1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) International Business Machines Corp., 2000-2005
4 * Portions Copyright (C) Christoph Hellwig, 2001-2002
5 */
6
7 #include <linux/fs.h>
8 #include <linux/mm.h>
9 #include <linux/module.h>
10 #include <linux/bio.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/buffer_head.h>
14 #include <linux/mempool.h>
15 #include <linux/seq_file.h>
16 #include <linux/writeback.h>
17 #include "jfs_incore.h"
18 #include "jfs_superblock.h"
19 #include "jfs_filsys.h"
20 #include "jfs_metapage.h"
21 #include "jfs_txnmgr.h"
22 #include "jfs_debug.h"
23
24 #ifdef CONFIG_JFS_STATISTICS
25 static struct {
26 uint pagealloc; /* # of page allocations */
27 uint pagefree; /* # of page frees */
28 uint lockwait; /* # of sleeping lock_metapage() calls */
29 } mpStat;
30 #endif
31
32 #define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
33 #define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag)
34
unlock_metapage(struct metapage * mp)35 static inline void unlock_metapage(struct metapage *mp)
36 {
37 clear_bit_unlock(META_locked, &mp->flag);
38 wake_up(&mp->wait);
39 }
40
__lock_metapage(struct metapage * mp)41 static inline void __lock_metapage(struct metapage *mp)
42 {
43 DECLARE_WAITQUEUE(wait, current);
44 INCREMENT(mpStat.lockwait);
45 add_wait_queue_exclusive(&mp->wait, &wait);
46 do {
47 set_current_state(TASK_UNINTERRUPTIBLE);
48 if (metapage_locked(mp)) {
49 unlock_page(mp->page);
50 io_schedule();
51 lock_page(mp->page);
52 }
53 } while (trylock_metapage(mp));
54 __set_current_state(TASK_RUNNING);
55 remove_wait_queue(&mp->wait, &wait);
56 }
57
58 /*
59 * Must have mp->page locked
60 */
lock_metapage(struct metapage * mp)61 static inline void lock_metapage(struct metapage *mp)
62 {
63 if (trylock_metapage(mp))
64 __lock_metapage(mp);
65 }
66
67 #define METAPOOL_MIN_PAGES 32
68 static struct kmem_cache *metapage_cache;
69 static mempool_t *metapage_mempool;
70
71 #define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)
72
73 #if MPS_PER_PAGE > 1
74
75 struct meta_anchor {
76 int mp_count;
77 atomic_t io_count;
78 struct metapage *mp[MPS_PER_PAGE];
79 };
80 #define mp_anchor(page) ((struct meta_anchor *)page_private(page))
81
page_to_mp(struct page * page,int offset)82 static inline struct metapage *page_to_mp(struct page *page, int offset)
83 {
84 if (!PagePrivate(page))
85 return NULL;
86 return mp_anchor(page)->mp[offset >> L2PSIZE];
87 }
88
insert_metapage(struct page * page,struct metapage * mp)89 static inline int insert_metapage(struct page *page, struct metapage *mp)
90 {
91 struct meta_anchor *a;
92 int index;
93 int l2mp_blocks; /* log2 blocks per metapage */
94
95 if (PagePrivate(page))
96 a = mp_anchor(page);
97 else {
98 a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS);
99 if (!a)
100 return -ENOMEM;
101 set_page_private(page, (unsigned long)a);
102 SetPagePrivate(page);
103 kmap(page);
104 }
105
106 if (mp) {
107 l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
108 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
109 a->mp_count++;
110 a->mp[index] = mp;
111 }
112
113 return 0;
114 }
115
remove_metapage(struct page * page,struct metapage * mp)116 static inline void remove_metapage(struct page *page, struct metapage *mp)
117 {
118 struct meta_anchor *a = mp_anchor(page);
119 int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
120 int index;
121
122 index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
123
124 BUG_ON(a->mp[index] != mp);
125
126 a->mp[index] = NULL;
127 if (--a->mp_count == 0) {
128 kfree(a);
129 set_page_private(page, 0);
130 ClearPagePrivate(page);
131 kunmap(page);
132 }
133 }
134
inc_io(struct page * page)135 static inline void inc_io(struct page *page)
136 {
137 atomic_inc(&mp_anchor(page)->io_count);
138 }
139
dec_io(struct page * page,void (* handler)(struct page *))140 static inline void dec_io(struct page *page, void (*handler) (struct page *))
141 {
142 if (atomic_dec_and_test(&mp_anchor(page)->io_count))
143 handler(page);
144 }
145
146 #else
page_to_mp(struct page * page,int offset)147 static inline struct metapage *page_to_mp(struct page *page, int offset)
148 {
149 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
150 }
151
insert_metapage(struct page * page,struct metapage * mp)152 static inline int insert_metapage(struct page *page, struct metapage *mp)
153 {
154 if (mp) {
155 set_page_private(page, (unsigned long)mp);
156 SetPagePrivate(page);
157 kmap(page);
158 }
159 return 0;
160 }
161
remove_metapage(struct page * page,struct metapage * mp)162 static inline void remove_metapage(struct page *page, struct metapage *mp)
163 {
164 set_page_private(page, 0);
165 ClearPagePrivate(page);
166 kunmap(page);
167 }
168
169 #define inc_io(page) do {} while(0)
170 #define dec_io(page, handler) handler(page)
171
172 #endif
173
alloc_metapage(gfp_t gfp_mask)174 static inline struct metapage *alloc_metapage(gfp_t gfp_mask)
175 {
176 struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask);
177
178 if (mp) {
179 mp->lid = 0;
180 mp->lsn = 0;
181 mp->data = NULL;
182 mp->clsn = 0;
183 mp->log = NULL;
184 init_waitqueue_head(&mp->wait);
185 }
186 return mp;
187 }
188
free_metapage(struct metapage * mp)189 static inline void free_metapage(struct metapage *mp)
190 {
191 mempool_free(mp, metapage_mempool);
192 }
193
metapage_init(void)194 int __init metapage_init(void)
195 {
196 /*
197 * Allocate the metapage structures
198 */
199 metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage),
200 0, 0, NULL);
201 if (metapage_cache == NULL)
202 return -ENOMEM;
203
204 metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES,
205 metapage_cache);
206
207 if (metapage_mempool == NULL) {
208 kmem_cache_destroy(metapage_cache);
209 return -ENOMEM;
210 }
211
212 return 0;
213 }
214
metapage_exit(void)215 void metapage_exit(void)
216 {
217 mempool_destroy(metapage_mempool);
218 kmem_cache_destroy(metapage_cache);
219 }
220
drop_metapage(struct page * page,struct metapage * mp)221 static inline void drop_metapage(struct page *page, struct metapage *mp)
222 {
223 if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
224 test_bit(META_io, &mp->flag))
225 return;
226 remove_metapage(page, mp);
227 INCREMENT(mpStat.pagefree);
228 free_metapage(mp);
229 }
230
231 /*
232 * Metapage address space operations
233 */
234
metapage_get_blocks(struct inode * inode,sector_t lblock,int * len)235 static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
236 int *len)
237 {
238 int rc = 0;
239 int xflag;
240 s64 xaddr;
241 sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
242 inode->i_blkbits;
243
244 if (lblock >= file_blocks)
245 return 0;
246 if (lblock + *len > file_blocks)
247 *len = file_blocks - lblock;
248
249 if (inode->i_ino) {
250 rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
251 if ((rc == 0) && *len)
252 lblock = (sector_t)xaddr;
253 else
254 lblock = 0;
255 } /* else no mapping */
256
257 return lblock;
258 }
259
last_read_complete(struct page * page)260 static void last_read_complete(struct page *page)
261 {
262 if (!PageError(page))
263 SetPageUptodate(page);
264 unlock_page(page);
265 }
266
metapage_read_end_io(struct bio * bio)267 static void metapage_read_end_io(struct bio *bio)
268 {
269 struct page *page = bio->bi_private;
270
271 if (bio->bi_status) {
272 printk(KERN_ERR "metapage_read_end_io: I/O error\n");
273 SetPageError(page);
274 }
275
276 dec_io(page, last_read_complete);
277 bio_put(bio);
278 }
279
remove_from_logsync(struct metapage * mp)280 static void remove_from_logsync(struct metapage *mp)
281 {
282 struct jfs_log *log = mp->log;
283 unsigned long flags;
284 /*
285 * This can race. Recheck that log hasn't been set to null, and after
286 * acquiring logsync lock, recheck lsn
287 */
288 if (!log)
289 return;
290
291 LOGSYNC_LOCK(log, flags);
292 if (mp->lsn) {
293 mp->log = NULL;
294 mp->lsn = 0;
295 mp->clsn = 0;
296 log->count--;
297 list_del(&mp->synclist);
298 }
299 LOGSYNC_UNLOCK(log, flags);
300 }
301
last_write_complete(struct page * page)302 static void last_write_complete(struct page *page)
303 {
304 struct metapage *mp;
305 unsigned int offset;
306
307 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
308 mp = page_to_mp(page, offset);
309 if (mp && test_bit(META_io, &mp->flag)) {
310 if (mp->lsn)
311 remove_from_logsync(mp);
312 clear_bit(META_io, &mp->flag);
313 }
314 /*
315 * I'd like to call drop_metapage here, but I don't think it's
316 * safe unless I have the page locked
317 */
318 }
319 end_page_writeback(page);
320 }
321
metapage_write_end_io(struct bio * bio)322 static void metapage_write_end_io(struct bio *bio)
323 {
324 struct page *page = bio->bi_private;
325
326 BUG_ON(!PagePrivate(page));
327
328 if (bio->bi_status) {
329 printk(KERN_ERR "metapage_write_end_io: I/O error\n");
330 SetPageError(page);
331 }
332 dec_io(page, last_write_complete);
333 bio_put(bio);
334 }
335
metapage_writepage(struct page * page,struct writeback_control * wbc)336 static int metapage_writepage(struct page *page, struct writeback_control *wbc)
337 {
338 struct bio *bio = NULL;
339 int block_offset; /* block offset of mp within page */
340 struct inode *inode = page->mapping->host;
341 int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
342 int len;
343 int xlen;
344 struct metapage *mp;
345 int redirty = 0;
346 sector_t lblock;
347 int nr_underway = 0;
348 sector_t pblock;
349 sector_t next_block = 0;
350 sector_t page_start;
351 unsigned long bio_bytes = 0;
352 unsigned long bio_offset = 0;
353 int offset;
354 int bad_blocks = 0;
355
356 page_start = (sector_t)page->index <<
357 (PAGE_SHIFT - inode->i_blkbits);
358 BUG_ON(!PageLocked(page));
359 BUG_ON(PageWriteback(page));
360 set_page_writeback(page);
361
362 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
363 mp = page_to_mp(page, offset);
364
365 if (!mp || !test_bit(META_dirty, &mp->flag))
366 continue;
367
368 if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
369 redirty = 1;
370 /*
371 * Make sure this page isn't blocked indefinitely.
372 * If the journal isn't undergoing I/O, push it
373 */
374 if (mp->log && !(mp->log->cflag & logGC_PAGEOUT))
375 jfs_flush_journal(mp->log, 0);
376 continue;
377 }
378
379 clear_bit(META_dirty, &mp->flag);
380 set_bit(META_io, &mp->flag);
381 block_offset = offset >> inode->i_blkbits;
382 lblock = page_start + block_offset;
383 if (bio) {
384 if (xlen && lblock == next_block) {
385 /* Contiguous, in memory & on disk */
386 len = min(xlen, blocks_per_mp);
387 xlen -= len;
388 bio_bytes += len << inode->i_blkbits;
389 continue;
390 }
391 /* Not contiguous */
392 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
393 bio_bytes)
394 goto add_failed;
395 /*
396 * Increment counter before submitting i/o to keep
397 * count from hitting zero before we're through
398 */
399 inc_io(page);
400 if (!bio->bi_iter.bi_size)
401 goto dump_bio;
402 submit_bio(bio);
403 nr_underway++;
404 bio = NULL;
405 } else
406 inc_io(page);
407 xlen = (PAGE_SIZE - offset) >> inode->i_blkbits;
408 pblock = metapage_get_blocks(inode, lblock, &xlen);
409 if (!pblock) {
410 printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
411 /*
412 * We already called inc_io(), but can't cancel it
413 * with dec_io() until we're done with the page
414 */
415 bad_blocks++;
416 continue;
417 }
418 len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage);
419
420 bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_WRITE, GFP_NOFS);
421 bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
422 bio->bi_end_io = metapage_write_end_io;
423 bio->bi_private = page;
424
425 /* Don't call bio_add_page yet, we may add to this vec */
426 bio_offset = offset;
427 bio_bytes = len << inode->i_blkbits;
428
429 xlen -= len;
430 next_block = lblock + len;
431 }
432 if (bio) {
433 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
434 goto add_failed;
435 if (!bio->bi_iter.bi_size)
436 goto dump_bio;
437
438 submit_bio(bio);
439 nr_underway++;
440 }
441 if (redirty)
442 redirty_page_for_writepage(wbc, page);
443
444 unlock_page(page);
445
446 if (bad_blocks)
447 goto err_out;
448
449 if (nr_underway == 0)
450 end_page_writeback(page);
451
452 return 0;
453 add_failed:
454 /* We should never reach here, since we're only adding one vec */
455 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
456 goto skip;
457 dump_bio:
458 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
459 4, bio, sizeof(*bio), 0);
460 skip:
461 bio_put(bio);
462 unlock_page(page);
463 dec_io(page, last_write_complete);
464 err_out:
465 while (bad_blocks--)
466 dec_io(page, last_write_complete);
467 return -EIO;
468 }
469
metapage_read_folio(struct file * fp,struct folio * folio)470 static int metapage_read_folio(struct file *fp, struct folio *folio)
471 {
472 struct page *page = &folio->page;
473 struct inode *inode = page->mapping->host;
474 struct bio *bio = NULL;
475 int block_offset;
476 int blocks_per_page = i_blocks_per_page(inode, page);
477 sector_t page_start; /* address of page in fs blocks */
478 sector_t pblock;
479 int xlen;
480 unsigned int len;
481 int offset;
482
483 BUG_ON(!PageLocked(page));
484 page_start = (sector_t)page->index <<
485 (PAGE_SHIFT - inode->i_blkbits);
486
487 block_offset = 0;
488 while (block_offset < blocks_per_page) {
489 xlen = blocks_per_page - block_offset;
490 pblock = metapage_get_blocks(inode, page_start + block_offset,
491 &xlen);
492 if (pblock) {
493 if (!PagePrivate(page))
494 insert_metapage(page, NULL);
495 inc_io(page);
496 if (bio)
497 submit_bio(bio);
498
499 bio = bio_alloc(inode->i_sb->s_bdev, 1, REQ_OP_READ,
500 GFP_NOFS);
501 bio->bi_iter.bi_sector =
502 pblock << (inode->i_blkbits - 9);
503 bio->bi_end_io = metapage_read_end_io;
504 bio->bi_private = page;
505 len = xlen << inode->i_blkbits;
506 offset = block_offset << inode->i_blkbits;
507 if (bio_add_page(bio, page, len, offset) < len)
508 goto add_failed;
509 block_offset += xlen;
510 } else
511 block_offset++;
512 }
513 if (bio)
514 submit_bio(bio);
515 else
516 unlock_page(page);
517
518 return 0;
519
520 add_failed:
521 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
522 bio_put(bio);
523 dec_io(page, last_read_complete);
524 return -EIO;
525 }
526
metapage_release_folio(struct folio * folio,gfp_t gfp_mask)527 static bool metapage_release_folio(struct folio *folio, gfp_t gfp_mask)
528 {
529 struct metapage *mp;
530 bool ret = true;
531 int offset;
532
533 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
534 mp = page_to_mp(&folio->page, offset);
535
536 if (!mp)
537 continue;
538
539 jfs_info("metapage_release_folio: mp = 0x%p", mp);
540 if (mp->count || mp->nohomeok ||
541 test_bit(META_dirty, &mp->flag)) {
542 jfs_info("count = %ld, nohomeok = %d", mp->count,
543 mp->nohomeok);
544 ret = false;
545 continue;
546 }
547 if (mp->lsn)
548 remove_from_logsync(mp);
549 remove_metapage(&folio->page, mp);
550 INCREMENT(mpStat.pagefree);
551 free_metapage(mp);
552 }
553 return ret;
554 }
555
metapage_invalidate_folio(struct folio * folio,size_t offset,size_t length)556 static void metapage_invalidate_folio(struct folio *folio, size_t offset,
557 size_t length)
558 {
559 BUG_ON(offset || length < folio_size(folio));
560
561 BUG_ON(folio_test_writeback(folio));
562
563 metapage_release_folio(folio, 0);
564 }
565
566 const struct address_space_operations jfs_metapage_aops = {
567 .read_folio = metapage_read_folio,
568 .writepage = metapage_writepage,
569 .release_folio = metapage_release_folio,
570 .invalidate_folio = metapage_invalidate_folio,
571 .dirty_folio = filemap_dirty_folio,
572 };
573
__get_metapage(struct inode * inode,unsigned long lblock,unsigned int size,int absolute,unsigned long new)574 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
575 unsigned int size, int absolute,
576 unsigned long new)
577 {
578 int l2BlocksPerPage;
579 int l2bsize;
580 struct address_space *mapping;
581 struct metapage *mp = NULL;
582 struct page *page;
583 unsigned long page_index;
584 unsigned long page_offset;
585
586 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
587 inode->i_ino, lblock, absolute);
588
589 l2bsize = inode->i_blkbits;
590 l2BlocksPerPage = PAGE_SHIFT - l2bsize;
591 page_index = lblock >> l2BlocksPerPage;
592 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
593 if ((page_offset + size) > PAGE_SIZE) {
594 jfs_err("MetaData crosses page boundary!!");
595 jfs_err("lblock = %lx, size = %d", lblock, size);
596 dump_stack();
597 return NULL;
598 }
599 if (absolute)
600 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
601 else {
602 /*
603 * If an nfs client tries to read an inode that is larger
604 * than any existing inodes, we may try to read past the
605 * end of the inode map
606 */
607 if ((lblock << inode->i_blkbits) >= inode->i_size)
608 return NULL;
609 mapping = inode->i_mapping;
610 }
611
612 if (new && (PSIZE == PAGE_SIZE)) {
613 page = grab_cache_page(mapping, page_index);
614 if (!page) {
615 jfs_err("grab_cache_page failed!");
616 return NULL;
617 }
618 SetPageUptodate(page);
619 } else {
620 page = read_mapping_page(mapping, page_index, NULL);
621 if (IS_ERR(page)) {
622 jfs_err("read_mapping_page failed!");
623 return NULL;
624 }
625 lock_page(page);
626 }
627
628 mp = page_to_mp(page, page_offset);
629 if (mp) {
630 if (mp->logical_size != size) {
631 jfs_error(inode->i_sb,
632 "get_mp->logical_size != size\n");
633 jfs_err("logical_size = %d, size = %d",
634 mp->logical_size, size);
635 dump_stack();
636 goto unlock;
637 }
638 mp->count++;
639 lock_metapage(mp);
640 if (test_bit(META_discard, &mp->flag)) {
641 if (!new) {
642 jfs_error(inode->i_sb,
643 "using a discarded metapage\n");
644 discard_metapage(mp);
645 goto unlock;
646 }
647 clear_bit(META_discard, &mp->flag);
648 }
649 } else {
650 INCREMENT(mpStat.pagealloc);
651 mp = alloc_metapage(GFP_NOFS);
652 if (!mp)
653 goto unlock;
654 mp->page = page;
655 mp->sb = inode->i_sb;
656 mp->flag = 0;
657 mp->xflag = COMMIT_PAGE;
658 mp->count = 1;
659 mp->nohomeok = 0;
660 mp->logical_size = size;
661 mp->data = page_address(page) + page_offset;
662 mp->index = lblock;
663 if (unlikely(insert_metapage(page, mp))) {
664 free_metapage(mp);
665 goto unlock;
666 }
667 lock_metapage(mp);
668 }
669
670 if (new) {
671 jfs_info("zeroing mp = 0x%p", mp);
672 memset(mp->data, 0, PSIZE);
673 }
674
675 unlock_page(page);
676 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
677 return mp;
678
679 unlock:
680 unlock_page(page);
681 return NULL;
682 }
683
grab_metapage(struct metapage * mp)684 void grab_metapage(struct metapage * mp)
685 {
686 jfs_info("grab_metapage: mp = 0x%p", mp);
687 get_page(mp->page);
688 lock_page(mp->page);
689 mp->count++;
690 lock_metapage(mp);
691 unlock_page(mp->page);
692 }
693
metapage_write_one(struct page * page)694 static int metapage_write_one(struct page *page)
695 {
696 struct folio *folio = page_folio(page);
697 struct address_space *mapping = folio->mapping;
698 struct writeback_control wbc = {
699 .sync_mode = WB_SYNC_ALL,
700 .nr_to_write = folio_nr_pages(folio),
701 };
702 int ret = 0;
703
704 BUG_ON(!folio_test_locked(folio));
705
706 folio_wait_writeback(folio);
707
708 if (folio_clear_dirty_for_io(folio)) {
709 folio_get(folio);
710 ret = metapage_writepage(page, &wbc);
711 if (ret == 0)
712 folio_wait_writeback(folio);
713 folio_put(folio);
714 } else {
715 folio_unlock(folio);
716 }
717
718 if (!ret)
719 ret = filemap_check_errors(mapping);
720 return ret;
721 }
722
force_metapage(struct metapage * mp)723 void force_metapage(struct metapage *mp)
724 {
725 struct page *page = mp->page;
726 jfs_info("force_metapage: mp = 0x%p", mp);
727 set_bit(META_forcewrite, &mp->flag);
728 clear_bit(META_sync, &mp->flag);
729 get_page(page);
730 lock_page(page);
731 set_page_dirty(page);
732 if (metapage_write_one(page))
733 jfs_error(mp->sb, "metapage_write_one() failed\n");
734 clear_bit(META_forcewrite, &mp->flag);
735 put_page(page);
736 }
737
hold_metapage(struct metapage * mp)738 void hold_metapage(struct metapage *mp)
739 {
740 lock_page(mp->page);
741 }
742
put_metapage(struct metapage * mp)743 void put_metapage(struct metapage *mp)
744 {
745 if (mp->count || mp->nohomeok) {
746 /* Someone else will release this */
747 unlock_page(mp->page);
748 return;
749 }
750 get_page(mp->page);
751 mp->count++;
752 lock_metapage(mp);
753 unlock_page(mp->page);
754 release_metapage(mp);
755 }
756
release_metapage(struct metapage * mp)757 void release_metapage(struct metapage * mp)
758 {
759 struct page *page = mp->page;
760 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
761
762 BUG_ON(!page);
763
764 lock_page(page);
765 unlock_metapage(mp);
766
767 assert(mp->count);
768 if (--mp->count || mp->nohomeok) {
769 unlock_page(page);
770 put_page(page);
771 return;
772 }
773
774 if (test_bit(META_dirty, &mp->flag)) {
775 set_page_dirty(page);
776 if (test_bit(META_sync, &mp->flag)) {
777 clear_bit(META_sync, &mp->flag);
778 if (metapage_write_one(page))
779 jfs_error(mp->sb, "metapage_write_one() failed\n");
780 lock_page(page);
781 }
782 } else if (mp->lsn) /* discard_metapage doesn't remove it */
783 remove_from_logsync(mp);
784
785 /* Try to keep metapages from using up too much memory */
786 drop_metapage(page, mp);
787
788 unlock_page(page);
789 put_page(page);
790 }
791
__invalidate_metapages(struct inode * ip,s64 addr,int len)792 void __invalidate_metapages(struct inode *ip, s64 addr, int len)
793 {
794 sector_t lblock;
795 int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
796 int BlocksPerPage = 1 << l2BlocksPerPage;
797 /* All callers are interested in block device's mapping */
798 struct address_space *mapping =
799 JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
800 struct metapage *mp;
801 struct page *page;
802 unsigned int offset;
803
804 /*
805 * Mark metapages to discard. They will eventually be
806 * released, but should not be written.
807 */
808 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
809 lblock += BlocksPerPage) {
810 page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
811 if (!page)
812 continue;
813 for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
814 mp = page_to_mp(page, offset);
815 if (!mp)
816 continue;
817 if (mp->index < addr)
818 continue;
819 if (mp->index >= addr + len)
820 break;
821
822 clear_bit(META_dirty, &mp->flag);
823 set_bit(META_discard, &mp->flag);
824 if (mp->lsn)
825 remove_from_logsync(mp);
826 }
827 unlock_page(page);
828 put_page(page);
829 }
830 }
831
832 #ifdef CONFIG_JFS_STATISTICS
jfs_mpstat_proc_show(struct seq_file * m,void * v)833 int jfs_mpstat_proc_show(struct seq_file *m, void *v)
834 {
835 seq_printf(m,
836 "JFS Metapage statistics\n"
837 "=======================\n"
838 "page allocations = %d\n"
839 "page frees = %d\n"
840 "lock waits = %d\n",
841 mpStat.pagealloc,
842 mpStat.pagefree,
843 mpStat.lockwait);
844 return 0;
845 }
846 #endif
847