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allow coexistance of N build and AC build.
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / fs / jfs / jfs_metapage.c
blob43d4f69afbeca923878a45d77fa68d4eb53a55f9
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/bio.h>
23 #include <linux/init.h>
24 #include <linux/buffer_head.h>
25 #include <linux/mempool.h>
26 #include "jfs_incore.h"
27 #include "jfs_superblock.h"
28 #include "jfs_filsys.h"
29 #include "jfs_metapage.h"
30 #include "jfs_txnmgr.h"
31 #include "jfs_debug.h"
32
33 #ifdef CONFIG_JFS_STATISTICS
34 static struct {
35 uint pagealloc; /* # of page allocations */
36 uint pagefree; /* # of page frees */
37 uint lockwait; /* # of sleeping lock_metapage() calls */
38 } mpStat;
39 #endif
40
41 #define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
42 #define trylock_metapage(mp) test_and_set_bit(META_locked, &(mp)->flag)
43
44 static inline void unlock_metapage(struct metapage *mp)
45 {
46 clear_bit(META_locked, &mp->flag);
47 wake_up(&mp->wait);
48 }
49
50 static inline void __lock_metapage(struct metapage *mp)
51 {
52 DECLARE_WAITQUEUE(wait, current);
53 INCREMENT(mpStat.lockwait);
54 add_wait_queue_exclusive(&mp->wait, &wait);
55 do {
56 set_current_state(TASK_UNINTERRUPTIBLE);
57 if (metapage_locked(mp)) {
58 unlock_page(mp->page);
59 io_schedule();
60 lock_page(mp->page);
61 }
62 } while (trylock_metapage(mp));
63 __set_current_state(TASK_RUNNING);
64 remove_wait_queue(&mp->wait, &wait);
65 }
66
67 /*
68 * Must have mp->page locked
69 */
70 static inline void lock_metapage(struct metapage *mp)
71 {
72 if (trylock_metapage(mp))
73 __lock_metapage(mp);
74 }
75
76 #define METAPOOL_MIN_PAGES 32
77 static struct kmem_cache *metapage_cache;
78 static mempool_t *metapage_mempool;
79
80 #define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE)
81
82 #if MPS_PER_PAGE > 1
83
84 struct meta_anchor {
85 int mp_count;
86 atomic_t io_count;
87 struct metapage *mp[MPS_PER_PAGE];
88 };
89 #define mp_anchor(page) ((struct meta_anchor *)page_private(page))
90
91 static inline struct metapage *page_to_mp(struct page *page, uint offset)
92 {
93 if (!PagePrivate(page))
94 return NULL;
95 return mp_anchor(page)->mp[offset >> L2PSIZE];
96 }
97
98 static inline int insert_metapage(struct page *page, struct metapage *mp)
99 {
100 struct meta_anchor *a;
101 int index;
102 int l2mp_blocks; /* log2 blocks per metapage */
103
104 if (PagePrivate(page))
105 a = mp_anchor(page);
106 else {
107 a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
108 if (!a)
109 return -ENOMEM;
110 set_page_private(page, (unsigned long)a);
111 SetPagePrivate(page);
112 kmap(page);
113 }
114
115 if (mp) {
116 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
117 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
118 a->mp_count++;
119 a->mp[index] = mp;
120 }
121
122 return 0;
123 }
124
125 static inline void remove_metapage(struct page *page, struct metapage *mp)
126 {
127 struct meta_anchor *a = mp_anchor(page);
128 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
129 int index;
130
131 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
132
133 BUG_ON(a->mp[index] != mp);
134
135 a->mp[index] = NULL;
136 if (--a->mp_count == 0) {
137 kfree(a);
138 set_page_private(page, 0);
139 ClearPagePrivate(page);
140 kunmap(page);
141 }
142 }
143
144 static inline void inc_io(struct page *page)
145 {
146 atomic_inc(&mp_anchor(page)->io_count);
147 }
148
149 static inline void dec_io(struct page *page, void (*handler) (struct page *))
150 {
151 if (atomic_dec_and_test(&mp_anchor(page)->io_count))
152 handler(page);
153 }
154
155 #else
156 static inline struct metapage *page_to_mp(struct page *page, uint offset)
157 {
158 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
159 }
160
161 static inline int insert_metapage(struct page *page, struct metapage *mp)
162 {
163 if (mp) {
164 set_page_private(page, (unsigned long)mp);
165 SetPagePrivate(page);
166 kmap(page);
167 }
168 return 0;
169 }
170
171 static inline void remove_metapage(struct page *page, struct metapage *mp)
172 {
173 set_page_private(page, 0);
174 ClearPagePrivate(page);
175 kunmap(page);
176 }
177
178 #define inc_io(page) do {} while(0)
179 #define dec_io(page, handler) handler(page)
180
181 #endif
182
183 static void init_once(void *foo, struct kmem_cache *cachep, unsigned long flags)
184 {
185 struct metapage *mp = (struct metapage *)foo;
186
187 mp->lid = 0;
188 mp->lsn = 0;
189 mp->flag = 0;
190 mp->data = NULL;
191 mp->clsn = 0;
192 mp->log = NULL;
193 set_bit(META_free, &mp->flag);
194 init_waitqueue_head(&mp->wait);
195 }
196
197 static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
198 {
199 return mempool_alloc(metapage_mempool, gfp_mask);
200 }
201
202 static inline void free_metapage(struct metapage *mp)
203 {
204 mp->flag = 0;
205 set_bit(META_free, &mp->flag);
206
207 mempool_free(mp, metapage_mempool);
208 }
209
210 int __init metapage_init(void)
211 {
212 /*
213 * Allocate the metapage structures
214 */
215 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
216 0, 0, init_once, NULL);
217 if (metapage_cache == NULL)
218 return -ENOMEM;
219
220 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
221 metapage_cache);
222
223 if (metapage_mempool == NULL) {
224 kmem_cache_destroy(metapage_cache);
225 return -ENOMEM;
226 }
227
228 return 0;
229 }
230
231 void metapage_exit(void)
232 {
233 mempool_destroy(metapage_mempool);
234 kmem_cache_destroy(metapage_cache);
235 }
236
237 static inline void drop_metapage(struct page *page, struct metapage *mp)
238 {
239 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
240 test_bit(META_io, &mp->flag))
241 return;
242 remove_metapage(page, mp);
243 INCREMENT(mpStat.pagefree);
244 free_metapage(mp);
245 }
246
247 /*
248 * Metapage address space operations
249 */
250
251 static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
252 unsigned int *len)
253 {
254 int rc = 0;
255 int xflag;
256 s64 xaddr;
257 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
258 inode->i_blkbits;
259
260 if (lblock >= file_blocks)
261 return 0;
262 if (lblock + *len > file_blocks)
263 *len = file_blocks - lblock;
264
265 if (inode->i_ino) {
266 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
267 if ((rc == 0) && *len)
268 lblock = (sector_t)xaddr;
269 else
270 lblock = 0;
271 } /* else no mapping */
272
273 return lblock;
274 }
275
276 static void last_read_complete(struct page *page)
277 {
278 if (!PageError(page))
279 SetPageUptodate(page);
280 unlock_page(page);
281 }
282
283 static int metapage_read_end_io(struct bio *bio, unsigned int bytes_done,
284 int err)
285 {
286 struct page *page = bio->bi_private;
287
288 if (bio->bi_size)
289 return 1;
290
291 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
292 printk(KERN_ERR "metapage_read_end_io: I/O error\n");
293 SetPageError(page);
294 }
295
296 dec_io(page, last_read_complete);
297 bio_put(bio);
298
299 return 0;
300 }
301
302 static void remove_from_logsync(struct metapage *mp)
303 {
304 struct jfs_log *log = mp->log;
305 unsigned long flags;
306 /*
307 * This can race. Recheck that log hasn't been set to null, and after
308 * acquiring logsync lock, recheck lsn
309 */
310 if (!log)
311 return;
312
313 LOGSYNC_LOCK(log, flags);
314 if (mp->lsn) {
315 mp->log = NULL;
316 mp->lsn = 0;
317 mp->clsn = 0;
318 log->count--;
319 list_del(&mp->synclist);
320 }
321 LOGSYNC_UNLOCK(log, flags);
322 }
323
324 static void last_write_complete(struct page *page)
325 {
326 struct metapage *mp;
327 unsigned int offset;
328
329 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
330 mp = page_to_mp(page, offset);
331 if (mp && test_bit(META_io, &mp->flag)) {
332 if (mp->lsn)
333 remove_from_logsync(mp);
334 clear_bit(META_io, &mp->flag);
335 }
336 /*
337 * I'd like to call drop_metapage here, but I don't think it's
338 * safe unless I have the page locked
339 */
340 }
341 end_page_writeback(page);
342 }
343
344 static int metapage_write_end_io(struct bio *bio, unsigned int bytes_done,
345 int err)
346 {
347 struct page *page = bio->bi_private;
348
349 BUG_ON(!PagePrivate(page));
350
351 if (bio->bi_size)
352 return 1;
353
354 if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
355 printk(KERN_ERR "metapage_write_end_io: I/O error\n");
356 SetPageError(page);
357 }
358 dec_io(page, last_write_complete);
359 bio_put(bio);
360 return 0;
361 }
362
363 static int metapage_writepage(struct page *page, struct writeback_control *wbc)
364 {
365 struct bio *bio = NULL;
366 unsigned int block_offset; /* block offset of mp within page */
367 struct inode *inode = page->mapping->host;
368 unsigned int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
369 unsigned int len;
370 unsigned int xlen;
371 struct metapage *mp;
372 int redirty = 0;
373 sector_t lblock;
374 sector_t pblock;
375 sector_t next_block = 0;
376 sector_t page_start;
377 unsigned long bio_bytes = 0;
378 unsigned long bio_offset = 0;
379 unsigned int offset;
380
381 page_start = (sector_t)page->index <<
382 (PAGE_CACHE_SHIFT - inode->i_blkbits);
383 BUG_ON(!PageLocked(page));
384 BUG_ON(PageWriteback(page));
385
386 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
387 mp = page_to_mp(page, offset);
388
389 if (!mp || !test_bit(META_dirty, &mp->flag))
390 continue;
391
392 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
393 redirty = 1;
394 /*
395 * Make sure this page isn't blocked indefinitely.
396 * If the journal isn't undergoing I/O, push it
397 */
398 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
399 jfs_flush_journal(mp->log, 0);
400 continue;
401 }
402
403 clear_bit(META_dirty, &mp->flag);
404 block_offset = offset >> inode->i_blkbits;
405 lblock = page_start + block_offset;
406 if (bio) {
407 if (xlen && lblock == next_block) {
408 /* Contiguous, in memory & on disk */
409 len = min(xlen, blocks_per_mp);
410 xlen -= len;
411 bio_bytes += len << inode->i_blkbits;
412 set_bit(META_io, &mp->flag);
413 continue;
414 }
415 /* Not contiguous */
416 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
417 bio_bytes)
418 goto add_failed;
419 /*
420 * Increment counter before submitting i/o to keep
421 * count from hitting zero before we're through
422 */
423 inc_io(page);
424 if (!bio->bi_size)
425 goto dump_bio;
426 submit_bio(WRITE, bio);
427 bio = NULL;
428 } else {
429 set_page_writeback(page);
430 inc_io(page);
431 }
432 xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
433 pblock = metapage_get_blocks(inode, lblock, &xlen);
434 if (!pblock) {
435 /* Need better error handling */
436 printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
437 dec_io(page, last_write_complete);
438 continue;
439 }
440 set_bit(META_io, &mp->flag);
441 len = min(xlen, (uint) JFS_SBI(inode->i_sb)->nbperpage);
442
443 bio = bio_alloc(GFP_NOFS, 1);
444 bio->bi_bdev = inode->i_sb->s_bdev;
445 bio->bi_sector = pblock << (inode->i_blkbits - 9);
446 bio->bi_end_io = metapage_write_end_io;
447 bio->bi_private = page;
448
449 /* Don't call bio_add_page yet, we may add to this vec */
450 bio_offset = offset;
451 bio_bytes = len << inode->i_blkbits;
452
453 xlen -= len;
454 next_block = lblock + len;
455 }
456 if (bio) {
457 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
458 goto add_failed;
459 if (!bio->bi_size)
460 goto dump_bio;
461
462 submit_bio(WRITE, bio);
463 }
464 if (redirty)
465 redirty_page_for_writepage(wbc, page);
466
467 unlock_page(page);
468
469 return 0;
470 add_failed:
471 /* We should never reach here, since we're only adding one vec */
472 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
473 goto skip;
474 dump_bio:
475 dump_mem("bio", bio, sizeof(*bio));
476 skip:
477 bio_put(bio);
478 unlock_page(page);
479 dec_io(page, last_write_complete);
480
481 return -EIO;
482 }
483
484 static int metapage_readpage(struct file *fp, struct page *page)
485 {
486 struct inode *inode = page->mapping->host;
487 struct bio *bio = NULL;
488 unsigned int block_offset;
489 unsigned int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
490 sector_t page_start; /* address of page in fs blocks */
491 sector_t pblock;
492 unsigned int xlen;
493 unsigned int len;
494 unsigned int offset;
495
496 BUG_ON(!PageLocked(page));
497 page_start = (sector_t)page->index <<
498 (PAGE_CACHE_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(READ, bio);
511
512 bio = bio_alloc(GFP_NOFS, 1);
513 bio->bi_bdev = inode->i_sb->s_bdev;
514 bio->bi_sector = pblock << (inode->i_blkbits - 9);
515 bio->bi_end_io = metapage_read_end_io;
516 bio->bi_private = page;
517 len = xlen << inode->i_blkbits;
518 offset = block_offset << inode->i_blkbits;
519 if (bio_add_page(bio, page, len, offset) < len)
520 goto add_failed;
521 block_offset += xlen;
522 } else
523 block_offset++;
524 }
525 if (bio)
526 submit_bio(READ, bio);
527 else
528 unlock_page(page);
529
530 return 0;
531
532 add_failed:
533 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
534 bio_put(bio);
535 dec_io(page, last_read_complete);
536 return -EIO;
537 }
538
539 static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
540 {
541 struct metapage *mp;
542 int ret = 1;
543 unsigned int offset;
544
545 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
546 mp = page_to_mp(page, offset);
547
548 if (!mp)
549 continue;
550
551 jfs_info("metapage_releasepage: mp = 0x%p", mp);
552 if (mp->count || mp->nohomeok ||
553 test_bit(META_dirty, &mp->flag)) {
554 jfs_info("count = %ld, nohomeok = %d", mp->count,
555 mp->nohomeok);
556 ret = 0;
557 continue;
558 }
559 if (mp->lsn)
560 remove_from_logsync(mp);
561 remove_metapage(page, mp);
562 INCREMENT(mpStat.pagefree);
563 free_metapage(mp);
564 }
565 return ret;
566 }
567
568 static void metapage_invalidatepage(struct page *page, unsigned long offset)
569 {
570 BUG_ON(offset);
571
572 BUG_ON(PageWriteback(page));
573
574 metapage_releasepage(page, 0);
575 }
576
577 const struct address_space_operations jfs_metapage_aops = {
578 .readpage = metapage_readpage,
579 .writepage = metapage_writepage,
580 .sync_page = block_sync_page,
581 .releasepage = metapage_releasepage,
582 .invalidatepage = metapage_invalidatepage,
583 .set_page_dirty = __set_page_dirty_nobuffers,
584 };
585
586 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
587 unsigned int size, int absolute,
588 unsigned long new)
589 {
590 int l2BlocksPerPage;
591 int l2bsize;
592 struct address_space *mapping;
593 struct metapage *mp = NULL;
594 struct page *page;
595 unsigned long page_index;
596 unsigned long page_offset;
597
598 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
599 inode->i_ino, lblock, absolute);
600
601 l2bsize = inode->i_blkbits;
602 l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
603 page_index = lblock >> l2BlocksPerPage;
604 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
605 if ((page_offset + size) > PAGE_CACHE_SIZE) {
606 jfs_err("MetaData crosses page boundary!!");
607 jfs_err("lblock = %lx, size = %d", lblock, size);
608 dump_stack();
609 return NULL;
610 }
611 if (absolute)
612 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
613 else {
614 /*
615 * If an nfs client tries to read an inode that is larger
616 * than any existing inodes, we may try to read past the
617 * end of the inode map
618 */
619 if ((lblock << inode->i_blkbits) >= inode->i_size)
620 return NULL;
621 mapping = inode->i_mapping;
622 }
623
624 if (new && (PSIZE == PAGE_CACHE_SIZE)) {
625 page = grab_cache_page(mapping, page_index);
626 if (!page) {
627 jfs_err("grab_cache_page failed!");
628 return NULL;
629 }
630 SetPageUptodate(page);
631 } else {
632 page = read_mapping_page(mapping, page_index, NULL);
633 if (IS_ERR(page) || !PageUptodate(page)) {
634 jfs_err("read_mapping_page failed!");
635 return NULL;
636 }
637 lock_page(page);
638 }
639
640 mp = page_to_mp(page, page_offset);
641 if (mp) {
642 if (mp->logical_size != size) {
643 jfs_error(inode->i_sb,
644 "__get_metapage: mp->logical_size != size");
645 jfs_err("logical_size = %d, size = %d",
646 mp->logical_size, size);
647 dump_stack();
648 goto unlock;
649 }
650 mp->count++;
651 lock_metapage(mp);
652 if (test_bit(META_discard, &mp->flag)) {
653 if (!new) {
654 jfs_error(inode->i_sb,
655 "__get_metapage: using a "
656 "discarded metapage");
657 discard_metapage(mp);
658 goto unlock;
659 }
660 clear_bit(META_discard, &mp->flag);
661 }
662 } else {
663 INCREMENT(mpStat.pagealloc);
664 mp = alloc_metapage(GFP_NOFS);
665 mp->page = page;
666 mp->flag = 0;
667 mp->xflag = COMMIT_PAGE;
668 mp->count = 1;
669 mp->nohomeok = 0;
670 mp->logical_size = size;
671 mp->data = page_address(page) + page_offset;
672 mp->index = lblock;
673 if (unlikely(insert_metapage(page, mp))) {
674 free_metapage(mp);
675 goto unlock;
676 }
677 lock_metapage(mp);
678 }
679
680 if (new) {
681 jfs_info("zeroing mp = 0x%p", mp);
682 memset(mp->data, 0, PSIZE);
683 }
684
685 unlock_page(page);
686 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
687 return mp;
688
689 unlock:
690 unlock_page(page);
691 return NULL;
692 }
693
694 void grab_metapage(struct metapage * mp)
695 {
696 jfs_info("grab_metapage: mp = 0x%p", mp);
697 page_cache_get(mp->page);
698 lock_page(mp->page);
699 mp->count++;
700 lock_metapage(mp);
701 unlock_page(mp->page);
702 }
703
704 void force_metapage(struct metapage *mp)
705 {
706 struct page *page = mp->page;
707 jfs_info("force_metapage: mp = 0x%p", mp);
708 set_bit(META_forcewrite, &mp->flag);
709 clear_bit(META_sync, &mp->flag);
710 page_cache_get(page);
711 lock_page(page);
712 set_page_dirty(page);
713 write_one_page(page, 1);
714 clear_bit(META_forcewrite, &mp->flag);
715 page_cache_release(page);
716 }
717
718 void hold_metapage(struct metapage *mp)
719 {
720 lock_page(mp->page);
721 }
722
723 void put_metapage(struct metapage *mp)
724 {
725 if (mp->count || mp->nohomeok) {
726 /* Someone else will release this */
727 unlock_page(mp->page);
728 return;
729 }
730 page_cache_get(mp->page);
731 mp->count++;
732 lock_metapage(mp);
733 unlock_page(mp->page);
734 release_metapage(mp);
735 }
736
737 void release_metapage(struct metapage * mp)
738 {
739 struct page *page = mp->page;
740 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
741
742 BUG_ON(!page);
743
744 lock_page(page);
745 unlock_metapage(mp);
746
747 assert(mp->count);
748 if (--mp->count || mp->nohomeok) {
749 unlock_page(page);
750 page_cache_release(page);
751 return;
752 }
753
754 if (test_bit(META_dirty, &mp->flag)) {
755 set_page_dirty(page);
756 if (test_bit(META_sync, &mp->flag)) {
757 clear_bit(META_sync, &mp->flag);
758 write_one_page(page, 1);
759 lock_page(page); /* write_one_page unlocks the page */
760 }
761 } else if (mp->lsn) /* discard_metapage doesn't remove it */
762 remove_from_logsync(mp);
763
764 /* Try to keep metapages from using up too much memory */
765 drop_metapage(page, mp);
766
767 unlock_page(page);
768 page_cache_release(page);
769 }
770
771 void __invalidate_metapages(struct inode *ip, s64 addr, int len)
772 {
773 sector_t lblock;
774 int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
775 int BlocksPerPage = 1 << l2BlocksPerPage;
776 /* All callers are interested in block device's mapping */
777 struct address_space *mapping =
778 JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
779 struct metapage *mp;
780 struct page *page;
781 unsigned int offset;
782
783 /*
784 * Mark metapages to discard. They will eventually be
785 * released, but should not be written.
786 */
787 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
788 lblock += BlocksPerPage) {
789 page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
790 if (!page)
791 continue;
792 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
793 mp = page_to_mp(page, offset);
794 if (!mp)
795 continue;
796 if (mp->index < addr)
797 continue;
798 if (mp->index >= addr + len)
799 break;
800
801 clear_bit(META_dirty, &mp->flag);
802 set_bit(META_discard, &mp->flag);
803 if (mp->lsn)
804 remove_from_logsync(mp);
805 }
806 unlock_page(page);
807 page_cache_release(page);
808 }
809 }
810
811 #ifdef CONFIG_JFS_STATISTICS
812 int jfs_mpstat_read(char *buffer, char **start, off_t offset, int length,
813 int *eof, void *data)
814 {
815 int len = 0;
816 off_t begin;
817
818 len += sprintf(buffer,
819 "JFS Metapage statistics\n"
820 "=======================\n"
821 "page allocations = %d\n"
822 "page frees = %d\n"
823 "lock waits = %d\n",
824 mpStat.pagealloc,
825 mpStat.pagefree,
826 mpStat.lockwait);
827
828 begin = offset;
829 *start = buffer + begin;
830 len -= begin;
831
832 if (len > length)
833 len = length;
834 else
835 *eof = 1;
836
837 if (len < 0)
838 len = 0;
839
840 return len;
841 }
842 #endif
Tomato firmware and modifications.