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[PATCH] ieee80211: Keep auth mode unchanged after iwconfig key off/on cycle
[linux-2.6/sactl.git] / fs / jfs / jfs_metapage.c
blob13d7e3f1feb4e0c8a0d18462fd5cfb657702da1f
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 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 kmem_cache_t *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)
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 = kmalloc(sizeof(struct meta_anchor), GFP_NOFS);
108 if (!a)
109 return -ENOMEM;
110 memset(a, 0, sizeof(struct meta_anchor));
111 page->private = (unsigned long)a;
112 SetPagePrivate(page);
113 kmap(page);
114 }
115
116 if (mp) {
117 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
118 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
119 a->mp_count++;
120 a->mp[index] = mp;
121 }
122
123 return 0;
124 }
125
126 static inline void remove_metapage(struct page *page, struct metapage *mp)
127 {
128 struct meta_anchor *a = mp_anchor(page);
129 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
130 int index;
131
132 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
133
134 BUG_ON(a->mp[index] != mp);
135
136 a->mp[index] = NULL;
137 if (--a->mp_count == 0) {
138 kfree(a);
139 page->private = 0;
140 ClearPagePrivate(page);
141 kunmap(page);
142 }
143 }
144
145 static inline void inc_io(struct page *page)
146 {
147 atomic_inc(&mp_anchor(page)->io_count);
148 }
149
150 static inline void dec_io(struct page *page, void (*handler) (struct page *))
151 {
152 if (atomic_dec_and_test(&mp_anchor(page)->io_count))
153 handler(page);
154 }
155
156 #else
157 static inline struct metapage *page_to_mp(struct page *page, uint offset)
158 {
159 return PagePrivate(page) ? (struct metapage *)page->private : NULL;
160 }
161
162 static inline int insert_metapage(struct page *page, struct metapage *mp)
163 {
164 if (mp) {
165 page->private = (unsigned long)mp;
166 SetPagePrivate(page);
167 kmap(page);
168 }
169 return 0;
170 }
171
172 static inline void remove_metapage(struct page *page, struct metapage *mp)
173 {
174 page->private = 0;
175 ClearPagePrivate(page);
176 kunmap(page);
177 }
178
179 #define inc_io(page) do {} while(0)
180 #define dec_io(page, handler) handler(page)
181
182 #endif
183
184 static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
185 {
186 struct metapage *mp = (struct metapage *)foo;
187
188 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
189 SLAB_CTOR_CONSTRUCTOR) {
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 }
200
201 static inline struct metapage *alloc_metapage(unsigned int gfp_mask)
202 {
203 return mempool_alloc(metapage_mempool, gfp_mask);
204 }
205
206 static inline void free_metapage(struct metapage *mp)
207 {
208 mp->flag = 0;
209 set_bit(META_free, &mp->flag);
210
211 mempool_free(mp, metapage_mempool);
212 }
213
214 int __init metapage_init(void)
215 {
216 /*
217 * Allocate the metapage structures
218 */
219 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
220 0, 0, init_once, NULL);
221 if (metapage_cache == NULL)
222 return -ENOMEM;
223
224 metapage_mempool = mempool_create(METAPOOL_MIN_PAGES, mempool_alloc_slab,
225 mempool_free_slab, metapage_cache);
226
227 if (metapage_mempool == NULL) {
228 kmem_cache_destroy(metapage_cache);
229 return -ENOMEM;
230 }
231
232 return 0;
233 }
234
235 void metapage_exit(void)
236 {
237 mempool_destroy(metapage_mempool);
238 kmem_cache_destroy(metapage_cache);
239 }
240
241 static inline void drop_metapage(struct page *page, struct metapage *mp)
242 {
243 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
244 test_bit(META_io, &mp->flag))
245 return;
246 remove_metapage(page, mp);
247 INCREMENT(mpStat.pagefree);
248 free_metapage(mp);
249 }
250
251 /*
252 * Metapage address space operations
253 */
254
255 static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
256 unsigned int *len)
257 {
258 int rc = 0;
259 int xflag;
260 s64 xaddr;
261 sector_t file_blocks = (inode->i_size + inode->i_blksize - 1) >>
262 inode->i_blkbits;
263
264 if (lblock >= file_blocks)
265 return 0;
266 if (lblock + *len > file_blocks)
267 *len = file_blocks - lblock;
268
269 if (inode->i_ino) {
270 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
271 if ((rc == 0) && *len)
272 lblock = (sector_t)xaddr;
273 else
274 lblock = 0;
275 } /* else no mapping */
276
277 return lblock;
278 }
279
280 static void last_read_complete(struct page *page)
281 {
282 if (!PageError(page))
283 SetPageUptodate(page);
284 unlock_page(page);
285 }
286
287 static int metapage_read_end_io(struct bio *bio, unsigned int bytes_done,
288 int err)
289 {
290 struct page *page = bio->bi_private;
291
292 if (bio->bi_size)
293 return 1;
294
295 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
296 printk(KERN_ERR "metapage_read_end_io: I/O error\n");
297 SetPageError(page);
298 }
299
300 dec_io(page, last_read_complete);
301 bio_put(bio);
302
303 return 0;
304 }
305
306 static void remove_from_logsync(struct metapage *mp)
307 {
308 struct jfs_log *log = mp->log;
309 unsigned long flags;
310 /*
311 * This can race. Recheck that log hasn't been set to null, and after
312 * acquiring logsync lock, recheck lsn
313 */
314 if (!log)
315 return;
316
317 LOGSYNC_LOCK(log, flags);
318 if (mp->lsn) {
319 mp->log = NULL;
320 mp->lsn = 0;
321 mp->clsn = 0;
322 log->count--;
323 list_del(&mp->synclist);
324 }
325 LOGSYNC_UNLOCK(log, flags);
326 }
327
328 static void last_write_complete(struct page *page)
329 {
330 struct metapage *mp;
331 unsigned int offset;
332
333 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
334 mp = page_to_mp(page, offset);
335 if (mp && test_bit(META_io, &mp->flag)) {
336 if (mp->lsn)
337 remove_from_logsync(mp);
338 clear_bit(META_io, &mp->flag);
339 }
340 /*
341 * I'd like to call drop_metapage here, but I don't think it's
342 * safe unless I have the page locked
343 */
344 }
345 end_page_writeback(page);
346 }
347
348 static int metapage_write_end_io(struct bio *bio, unsigned int bytes_done,
349 int err)
350 {
351 struct page *page = bio->bi_private;
352
353 BUG_ON(!PagePrivate(page));
354
355 if (bio->bi_size)
356 return 1;
357
358 if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
359 printk(KERN_ERR "metapage_write_end_io: I/O error\n");
360 SetPageError(page);
361 }
362 dec_io(page, last_write_complete);
363 bio_put(bio);
364 return 0;
365 }
366
367 static int metapage_writepage(struct page *page, struct writeback_control *wbc)
368 {
369 struct bio *bio = NULL;
370 unsigned int block_offset; /* block offset of mp within page */
371 struct inode *inode = page->mapping->host;
372 unsigned int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
373 unsigned int len;
374 unsigned int xlen;
375 struct metapage *mp;
376 int redirty = 0;
377 sector_t lblock;
378 sector_t pblock;
379 sector_t next_block = 0;
380 sector_t page_start;
381 unsigned long bio_bytes = 0;
382 unsigned long bio_offset = 0;
383 unsigned int offset;
384
385 page_start = (sector_t)page->index <<
386 (PAGE_CACHE_SHIFT - inode->i_blkbits);
387 BUG_ON(!PageLocked(page));
388 BUG_ON(PageWriteback(page));
389
390 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
391 mp = page_to_mp(page, offset);
392
393 if (!mp || !test_bit(META_dirty, &mp->flag))
394 continue;
395
396 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
397 redirty = 1;
398 continue;
399 }
400
401 clear_bit(META_dirty, &mp->flag);
402 block_offset = offset >> inode->i_blkbits;
403 lblock = page_start + block_offset;
404 if (bio) {
405 if (xlen && lblock == next_block) {
406 /* Contiguous, in memory & on disk */
407 len = min(xlen, blocks_per_mp);
408 xlen -= len;
409 bio_bytes += len << inode->i_blkbits;
410 set_bit(META_io, &mp->flag);
411 continue;
412 }
413 /* Not contiguous */
414 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
415 bio_bytes)
416 goto add_failed;
417 /*
418 * Increment counter before submitting i/o to keep
419 * count from hitting zero before we're through
420 */
421 inc_io(page);
422 if (!bio->bi_size)
423 goto dump_bio;
424 submit_bio(WRITE, bio);
425 bio = NULL;
426 } else {
427 set_page_writeback(page);
428 inc_io(page);
429 }
430 xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
431 pblock = metapage_get_blocks(inode, lblock, &xlen);
432 if (!pblock) {
433 /* Need better error handling */
434 printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
435 dec_io(page, last_write_complete);
436 continue;
437 }
438 set_bit(META_io, &mp->flag);
439 len = min(xlen, (uint) JFS_SBI(inode->i_sb)->nbperpage);
440
441 bio = bio_alloc(GFP_NOFS, 1);
442 bio->bi_bdev = inode->i_sb->s_bdev;
443 bio->bi_sector = pblock << (inode->i_blkbits - 9);
444 bio->bi_end_io = metapage_write_end_io;
445 bio->bi_private = page;
446
447 /* Don't call bio_add_page yet, we may add to this vec */
448 bio_offset = offset;
449 bio_bytes = len << inode->i_blkbits;
450
451 xlen -= len;
452 next_block = lblock + len;
453 }
454 if (bio) {
455 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
456 goto add_failed;
457 if (!bio->bi_size)
458 goto dump_bio;
459
460 submit_bio(WRITE, bio);
461 }
462 if (redirty)
463 redirty_page_for_writepage(wbc, page);
464
465 unlock_page(page);
466
467 return 0;
468 add_failed:
469 /* We should never reach here, since we're only adding one vec */
470 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
471 goto skip;
472 dump_bio:
473 dump_mem("bio", bio, sizeof(*bio));
474 skip:
475 bio_put(bio);
476 unlock_page(page);
477 dec_io(page, last_write_complete);
478
479 return -EIO;
480 }
481
482 static int metapage_readpage(struct file *fp, struct page *page)
483 {
484 struct inode *inode = page->mapping->host;
485 struct bio *bio = NULL;
486 unsigned int block_offset;
487 unsigned int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
488 sector_t page_start; /* address of page in fs blocks */
489 sector_t pblock;
490 unsigned int xlen;
491 unsigned int len;
492 unsigned int offset;
493
494 BUG_ON(!PageLocked(page));
495 page_start = (sector_t)page->index <<
496 (PAGE_CACHE_SHIFT - inode->i_blkbits);
497
498 block_offset = 0;
499 while (block_offset < blocks_per_page) {
500 xlen = blocks_per_page - block_offset;
501 pblock = metapage_get_blocks(inode, page_start + block_offset,
502 &xlen);
503 if (pblock) {
504 if (!PagePrivate(page))
505 insert_metapage(page, NULL);
506 inc_io(page);
507 if (bio)
508 submit_bio(READ, bio);
509
510 bio = bio_alloc(GFP_NOFS, 1);
511 bio->bi_bdev = inode->i_sb->s_bdev;
512 bio->bi_sector = pblock << (inode->i_blkbits - 9);
513 bio->bi_end_io = metapage_read_end_io;
514 bio->bi_private = page;
515 len = xlen << inode->i_blkbits;
516 offset = block_offset << inode->i_blkbits;
517 if (bio_add_page(bio, page, len, offset) < len)
518 goto add_failed;
519 block_offset += xlen;
520 } else
521 block_offset++;
522 }
523 if (bio)
524 submit_bio(READ, bio);
525 else
526 unlock_page(page);
527
528 return 0;
529
530 add_failed:
531 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
532 bio_put(bio);
533 dec_io(page, last_read_complete);
534 return -EIO;
535 }
536
537 static int metapage_releasepage(struct page *page, int gfp_mask)
538 {
539 struct metapage *mp;
540 int busy = 0;
541 unsigned int offset;
542
543 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
544 mp = page_to_mp(page, offset);
545
546 if (!mp)
547 continue;
548
549 jfs_info("metapage_releasepage: mp = 0x%p", mp);
550 if (mp->count || mp->nohomeok) {
551 jfs_info("count = %ld, nohomeok = %d", mp->count,
552 mp->nohomeok);
553 busy = 1;
554 continue;
555 }
556 wait_on_page_writeback(page);
557 //WARN_ON(test_bit(META_dirty, &mp->flag));
558 if (test_bit(META_dirty, &mp->flag)) {
559 dump_mem("dirty mp in metapage_releasepage", mp,
560 sizeof(struct metapage));
561 dump_mem("page", page, sizeof(struct page));
562 dump_stack();
563 }
564 if (mp->lsn)
565 remove_from_logsync(mp);
566 remove_metapage(page, mp);
567 INCREMENT(mpStat.pagefree);
568 free_metapage(mp);
569 }
570 if (busy)
571 return -1;
572
573 return 0;
574 }
575
576 static int metapage_invalidatepage(struct page *page, unsigned long offset)
577 {
578 BUG_ON(offset);
579
580 if (PageWriteback(page))
581 return 0;
582
583 return metapage_releasepage(page, 0);
584 }
585
586 struct address_space_operations jfs_metapage_aops = {
587 .readpage = metapage_readpage,
588 .writepage = metapage_writepage,
589 .sync_page = block_sync_page,
590 .releasepage = metapage_releasepage,
591 .invalidatepage = metapage_invalidatepage,
592 .set_page_dirty = __set_page_dirty_nobuffers,
593 };
594
595 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
596 unsigned int size, int absolute,
597 unsigned long new)
598 {
599 int l2BlocksPerPage;
600 int l2bsize;
601 struct address_space *mapping;
602 struct metapage *mp = NULL;
603 struct page *page;
604 unsigned long page_index;
605 unsigned long page_offset;
606
607 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
608 inode->i_ino, lblock, absolute);
609
610 l2bsize = inode->i_blkbits;
611 l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
612 page_index = lblock >> l2BlocksPerPage;
613 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
614 if ((page_offset + size) > PAGE_CACHE_SIZE) {
615 jfs_err("MetaData crosses page boundary!!");
616 jfs_err("lblock = %lx, size = %d", lblock, size);
617 dump_stack();
618 return NULL;
619 }
620 if (absolute)
621 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
622 else {
623 /*
624 * If an nfs client tries to read an inode that is larger
625 * than any existing inodes, we may try to read past the
626 * end of the inode map
627 */
628 if ((lblock << inode->i_blkbits) >= inode->i_size)
629 return NULL;
630 mapping = inode->i_mapping;
631 }
632
633 if (new && (PSIZE == PAGE_CACHE_SIZE)) {
634 page = grab_cache_page(mapping, page_index);
635 if (!page) {
636 jfs_err("grab_cache_page failed!");
637 return NULL;
638 }
639 SetPageUptodate(page);
640 } else {
641 page = read_cache_page(mapping, page_index,
642 (filler_t *)mapping->a_ops->readpage, NULL);
643 if (IS_ERR(page) || !PageUptodate(page)) {
644 jfs_err("read_cache_page failed!");
645 return NULL;
646 }
647 lock_page(page);
648 }
649
650 mp = page_to_mp(page, page_offset);
651 if (mp) {
652 if (mp->logical_size != size) {
653 jfs_error(inode->i_sb,
654 "__get_metapage: mp->logical_size != size");
655 jfs_err("logical_size = %d, size = %d",
656 mp->logical_size, size);
657 dump_stack();
658 goto unlock;
659 }
660 mp->count++;
661 lock_metapage(mp);
662 if (test_bit(META_discard, &mp->flag)) {
663 if (!new) {
664 jfs_error(inode->i_sb,
665 "__get_metapage: using a "
666 "discarded metapage");
667 discard_metapage(mp);
668 goto unlock;
669 }
670 clear_bit(META_discard, &mp->flag);
671 }
672 } else {
673 INCREMENT(mpStat.pagealloc);
674 mp = alloc_metapage(GFP_NOFS);
675 mp->page = page;
676 mp->flag = 0;
677 mp->xflag = COMMIT_PAGE;
678 mp->count = 1;
679 mp->nohomeok = 0;
680 mp->logical_size = size;
681 mp->data = page_address(page) + page_offset;
682 mp->index = lblock;
683 if (unlikely(insert_metapage(page, mp))) {
684 free_metapage(mp);
685 goto unlock;
686 }
687 lock_metapage(mp);
688 }
689
690 if (new) {
691 jfs_info("zeroing mp = 0x%p", mp);
692 memset(mp->data, 0, PSIZE);
693 }
694
695 unlock_page(page);
696 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
697 return mp;
698
699 unlock:
700 unlock_page(page);
701 return NULL;
702 }
703
704 void grab_metapage(struct metapage * mp)
705 {
706 jfs_info("grab_metapage: mp = 0x%p", mp);
707 page_cache_get(mp->page);
708 lock_page(mp->page);
709 mp->count++;
710 lock_metapage(mp);
711 unlock_page(mp->page);
712 }
713
714 void force_metapage(struct metapage *mp)
715 {
716 struct page *page = mp->page;
717 jfs_info("force_metapage: mp = 0x%p", mp);
718 set_bit(META_forcewrite, &mp->flag);
719 clear_bit(META_sync, &mp->flag);
720 page_cache_get(page);
721 lock_page(page);
722 set_page_dirty(page);
723 write_one_page(page, 1);
724 clear_bit(META_forcewrite, &mp->flag);
725 page_cache_release(page);
726 }
727
728 void hold_metapage(struct metapage *mp)
729 {
730 lock_page(mp->page);
731 }
732
733 void put_metapage(struct metapage *mp)
734 {
735 if (mp->count || mp->nohomeok) {
736 /* Someone else will release this */
737 unlock_page(mp->page);
738 return;
739 }
740 page_cache_get(mp->page);
741 mp->count++;
742 lock_metapage(mp);
743 unlock_page(mp->page);
744 release_metapage(mp);
745 }
746
747 void release_metapage(struct metapage * mp)
748 {
749 struct page *page = mp->page;
750 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
751
752 BUG_ON(!page);
753
754 lock_page(page);
755 unlock_metapage(mp);
756
757 assert(mp->count);
758 if (--mp->count || mp->nohomeok) {
759 unlock_page(page);
760 page_cache_release(page);
761 return;
762 }
763
764 if (test_bit(META_dirty, &mp->flag)) {
765 set_page_dirty(page);
766 if (test_bit(META_sync, &mp->flag)) {
767 clear_bit(META_sync, &mp->flag);
768 write_one_page(page, 1);
769 lock_page(page); /* write_one_page unlocks the page */
770 }
771 } else if (mp->lsn) /* discard_metapage doesn't remove it */
772 remove_from_logsync(mp);
773
774 #if MPS_PER_PAGE == 1
775 /*
776 * If we know this is the only thing in the page, we can throw
777 * the page out of the page cache. If pages are larger, we
778 * don't want to do this.
779 */
780
781 /* Retest mp->count since we may have released page lock */
782 if (test_bit(META_discard, &mp->flag) && !mp->count) {
783 clear_page_dirty(page);
784 ClearPageUptodate(page);
785 }
786 #else
787 /* Try to keep metapages from using up too much memory */
788 drop_metapage(page, mp);
789 #endif
790 unlock_page(page);
791 page_cache_release(page);
792 }
793
794 void __invalidate_metapages(struct inode *ip, s64 addr, int len)
795 {
796 sector_t lblock;
797 int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
798 int BlocksPerPage = 1 << l2BlocksPerPage;
799 /* All callers are interested in block device's mapping */
800 struct address_space *mapping =
801 JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
802 struct metapage *mp;
803 struct page *page;
804 unsigned int offset;
805
806 /*
807 * Mark metapages to discard. They will eventually be
808 * released, but should not be written.
809 */
810 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
811 lblock += BlocksPerPage) {
812 page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
813 if (!page)
814 continue;
815 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
816 mp = page_to_mp(page, offset);
817 if (!mp)
818 continue;
819 if (mp->index < addr)
820 continue;
821 if (mp->index >= addr + len)
822 break;
823
824 clear_bit(META_dirty, &mp->flag);
825 set_bit(META_discard, &mp->flag);
826 if (mp->lsn)
827 remove_from_logsync(mp);
828 }
829 unlock_page(page);
830 page_cache_release(page);
831 }
832 }
833
834 #ifdef CONFIG_JFS_STATISTICS
835 int jfs_mpstat_read(char *buffer, char **start, off_t offset, int length,
836 int *eof, void *data)
837 {
838 int len = 0;
839 off_t begin;
840
841 len += sprintf(buffer,
842 "JFS Metapage statistics\n"
843 "=======================\n"
844 "page allocations = %d\n"
845 "page frees = %d\n"
846 "lock waits = %d\n",
847 mpStat.pagealloc,
848 mpStat.pagefree,
849 mpStat.lockwait);
850
851 begin = offset;
852 *start = buffer + begin;
853 len -= begin;
854
855 if (len > length)
856 len = length;
857 else
858 *eof = 1;
859
860 if (len < 0)
861 len = 0;
862
863 return len;
864 }
865 #endif
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