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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 | |
37 | static 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 | ||
47 | static inline void unlock_metapage(struct metapage *mp) | |
48 | { | |
49 | clear_bit_unlock(META_locked, &mp->flag); | |
50 | wake_up(&mp->wait); | |
51 | } | |
52 | ||
53 | static 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 | */ | |
73 | static 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 | |
80 | static struct kmem_cache *metapage_cache; | |
81 | static mempool_t *metapage_mempool; | |
82 | ||
83 | #define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE) | |
84 | ||
85 | #if MPS_PER_PAGE > 1 | |
86 | ||
87 | struct 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 | ||
94 | static 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 | ||
101 | static 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 | ||
128 | static 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 | ||
147 | static inline void inc_io(struct page *page) | |
148 | { | |
149 | atomic_inc(&mp_anchor(page)->io_count); | |
150 | } | |
151 | ||
152 | static 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 | |
159 | static inline struct metapage *page_to_mp(struct page *page, int offset) | |
160 | { | |
161 | return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; | |
162 | } | |
163 | ||
164 | static 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 | ||
174 | static 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 | ||
186 | static 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 | ||
200 | static inline struct metapage *alloc_metapage(gfp_t gfp_mask) | |
201 | { | |
202 | return mempool_alloc(metapage_mempool, gfp_mask); | |
203 | } | |
204 | ||
205 | static 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 | ||
213 | int __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 | ||
234 | void metapage_exit(void) | |
235 | { | |
236 | mempool_destroy(metapage_mempool); | |
237 | kmem_cache_destroy(metapage_cache); | |
238 | } | |
239 | ||
240 | static 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 | ||
254 | static 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 | ||
279 | static void last_read_complete(struct page *page) | |
280 | { | |
281 | if (!PageError(page)) | |
282 | SetPageUptodate(page); | |
283 | unlock_page(page); | |
284 | } | |
285 | ||
286 | static 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 | ||
299 | static 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 | ||
321 | static 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 | ||
341 | static 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 | ||
355 | static 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_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_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_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; | |
473 | add_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; | |
477 | dump_bio: | |
478 | print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, | |
479 | 4, bio, sizeof(*bio), 0); | |
480 | skip: | |
481 | bio_put(bio); | |
482 | unlock_page(page); | |
483 | dec_io(page, last_write_complete); | |
484 | err_out: | |
485 | while (bad_blocks--) | |
486 | dec_io(page, last_write_complete); | |
487 | return -EIO; | |
488 | } | |
489 | ||
490 | static 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_sector = pblock << (inode->i_blkbits - 9); | |
521 | bio->bi_end_io = metapage_read_end_io; | |
522 | bio->bi_private = page; | |
523 | len = xlen << inode->i_blkbits; | |
524 | offset = block_offset << inode->i_blkbits; | |
525 | if (bio_add_page(bio, page, len, offset) < len) | |
526 | goto add_failed; | |
527 | block_offset += xlen; | |
528 | } else | |
529 | block_offset++; | |
530 | } | |
531 | if (bio) | |
532 | submit_bio(READ, bio); | |
533 | else | |
534 | unlock_page(page); | |
535 | ||
536 | return 0; | |
537 | ||
538 | add_failed: | |
539 | printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); | |
540 | bio_put(bio); | |
541 | dec_io(page, last_read_complete); | |
542 | return -EIO; | |
543 | } | |
544 | ||
545 | static int metapage_releasepage(struct page *page, gfp_t gfp_mask) | |
546 | { | |
547 | struct metapage *mp; | |
548 | int ret = 1; | |
549 | int offset; | |
550 | ||
551 | for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { | |
552 | mp = page_to_mp(page, offset); | |
553 | ||
554 | if (!mp) | |
555 | continue; | |
556 | ||
557 | jfs_info("metapage_releasepage: mp = 0x%p", mp); | |
558 | if (mp->count || mp->nohomeok || | |
559 | test_bit(META_dirty, &mp->flag)) { | |
560 | jfs_info("count = %ld, nohomeok = %d", mp->count, | |
561 | mp->nohomeok); | |
562 | ret = 0; | |
563 | continue; | |
564 | } | |
565 | if (mp->lsn) | |
566 | remove_from_logsync(mp); | |
567 | remove_metapage(page, mp); | |
568 | INCREMENT(mpStat.pagefree); | |
569 | free_metapage(mp); | |
570 | } | |
571 | return ret; | |
572 | } | |
573 | ||
574 | static void metapage_invalidatepage(struct page *page, unsigned long offset) | |
575 | { | |
576 | BUG_ON(offset); | |
577 | ||
578 | BUG_ON(PageWriteback(page)); | |
579 | ||
580 | metapage_releasepage(page, 0); | |
581 | } | |
582 | ||
583 | const struct address_space_operations jfs_metapage_aops = { | |
584 | .readpage = metapage_readpage, | |
585 | .writepage = metapage_writepage, | |
586 | .sync_page = block_sync_page, | |
587 | .releasepage = metapage_releasepage, | |
588 | .invalidatepage = metapage_invalidatepage, | |
589 | .set_page_dirty = __set_page_dirty_nobuffers, | |
590 | }; | |
591 | ||
592 | struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, | |
593 | unsigned int size, int absolute, | |
594 | unsigned long new) | |
595 | { | |
596 | int l2BlocksPerPage; | |
597 | int l2bsize; | |
598 | struct address_space *mapping; | |
599 | struct metapage *mp = NULL; | |
600 | struct page *page; | |
601 | unsigned long page_index; | |
602 | unsigned long page_offset; | |
603 | ||
604 | jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", | |
605 | inode->i_ino, lblock, absolute); | |
606 | ||
607 | l2bsize = inode->i_blkbits; | |
608 | l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize; | |
609 | page_index = lblock >> l2BlocksPerPage; | |
610 | page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; | |
611 | if ((page_offset + size) > PAGE_CACHE_SIZE) { | |
612 | jfs_err("MetaData crosses page boundary!!"); | |
613 | jfs_err("lblock = %lx, size = %d", lblock, size); | |
614 | dump_stack(); | |
615 | return NULL; | |
616 | } | |
617 | if (absolute) | |
618 | mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; | |
619 | else { | |
620 | /* | |
621 | * If an nfs client tries to read an inode that is larger | |
622 | * than any existing inodes, we may try to read past the | |
623 | * end of the inode map | |
624 | */ | |
625 | if ((lblock << inode->i_blkbits) >= inode->i_size) | |
626 | return NULL; | |
627 | mapping = inode->i_mapping; | |
628 | } | |
629 | ||
630 | if (new && (PSIZE == PAGE_CACHE_SIZE)) { | |
631 | page = grab_cache_page(mapping, page_index); | |
632 | if (!page) { | |
633 | jfs_err("grab_cache_page failed!"); | |
634 | return NULL; | |
635 | } | |
636 | SetPageUptodate(page); | |
637 | } else { | |
638 | page = read_mapping_page(mapping, page_index, NULL); | |
639 | if (IS_ERR(page) || !PageUptodate(page)) { | |
640 | jfs_err("read_mapping_page failed!"); | |
641 | return NULL; | |
642 | } | |
643 | lock_page(page); | |
644 | } | |
645 | ||
646 | mp = page_to_mp(page, page_offset); | |
647 | if (mp) { | |
648 | if (mp->logical_size != size) { | |
649 | jfs_error(inode->i_sb, | |
650 | "__get_metapage: mp->logical_size != size"); | |
651 | jfs_err("logical_size = %d, size = %d", | |
652 | mp->logical_size, size); | |
653 | dump_stack(); | |
654 | goto unlock; | |
655 | } | |
656 | mp->count++; | |
657 | lock_metapage(mp); | |
658 | if (test_bit(META_discard, &mp->flag)) { | |
659 | if (!new) { | |
660 | jfs_error(inode->i_sb, | |
661 | "__get_metapage: using a " | |
662 | "discarded metapage"); | |
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 | ||
695 | unlock: | |
696 | unlock_page(page); | |
697 | return NULL; | |
698 | } | |
699 | ||
700 | void 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 | ||
710 | void 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 | ||
724 | void hold_metapage(struct metapage *mp) | |
725 | { | |
726 | lock_page(mp->page); | |
727 | } | |
728 | ||
729 | void 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 | ||
743 | void 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 | ||
777 | void __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 | |
818 | static 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 | ||
832 | static int jfs_mpstat_proc_open(struct inode *inode, struct file *file) | |
833 | { | |
834 | return single_open(file, jfs_mpstat_proc_show, NULL); | |
835 | } | |
836 | ||
837 | const 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 |