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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_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 inline struct metapage *alloc_metapage(gfp_t gfp_mask) | |
187 | { | |
188 | struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask); | |
189 | ||
190 | if (mp) { | |
191 | mp->lid = 0; | |
192 | mp->lsn = 0; | |
193 | mp->data = NULL; | |
194 | mp->clsn = 0; | |
195 | mp->log = NULL; | |
196 | init_waitqueue_head(&mp->wait); | |
197 | } | |
198 | return mp; | |
199 | } | |
200 | ||
201 | static inline void free_metapage(struct metapage *mp) | |
202 | { | |
203 | mempool_free(mp, metapage_mempool); | |
204 | } | |
205 | ||
206 | int __init metapage_init(void) | |
207 | { | |
208 | /* | |
209 | * Allocate the metapage structures | |
210 | */ | |
211 | metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage), | |
212 | 0, 0, NULL); | |
213 | if (metapage_cache == NULL) | |
214 | return -ENOMEM; | |
215 | ||
216 | metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES, | |
217 | metapage_cache); | |
218 | ||
219 | if (metapage_mempool == NULL) { | |
220 | kmem_cache_destroy(metapage_cache); | |
221 | return -ENOMEM; | |
222 | } | |
223 | ||
224 | return 0; | |
225 | } | |
226 | ||
227 | void metapage_exit(void) | |
228 | { | |
229 | mempool_destroy(metapage_mempool); | |
230 | kmem_cache_destroy(metapage_cache); | |
231 | } | |
232 | ||
233 | static inline void drop_metapage(struct page *page, struct metapage *mp) | |
234 | { | |
235 | if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) || | |
236 | test_bit(META_io, &mp->flag)) | |
237 | return; | |
238 | remove_metapage(page, mp); | |
239 | INCREMENT(mpStat.pagefree); | |
240 | free_metapage(mp); | |
241 | } | |
242 | ||
243 | /* | |
244 | * Metapage address space operations | |
245 | */ | |
246 | ||
247 | static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock, | |
248 | int *len) | |
249 | { | |
250 | int rc = 0; | |
251 | int xflag; | |
252 | s64 xaddr; | |
253 | sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >> | |
254 | inode->i_blkbits; | |
255 | ||
256 | if (lblock >= file_blocks) | |
257 | return 0; | |
258 | if (lblock + *len > file_blocks) | |
259 | *len = file_blocks - lblock; | |
260 | ||
261 | if (inode->i_ino) { | |
262 | rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0); | |
263 | if ((rc == 0) && *len) | |
264 | lblock = (sector_t)xaddr; | |
265 | else | |
266 | lblock = 0; | |
267 | } /* else no mapping */ | |
268 | ||
269 | return lblock; | |
270 | } | |
271 | ||
272 | static void last_read_complete(struct page *page) | |
273 | { | |
274 | if (!PageError(page)) | |
275 | SetPageUptodate(page); | |
276 | unlock_page(page); | |
277 | } | |
278 | ||
279 | static void metapage_read_end_io(struct bio *bio) | |
280 | { | |
281 | struct page *page = bio->bi_private; | |
282 | ||
283 | if (bio->bi_status) { | |
284 | printk(KERN_ERR "metapage_read_end_io: I/O error\n"); | |
285 | SetPageError(page); | |
286 | } | |
287 | ||
288 | dec_io(page, last_read_complete); | |
289 | bio_put(bio); | |
290 | } | |
291 | ||
292 | static void remove_from_logsync(struct metapage *mp) | |
293 | { | |
294 | struct jfs_log *log = mp->log; | |
295 | unsigned long flags; | |
296 | /* | |
297 | * This can race. Recheck that log hasn't been set to null, and after | |
298 | * acquiring logsync lock, recheck lsn | |
299 | */ | |
300 | if (!log) | |
301 | return; | |
302 | ||
303 | LOGSYNC_LOCK(log, flags); | |
304 | if (mp->lsn) { | |
305 | mp->log = NULL; | |
306 | mp->lsn = 0; | |
307 | mp->clsn = 0; | |
308 | log->count--; | |
309 | list_del(&mp->synclist); | |
310 | } | |
311 | LOGSYNC_UNLOCK(log, flags); | |
312 | } | |
313 | ||
314 | static void last_write_complete(struct page *page) | |
315 | { | |
316 | struct metapage *mp; | |
317 | unsigned int offset; | |
318 | ||
319 | for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { | |
320 | mp = page_to_mp(page, offset); | |
321 | if (mp && test_bit(META_io, &mp->flag)) { | |
322 | if (mp->lsn) | |
323 | remove_from_logsync(mp); | |
324 | clear_bit(META_io, &mp->flag); | |
325 | } | |
326 | /* | |
327 | * I'd like to call drop_metapage here, but I don't think it's | |
328 | * safe unless I have the page locked | |
329 | */ | |
330 | } | |
331 | end_page_writeback(page); | |
332 | } | |
333 | ||
334 | static void metapage_write_end_io(struct bio *bio) | |
335 | { | |
336 | struct page *page = bio->bi_private; | |
337 | ||
338 | BUG_ON(!PagePrivate(page)); | |
339 | ||
340 | if (bio->bi_status) { | |
341 | printk(KERN_ERR "metapage_write_end_io: I/O error\n"); | |
342 | SetPageError(page); | |
343 | } | |
344 | dec_io(page, last_write_complete); | |
345 | bio_put(bio); | |
346 | } | |
347 | ||
348 | static int metapage_writepage(struct page *page, struct writeback_control *wbc) | |
349 | { | |
350 | struct bio *bio = NULL; | |
351 | int block_offset; /* block offset of mp within page */ | |
352 | struct inode *inode = page->mapping->host; | |
353 | int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage; | |
354 | int len; | |
355 | int xlen; | |
356 | struct metapage *mp; | |
357 | int redirty = 0; | |
358 | sector_t lblock; | |
359 | int nr_underway = 0; | |
360 | sector_t pblock; | |
361 | sector_t next_block = 0; | |
362 | sector_t page_start; | |
363 | unsigned long bio_bytes = 0; | |
364 | unsigned long bio_offset = 0; | |
365 | int offset; | |
366 | int bad_blocks = 0; | |
367 | ||
368 | page_start = (sector_t)page->index << | |
369 | (PAGE_SHIFT - inode->i_blkbits); | |
370 | BUG_ON(!PageLocked(page)); | |
371 | BUG_ON(PageWriteback(page)); | |
372 | set_page_writeback(page); | |
373 | ||
374 | for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { | |
375 | mp = page_to_mp(page, offset); | |
376 | ||
377 | if (!mp || !test_bit(META_dirty, &mp->flag)) | |
378 | continue; | |
379 | ||
380 | if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) { | |
381 | redirty = 1; | |
382 | /* | |
383 | * Make sure this page isn't blocked indefinitely. | |
384 | * If the journal isn't undergoing I/O, push it | |
385 | */ | |
386 | if (mp->log && !(mp->log->cflag & logGC_PAGEOUT)) | |
387 | jfs_flush_journal(mp->log, 0); | |
388 | continue; | |
389 | } | |
390 | ||
391 | clear_bit(META_dirty, &mp->flag); | |
392 | set_bit(META_io, &mp->flag); | |
393 | block_offset = offset >> inode->i_blkbits; | |
394 | lblock = page_start + block_offset; | |
395 | if (bio) { | |
396 | if (xlen && lblock == next_block) { | |
397 | /* Contiguous, in memory & on disk */ | |
398 | len = min(xlen, blocks_per_mp); | |
399 | xlen -= len; | |
400 | bio_bytes += len << inode->i_blkbits; | |
401 | continue; | |
402 | } | |
403 | /* Not contiguous */ | |
404 | if (bio_add_page(bio, page, bio_bytes, bio_offset) < | |
405 | bio_bytes) | |
406 | goto add_failed; | |
407 | /* | |
408 | * Increment counter before submitting i/o to keep | |
409 | * count from hitting zero before we're through | |
410 | */ | |
411 | inc_io(page); | |
412 | if (!bio->bi_iter.bi_size) | |
413 | goto dump_bio; | |
414 | submit_bio(bio); | |
415 | nr_underway++; | |
416 | bio = NULL; | |
417 | } else | |
418 | inc_io(page); | |
419 | xlen = (PAGE_SIZE - offset) >> inode->i_blkbits; | |
420 | pblock = metapage_get_blocks(inode, lblock, &xlen); | |
421 | if (!pblock) { | |
422 | printk(KERN_ERR "JFS: metapage_get_blocks failed\n"); | |
423 | /* | |
424 | * We already called inc_io(), but can't cancel it | |
425 | * with dec_io() until we're done with the page | |
426 | */ | |
427 | bad_blocks++; | |
428 | continue; | |
429 | } | |
430 | len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage); | |
431 | ||
432 | bio = bio_alloc(GFP_NOFS, 1); | |
433 | bio_set_dev(bio, inode->i_sb->s_bdev); | |
434 | bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9); | |
435 | bio->bi_end_io = metapage_write_end_io; | |
436 | bio->bi_private = page; | |
437 | bio_set_op_attrs(bio, REQ_OP_WRITE, 0); | |
438 | ||
439 | /* Don't call bio_add_page yet, we may add to this vec */ | |
440 | bio_offset = offset; | |
441 | bio_bytes = len << inode->i_blkbits; | |
442 | ||
443 | xlen -= len; | |
444 | next_block = lblock + len; | |
445 | } | |
446 | if (bio) { | |
447 | if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) | |
448 | goto add_failed; | |
449 | if (!bio->bi_iter.bi_size) | |
450 | goto dump_bio; | |
451 | ||
452 | submit_bio(bio); | |
453 | nr_underway++; | |
454 | } | |
455 | if (redirty) | |
456 | redirty_page_for_writepage(wbc, page); | |
457 | ||
458 | unlock_page(page); | |
459 | ||
460 | if (bad_blocks) | |
461 | goto err_out; | |
462 | ||
463 | if (nr_underway == 0) | |
464 | end_page_writeback(page); | |
465 | ||
466 | return 0; | |
467 | add_failed: | |
468 | /* We should never reach here, since we're only adding one vec */ | |
469 | printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); | |
470 | goto skip; | |
471 | dump_bio: | |
472 | print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, | |
473 | 4, bio, sizeof(*bio), 0); | |
474 | skip: | |
475 | bio_put(bio); | |
476 | unlock_page(page); | |
477 | dec_io(page, last_write_complete); | |
478 | err_out: | |
479 | while (bad_blocks--) | |
480 | dec_io(page, last_write_complete); | |
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 | int block_offset; | |
489 | int blocks_per_page = PAGE_SIZE >> inode->i_blkbits; | |
490 | sector_t page_start; /* address of page in fs blocks */ | |
491 | sector_t pblock; | |
492 | int xlen; | |
493 | unsigned int len; | |
494 | int offset; | |
495 | ||
496 | BUG_ON(!PageLocked(page)); | |
497 | page_start = (sector_t)page->index << | |
498 | (PAGE_SHIFT - inode->i_blkbits); | |
499 | ||
500 | block_offset = 0; | |
501 | while (block_offset < blocks_per_page) { | |
502 | xlen = blocks_per_page - block_offset; | |
503 | pblock = metapage_get_blocks(inode, page_start + block_offset, | |
504 | &xlen); | |
505 | if (pblock) { | |
506 | if (!PagePrivate(page)) | |
507 | insert_metapage(page, NULL); | |
508 | inc_io(page); | |
509 | if (bio) | |
510 | submit_bio(bio); | |
511 | ||
512 | bio = bio_alloc(GFP_NOFS, 1); | |
513 | bio_set_dev(bio, inode->i_sb->s_bdev); | |
514 | bio->bi_iter.bi_sector = | |
515 | pblock << (inode->i_blkbits - 9); | |
516 | bio->bi_end_io = metapage_read_end_io; | |
517 | bio->bi_private = page; | |
518 | bio_set_op_attrs(bio, REQ_OP_READ, 0); | |
519 | len = xlen << inode->i_blkbits; | |
520 | offset = block_offset << inode->i_blkbits; | |
521 | if (bio_add_page(bio, page, len, offset) < len) | |
522 | goto add_failed; | |
523 | block_offset += xlen; | |
524 | } else | |
525 | block_offset++; | |
526 | } | |
527 | if (bio) | |
528 | submit_bio(bio); | |
529 | else | |
530 | unlock_page(page); | |
531 | ||
532 | return 0; | |
533 | ||
534 | add_failed: | |
535 | printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); | |
536 | bio_put(bio); | |
537 | dec_io(page, last_read_complete); | |
538 | return -EIO; | |
539 | } | |
540 | ||
541 | static int metapage_releasepage(struct page *page, gfp_t gfp_mask) | |
542 | { | |
543 | struct metapage *mp; | |
544 | int ret = 1; | |
545 | int offset; | |
546 | ||
547 | for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { | |
548 | mp = page_to_mp(page, offset); | |
549 | ||
550 | if (!mp) | |
551 | continue; | |
552 | ||
553 | jfs_info("metapage_releasepage: mp = 0x%p", mp); | |
554 | if (mp->count || mp->nohomeok || | |
555 | test_bit(META_dirty, &mp->flag)) { | |
556 | jfs_info("count = %ld, nohomeok = %d", mp->count, | |
557 | mp->nohomeok); | |
558 | ret = 0; | |
559 | continue; | |
560 | } | |
561 | if (mp->lsn) | |
562 | remove_from_logsync(mp); | |
563 | remove_metapage(page, mp); | |
564 | INCREMENT(mpStat.pagefree); | |
565 | free_metapage(mp); | |
566 | } | |
567 | return ret; | |
568 | } | |
569 | ||
570 | static void metapage_invalidatepage(struct page *page, unsigned int offset, | |
571 | unsigned int length) | |
572 | { | |
573 | BUG_ON(offset || length < PAGE_SIZE); | |
574 | ||
575 | BUG_ON(PageWriteback(page)); | |
576 | ||
577 | metapage_releasepage(page, 0); | |
578 | } | |
579 | ||
580 | const struct address_space_operations jfs_metapage_aops = { | |
581 | .readpage = metapage_readpage, | |
582 | .writepage = metapage_writepage, | |
583 | .releasepage = metapage_releasepage, | |
584 | .invalidatepage = metapage_invalidatepage, | |
585 | .set_page_dirty = __set_page_dirty_nobuffers, | |
586 | }; | |
587 | ||
588 | struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, | |
589 | unsigned int size, int absolute, | |
590 | unsigned long new) | |
591 | { | |
592 | int l2BlocksPerPage; | |
593 | int l2bsize; | |
594 | struct address_space *mapping; | |
595 | struct metapage *mp = NULL; | |
596 | struct page *page; | |
597 | unsigned long page_index; | |
598 | unsigned long page_offset; | |
599 | ||
600 | jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", | |
601 | inode->i_ino, lblock, absolute); | |
602 | ||
603 | l2bsize = inode->i_blkbits; | |
604 | l2BlocksPerPage = PAGE_SHIFT - l2bsize; | |
605 | page_index = lblock >> l2BlocksPerPage; | |
606 | page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; | |
607 | if ((page_offset + size) > PAGE_SIZE) { | |
608 | jfs_err("MetaData crosses page boundary!!"); | |
609 | jfs_err("lblock = %lx, size = %d", lblock, size); | |
610 | dump_stack(); | |
611 | return NULL; | |
612 | } | |
613 | if (absolute) | |
614 | mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; | |
615 | else { | |
616 | /* | |
617 | * If an nfs client tries to read an inode that is larger | |
618 | * than any existing inodes, we may try to read past the | |
619 | * end of the inode map | |
620 | */ | |
621 | if ((lblock << inode->i_blkbits) >= inode->i_size) | |
622 | return NULL; | |
623 | mapping = inode->i_mapping; | |
624 | } | |
625 | ||
626 | if (new && (PSIZE == PAGE_SIZE)) { | |
627 | page = grab_cache_page(mapping, page_index); | |
628 | if (!page) { | |
629 | jfs_err("grab_cache_page failed!"); | |
630 | return NULL; | |
631 | } | |
632 | SetPageUptodate(page); | |
633 | } else { | |
634 | page = read_mapping_page(mapping, page_index, NULL); | |
635 | if (IS_ERR(page) || !PageUptodate(page)) { | |
636 | jfs_err("read_mapping_page failed!"); | |
637 | return NULL; | |
638 | } | |
639 | lock_page(page); | |
640 | } | |
641 | ||
642 | mp = page_to_mp(page, page_offset); | |
643 | if (mp) { | |
644 | if (mp->logical_size != size) { | |
645 | jfs_error(inode->i_sb, | |
646 | "get_mp->logical_size != size\n"); | |
647 | jfs_err("logical_size = %d, size = %d", | |
648 | mp->logical_size, size); | |
649 | dump_stack(); | |
650 | goto unlock; | |
651 | } | |
652 | mp->count++; | |
653 | lock_metapage(mp); | |
654 | if (test_bit(META_discard, &mp->flag)) { | |
655 | if (!new) { | |
656 | jfs_error(inode->i_sb, | |
657 | "using a discarded metapage\n"); | |
658 | discard_metapage(mp); | |
659 | goto unlock; | |
660 | } | |
661 | clear_bit(META_discard, &mp->flag); | |
662 | } | |
663 | } else { | |
664 | INCREMENT(mpStat.pagealloc); | |
665 | mp = alloc_metapage(GFP_NOFS); | |
666 | mp->page = page; | |
667 | mp->sb = inode->i_sb; | |
668 | mp->flag = 0; | |
669 | mp->xflag = COMMIT_PAGE; | |
670 | mp->count = 1; | |
671 | mp->nohomeok = 0; | |
672 | mp->logical_size = size; | |
673 | mp->data = page_address(page) + page_offset; | |
674 | mp->index = lblock; | |
675 | if (unlikely(insert_metapage(page, mp))) { | |
676 | free_metapage(mp); | |
677 | goto unlock; | |
678 | } | |
679 | lock_metapage(mp); | |
680 | } | |
681 | ||
682 | if (new) { | |
683 | jfs_info("zeroing mp = 0x%p", mp); | |
684 | memset(mp->data, 0, PSIZE); | |
685 | } | |
686 | ||
687 | unlock_page(page); | |
688 | jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); | |
689 | return mp; | |
690 | ||
691 | unlock: | |
692 | unlock_page(page); | |
693 | return NULL; | |
694 | } | |
695 | ||
696 | void grab_metapage(struct metapage * mp) | |
697 | { | |
698 | jfs_info("grab_metapage: mp = 0x%p", mp); | |
699 | get_page(mp->page); | |
700 | lock_page(mp->page); | |
701 | mp->count++; | |
702 | lock_metapage(mp); | |
703 | unlock_page(mp->page); | |
704 | } | |
705 | ||
706 | void force_metapage(struct metapage *mp) | |
707 | { | |
708 | struct page *page = mp->page; | |
709 | jfs_info("force_metapage: mp = 0x%p", mp); | |
710 | set_bit(META_forcewrite, &mp->flag); | |
711 | clear_bit(META_sync, &mp->flag); | |
712 | get_page(page); | |
713 | lock_page(page); | |
714 | set_page_dirty(page); | |
715 | if (write_one_page(page)) | |
716 | jfs_error(mp->sb, "write_one_page() failed\n"); | |
717 | clear_bit(META_forcewrite, &mp->flag); | |
718 | put_page(page); | |
719 | } | |
720 | ||
721 | void hold_metapage(struct metapage *mp) | |
722 | { | |
723 | lock_page(mp->page); | |
724 | } | |
725 | ||
726 | void put_metapage(struct metapage *mp) | |
727 | { | |
728 | if (mp->count || mp->nohomeok) { | |
729 | /* Someone else will release this */ | |
730 | unlock_page(mp->page); | |
731 | return; | |
732 | } | |
733 | get_page(mp->page); | |
734 | mp->count++; | |
735 | lock_metapage(mp); | |
736 | unlock_page(mp->page); | |
737 | release_metapage(mp); | |
738 | } | |
739 | ||
740 | void release_metapage(struct metapage * mp) | |
741 | { | |
742 | struct page *page = mp->page; | |
743 | jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag); | |
744 | ||
745 | BUG_ON(!page); | |
746 | ||
747 | lock_page(page); | |
748 | unlock_metapage(mp); | |
749 | ||
750 | assert(mp->count); | |
751 | if (--mp->count || mp->nohomeok) { | |
752 | unlock_page(page); | |
753 | put_page(page); | |
754 | return; | |
755 | } | |
756 | ||
757 | if (test_bit(META_dirty, &mp->flag)) { | |
758 | set_page_dirty(page); | |
759 | if (test_bit(META_sync, &mp->flag)) { | |
760 | clear_bit(META_sync, &mp->flag); | |
761 | if (write_one_page(page)) | |
762 | jfs_error(mp->sb, "write_one_page() failed\n"); | |
763 | lock_page(page); /* write_one_page unlocks the page */ | |
764 | } | |
765 | } else if (mp->lsn) /* discard_metapage doesn't remove it */ | |
766 | remove_from_logsync(mp); | |
767 | ||
768 | /* Try to keep metapages from using up too much memory */ | |
769 | drop_metapage(page, mp); | |
770 | ||
771 | unlock_page(page); | |
772 | put_page(page); | |
773 | } | |
774 | ||
775 | void __invalidate_metapages(struct inode *ip, s64 addr, int len) | |
776 | { | |
777 | sector_t lblock; | |
778 | int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits; | |
779 | int BlocksPerPage = 1 << l2BlocksPerPage; | |
780 | /* All callers are interested in block device's mapping */ | |
781 | struct address_space *mapping = | |
782 | JFS_SBI(ip->i_sb)->direct_inode->i_mapping; | |
783 | struct metapage *mp; | |
784 | struct page *page; | |
785 | unsigned int offset; | |
786 | ||
787 | /* | |
788 | * Mark metapages to discard. They will eventually be | |
789 | * released, but should not be written. | |
790 | */ | |
791 | for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; | |
792 | lblock += BlocksPerPage) { | |
793 | page = find_lock_page(mapping, lblock >> l2BlocksPerPage); | |
794 | if (!page) | |
795 | continue; | |
796 | for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) { | |
797 | mp = page_to_mp(page, offset); | |
798 | if (!mp) | |
799 | continue; | |
800 | if (mp->index < addr) | |
801 | continue; | |
802 | if (mp->index >= addr + len) | |
803 | break; | |
804 | ||
805 | clear_bit(META_dirty, &mp->flag); | |
806 | set_bit(META_discard, &mp->flag); | |
807 | if (mp->lsn) | |
808 | remove_from_logsync(mp); | |
809 | } | |
810 | unlock_page(page); | |
811 | put_page(page); | |
812 | } | |
813 | } | |
814 | ||
815 | #ifdef CONFIG_JFS_STATISTICS | |
816 | static int jfs_mpstat_proc_show(struct seq_file *m, void *v) | |
817 | { | |
818 | seq_printf(m, | |
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 | return 0; | |
828 | } | |
829 | ||
830 | static int jfs_mpstat_proc_open(struct inode *inode, struct file *file) | |
831 | { | |
832 | return single_open(file, jfs_mpstat_proc_show, NULL); | |
833 | } | |
834 | ||
835 | const struct file_operations jfs_mpstat_proc_fops = { | |
836 | .open = jfs_mpstat_proc_open, | |
837 | .read = seq_read, | |
838 | .llseek = seq_lseek, | |
839 | .release = single_release, | |
840 | }; | |
841 | #endif |