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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/*
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_CACHE_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 void init_once(void *foo)
187{
188 struct metapage *mp = (struct metapage *)foo;
189
190 mp->lid = 0;
191 mp->lsn = 0;
192 mp->flag = 0;
193 mp->data = NULL;
194 mp->clsn = 0;
195 mp->log = NULL;
196 set_bit(META_free, &mp->flag);
197 init_waitqueue_head(&mp->wait);
198}
199
200static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
201{
202 return mempool_alloc(metapage_mempool, gfp_mask);
203}
204
205static inline void free_metapage(struct metapage *mp)
206{
207 mp->flag = 0;
208 set_bit(META_free, &mp->flag);
209
210 mempool_free(mp, metapage_mempool);
211}
212
213int __init metapage_init(void)
214{
215 /*
216 * Allocate the metapage structures
217 */
218 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
219 0, 0, init_once);
220 if (metapage_cache == NULL)
221 return -ENOMEM;
222
223 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
224 metapage_cache);
225
226 if (metapage_mempool == NULL) {
227 kmem_cache_destroy(metapage_cache);
228 return -ENOMEM;
229 }
230
231 return 0;
232}
233
234void metapage_exit(void)
235{
236 mempool_destroy(metapage_mempool);
237 kmem_cache_destroy(metapage_cache);
238}
239
240static inline void drop_metapage(struct page *page, struct metapage *mp)
241{
242 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
243 test_bit(META_io, &mp->flag))
244 return;
245 remove_metapage(page, mp);
246 INCREMENT(mpStat.pagefree);
247 free_metapage(mp);
248}
249
250/*
251 * Metapage address space operations
252 */
253
254static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
255 int *len)
256{
257 int rc = 0;
258 int xflag;
259 s64 xaddr;
260 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
261 inode->i_blkbits;
262
263 if (lblock >= file_blocks)
264 return 0;
265 if (lblock + *len > file_blocks)
266 *len = file_blocks - lblock;
267
268 if (inode->i_ino) {
269 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
270 if ((rc == 0) && *len)
271 lblock = (sector_t)xaddr;
272 else
273 lblock = 0;
274 } /* else no mapping */
275
276 return lblock;
277}
278
279static void last_read_complete(struct page *page)
280{
281 if (!PageError(page))
282 SetPageUptodate(page);
283 unlock_page(page);
284}
285
286static void metapage_read_end_io(struct bio *bio, int err)
287{
288 struct page *page = bio->bi_private;
289
290 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
291 printk(KERN_ERR "metapage_read_end_io: I/O error\n");
292 SetPageError(page);
293 }
294
295 dec_io(page, last_read_complete);
296 bio_put(bio);
297}
298
299static void remove_from_logsync(struct metapage *mp)
300{
301 struct jfs_log *log = mp->log;
302 unsigned long flags;
303/*
304 * This can race. Recheck that log hasn't been set to null, and after
305 * acquiring logsync lock, recheck lsn
306 */
307 if (!log)
308 return;
309
310 LOGSYNC_LOCK(log, flags);
311 if (mp->lsn) {
312 mp->log = NULL;
313 mp->lsn = 0;
314 mp->clsn = 0;
315 log->count--;
316 list_del(&mp->synclist);
317 }
318 LOGSYNC_UNLOCK(log, flags);
319}
320
321static void last_write_complete(struct page *page)
322{
323 struct metapage *mp;
324 unsigned int offset;
325
326 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
327 mp = page_to_mp(page, offset);
328 if (mp && test_bit(META_io, &mp->flag)) {
329 if (mp->lsn)
330 remove_from_logsync(mp);
331 clear_bit(META_io, &mp->flag);
332 }
333 /*
334 * I'd like to call drop_metapage here, but I don't think it's
335 * safe unless I have the page locked
336 */
337 }
338 end_page_writeback(page);
339}
340
341static void metapage_write_end_io(struct bio *bio, int err)
342{
343 struct page *page = bio->bi_private;
344
345 BUG_ON(!PagePrivate(page));
346
347 if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
348 printk(KERN_ERR "metapage_write_end_io: I/O error\n");
349 SetPageError(page);
350 }
351 dec_io(page, last_write_complete);
352 bio_put(bio);
353}
354
355static int metapage_writepage(struct page *page, struct writeback_control *wbc)
356{
357 struct bio *bio = NULL;
358 int block_offset; /* block offset of mp within page */
359 struct inode *inode = page->mapping->host;
360 int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
361 int len;
362 int xlen;
363 struct metapage *mp;
364 int redirty = 0;
365 sector_t lblock;
366 int nr_underway = 0;
367 sector_t pblock;
368 sector_t next_block = 0;
369 sector_t page_start;
370 unsigned long bio_bytes = 0;
371 unsigned long bio_offset = 0;
372 int offset;
373 int bad_blocks = 0;
374
375 page_start = (sector_t)page->index <<
376 (PAGE_CACHE_SHIFT - inode->i_blkbits);
377 BUG_ON(!PageLocked(page));
378 BUG_ON(PageWriteback(page));
379 set_page_writeback(page);
380
381 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
382 mp = page_to_mp(page, offset);
383
384 if (!mp || !test_bit(META_dirty, &mp->flag))
385 continue;
386
387 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
388 redirty = 1;
389 /*
390 * Make sure this page isn't blocked indefinitely.
391 * If the journal isn't undergoing I/O, push it
392 */
393 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
394 jfs_flush_journal(mp->log, 0);
395 continue;
396 }
397
398 clear_bit(META_dirty, &mp->flag);
399 set_bit(META_io, &mp->flag);
400 block_offset = offset >> inode->i_blkbits;
401 lblock = page_start + block_offset;
402 if (bio) {
403 if (xlen && lblock == next_block) {
404 /* Contiguous, in memory & on disk */
405 len = min(xlen, blocks_per_mp);
406 xlen -= len;
407 bio_bytes += len << inode->i_blkbits;
408 continue;
409 }
410 /* Not contiguous */
411 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
412 bio_bytes)
413 goto add_failed;
414 /*
415 * Increment counter before submitting i/o to keep
416 * count from hitting zero before we're through
417 */
418 inc_io(page);
419 if (!bio->bi_iter.bi_size)
420 goto dump_bio;
421 submit_bio(WRITE, bio);
422 nr_underway++;
423 bio = NULL;
424 } else
425 inc_io(page);
426 xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
427 pblock = metapage_get_blocks(inode, lblock, &xlen);
428 if (!pblock) {
429 printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
430 /*
431 * We already called inc_io(), but can't cancel it
432 * with dec_io() until we're done with the page
433 */
434 bad_blocks++;
435 continue;
436 }
437 len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
438
439 bio = bio_alloc(GFP_NOFS, 1);
440 bio->bi_bdev = inode->i_sb->s_bdev;
441 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
442 bio->bi_end_io = metapage_write_end_io;
443 bio->bi_private = page;
444
445 /* Don't call bio_add_page yet, we may add to this vec */
446 bio_offset = offset;
447 bio_bytes = len << inode->i_blkbits;
448
449 xlen -= len;
450 next_block = lblock + len;
451 }
452 if (bio) {
453 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
454 goto add_failed;
455 if (!bio->bi_iter.bi_size)
456 goto dump_bio;
457
458 submit_bio(WRITE, bio);
459 nr_underway++;
460 }
461 if (redirty)
462 redirty_page_for_writepage(wbc, page);
463
464 unlock_page(page);
465
466 if (bad_blocks)
467 goto err_out;
468
469 if (nr_underway == 0)
470 end_page_writeback(page);
471
472 return 0;
473add_failed:
474 /* We should never reach here, since we're only adding one vec */
475 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
476 goto skip;
477dump_bio:
478 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
479 4, bio, sizeof(*bio), 0);
480skip:
481 bio_put(bio);
482 unlock_page(page);
483 dec_io(page, last_write_complete);
484err_out:
485 while (bad_blocks--)
486 dec_io(page, last_write_complete);
487 return -EIO;
488}
489
490static int metapage_readpage(struct file *fp, struct page *page)
491{
492 struct inode *inode = page->mapping->host;
493 struct bio *bio = NULL;
494 int block_offset;
495 int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
496 sector_t page_start; /* address of page in fs blocks */
497 sector_t pblock;
498 int xlen;
499 unsigned int len;
500 int offset;
501
502 BUG_ON(!PageLocked(page));
503 page_start = (sector_t)page->index <<
504 (PAGE_CACHE_SHIFT - inode->i_blkbits);
505
506 block_offset = 0;
507 while (block_offset < blocks_per_page) {
508 xlen = blocks_per_page - block_offset;
509 pblock = metapage_get_blocks(inode, page_start + block_offset,
510 &xlen);
511 if (pblock) {
512 if (!PagePrivate(page))
513 insert_metapage(page, NULL);
514 inc_io(page);
515 if (bio)
516 submit_bio(READ, bio);
517
518 bio = bio_alloc(GFP_NOFS, 1);
519 bio->bi_bdev = inode->i_sb->s_bdev;
520 bio->bi_iter.bi_sector =
521 pblock << (inode->i_blkbits - 9);
522 bio->bi_end_io = metapage_read_end_io;
523 bio->bi_private = page;
524 len = xlen << inode->i_blkbits;
525 offset = block_offset << inode->i_blkbits;
526 if (bio_add_page(bio, page, len, offset) < len)
527 goto add_failed;
528 block_offset += xlen;
529 } else
530 block_offset++;
531 }
532 if (bio)
533 submit_bio(READ, bio);
534 else
535 unlock_page(page);
536
537 return 0;
538
539add_failed:
540 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
541 bio_put(bio);
542 dec_io(page, last_read_complete);
543 return -EIO;
544}
545
546static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
547{
548 struct metapage *mp;
549 int ret = 1;
550 int offset;
551
552 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
553 mp = page_to_mp(page, offset);
554
555 if (!mp)
556 continue;
557
558 jfs_info("metapage_releasepage: mp = 0x%p", mp);
559 if (mp->count || mp->nohomeok ||
560 test_bit(META_dirty, &mp->flag)) {
561 jfs_info("count = %ld, nohomeok = %d", mp->count,
562 mp->nohomeok);
563 ret = 0;
564 continue;
565 }
566 if (mp->lsn)
567 remove_from_logsync(mp);
568 remove_metapage(page, mp);
569 INCREMENT(mpStat.pagefree);
570 free_metapage(mp);
571 }
572 return ret;
573}
574
575static void metapage_invalidatepage(struct page *page, unsigned int offset,
576 unsigned int length)
577{
578 BUG_ON(offset || length < PAGE_CACHE_SIZE);
579
580 BUG_ON(PageWriteback(page));
581
582 metapage_releasepage(page, 0);
583}
584
585const struct address_space_operations jfs_metapage_aops = {
586 .readpage = metapage_readpage,
587 .writepage = metapage_writepage,
588 .releasepage = metapage_releasepage,
589 .invalidatepage = metapage_invalidatepage,
590 .set_page_dirty = __set_page_dirty_nobuffers,
591};
592
593struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
594 unsigned int size, int absolute,
595 unsigned long new)
596{
597 int l2BlocksPerPage;
598 int l2bsize;
599 struct address_space *mapping;
600 struct metapage *mp = NULL;
601 struct page *page;
602 unsigned long page_index;
603 unsigned long page_offset;
604
605 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
606 inode->i_ino, lblock, absolute);
607
608 l2bsize = inode->i_blkbits;
609 l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
610 page_index = lblock >> l2BlocksPerPage;
611 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
612 if ((page_offset + size) > PAGE_CACHE_SIZE) {
613 jfs_err("MetaData crosses page boundary!!");
614 jfs_err("lblock = %lx, size = %d", lblock, size);
615 dump_stack();
616 return NULL;
617 }
618 if (absolute)
619 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
620 else {
621 /*
622 * If an nfs client tries to read an inode that is larger
623 * than any existing inodes, we may try to read past the
624 * end of the inode map
625 */
626 if ((lblock << inode->i_blkbits) >= inode->i_size)
627 return NULL;
628 mapping = inode->i_mapping;
629 }
630
631 if (new && (PSIZE == PAGE_CACHE_SIZE)) {
632 page = grab_cache_page(mapping, page_index);
633 if (!page) {
634 jfs_err("grab_cache_page failed!");
635 return NULL;
636 }
637 SetPageUptodate(page);
638 } else {
639 page = read_mapping_page(mapping, page_index, NULL);
640 if (IS_ERR(page) || !PageUptodate(page)) {
641 jfs_err("read_mapping_page failed!");
642 return NULL;
643 }
644 lock_page(page);
645 }
646
647 mp = page_to_mp(page, page_offset);
648 if (mp) {
649 if (mp->logical_size != size) {
650 jfs_error(inode->i_sb,
651 "get_mp->logical_size != size\n");
652 jfs_err("logical_size = %d, size = %d",
653 mp->logical_size, size);
654 dump_stack();
655 goto unlock;
656 }
657 mp->count++;
658 lock_metapage(mp);
659 if (test_bit(META_discard, &mp->flag)) {
660 if (!new) {
661 jfs_error(inode->i_sb,
662 "using a discarded metapage\n");
663 discard_metapage(mp);
664 goto unlock;
665 }
666 clear_bit(META_discard, &mp->flag);
667 }
668 } else {
669 INCREMENT(mpStat.pagealloc);
670 mp = alloc_metapage(GFP_NOFS);
671 mp->page = page;
672 mp->flag = 0;
673 mp->xflag = COMMIT_PAGE;
674 mp->count = 1;
675 mp->nohomeok = 0;
676 mp->logical_size = size;
677 mp->data = page_address(page) + page_offset;
678 mp->index = lblock;
679 if (unlikely(insert_metapage(page, mp))) {
680 free_metapage(mp);
681 goto unlock;
682 }
683 lock_metapage(mp);
684 }
685
686 if (new) {
687 jfs_info("zeroing mp = 0x%p", mp);
688 memset(mp->data, 0, PSIZE);
689 }
690
691 unlock_page(page);
692 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
693 return mp;
694
695unlock:
696 unlock_page(page);
697 return NULL;
698}
699
700void grab_metapage(struct metapage * mp)
701{
702 jfs_info("grab_metapage: mp = 0x%p", mp);
703 page_cache_get(mp->page);
704 lock_page(mp->page);
705 mp->count++;
706 lock_metapage(mp);
707 unlock_page(mp->page);
708}
709
710void force_metapage(struct metapage *mp)
711{
712 struct page *page = mp->page;
713 jfs_info("force_metapage: mp = 0x%p", mp);
714 set_bit(META_forcewrite, &mp->flag);
715 clear_bit(META_sync, &mp->flag);
716 page_cache_get(page);
717 lock_page(page);
718 set_page_dirty(page);
719 write_one_page(page, 1);
720 clear_bit(META_forcewrite, &mp->flag);
721 page_cache_release(page);
722}
723
724void hold_metapage(struct metapage *mp)
725{
726 lock_page(mp->page);
727}
728
729void put_metapage(struct metapage *mp)
730{
731 if (mp->count || mp->nohomeok) {
732 /* Someone else will release this */
733 unlock_page(mp->page);
734 return;
735 }
736 page_cache_get(mp->page);
737 mp->count++;
738 lock_metapage(mp);
739 unlock_page(mp->page);
740 release_metapage(mp);
741}
742
743void release_metapage(struct metapage * mp)
744{
745 struct page *page = mp->page;
746 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
747
748 BUG_ON(!page);
749
750 lock_page(page);
751 unlock_metapage(mp);
752
753 assert(mp->count);
754 if (--mp->count || mp->nohomeok) {
755 unlock_page(page);
756 page_cache_release(page);
757 return;
758 }
759
760 if (test_bit(META_dirty, &mp->flag)) {
761 set_page_dirty(page);
762 if (test_bit(META_sync, &mp->flag)) {
763 clear_bit(META_sync, &mp->flag);
764 write_one_page(page, 1);
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 page_cache_release(page);
775}
776
777void __invalidate_metapages(struct inode *ip, s64 addr, int len)
778{
779 sector_t lblock;
780 int l2BlocksPerPage = PAGE_CACHE_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_CACHE_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 page_cache_release(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 .owner = THIS_MODULE,
839 .open = jfs_mpstat_proc_open,
840 .read = seq_read,
841 .llseek = seq_lseek,
842 .release = single_release,
843};
844#endif