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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/init.h> |
25 | #include <linux/buffer_head.h> |
26 | #include <linux/mempool.h> |
27 | #include <linux/seq_file.h> |
28 | #include "jfs_incore.h" |
29 | #include "jfs_superblock.h" |
30 | #include "jfs_filsys.h" |
31 | #include "jfs_metapage.h" |
32 | #include "jfs_txnmgr.h" |
33 | #include "jfs_debug.h" |
34 | |
35 | #ifdef CONFIG_JFS_STATISTICS |
36 | static struct { |
37 | uint pagealloc; /* # of page allocations */ |
38 | uint pagefree; /* # of page frees */ |
39 | uint lockwait; /* # of sleeping lock_metapage() calls */ |
40 | } mpStat; |
41 | #endif |
42 | |
43 | #define metapage_locked(mp) test_bit(META_locked, &(mp)->flag) |
44 | #define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag) |
45 | |
46 | static inline void unlock_metapage(struct metapage *mp) |
47 | { |
48 | clear_bit_unlock(META_locked, &mp->flag); |
49 | wake_up(&mp->wait); |
50 | } |
51 | |
52 | static inline void __lock_metapage(struct metapage *mp) |
53 | { |
54 | DECLARE_WAITQUEUE(wait, current); |
55 | INCREMENT(mpStat.lockwait); |
56 | add_wait_queue_exclusive(&mp->wait, &wait); |
57 | do { |
58 | set_current_state(TASK_UNINTERRUPTIBLE); |
59 | if (metapage_locked(mp)) { |
60 | unlock_page(mp->page); |
61 | io_schedule(); |
62 | lock_page(mp->page); |
63 | } |
64 | } while (trylock_metapage(mp)); |
65 | __set_current_state(TASK_RUNNING); |
66 | remove_wait_queue(&mp->wait, &wait); |
67 | } |
68 | |
69 | /* |
70 | * Must have mp->page locked |
71 | */ |
72 | static inline void lock_metapage(struct metapage *mp) |
73 | { |
74 | if (trylock_metapage(mp)) |
75 | __lock_metapage(mp); |
76 | } |
77 | |
78 | #define METAPOOL_MIN_PAGES 32 |
79 | static struct kmem_cache *metapage_cache; |
80 | static mempool_t *metapage_mempool; |
81 | |
82 | #define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE) |
83 | |
84 | #if MPS_PER_PAGE > 1 |
85 | |
86 | struct meta_anchor { |
87 | int mp_count; |
88 | atomic_t io_count; |
89 | struct metapage *mp[MPS_PER_PAGE]; |
90 | }; |
91 | #define mp_anchor(page) ((struct meta_anchor *)page_private(page)) |
92 | |
93 | static inline struct metapage *page_to_mp(struct page *page, int offset) |
94 | { |
95 | if (!PagePrivate(page)) |
96 | return NULL; |
97 | return mp_anchor(page)->mp[offset >> L2PSIZE]; |
98 | } |
99 | |
100 | static inline int insert_metapage(struct page *page, struct metapage *mp) |
101 | { |
102 | struct meta_anchor *a; |
103 | int index; |
104 | int l2mp_blocks; /* log2 blocks per metapage */ |
105 | |
106 | if (PagePrivate(page)) |
107 | a = mp_anchor(page); |
108 | else { |
109 | a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS); |
110 | if (!a) |
111 | return -ENOMEM; |
112 | set_page_private(page, (unsigned long)a); |
113 | SetPagePrivate(page); |
114 | kmap(page); |
115 | } |
116 | |
117 | if (mp) { |
118 | l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; |
119 | index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); |
120 | a->mp_count++; |
121 | a->mp[index] = mp; |
122 | } |
123 | |
124 | return 0; |
125 | } |
126 | |
127 | static inline void remove_metapage(struct page *page, struct metapage *mp) |
128 | { |
129 | struct meta_anchor *a = mp_anchor(page); |
130 | int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; |
131 | int index; |
132 | |
133 | index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); |
134 | |
135 | BUG_ON(a->mp[index] != mp); |
136 | |
137 | a->mp[index] = NULL; |
138 | if (--a->mp_count == 0) { |
139 | kfree(a); |
140 | set_page_private(page, 0); |
141 | ClearPagePrivate(page); |
142 | kunmap(page); |
143 | } |
144 | } |
145 | |
146 | static inline void inc_io(struct page *page) |
147 | { |
148 | atomic_inc(&mp_anchor(page)->io_count); |
149 | } |
150 | |
151 | static inline void dec_io(struct page *page, void (*handler) (struct page *)) |
152 | { |
153 | if (atomic_dec_and_test(&mp_anchor(page)->io_count)) |
154 | handler(page); |
155 | } |
156 | |
157 | #else |
158 | static inline struct metapage *page_to_mp(struct page *page, int offset) |
159 | { |
160 | return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; |
161 | } |
162 | |
163 | static inline int insert_metapage(struct page *page, struct metapage *mp) |
164 | { |
165 | if (mp) { |
166 | set_page_private(page, (unsigned long)mp); |
167 | SetPagePrivate(page); |
168 | kmap(page); |
169 | } |
170 | return 0; |
171 | } |
172 | |
173 | static inline void remove_metapage(struct page *page, struct metapage *mp) |
174 | { |
175 | set_page_private(page, 0); |
176 | ClearPagePrivate(page); |
177 | kunmap(page); |
178 | } |
179 | |
180 | #define inc_io(page) do {} while(0) |
181 | #define dec_io(page, handler) handler(page) |
182 | |
183 | #endif |
184 | |
185 | static void init_once(void *foo) |
186 | { |
187 | struct metapage *mp = (struct metapage *)foo; |
188 | |
189 | mp->lid = 0; |
190 | mp->lsn = 0; |
191 | mp->flag = 0; |
192 | mp->data = NULL; |
193 | mp->clsn = 0; |
194 | mp->log = NULL; |
195 | set_bit(META_free, &mp->flag); |
196 | init_waitqueue_head(&mp->wait); |
197 | } |
198 | |
199 | static inline struct metapage *alloc_metapage(gfp_t gfp_mask) |
200 | { |
201 | return mempool_alloc(metapage_mempool, gfp_mask); |
202 | } |
203 | |
204 | static inline void free_metapage(struct metapage *mp) |
205 | { |
206 | mp->flag = 0; |
207 | set_bit(META_free, &mp->flag); |
208 | |
209 | mempool_free(mp, metapage_mempool); |
210 | } |
211 | |
212 | int __init metapage_init(void) |
213 | { |
214 | /* |
215 | * Allocate the metapage structures |
216 | */ |
217 | metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage), |
218 | 0, 0, init_once); |
219 | if (metapage_cache == NULL) |
220 | return -ENOMEM; |
221 | |
222 | metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES, |
223 | metapage_cache); |
224 | |
225 | if (metapage_mempool == NULL) { |
226 | kmem_cache_destroy(metapage_cache); |
227 | return -ENOMEM; |
228 | } |
229 | |
230 | return 0; |
231 | } |
232 | |
233 | void metapage_exit(void) |
234 | { |
235 | mempool_destroy(metapage_mempool); |
236 | kmem_cache_destroy(metapage_cache); |
237 | } |
238 | |
239 | static inline void drop_metapage(struct page *page, struct metapage *mp) |
240 | { |
241 | if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) || |
242 | test_bit(META_io, &mp->flag)) |
243 | return; |
244 | remove_metapage(page, mp); |
245 | INCREMENT(mpStat.pagefree); |
246 | free_metapage(mp); |
247 | } |
248 | |
249 | /* |
250 | * Metapage address space operations |
251 | */ |
252 | |
253 | static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock, |
254 | int *len) |
255 | { |
256 | int rc = 0; |
257 | int xflag; |
258 | s64 xaddr; |
259 | sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >> |
260 | inode->i_blkbits; |
261 | |
262 | if (lblock >= file_blocks) |
263 | return 0; |
264 | if (lblock + *len > file_blocks) |
265 | *len = file_blocks - lblock; |
266 | |
267 | if (inode->i_ino) { |
268 | rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0); |
269 | if ((rc == 0) && *len) |
270 | lblock = (sector_t)xaddr; |
271 | else |
272 | lblock = 0; |
273 | } /* else no mapping */ |
274 | |
275 | return lblock; |
276 | } |
277 | |
278 | static void last_read_complete(struct page *page) |
279 | { |
280 | if (!PageError(page)) |
281 | SetPageUptodate(page); |
282 | unlock_page(page); |
283 | } |
284 | |
285 | static void metapage_read_end_io(struct bio *bio, int err) |
286 | { |
287 | struct page *page = bio->bi_private; |
288 | |
289 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) { |
290 | printk(KERN_ERR "metapage_read_end_io: I/O error\n"); |
291 | SetPageError(page); |
292 | } |
293 | |
294 | dec_io(page, last_read_complete); |
295 | bio_put(bio); |
296 | } |
297 | |
298 | static void remove_from_logsync(struct metapage *mp) |
299 | { |
300 | struct jfs_log *log = mp->log; |
301 | unsigned long flags; |
302 | /* |
303 | * This can race. Recheck that log hasn't been set to null, and after |
304 | * acquiring logsync lock, recheck lsn |
305 | */ |
306 | if (!log) |
307 | return; |
308 | |
309 | LOGSYNC_LOCK(log, flags); |
310 | if (mp->lsn) { |
311 | mp->log = NULL; |
312 | mp->lsn = 0; |
313 | mp->clsn = 0; |
314 | log->count--; |
315 | list_del(&mp->synclist); |
316 | } |
317 | LOGSYNC_UNLOCK(log, flags); |
318 | } |
319 | |
320 | static void last_write_complete(struct page *page) |
321 | { |
322 | struct metapage *mp; |
323 | unsigned int offset; |
324 | |
325 | for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { |
326 | mp = page_to_mp(page, offset); |
327 | if (mp && test_bit(META_io, &mp->flag)) { |
328 | if (mp->lsn) |
329 | remove_from_logsync(mp); |
330 | clear_bit(META_io, &mp->flag); |
331 | } |
332 | /* |
333 | * I'd like to call drop_metapage here, but I don't think it's |
334 | * safe unless I have the page locked |
335 | */ |
336 | } |
337 | end_page_writeback(page); |
338 | } |
339 | |
340 | static void metapage_write_end_io(struct bio *bio, int err) |
341 | { |
342 | struct page *page = bio->bi_private; |
343 | |
344 | BUG_ON(!PagePrivate(page)); |
345 | |
346 | if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) { |
347 | printk(KERN_ERR "metapage_write_end_io: I/O error\n"); |
348 | SetPageError(page); |
349 | } |
350 | dec_io(page, last_write_complete); |
351 | bio_put(bio); |
352 | } |
353 | |
354 | static int metapage_writepage(struct page *page, struct writeback_control *wbc) |
355 | { |
356 | struct bio *bio = NULL; |
357 | int block_offset; /* block offset of mp within page */ |
358 | struct inode *inode = page->mapping->host; |
359 | int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage; |
360 | int len; |
361 | int xlen; |
362 | struct metapage *mp; |
363 | int redirty = 0; |
364 | sector_t lblock; |
365 | int nr_underway = 0; |
366 | sector_t pblock; |
367 | sector_t next_block = 0; |
368 | sector_t page_start; |
369 | unsigned long bio_bytes = 0; |
370 | unsigned long bio_offset = 0; |
371 | int offset; |
372 | int bad_blocks = 0; |
373 | |
374 | page_start = (sector_t)page->index << |
375 | (PAGE_CACHE_SHIFT - inode->i_blkbits); |
376 | BUG_ON(!PageLocked(page)); |
377 | BUG_ON(PageWriteback(page)); |
378 | set_page_writeback(page); |
379 | |
380 | for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { |
381 | mp = page_to_mp(page, offset); |
382 | |
383 | if (!mp || !test_bit(META_dirty, &mp->flag)) |
384 | continue; |
385 | |
386 | if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) { |
387 | redirty = 1; |
388 | /* |
389 | * Make sure this page isn't blocked indefinitely. |
390 | * If the journal isn't undergoing I/O, push it |
391 | */ |
392 | if (mp->log && !(mp->log->cflag & logGC_PAGEOUT)) |
393 | jfs_flush_journal(mp->log, 0); |
394 | continue; |
395 | } |
396 | |
397 | clear_bit(META_dirty, &mp->flag); |
398 | set_bit(META_io, &mp->flag); |
399 | block_offset = offset >> inode->i_blkbits; |
400 | lblock = page_start + block_offset; |
401 | if (bio) { |
402 | if (xlen && lblock == next_block) { |
403 | /* Contiguous, in memory & on disk */ |
404 | len = min(xlen, blocks_per_mp); |
405 | xlen -= len; |
406 | bio_bytes += len << inode->i_blkbits; |
407 | continue; |
408 | } |
409 | /* Not contiguous */ |
410 | if (bio_add_page(bio, page, bio_bytes, bio_offset) < |
411 | bio_bytes) |
412 | goto add_failed; |
413 | /* |
414 | * Increment counter before submitting i/o to keep |
415 | * count from hitting zero before we're through |
416 | */ |
417 | inc_io(page); |
418 | if (!bio->bi_size) |
419 | goto dump_bio; |
420 | submit_bio(WRITE, bio); |
421 | nr_underway++; |
422 | bio = NULL; |
423 | } else |
424 | inc_io(page); |
425 | xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits; |
426 | pblock = metapage_get_blocks(inode, lblock, &xlen); |
427 | if (!pblock) { |
428 | printk(KERN_ERR "JFS: metapage_get_blocks failed\n"); |
429 | /* |
430 | * We already called inc_io(), but can't cancel it |
431 | * with dec_io() until we're done with the page |
432 | */ |
433 | bad_blocks++; |
434 | continue; |
435 | } |
436 | len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage); |
437 | |
438 | bio = bio_alloc(GFP_NOFS, 1); |
439 | bio->bi_bdev = inode->i_sb->s_bdev; |
440 | bio->bi_sector = pblock << (inode->i_blkbits - 9); |
441 | bio->bi_end_io = metapage_write_end_io; |
442 | bio->bi_private = page; |
443 | |
444 | /* Don't call bio_add_page yet, we may add to this vec */ |
445 | bio_offset = offset; |
446 | bio_bytes = len << inode->i_blkbits; |
447 | |
448 | xlen -= len; |
449 | next_block = lblock + len; |
450 | } |
451 | if (bio) { |
452 | if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) |
453 | goto add_failed; |
454 | if (!bio->bi_size) |
455 | goto dump_bio; |
456 | |
457 | submit_bio(WRITE, bio); |
458 | nr_underway++; |
459 | } |
460 | if (redirty) |
461 | redirty_page_for_writepage(wbc, page); |
462 | |
463 | unlock_page(page); |
464 | |
465 | if (bad_blocks) |
466 | goto err_out; |
467 | |
468 | if (nr_underway == 0) |
469 | end_page_writeback(page); |
470 | |
471 | return 0; |
472 | add_failed: |
473 | /* We should never reach here, since we're only adding one vec */ |
474 | printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); |
475 | goto skip; |
476 | dump_bio: |
477 | print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, |
478 | 4, bio, sizeof(*bio), 0); |
479 | skip: |
480 | bio_put(bio); |
481 | unlock_page(page); |
482 | dec_io(page, last_write_complete); |
483 | err_out: |
484 | while (bad_blocks--) |
485 | dec_io(page, last_write_complete); |
486 | return -EIO; |
487 | } |
488 | |
489 | static int metapage_readpage(struct file *fp, struct page *page) |
490 | { |
491 | struct inode *inode = page->mapping->host; |
492 | struct bio *bio = NULL; |
493 | int block_offset; |
494 | int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits; |
495 | sector_t page_start; /* address of page in fs blocks */ |
496 | sector_t pblock; |
497 | int xlen; |
498 | unsigned int len; |
499 | int offset; |
500 | |
501 | BUG_ON(!PageLocked(page)); |
502 | page_start = (sector_t)page->index << |
503 | (PAGE_CACHE_SHIFT - inode->i_blkbits); |
504 | |
505 | block_offset = 0; |
506 | while (block_offset < blocks_per_page) { |
507 | xlen = blocks_per_page - block_offset; |
508 | pblock = metapage_get_blocks(inode, page_start + block_offset, |
509 | &xlen); |
510 | if (pblock) { |
511 | if (!PagePrivate(page)) |
512 | insert_metapage(page, NULL); |
513 | inc_io(page); |
514 | if (bio) |
515 | submit_bio(READ, bio); |
516 | |
517 | bio = bio_alloc(GFP_NOFS, 1); |
518 | bio->bi_bdev = inode->i_sb->s_bdev; |
519 | bio->bi_sector = pblock << (inode->i_blkbits - 9); |
520 | bio->bi_end_io = metapage_read_end_io; |
521 | bio->bi_private = page; |
522 | len = xlen << inode->i_blkbits; |
523 | offset = block_offset << inode->i_blkbits; |
524 | if (bio_add_page(bio, page, len, offset) < len) |
525 | goto add_failed; |
526 | block_offset += xlen; |
527 | } else |
528 | block_offset++; |
529 | } |
530 | if (bio) |
531 | submit_bio(READ, bio); |
532 | else |
533 | unlock_page(page); |
534 | |
535 | return 0; |
536 | |
537 | add_failed: |
538 | printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); |
539 | bio_put(bio); |
540 | dec_io(page, last_read_complete); |
541 | return -EIO; |
542 | } |
543 | |
544 | static int metapage_releasepage(struct page *page, gfp_t gfp_mask) |
545 | { |
546 | struct metapage *mp; |
547 | int ret = 1; |
548 | int offset; |
549 | |
550 | for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { |
551 | mp = page_to_mp(page, offset); |
552 | |
553 | if (!mp) |
554 | continue; |
555 | |
556 | jfs_info("metapage_releasepage: mp = 0x%p", mp); |
557 | if (mp->count || mp->nohomeok || |
558 | test_bit(META_dirty, &mp->flag)) { |
559 | jfs_info("count = %ld, nohomeok = %d", mp->count, |
560 | mp->nohomeok); |
561 | ret = 0; |
562 | continue; |
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 | return ret; |
571 | } |
572 | |
573 | static void metapage_invalidatepage(struct page *page, unsigned long offset) |
574 | { |
575 | BUG_ON(offset); |
576 | |
577 | BUG_ON(PageWriteback(page)); |
578 | |
579 | metapage_releasepage(page, 0); |
580 | } |
581 | |
582 | const struct address_space_operations jfs_metapage_aops = { |
583 | .readpage = metapage_readpage, |
584 | .writepage = metapage_writepage, |
585 | .sync_page = block_sync_page, |
586 | .releasepage = metapage_releasepage, |
587 | .invalidatepage = metapage_invalidatepage, |
588 | .set_page_dirty = __set_page_dirty_nobuffers, |
589 | }; |
590 | |
591 | struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, |
592 | unsigned int size, int absolute, |
593 | unsigned long new) |
594 | { |
595 | int l2BlocksPerPage; |
596 | int l2bsize; |
597 | struct address_space *mapping; |
598 | struct metapage *mp = NULL; |
599 | struct page *page; |
600 | unsigned long page_index; |
601 | unsigned long page_offset; |
602 | |
603 | jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", |
604 | inode->i_ino, lblock, absolute); |
605 | |
606 | l2bsize = inode->i_blkbits; |
607 | l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize; |
608 | page_index = lblock >> l2BlocksPerPage; |
609 | page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; |
610 | if ((page_offset + size) > PAGE_CACHE_SIZE) { |
611 | jfs_err("MetaData crosses page boundary!!"); |
612 | jfs_err("lblock = %lx, size = %d", lblock, size); |
613 | dump_stack(); |
614 | return NULL; |
615 | } |
616 | if (absolute) |
617 | mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; |
618 | else { |
619 | /* |
620 | * If an nfs client tries to read an inode that is larger |
621 | * than any existing inodes, we may try to read past the |
622 | * end of the inode map |
623 | */ |
624 | if ((lblock << inode->i_blkbits) >= inode->i_size) |
625 | return NULL; |
626 | mapping = inode->i_mapping; |
627 | } |
628 | |
629 | if (new && (PSIZE == PAGE_CACHE_SIZE)) { |
630 | page = grab_cache_page(mapping, page_index); |
631 | if (!page) { |
632 | jfs_err("grab_cache_page failed!"); |
633 | return NULL; |
634 | } |
635 | SetPageUptodate(page); |
636 | } else { |
637 | page = read_mapping_page(mapping, page_index, NULL); |
638 | if (IS_ERR(page) || !PageUptodate(page)) { |
639 | jfs_err("read_mapping_page failed!"); |
640 | return NULL; |
641 | } |
642 | lock_page(page); |
643 | } |
644 | |
645 | mp = page_to_mp(page, page_offset); |
646 | if (mp) { |
647 | if (mp->logical_size != size) { |
648 | jfs_error(inode->i_sb, |
649 | "__get_metapage: mp->logical_size != size"); |
650 | jfs_err("logical_size = %d, size = %d", |
651 | mp->logical_size, size); |
652 | dump_stack(); |
653 | goto unlock; |
654 | } |
655 | mp->count++; |
656 | lock_metapage(mp); |
657 | if (test_bit(META_discard, &mp->flag)) { |
658 | if (!new) { |
659 | jfs_error(inode->i_sb, |
660 | "__get_metapage: using a " |
661 | "discarded metapage"); |
662 | discard_metapage(mp); |
663 | goto unlock; |
664 | } |
665 | clear_bit(META_discard, &mp->flag); |
666 | } |
667 | } else { |
668 | INCREMENT(mpStat.pagealloc); |
669 | mp = alloc_metapage(GFP_NOFS); |
670 | mp->page = page; |
671 | mp->flag = 0; |
672 | mp->xflag = COMMIT_PAGE; |
673 | mp->count = 1; |
674 | mp->nohomeok = 0; |
675 | mp->logical_size = size; |
676 | mp->data = page_address(page) + page_offset; |
677 | mp->index = lblock; |
678 | if (unlikely(insert_metapage(page, mp))) { |
679 | free_metapage(mp); |
680 | goto unlock; |
681 | } |
682 | lock_metapage(mp); |
683 | } |
684 | |
685 | if (new) { |
686 | jfs_info("zeroing mp = 0x%p", mp); |
687 | memset(mp->data, 0, PSIZE); |
688 | } |
689 | |
690 | unlock_page(page); |
691 | jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); |
692 | return mp; |
693 | |
694 | unlock: |
695 | unlock_page(page); |
696 | return NULL; |
697 | } |
698 | |
699 | void grab_metapage(struct metapage * mp) |
700 | { |
701 | jfs_info("grab_metapage: mp = 0x%p", mp); |
702 | page_cache_get(mp->page); |
703 | lock_page(mp->page); |
704 | mp->count++; |
705 | lock_metapage(mp); |
706 | unlock_page(mp->page); |
707 | } |
708 | |
709 | void force_metapage(struct metapage *mp) |
710 | { |
711 | struct page *page = mp->page; |
712 | jfs_info("force_metapage: mp = 0x%p", mp); |
713 | set_bit(META_forcewrite, &mp->flag); |
714 | clear_bit(META_sync, &mp->flag); |
715 | page_cache_get(page); |
716 | lock_page(page); |
717 | set_page_dirty(page); |
718 | write_one_page(page, 1); |
719 | clear_bit(META_forcewrite, &mp->flag); |
720 | page_cache_release(page); |
721 | } |
722 | |
723 | void hold_metapage(struct metapage *mp) |
724 | { |
725 | lock_page(mp->page); |
726 | } |
727 | |
728 | void 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 | page_cache_get(mp->page); |
736 | mp->count++; |
737 | lock_metapage(mp); |
738 | unlock_page(mp->page); |
739 | release_metapage(mp); |
740 | } |
741 | |
742 | void 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 | page_cache_release(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 | write_one_page(page, 1); |
764 | lock_page(page); /* write_one_page unlocks the page */ |
765 | } |
766 | } else if (mp->lsn) /* discard_metapage doesn't remove it */ |
767 | remove_from_logsync(mp); |
768 | |
769 | /* Try to keep metapages from using up too much memory */ |
770 | drop_metapage(page, mp); |
771 | |
772 | unlock_page(page); |
773 | page_cache_release(page); |
774 | } |
775 | |
776 | void __invalidate_metapages(struct inode *ip, s64 addr, int len) |
777 | { |
778 | sector_t lblock; |
779 | int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits; |
780 | int BlocksPerPage = 1 << l2BlocksPerPage; |
781 | /* All callers are interested in block device's mapping */ |
782 | struct address_space *mapping = |
783 | JFS_SBI(ip->i_sb)->direct_inode->i_mapping; |
784 | struct metapage *mp; |
785 | struct page *page; |
786 | unsigned int offset; |
787 | |
788 | /* |
789 | * Mark metapages to discard. They will eventually be |
790 | * released, but should not be written. |
791 | */ |
792 | for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; |
793 | lblock += BlocksPerPage) { |
794 | page = find_lock_page(mapping, lblock >> l2BlocksPerPage); |
795 | if (!page) |
796 | continue; |
797 | for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { |
798 | mp = page_to_mp(page, offset); |
799 | if (!mp) |
800 | continue; |
801 | if (mp->index < addr) |
802 | continue; |
803 | if (mp->index >= addr + len) |
804 | break; |
805 | |
806 | clear_bit(META_dirty, &mp->flag); |
807 | set_bit(META_discard, &mp->flag); |
808 | if (mp->lsn) |
809 | remove_from_logsync(mp); |
810 | } |
811 | unlock_page(page); |
812 | page_cache_release(page); |
813 | } |
814 | } |
815 | |
816 | #ifdef CONFIG_JFS_STATISTICS |
817 | static int jfs_mpstat_proc_show(struct seq_file *m, void *v) |
818 | { |
819 | seq_printf(m, |
820 | "JFS Metapage statistics\n" |
821 | "=======================\n" |
822 | "page allocations = %d\n" |
823 | "page frees = %d\n" |
824 | "lock waits = %d\n", |
825 | mpStat.pagealloc, |
826 | mpStat.pagefree, |
827 | mpStat.lockwait); |
828 | return 0; |
829 | } |
830 | |
831 | static int jfs_mpstat_proc_open(struct inode *inode, struct file *file) |
832 | { |
833 | return single_open(file, jfs_mpstat_proc_show, NULL); |
834 | } |
835 | |
836 | const struct file_operations jfs_mpstat_proc_fops = { |
837 | .owner = THIS_MODULE, |
838 | .open = jfs_mpstat_proc_open, |
839 | .read = seq_read, |
840 | .llseek = seq_lseek, |
841 | .release = single_release, |
842 | }; |
843 | #endif |
844 |
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Tags:
od-2011-09-04
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v2.6.34-rc5
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v3.9