapage_invalidate_folio(struct folio *folio, size_t offset,
557				    size_t length)
558{
559	BUG_ON(offset || length < folio_size(folio));
560
561	BUG_ON(folio_test_writeback(folio));
562
563	metapage_release_folio(folio, 0);
564}
565
566const struct address_space_operations jfs_metapage_aops = {
567	.read_folio	= metapage_read_folio,
568	.writepage	= metapage_writepage,
569	.release_folio	= metapage_release_folio,
570	.invalidate_folio = metapage_invalidate_folio,
571	.dirty_folio	= filemap_dirty_folio,
572};
573
574struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
575				unsigned int size, int absolute,
576				unsigned long new)
577{
578	int l2BlocksPerPage;
579	int l2bsize;
580	struct address_space *mapping;
581	struct metapage *mp = NULL;
582	struct page *page;
583	unsigned long page_index;
584	unsigned long page_offset;
585
586	jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
587		 inode->i_ino, lblock, absolute);
588
589	l2bsize = inode->i_blkbits;
590	l2BlocksPerPage = PAGE_SHIFT - l2bsize;
591	page_index = lblock >> l2BlocksPerPage;
592	page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
593	if ((page_offset + size) > PAGE_SIZE) {
594		jfs_err("MetaData crosses page boundary!!");
595		jfs_err("lblock = %lx, size  = %d", lblock, size);
596		dump_stack();
597		return NULL;
598	}
599	if (absolute)
600		mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
601	else {
602		/*
603		 * If an nfs client tries to read an inode that is larger
604		 * than any existing inodes, we may try to read past the
605		 * end of the inode map
606		 */
607		if ((lblock << inode->i_blkbits) >= inode->i_size)
608			return NULL;
609		mapping = inode->i_mapping;
610	}
611
612	if (new && (PSIZE == PAGE_SIZE)) {
613		page = grab_cache_page(mapping, page_index);
614		if (!page) {
615			jfs_err("grab_cache_page failed!");
616			return NULL;
617		}
618		SetPageUptodate(page);
619	} else {
620		page = read_mapping_page(mapping, page_index, NULL);
621		if (IS_ERR(page)) {
622			jfs_err("read_mapping_page failed!");
623			return NULL;
624		}
625		lock_page(page);
626	}
627
628	mp = page_to_mp(page, page_offset);
629	if (mp) {
630		if (mp->logical_size != size) {
631			jfs_error(inode->i_sb,
632				  "get_mp->logical_size != size\n");
633			jfs_err("logical_size = %d, size = %d",
634				mp->logical_size, size);
635			dump_stack();
636			goto unlock;
637		}
638		mp->count++;
639		lock_metapage(mp);
640		if (test_bit(META_discard, &mp->flag)) {
641			if (!new) {
642				jfs_error(inode->i_sb,
643					  "using a discarded metapage\n");
644				discard_metapage(mp);
645				goto unlock;
646			}
647			clear_bit(META_discard, &mp->flag);
648		}
649	} else {
650		INCREMENT(mpStat.pagealloc);
651		mp = alloc_metapage(GFP_NOFS);
652		if (!mp)
653			goto unlock;
654		mp->page = page;
655		mp->sb = inode->i_sb;
656		mp->flag = 0;
657		mp->xflag = COMMIT_PAGE;
658		mp->count = 1;
659		mp->nohomeok = 0;
660		mp->logical_size = size;
661		mp->data = page_address(page) + page_offset;
662		mp->index = lblock;
663		if (unlikely(insert_metapage(page, mp))) {
664			free_metapage(mp);
665			goto unlock;
666		}
667		lock_metapage(mp);
668	}
669
670	if (new) {
671		jfs_info("zeroing mp = 0x%p", mp);
672		memset(mp->data, 0, PSIZE);
673	}
674
675	unlock_page(page);
676	jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
677	return mp;
678
679unlock:
680	unlock_page(page);
681	return NULL;
682}
683
684void grab_metapage(struct metapage * mp)
685{
686	jfs_info("grab_metapage: mp = 0x%p", mp);
687	get_page(mp->page);
688	lock_page(mp->page);
689	mp->count++;
690	lock_metapage(mp);
691	unlock_page(mp->page);
692}
693
694static int metapage_write_one(struct page *page)
695{
696	struct folio *folio = page_folio(page);
697	struct address_space *mapping = folio->mapping;
698	struct writeback_control wbc = {
699		.sync_mode = WB_SYNC_ALL,
700		.nr_to_write = folio_nr_pages(folio),
701	};
702	int ret = 0;
703
704	BUG_ON(!folio_test_locked(folio));
705
706	folio_wait_writeback(folio);
707
708	if (folio_clear_dirty_for_io(folio)) {
709		folio_get(folio);
710		ret = metapage_writepage(page, &wbc);
711		if (ret == 0)
712			folio_wait_writeback(folio);
713		folio_put(folio);
714	} else {
715		folio_unlock(folio);
716	}
717
718	if (!ret)
719		ret = filemap_check_errors(mapping);
720	return ret;
721}
722
723void force_metapage(struct metapage *mp)
724{
725	struct page *page = mp->page;
726	jfs_info("force_metapage: mp = 0x%p", mp);
727	set_bit(META_forcewrite, &mp->flag);
728	clear_bit(META_sync, &mp->flag);
729	get_page(page);
730	lock_page(page);
731	set_page_dirty(page);
732	if (metapage_write_one(page))
733		jfs_error(mp->sb, "metapage_write_one() failed\n");
734	clear_bit(META_forcewrite, &mp->flag);
735	put_page(page);
736}
737
738void hold_metapage(struct metapage *mp)
739{
740	lock_page(mp->page);
741}
742
743void put_metapage(struct metapage *mp)
744{
745	if (mp->count || mp->nohomeok) {
746		/* Someone else will release this */
747		unlock_page(mp->page);
748		return;
749	}
750	get_page(mp->page);
751	mp->count++;
752	lock_metapage(mp);
753	unlock_page(mp->page);
754	release_metapage(mp);
755}
756
757void release_metapage(struct metapage * mp)
758{
759	struct page *page = mp->page;
760	jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
761
762	BUG_ON(!page);
763
764	lock_page(page);
765	unlock_metapage(mp);
766
767	assert(mp->count);
768	if (--mp->count || mp->nohomeok) {
769		unlock_page(page);
770		put_page(page);
771		return;
772	}
773
774	if (test_bit(META_dirty, &mp->flag)) {
775		set_page_dirty(page);
776		if (test_bit(META_sync, &mp->flag)) {
777			clear_bit(META_sync, &mp->flag);
778			if (metapage_write_one(page))
779				jfs_error(mp->sb, "metapage_write_one() failed\n");
780			lock_page(page);
781		}
782	} else if (mp->lsn)	/* discard_metapage doesn't remove it */
783		remove_from_logsync(mp);
784
785	/* Try to keep metapages from using up too much memory */
786	drop_metapage(page, mp);
787
788	unlock_page(page);
789	put_page(page);
790}
791
792void __invalidate_metapages(struct inode *ip, s64 addr, int len)
793{
794	sector_t lblock;
795	int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
796	int BlocksPerPage = 1 << l2BlocksPerPage;
797	/* All callers are interested in block device's mapping */
798	struct address_space *mapping =
799		JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
800	struct metapage *mp;
801	struct page *page;
802	unsigned int offset;
803
804	/*
805	 * Mark metapages to discard.  They will eventually be
806	 * released, but should not be written.
807	 */
808	for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
809	     lblock += BlocksPerPage) {
810		page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
811		if (!page)
 
812			continue;
813		for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
814			mp = page_to_mp(page, offset);
815			if (!mp)
816				continue;
817			if (mp->index < addr)
818				continue;
819			if (mp->index >= addr + len)
820				break;
821
822			clear_bit(META_dirty, &mp->flag);
823			set_bit(META_discard, &mp->flag);
824			if (mp->lsn)
825				remove_from_logsync(mp);
826		}
827		unlock_page(page);
828		put_page(page);
829	}
830}
831
832#ifdef CONFIG_JFS_STATISTICS
833int jfs_mpstat_proc_show(struct seq_file *m, void *v)
834{
835	seq_printf(m,
836		       "JFS Metapage statistics\n"
837		       "=======================\n"
838		       "page allocations = %d\n"
839		       "page frees = %d\n"
840		       "lock waits = %d\n",
841		       mpStat.pagealloc,
842		       mpStat.pagefree,
843		       mpStat.lockwait);
844	return 0;
845}
846#endif
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *   Copyright (C) International Business Machines Corp., 2000-2005
  4 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
  5 */
  6
  7#include <linux/blkdev.h>
  8#include <linux/fs.h>
  9#include <linux/mm.h>
 10#include <linux/module.h>
 11#include <linux/bio.h>
 12#include <linux/slab.h>
 13#include <linux/init.h>
 14#include <linux/buffer_head.h>
 15#include <linux/mempool.h>
 16#include <linux/seq_file.h>
 17#include <linux/writeback.h>
 18#include "jfs_incore.h"
 19#include "jfs_superblock.h"
 20#include "jfs_filsys.h"
 21#include "jfs_metapage.h"
 22#include "jfs_txnmgr.h"
 23#include "jfs_debug.h"
 24
 25#ifdef CONFIG_JFS_STATISTICS
 26static struct {
 27	uint	pagealloc;	/* # of page allocations */
 28	uint	pagefree;	/* # of page frees */
 29	uint	lockwait;	/* # of sleeping lock_metapage() calls */
 30} mpStat;
 31#endif
 32
 33#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
 34#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag)
 35
 36static inline void unlock_metapage(struct metapage *mp)
 37{
 38	clear_bit_unlock(META_locked, &mp->flag);
 39	wake_up(&mp->wait);
 40}
 41
 42static inline void __lock_metapage(struct metapage *mp)
 43{
 44	DECLARE_WAITQUEUE(wait, current);
 45	INCREMENT(mpStat.lockwait);
 46	add_wait_queue_exclusive(&mp->wait, &wait);
 47	do {
 48		set_current_state(TASK_UNINTERRUPTIBLE);
 49		if (metapage_locked(mp)) {
 50			folio_unlock(mp->folio);
 51			io_schedule();
 52			folio_lock(mp->folio);
 53		}
 54	} while (trylock_metapage(mp));
 55	__set_current_state(TASK_RUNNING);
 56	remove_wait_queue(&mp->wait, &wait);
 57}
 58
 59/*
 60 * Must have mp->folio locked
 61 */
 62static inline void lock_metapage(struct metapage *mp)
 63{
 64	if (trylock_metapage(mp))
 65		__lock_metapage(mp);
 66}
 67
 68#define METAPOOL_MIN_PAGES 32
 69static struct kmem_cache *metapage_cache;
 70static mempool_t *metapage_mempool;
 71
 72#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)
 73
 74#if MPS_PER_PAGE > 1
 75
 76struct meta_anchor {
 77	int mp_count;
 78	atomic_t io_count;
 79	blk_status_t status;
 80	struct metapage *mp[MPS_PER_PAGE];
 81};
 
 82
 83static inline struct metapage *folio_to_mp(struct folio *folio, int offset)
 84{
 85	struct meta_anchor *anchor = folio->private;
 86
 87	if (!anchor)
 88		return NULL;
 89	return anchor->mp[offset >> L2PSIZE];
 90}
 91
 92static inline int insert_metapage(struct folio *folio, struct metapage *mp)
 93{
 94	struct meta_anchor *a;
 95	int index;
 96	int l2mp_blocks;	/* log2 blocks per metapage */
 97
 98	a = folio->private;
 99	if (!a) {
 
100		a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
101		if (!a)
102			return -ENOMEM;
103		folio_attach_private(folio, a);
104		kmap(&folio->page);
 
105	}
106
107	if (mp) {
108		l2mp_blocks = L2PSIZE - folio->mapping->host->i_blkbits;
109		index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
110		a->mp_count++;
111		a->mp[index] = mp;
112	}
113
114	return 0;
115}
116
117static inline void remove_metapage(struct folio *folio, struct metapage *mp)
118{
119	struct meta_anchor *a = folio->private;
120	int l2mp_blocks = L2PSIZE - folio->mapping->host->i_blkbits;
121	int index;
122
123	index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
124
125	BUG_ON(a->mp[index] != mp);
126
127	a->mp[index] = NULL;
128	if (--a->mp_count == 0) {
129		kfree(a);
130		folio_detach_private(folio);
131		kunmap(&folio->page);
 
132	}
133}
134
135static inline void inc_io(struct folio *folio)
136{
137	struct meta_anchor *anchor = folio->private;
138
139	atomic_inc(&anchor->io_count);
140}
141
142static inline void dec_io(struct folio *folio, blk_status_t status,
143		void (*handler)(struct folio *, blk_status_t))
144{
145	struct meta_anchor *anchor = folio->private;
146
147	if (anchor->status == BLK_STS_OK)
148		anchor->status = status;
149
150	if (atomic_dec_and_test(&anchor->io_count))
151		handler(folio, anchor->status);
152}
153
154#else
155static inline struct metapage *folio_to_mp(struct folio *folio, int offset)
156{
157	return folio->private;
158}
159
160static inline int insert_metapage(struct folio *folio, struct metapage *mp)
161{
162	if (mp) {
163		folio_attach_private(folio, mp);
164		kmap(&folio->page);
 
165	}
166	return 0;
167}
168
169static inline void remove_metapage(struct folio *folio, struct metapage *mp)
170{
171	folio_detach_private(folio);
172	kunmap(&folio->page);
 
173}
174
175#define inc_io(folio) do {} while(0)
176#define dec_io(folio, status, handler) handler(folio, status)
177
178#endif
179
180static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
181{
182	struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask);
183
184	if (mp) {
185		mp->lid = 0;
186		mp->lsn = 0;
187		mp->data = NULL;
188		mp->clsn = 0;
189		mp->log = NULL;
190		init_waitqueue_head(&mp->wait);
191	}
192	return mp;
193}
194
195static inline void free_metapage(struct metapage *mp)
196{
197	mempool_free(mp, metapage_mempool);
198}
199
200int __init metapage_init(void)
201{
202	/*
203	 * Allocate the metapage structures
204	 */
205	metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
206					   0, 0, NULL);
207	if (metapage_cache == NULL)
208		return -ENOMEM;
209
210	metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
211						    metapage_cache);
212
213	if (metapage_mempool == NULL) {
214		kmem_cache_destroy(metapage_cache);
215		return -ENOMEM;
216	}
217
218	return 0;
219}
220
221void metapage_exit(void)
222{
223	mempool_destroy(metapage_mempool);
224	kmem_cache_destroy(metapage_cache);
225}
226
227static inline void drop_metapage(struct folio *folio, struct metapage *mp)
228{
229	if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
230	    test_bit(META_io, &mp->flag))
231		return;
232	remove_metapage(folio, mp);
233	INCREMENT(mpStat.pagefree);
234	free_metapage(mp);
235}
236
237/*
238 * Metapage address space operations
239 */
240
241static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
242				    int *len)
243{
244	int rc = 0;
245	int xflag;
246	s64 xaddr;
247	sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
248			       inode->i_blkbits;
249
250	if (lblock >= file_blocks)
251		return 0;
252	if (lblock + *len > file_blocks)
253		*len = file_blocks - lblock;
254
255	if (inode->i_ino) {
256		rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
257		if ((rc == 0) && *len)
258			lblock = (sector_t)xaddr;
259		else
260			lblock = 0;
261	} /* else no mapping */
262
263	return lblock;
264}
265
266static void last_read_complete(struct folio *folio, blk_status_t status)
267{
268	if (status)
269		printk(KERN_ERR "Read error %d at %#llx\n", status,
270				folio_pos(folio));
271
272	folio_end_read(folio, status == 0);
273}
274
275static void metapage_read_end_io(struct bio *bio)
276{
277	struct folio *folio = bio->bi_private;
 
 
 
 
 
278
279	dec_io(folio, bio->bi_status, last_read_complete);
280	bio_put(bio);
281}
282
283static void remove_from_logsync(struct metapage *mp)
284{
285	struct jfs_log *log = mp->log;
286	unsigned long flags;
287/*
288 * This can race.  Recheck that log hasn't been set to null, and after
289 * acquiring logsync lock, recheck lsn
290 */
291	if (!log)
292		return;
293
294	LOGSYNC_LOCK(log, flags);
295	if (mp->lsn) {
296		mp->log = NULL;
297		mp->lsn = 0;
298		mp->clsn = 0;
299		log->count--;
300		list_del(&mp->synclist);
301	}
302	LOGSYNC_UNLOCK(log, flags);
303}
304
305static void last_write_complete(struct folio *folio, blk_status_t status)
306{
307	struct metapage *mp;
308	unsigned int offset;
309
310	if (status) {
311		int err = blk_status_to_errno(status);
312		printk(KERN_ERR "metapage_write_end_io: I/O error\n");
313		mapping_set_error(folio->mapping, err);
314	}
315
316	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
317		mp = folio_to_mp(folio, offset);
318		if (mp && test_bit(META_io, &mp->flag)) {
319			if (mp->lsn)
320				remove_from_logsync(mp);
321			clear_bit(META_io, &mp->flag);
322		}
323		/*
324		 * I'd like to call drop_metapage here, but I don't think it's
325		 * safe unless I have the page locked
326		 */
327	}
328	folio_end_writeback(folio);
329}
330
331static void metapage_write_end_io(struct bio *bio)
332{
333	struct folio *folio = bio->bi_private;
334
335	BUG_ON(!folio->private);
336
337	dec_io(folio, bio->bi_status, last_write_complete);
 
 
 
 
338	bio_put(bio);
339}
340
341static int metapage_write_folio(struct folio *folio,
342		struct writeback_control *wbc, void *unused)
343{
344	struct bio *bio = NULL;
345	int block_offset;	/* block offset of mp within page */
346	struct inode *inode = folio->mapping->host;
347	int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
348	int len;
349	int xlen;
350	struct metapage *mp;
351	int redirty = 0;
352	sector_t lblock;
353	int nr_underway = 0;
354	sector_t pblock;
355	sector_t next_block = 0;
356	sector_t page_start;
357	unsigned long bio_bytes = 0;
358	unsigned long bio_offset = 0;
359	int offset;
360	int bad_blocks = 0;
361
362	page_start = folio_pos(folio) >> inode->i_blkbits;
363	BUG_ON(!folio_test_locked(folio));
364	BUG_ON(folio_test_writeback(folio));
365	folio_start_writeback(folio);
 
366
367	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
368		mp = folio_to_mp(folio, offset);
369
370		if (!mp || !test_bit(META_dirty, &mp->flag))
371			continue;
372
373		if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
374			redirty = 1;
375			/*
376			 * Make sure this page isn't blocked indefinitely.
377			 * If the journal isn't undergoing I/O, push it
378			 */
379			if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
380				jfs_flush_journal(mp->log, 0);
381			continue;
382		}
383
384		clear_bit(META_dirty, &mp->flag);
385		set_bit(META_io, &mp->flag);
386		block_offset = offset >> inode->i_blkbits;
387		lblock = page_start + block_offset;
388		if (bio) {
389			if (xlen && lblock == next_block) {
390				/* Contiguous, in memory & on disk */
391				len = min(xlen, blocks_per_mp);
392				xlen -= len;
393				bio_bytes += len << inode->i_blkbits;
394				continue;
395			}
396			/* Not contiguous */
397			bio_add_folio_nofail(bio, folio, bio_bytes, bio_offset);
 
 
398			/*
399			 * Increment counter before submitting i/o to keep
400			 * count from hitting zero before we're through
401			 */
402			inc_io(folio);
403			if (!bio->bi_iter.bi_size)
404				goto dump_bio;
405			submit_bio(bio);
406			nr_underway++;
407			bio = NULL;
408		} else
409			inc_io(folio);
410		xlen = (folio_size(folio) - offset) >> inode->i_blkbits;
411		pblock = metapage_get_blocks(inode, lblock, &xlen);
412		if (!pblock) {
413			printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
414			/*
415			 * We already called inc_io(), but can't cancel it
416			 * with dec_io() until we're done with the page
417			 */
418			bad_blocks++;
419			continue;
420		}
421		len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
422
423		bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOFS);
424		bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
425		bio->bi_end_io = metapage_write_end_io;
426		bio->bi_private = folio;
427
428		/* Don't call bio_add_page yet, we may add to this vec */
429		bio_offset = offset;
430		bio_bytes = len << inode->i_blkbits;
431
432		xlen -= len;
433		next_block = lblock + len;
434	}
435	if (bio) {
436		bio_add_folio_nofail(bio, folio, bio_bytes, bio_offset);
 
437		if (!bio->bi_iter.bi_size)
438			goto dump_bio;
439
440		submit_bio(bio);
441		nr_underway++;
442	}
443	if (redirty)
444		folio_redirty_for_writepage(wbc, folio);
445
446	folio_unlock(folio);
447
448	if (bad_blocks)
449		goto err_out;
450
451	if (nr_underway == 0)
452		folio_end_writeback(folio);
453
454	return 0;
 
 
 
 
455dump_bio:
456	print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
457		       4, bio, sizeof(*bio), 0);
 
458	bio_put(bio);
459	folio_unlock(folio);
460	dec_io(folio, BLK_STS_OK, last_write_complete);
461err_out:
462	while (bad_blocks--)
463		dec_io(folio, BLK_STS_OK, last_write_complete);
464	return -EIO;
465}
466
467static int metapage_writepages(struct address_space *mapping,
468		struct writeback_control *wbc)
469{
470	struct blk_plug plug;
471	int err;
472
473	blk_start_plug(&plug);
474	err = write_cache_pages(mapping, wbc, metapage_write_folio, NULL);
475	blk_finish_plug(&plug);
476
477	return err;
478}
479
480static int metapage_read_folio(struct file *fp, struct folio *folio)
481{
482	struct inode *inode = folio->mapping->host;
 
483	struct bio *bio = NULL;
484	int block_offset;
485	int blocks_per_page = i_blocks_per_folio(inode, folio);
486	sector_t page_start;	/* address of page in fs blocks */
487	sector_t pblock;
488	int xlen;
489	unsigned int len;
490	int offset;
491
492	BUG_ON(!folio_test_locked(folio));
493	page_start = folio_pos(folio) >> inode->i_blkbits;
 
494
495	block_offset = 0;
496	while (block_offset < blocks_per_page) {
497		xlen = blocks_per_page - block_offset;
498		pblock = metapage_get_blocks(inode, page_start + block_offset,
499					     &xlen);
500		if (pblock) {
501			if (!folio->private)
502				insert_metapage(folio, NULL);
503			inc_io(folio);
504			if (bio)
505				submit_bio(bio);
506
507			bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_READ,
508					GFP_NOFS);
509			bio->bi_iter.bi_sector =
510				pblock << (inode->i_blkbits - 9);
511			bio->bi_end_io = metapage_read_end_io;
512			bio->bi_private = folio;
513			len = xlen << inode->i_blkbits;
514			offset = block_offset << inode->i_blkbits;
515			bio_add_folio_nofail(bio, folio, len, offset);
 
516			block_offset += xlen;
517		} else
518			block_offset++;
519	}
520	if (bio)
521		submit_bio(bio);
522	else
523		folio_unlock(folio);
524
525	return 0;
 
 
 
 
 
 
526}
527
528static bool metapage_release_folio(struct folio *folio, gfp_t gfp_mask)
529{
530	struct metapage *mp;
531	bool ret = true;
532	int offset;
533
534	for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
535		mp = folio_to_mp(folio, offset);
536
537		if (!mp)
538			continue;
539
540		jfs_info("metapage_release_folio: mp = 0x%p", mp);
541		if (mp->count || mp->nohomeok ||
542		    test_bit(META_dirty, &mp->flag)) {
543			jfs_info("count = %ld, nohomeok = %d", mp->count,
544				 mp->nohomeok);
545			ret = false;
546			continue;
547		}
548		if (mp->lsn)
549			remove_from_logsync(mp);
550		remove_metapage(folio, mp);
551		INCREMENT(mpStat.pagefree);
552		free_metapage(mp);
553	}
554	return ret;
555}
556
557static void metapage_invalidate_folio(struct folio *folio, size_t offset,
558				    size_t length)
559{
560	BUG_ON(offset || length < folio_size(folio));
561
562	BUG_ON(folio_test_writeback(folio));
563
564	metapage_release_folio(folio, 0);
565}
566
567const struct address_space_operations jfs_metapage_aops = {
568	.read_folio	= metapage_read_folio,
569	.writepages	= metapage_writepages,
570	.release_folio	= metapage_release_folio,
571	.invalidate_folio = metapage_invalidate_folio,
572	.dirty_folio	= filemap_dirty_folio,
573};
574
575struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
576				unsigned int size, int absolute,
577				unsigned long new)
578{
579	int l2BlocksPerPage;
580	int l2bsize;
581	struct address_space *mapping;
582	struct metapage *mp = NULL;
583	struct folio *folio;
584	unsigned long page_index;
585	unsigned long page_offset;
586
587	jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
588		 inode->i_ino, lblock, absolute);
589
590	l2bsize = inode->i_blkbits;
591	l2BlocksPerPage = PAGE_SHIFT - l2bsize;
592	page_index = lblock >> l2BlocksPerPage;
593	page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
594	if ((page_offset + size) > PAGE_SIZE) {
595		jfs_err("MetaData crosses page boundary!!");
596		jfs_err("lblock = %lx, size  = %d", lblock, size);
597		dump_stack();
598		return NULL;
599	}
600	if (absolute)
601		mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
602	else {
603		/*
604		 * If an nfs client tries to read an inode that is larger
605		 * than any existing inodes, we may try to read past the
606		 * end of the inode map
607		 */
608		if ((lblock << inode->i_blkbits) >= inode->i_size)
609			return NULL;
610		mapping = inode->i_mapping;
611	}
612
613	if (new && (PSIZE == PAGE_SIZE)) {
614		folio = filemap_grab_folio(mapping, page_index);
615		if (IS_ERR(folio)) {
616			jfs_err("filemap_grab_folio failed!");
617			return NULL;
618		}
619		folio_mark_uptodate(folio);
620	} else {
621		folio = read_mapping_folio(mapping, page_index, NULL);
622		if (IS_ERR(folio)) {
623			jfs_err("read_mapping_page failed!");
624			return NULL;
625		}
626		folio_lock(folio);
627	}
628
629	mp = folio_to_mp(folio, page_offset);
630	if (mp) {
631		if (mp->logical_size != size) {
632			jfs_error(inode->i_sb,
633				  "get_mp->logical_size != size\n");
634			jfs_err("logical_size = %d, size = %d",
635				mp->logical_size, size);
636			dump_stack();
637			goto unlock;
638		}
639		mp->count++;
640		lock_metapage(mp);
641		if (test_bit(META_discard, &mp->flag)) {
642			if (!new) {
643				jfs_error(inode->i_sb,
644					  "using a discarded metapage\n");
645				discard_metapage(mp);
646				goto unlock;
647			}
648			clear_bit(META_discard, &mp->flag);
649		}
650	} else {
651		INCREMENT(mpStat.pagealloc);
652		mp = alloc_metapage(GFP_NOFS);
653		if (!mp)
654			goto unlock;
655		mp->folio = folio;
656		mp->sb = inode->i_sb;
657		mp->flag = 0;
658		mp->xflag = COMMIT_PAGE;
659		mp->count = 1;
660		mp->nohomeok = 0;
661		mp->logical_size = size;
662		mp->data = folio_address(folio) + page_offset;
663		mp->index = lblock;
664		if (unlikely(insert_metapage(folio, mp))) {
665			free_metapage(mp);
666			goto unlock;
667		}
668		lock_metapage(mp);
669	}
670
671	if (new) {
672		jfs_info("zeroing mp = 0x%p", mp);
673		memset(mp->data, 0, PSIZE);
674	}
675
676	folio_unlock(folio);
677	jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
678	return mp;
679
680unlock:
681	folio_unlock(folio);
682	return NULL;
683}
684
685void grab_metapage(struct metapage * mp)
686{
687	jfs_info("grab_metapage: mp = 0x%p", mp);
688	folio_get(mp->folio);
689	folio_lock(mp->folio);
690	mp->count++;
691	lock_metapage(mp);
692	folio_unlock(mp->folio);
693}
694
695static int metapage_write_one(struct folio *folio)
696{
 
697	struct address_space *mapping = folio->mapping;
698	struct writeback_control wbc = {
699		.sync_mode = WB_SYNC_ALL,
700		.nr_to_write = folio_nr_pages(folio),
701	};
702	int ret = 0;
703
704	BUG_ON(!folio_test_locked(folio));
705
706	folio_wait_writeback(folio);
707
708	if (folio_clear_dirty_for_io(folio)) {
709		folio_get(folio);
710		ret = metapage_write_folio(folio, &wbc, NULL);
711		if (ret == 0)
712			folio_wait_writeback(folio);
713		folio_put(folio);
714	} else {
715		folio_unlock(folio);
716	}
717
718	if (!ret)
719		ret = filemap_check_errors(mapping);
720	return ret;
721}
722
723void force_metapage(struct metapage *mp)
724{
725	struct folio *folio = mp->folio;
726	jfs_info("force_metapage: mp = 0x%p", mp);
727	set_bit(META_forcewrite, &mp->flag);
728	clear_bit(META_sync, &mp->flag);
729	folio_get(folio);
730	folio_lock(folio);
731	folio_mark_dirty(folio);
732	if (metapage_write_one(folio))
733		jfs_error(mp->sb, "metapage_write_one() failed\n");
734	clear_bit(META_forcewrite, &mp->flag);
735	folio_put(folio);
736}
737
738void hold_metapage(struct metapage *mp)
739{
740	folio_lock(mp->folio);
741}
742
743void put_metapage(struct metapage *mp)
744{
745	if (mp->count || mp->nohomeok) {
746		/* Someone else will release this */
747		folio_unlock(mp->folio);
748		return;
749	}
750	folio_get(mp->folio);
751	mp->count++;
752	lock_metapage(mp);
753	folio_unlock(mp->folio);
754	release_metapage(mp);
755}
756
757void release_metapage(struct metapage * mp)
758{
759	struct folio *folio = mp->folio;
760	jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
761
762	folio_lock(folio);
 
 
763	unlock_metapage(mp);
764
765	assert(mp->count);
766	if (--mp->count || mp->nohomeok) {
767		folio_unlock(folio);
768		folio_put(folio);
769		return;
770	}
771
772	if (test_bit(META_dirty, &mp->flag)) {
773		folio_mark_dirty(folio);
774		if (test_bit(META_sync, &mp->flag)) {
775			clear_bit(META_sync, &mp->flag);
776			if (metapage_write_one(folio))
777				jfs_error(mp->sb, "metapage_write_one() failed\n");
778			folio_lock(folio);
779		}
780	} else if (mp->lsn)	/* discard_metapage doesn't remove it */
781		remove_from_logsync(mp);
782
783	/* Try to keep metapages from using up too much memory */
784	drop_metapage(folio, mp);
785
786	folio_unlock(folio);
787	folio_put(folio);
788}
789
790void __invalidate_metapages(struct inode *ip, s64 addr, int len)
791{
792	sector_t lblock;
793	int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
794	int BlocksPerPage = 1 << l2BlocksPerPage;
795	/* All callers are interested in block device's mapping */
796	struct address_space *mapping =
797		JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
798	struct metapage *mp;
 
799	unsigned int offset;
800
801	/*
802	 * Mark metapages to discard.  They will eventually be
803	 * released, but should not be written.
804	 */
805	for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
806	     lblock += BlocksPerPage) {
807		struct folio *folio = filemap_lock_folio(mapping,
808				lblock >> l2BlocksPerPage);
809		if (IS_ERR(folio))
810			continue;
811		for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
812			mp = folio_to_mp(folio, offset);
813			if (!mp)
814				continue;
815			if (mp->index < addr)
816				continue;
817			if (mp->index >= addr + len)
818				break;
819
820			clear_bit(META_dirty, &mp->flag);
821			set_bit(META_discard, &mp->flag);
822			if (mp->lsn)
823				remove_from_logsync(mp);
824		}
825		folio_unlock(folio);
826		folio_put(folio);
827	}
828}
829
830#ifdef CONFIG_JFS_STATISTICS
831int jfs_mpstat_proc_show(struct seq_file *m, void *v)
832{
833	seq_printf(m,
834		       "JFS Metapage statistics\n"
835		       "=======================\n"
836		       "page allocations = %d\n"
837		       "page frees = %d\n"
838		       "lock waits = %d\n",
839		       mpStat.pagealloc,
840		       mpStat.pagefree,
841		       mpStat.lockwait);
842	return 0;
843}
844#endif