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1/*
2 * Copyright (C) International Business Machines Corp., 2000-2005
3 * Portions Copyright (C) Christoph Hellwig, 2001-2002
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/fs.h>
21#include <linux/mm.h>
22#include <linux/module.h>
23#include <linux/bio.h>
24#include <linux/slab.h>
25#include <linux/init.h>
26#include <linux/buffer_head.h>
27#include <linux/mempool.h>
28#include <linux/seq_file.h>
29#include "jfs_incore.h"
30#include "jfs_superblock.h"
31#include "jfs_filsys.h"
32#include "jfs_metapage.h"
33#include "jfs_txnmgr.h"
34#include "jfs_debug.h"
35
36#ifdef CONFIG_JFS_STATISTICS
37static struct {
38 uint pagealloc; /* # of page allocations */
39 uint pagefree; /* # of page frees */
40 uint lockwait; /* # of sleeping lock_metapage() calls */
41} mpStat;
42#endif
43
44#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
45#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag)
46
47static inline void unlock_metapage(struct metapage *mp)
48{
49 clear_bit_unlock(META_locked, &mp->flag);
50 wake_up(&mp->wait);
51}
52
53static inline void __lock_metapage(struct metapage *mp)
54{
55 DECLARE_WAITQUEUE(wait, current);
56 INCREMENT(mpStat.lockwait);
57 add_wait_queue_exclusive(&mp->wait, &wait);
58 do {
59 set_current_state(TASK_UNINTERRUPTIBLE);
60 if (metapage_locked(mp)) {
61 unlock_page(mp->page);
62 io_schedule();
63 lock_page(mp->page);
64 }
65 } while (trylock_metapage(mp));
66 __set_current_state(TASK_RUNNING);
67 remove_wait_queue(&mp->wait, &wait);
68}
69
70/*
71 * Must have mp->page locked
72 */
73static inline void lock_metapage(struct metapage *mp)
74{
75 if (trylock_metapage(mp))
76 __lock_metapage(mp);
77}
78
79#define METAPOOL_MIN_PAGES 32
80static struct kmem_cache *metapage_cache;
81static mempool_t *metapage_mempool;
82
83#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)
84
85#if MPS_PER_PAGE > 1
86
87struct meta_anchor {
88 int mp_count;
89 atomic_t io_count;
90 struct metapage *mp[MPS_PER_PAGE];
91};
92#define mp_anchor(page) ((struct meta_anchor *)page_private(page))
93
94static inline struct metapage *page_to_mp(struct page *page, int offset)
95{
96 if (!PagePrivate(page))
97 return NULL;
98 return mp_anchor(page)->mp[offset >> L2PSIZE];
99}
100
101static inline int insert_metapage(struct page *page, struct metapage *mp)
102{
103 struct meta_anchor *a;
104 int index;
105 int l2mp_blocks; /* log2 blocks per metapage */
106
107 if (PagePrivate(page))
108 a = mp_anchor(page);
109 else {
110 a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
111 if (!a)
112 return -ENOMEM;
113 set_page_private(page, (unsigned long)a);
114 SetPagePrivate(page);
115 kmap(page);
116 }
117
118 if (mp) {
119 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
120 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
121 a->mp_count++;
122 a->mp[index] = mp;
123 }
124
125 return 0;
126}
127
128static inline void remove_metapage(struct page *page, struct metapage *mp)
129{
130 struct meta_anchor *a = mp_anchor(page);
131 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
132 int index;
133
134 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
135
136 BUG_ON(a->mp[index] != mp);
137
138 a->mp[index] = NULL;
139 if (--a->mp_count == 0) {
140 kfree(a);
141 set_page_private(page, 0);
142 ClearPagePrivate(page);
143 kunmap(page);
144 }
145}
146
147static inline void inc_io(struct page *page)
148{
149 atomic_inc(&mp_anchor(page)->io_count);
150}
151
152static inline void dec_io(struct page *page, void (*handler) (struct page *))
153{
154 if (atomic_dec_and_test(&mp_anchor(page)->io_count))
155 handler(page);
156}
157
158#else
159static inline struct metapage *page_to_mp(struct page *page, int offset)
160{
161 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
162}
163
164static inline int insert_metapage(struct page *page, struct metapage *mp)
165{
166 if (mp) {
167 set_page_private(page, (unsigned long)mp);
168 SetPagePrivate(page);
169 kmap(page);
170 }
171 return 0;
172}
173
174static inline void remove_metapage(struct page *page, struct metapage *mp)
175{
176 set_page_private(page, 0);
177 ClearPagePrivate(page);
178 kunmap(page);
179}
180
181#define inc_io(page) do {} while(0)
182#define dec_io(page, handler) handler(page)
183
184#endif
185
186static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
187{
188 struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask);
189
190 if (mp) {
191 mp->lid = 0;
192 mp->lsn = 0;
193 mp->data = NULL;
194 mp->clsn = 0;
195 mp->log = NULL;
196 init_waitqueue_head(&mp->wait);
197 }
198 return mp;
199}
200
201static inline void free_metapage(struct metapage *mp)
202{
203 mempool_free(mp, metapage_mempool);
204}
205
206int __init metapage_init(void)
207{
208 /*
209 * Allocate the metapage structures
210 */
211 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
212 0, 0, NULL);
213 if (metapage_cache == NULL)
214 return -ENOMEM;
215
216 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
217 metapage_cache);
218
219 if (metapage_mempool == NULL) {
220 kmem_cache_destroy(metapage_cache);
221 return -ENOMEM;
222 }
223
224 return 0;
225}
226
227void metapage_exit(void)
228{
229 mempool_destroy(metapage_mempool);
230 kmem_cache_destroy(metapage_cache);
231}
232
233static inline void drop_metapage(struct page *page, struct metapage *mp)
234{
235 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
236 test_bit(META_io, &mp->flag))
237 return;
238 remove_metapage(page, mp);
239 INCREMENT(mpStat.pagefree);
240 free_metapage(mp);
241}
242
243/*
244 * Metapage address space operations
245 */
246
247static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
248 int *len)
249{
250 int rc = 0;
251 int xflag;
252 s64 xaddr;
253 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
254 inode->i_blkbits;
255
256 if (lblock >= file_blocks)
257 return 0;
258 if (lblock + *len > file_blocks)
259 *len = file_blocks - lblock;
260
261 if (inode->i_ino) {
262 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
263 if ((rc == 0) && *len)
264 lblock = (sector_t)xaddr;
265 else
266 lblock = 0;
267 } /* else no mapping */
268
269 return lblock;
270}
271
272static void last_read_complete(struct page *page)
273{
274 if (!PageError(page))
275 SetPageUptodate(page);
276 unlock_page(page);
277}
278
279static void metapage_read_end_io(struct bio *bio)
280{
281 struct page *page = bio->bi_private;
282
283 if (bio->bi_status) {
284 printk(KERN_ERR "metapage_read_end_io: I/O error\n");
285 SetPageError(page);
286 }
287
288 dec_io(page, last_read_complete);
289 bio_put(bio);
290}
291
292static void remove_from_logsync(struct metapage *mp)
293{
294 struct jfs_log *log = mp->log;
295 unsigned long flags;
296/*
297 * This can race. Recheck that log hasn't been set to null, and after
298 * acquiring logsync lock, recheck lsn
299 */
300 if (!log)
301 return;
302
303 LOGSYNC_LOCK(log, flags);
304 if (mp->lsn) {
305 mp->log = NULL;
306 mp->lsn = 0;
307 mp->clsn = 0;
308 log->count--;
309 list_del(&mp->synclist);
310 }
311 LOGSYNC_UNLOCK(log, flags);
312}
313
314static void last_write_complete(struct page *page)
315{
316 struct metapage *mp;
317 unsigned int offset;
318
319 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
320 mp = page_to_mp(page, offset);
321 if (mp && test_bit(META_io, &mp->flag)) {
322 if (mp->lsn)
323 remove_from_logsync(mp);
324 clear_bit(META_io, &mp->flag);
325 }
326 /*
327 * I'd like to call drop_metapage here, but I don't think it's
328 * safe unless I have the page locked
329 */
330 }
331 end_page_writeback(page);
332}
333
334static void metapage_write_end_io(struct bio *bio)
335{
336 struct page *page = bio->bi_private;
337
338 BUG_ON(!PagePrivate(page));
339
340 if (bio->bi_status) {
341 printk(KERN_ERR "metapage_write_end_io: I/O error\n");
342 SetPageError(page);
343 }
344 dec_io(page, last_write_complete);
345 bio_put(bio);
346}
347
348static int metapage_writepage(struct page *page, struct writeback_control *wbc)
349{
350 struct bio *bio = NULL;
351 int block_offset; /* block offset of mp within page */
352 struct inode *inode = page->mapping->host;
353 int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
354 int len;
355 int xlen;
356 struct metapage *mp;
357 int redirty = 0;
358 sector_t lblock;
359 int nr_underway = 0;
360 sector_t pblock;
361 sector_t next_block = 0;
362 sector_t page_start;
363 unsigned long bio_bytes = 0;
364 unsigned long bio_offset = 0;
365 int offset;
366 int bad_blocks = 0;
367
368 page_start = (sector_t)page->index <<
369 (PAGE_SHIFT - inode->i_blkbits);
370 BUG_ON(!PageLocked(page));
371 BUG_ON(PageWriteback(page));
372 set_page_writeback(page);
373
374 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
375 mp = page_to_mp(page, offset);
376
377 if (!mp || !test_bit(META_dirty, &mp->flag))
378 continue;
379
380 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
381 redirty = 1;
382 /*
383 * Make sure this page isn't blocked indefinitely.
384 * If the journal isn't undergoing I/O, push it
385 */
386 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
387 jfs_flush_journal(mp->log, 0);
388 continue;
389 }
390
391 clear_bit(META_dirty, &mp->flag);
392 set_bit(META_io, &mp->flag);
393 block_offset = offset >> inode->i_blkbits;
394 lblock = page_start + block_offset;
395 if (bio) {
396 if (xlen && lblock == next_block) {
397 /* Contiguous, in memory & on disk */
398 len = min(xlen, blocks_per_mp);
399 xlen -= len;
400 bio_bytes += len << inode->i_blkbits;
401 continue;
402 }
403 /* Not contiguous */
404 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
405 bio_bytes)
406 goto add_failed;
407 /*
408 * Increment counter before submitting i/o to keep
409 * count from hitting zero before we're through
410 */
411 inc_io(page);
412 if (!bio->bi_iter.bi_size)
413 goto dump_bio;
414 submit_bio(bio);
415 nr_underway++;
416 bio = NULL;
417 } else
418 inc_io(page);
419 xlen = (PAGE_SIZE - offset) >> inode->i_blkbits;
420 pblock = metapage_get_blocks(inode, lblock, &xlen);
421 if (!pblock) {
422 printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
423 /*
424 * We already called inc_io(), but can't cancel it
425 * with dec_io() until we're done with the page
426 */
427 bad_blocks++;
428 continue;
429 }
430 len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
431
432 bio = bio_alloc(GFP_NOFS, 1);
433 bio_set_dev(bio, inode->i_sb->s_bdev);
434 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
435 bio->bi_end_io = metapage_write_end_io;
436 bio->bi_private = page;
437 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
438
439 /* Don't call bio_add_page yet, we may add to this vec */
440 bio_offset = offset;
441 bio_bytes = len << inode->i_blkbits;
442
443 xlen -= len;
444 next_block = lblock + len;
445 }
446 if (bio) {
447 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
448 goto add_failed;
449 if (!bio->bi_iter.bi_size)
450 goto dump_bio;
451
452 submit_bio(bio);
453 nr_underway++;
454 }
455 if (redirty)
456 redirty_page_for_writepage(wbc, page);
457
458 unlock_page(page);
459
460 if (bad_blocks)
461 goto err_out;
462
463 if (nr_underway == 0)
464 end_page_writeback(page);
465
466 return 0;
467add_failed:
468 /* We should never reach here, since we're only adding one vec */
469 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
470 goto skip;
471dump_bio:
472 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
473 4, bio, sizeof(*bio), 0);
474skip:
475 bio_put(bio);
476 unlock_page(page);
477 dec_io(page, last_write_complete);
478err_out:
479 while (bad_blocks--)
480 dec_io(page, last_write_complete);
481 return -EIO;
482}
483
484static int metapage_readpage(struct file *fp, struct page *page)
485{
486 struct inode *inode = page->mapping->host;
487 struct bio *bio = NULL;
488 int block_offset;
489 int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
490 sector_t page_start; /* address of page in fs blocks */
491 sector_t pblock;
492 int xlen;
493 unsigned int len;
494 int offset;
495
496 BUG_ON(!PageLocked(page));
497 page_start = (sector_t)page->index <<
498 (PAGE_SHIFT - inode->i_blkbits);
499
500 block_offset = 0;
501 while (block_offset < blocks_per_page) {
502 xlen = blocks_per_page - block_offset;
503 pblock = metapage_get_blocks(inode, page_start + block_offset,
504 &xlen);
505 if (pblock) {
506 if (!PagePrivate(page))
507 insert_metapage(page, NULL);
508 inc_io(page);
509 if (bio)
510 submit_bio(bio);
511
512 bio = bio_alloc(GFP_NOFS, 1);
513 bio_set_dev(bio, inode->i_sb->s_bdev);
514 bio->bi_iter.bi_sector =
515 pblock << (inode->i_blkbits - 9);
516 bio->bi_end_io = metapage_read_end_io;
517 bio->bi_private = page;
518 bio_set_op_attrs(bio, REQ_OP_READ, 0);
519 len = xlen << inode->i_blkbits;
520 offset = block_offset << inode->i_blkbits;
521 if (bio_add_page(bio, page, len, offset) < len)
522 goto add_failed;
523 block_offset += xlen;
524 } else
525 block_offset++;
526 }
527 if (bio)
528 submit_bio(bio);
529 else
530 unlock_page(page);
531
532 return 0;
533
534add_failed:
535 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
536 bio_put(bio);
537 dec_io(page, last_read_complete);
538 return -EIO;
539}
540
541static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
542{
543 struct metapage *mp;
544 int ret = 1;
545 int offset;
546
547 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
548 mp = page_to_mp(page, offset);
549
550 if (!mp)
551 continue;
552
553 jfs_info("metapage_releasepage: mp = 0x%p", mp);
554 if (mp->count || mp->nohomeok ||
555 test_bit(META_dirty, &mp->flag)) {
556 jfs_info("count = %ld, nohomeok = %d", mp->count,
557 mp->nohomeok);
558 ret = 0;
559 continue;
560 }
561 if (mp->lsn)
562 remove_from_logsync(mp);
563 remove_metapage(page, mp);
564 INCREMENT(mpStat.pagefree);
565 free_metapage(mp);
566 }
567 return ret;
568}
569
570static void metapage_invalidatepage(struct page *page, unsigned int offset,
571 unsigned int length)
572{
573 BUG_ON(offset || length < PAGE_SIZE);
574
575 BUG_ON(PageWriteback(page));
576
577 metapage_releasepage(page, 0);
578}
579
580const struct address_space_operations jfs_metapage_aops = {
581 .readpage = metapage_readpage,
582 .writepage = metapage_writepage,
583 .releasepage = metapage_releasepage,
584 .invalidatepage = metapage_invalidatepage,
585 .set_page_dirty = __set_page_dirty_nobuffers,
586};
587
588struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
589 unsigned int size, int absolute,
590 unsigned long new)
591{
592 int l2BlocksPerPage;
593 int l2bsize;
594 struct address_space *mapping;
595 struct metapage *mp = NULL;
596 struct page *page;
597 unsigned long page_index;
598 unsigned long page_offset;
599
600 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
601 inode->i_ino, lblock, absolute);
602
603 l2bsize = inode->i_blkbits;
604 l2BlocksPerPage = PAGE_SHIFT - l2bsize;
605 page_index = lblock >> l2BlocksPerPage;
606 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
607 if ((page_offset + size) > PAGE_SIZE) {
608 jfs_err("MetaData crosses page boundary!!");
609 jfs_err("lblock = %lx, size = %d", lblock, size);
610 dump_stack();
611 return NULL;
612 }
613 if (absolute)
614 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
615 else {
616 /*
617 * If an nfs client tries to read an inode that is larger
618 * than any existing inodes, we may try to read past the
619 * end of the inode map
620 */
621 if ((lblock << inode->i_blkbits) >= inode->i_size)
622 return NULL;
623 mapping = inode->i_mapping;
624 }
625
626 if (new && (PSIZE == PAGE_SIZE)) {
627 page = grab_cache_page(mapping, page_index);
628 if (!page) {
629 jfs_err("grab_cache_page failed!");
630 return NULL;
631 }
632 SetPageUptodate(page);
633 } else {
634 page = read_mapping_page(mapping, page_index, NULL);
635 if (IS_ERR(page) || !PageUptodate(page)) {
636 jfs_err("read_mapping_page failed!");
637 return NULL;
638 }
639 lock_page(page);
640 }
641
642 mp = page_to_mp(page, page_offset);
643 if (mp) {
644 if (mp->logical_size != size) {
645 jfs_error(inode->i_sb,
646 "get_mp->logical_size != size\n");
647 jfs_err("logical_size = %d, size = %d",
648 mp->logical_size, size);
649 dump_stack();
650 goto unlock;
651 }
652 mp->count++;
653 lock_metapage(mp);
654 if (test_bit(META_discard, &mp->flag)) {
655 if (!new) {
656 jfs_error(inode->i_sb,
657 "using a discarded metapage\n");
658 discard_metapage(mp);
659 goto unlock;
660 }
661 clear_bit(META_discard, &mp->flag);
662 }
663 } else {
664 INCREMENT(mpStat.pagealloc);
665 mp = alloc_metapage(GFP_NOFS);
666 if (!mp)
667 goto unlock;
668 mp->page = page;
669 mp->sb = inode->i_sb;
670 mp->flag = 0;
671 mp->xflag = COMMIT_PAGE;
672 mp->count = 1;
673 mp->nohomeok = 0;
674 mp->logical_size = size;
675 mp->data = page_address(page) + page_offset;
676 mp->index = lblock;
677 if (unlikely(insert_metapage(page, mp))) {
678 free_metapage(mp);
679 goto unlock;
680 }
681 lock_metapage(mp);
682 }
683
684 if (new) {
685 jfs_info("zeroing mp = 0x%p", mp);
686 memset(mp->data, 0, PSIZE);
687 }
688
689 unlock_page(page);
690 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
691 return mp;
692
693unlock:
694 unlock_page(page);
695 return NULL;
696}
697
698void grab_metapage(struct metapage * mp)
699{
700 jfs_info("grab_metapage: mp = 0x%p", mp);
701 get_page(mp->page);
702 lock_page(mp->page);
703 mp->count++;
704 lock_metapage(mp);
705 unlock_page(mp->page);
706}
707
708void force_metapage(struct metapage *mp)
709{
710 struct page *page = mp->page;
711 jfs_info("force_metapage: mp = 0x%p", mp);
712 set_bit(META_forcewrite, &mp->flag);
713 clear_bit(META_sync, &mp->flag);
714 get_page(page);
715 lock_page(page);
716 set_page_dirty(page);
717 if (write_one_page(page))
718 jfs_error(mp->sb, "write_one_page() failed\n");
719 clear_bit(META_forcewrite, &mp->flag);
720 put_page(page);
721}
722
723void hold_metapage(struct metapage *mp)
724{
725 lock_page(mp->page);
726}
727
728void put_metapage(struct metapage *mp)
729{
730 if (mp->count || mp->nohomeok) {
731 /* Someone else will release this */
732 unlock_page(mp->page);
733 return;
734 }
735 get_page(mp->page);
736 mp->count++;
737 lock_metapage(mp);
738 unlock_page(mp->page);
739 release_metapage(mp);
740}
741
742void release_metapage(struct metapage * mp)
743{
744 struct page *page = mp->page;
745 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
746
747 BUG_ON(!page);
748
749 lock_page(page);
750 unlock_metapage(mp);
751
752 assert(mp->count);
753 if (--mp->count || mp->nohomeok) {
754 unlock_page(page);
755 put_page(page);
756 return;
757 }
758
759 if (test_bit(META_dirty, &mp->flag)) {
760 set_page_dirty(page);
761 if (test_bit(META_sync, &mp->flag)) {
762 clear_bit(META_sync, &mp->flag);
763 if (write_one_page(page))
764 jfs_error(mp->sb, "write_one_page() failed\n");
765 lock_page(page); /* write_one_page unlocks the page */
766 }
767 } else if (mp->lsn) /* discard_metapage doesn't remove it */
768 remove_from_logsync(mp);
769
770 /* Try to keep metapages from using up too much memory */
771 drop_metapage(page, mp);
772
773 unlock_page(page);
774 put_page(page);
775}
776
777void __invalidate_metapages(struct inode *ip, s64 addr, int len)
778{
779 sector_t lblock;
780 int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
781 int BlocksPerPage = 1 << l2BlocksPerPage;
782 /* All callers are interested in block device's mapping */
783 struct address_space *mapping =
784 JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
785 struct metapage *mp;
786 struct page *page;
787 unsigned int offset;
788
789 /*
790 * Mark metapages to discard. They will eventually be
791 * released, but should not be written.
792 */
793 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
794 lblock += BlocksPerPage) {
795 page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
796 if (!page)
797 continue;
798 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
799 mp = page_to_mp(page, offset);
800 if (!mp)
801 continue;
802 if (mp->index < addr)
803 continue;
804 if (mp->index >= addr + len)
805 break;
806
807 clear_bit(META_dirty, &mp->flag);
808 set_bit(META_discard, &mp->flag);
809 if (mp->lsn)
810 remove_from_logsync(mp);
811 }
812 unlock_page(page);
813 put_page(page);
814 }
815}
816
817#ifdef CONFIG_JFS_STATISTICS
818static int jfs_mpstat_proc_show(struct seq_file *m, void *v)
819{
820 seq_printf(m,
821 "JFS Metapage statistics\n"
822 "=======================\n"
823 "page allocations = %d\n"
824 "page frees = %d\n"
825 "lock waits = %d\n",
826 mpStat.pagealloc,
827 mpStat.pagefree,
828 mpStat.lockwait);
829 return 0;
830}
831
832static int jfs_mpstat_proc_open(struct inode *inode, struct file *file)
833{
834 return single_open(file, jfs_mpstat_proc_show, NULL);
835}
836
837const struct file_operations jfs_mpstat_proc_fops = {
838 .open = jfs_mpstat_proc_open,
839 .read = seq_read,
840 .llseek = seq_lseek,
841 .release = single_release,
842};
843#endif
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