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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
37static struct {
38 uint pagealloc;
39 uint pagefree;
40 uint lockwait;
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
47static inline void unlock_metapage(struct metapage *mp)
48{
49 clear_bit_unlock(META_locked, &mp->flag);
50 wake_up(&mp->wait);
51}
52
53static 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
72
73static 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
80static struct kmem_cache *metapage_cache;
81static mempool_t *metapage_mempool;
82
83#define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE)
84
85#if MPS_PER_PAGE > 1
86
87struct 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
94static 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
101static inline int insert_metapage(struct page *page, struct metapage *mp)
102{
103 struct meta_anchor *a;
104 int index;
105 int l2mp_blocks;
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
128static 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
147static inline void inc_io(struct page *page)
148{
149 atomic_inc(&mp_anchor(page)->io_count);
150}
151
152static 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
159static inline struct metapage *page_to_mp(struct page *page, int offset)
160{
161 return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL;
162}
163
164static 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
174static 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
186static 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
201static inline void free_metapage(struct metapage *mp)
202{
203 mempool_free(mp, metapage_mempool);
204}
205
206int __init metapage_init(void)
207{
208
209
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
227void metapage_exit(void)
228{
229 mempool_destroy(metapage_mempool);
230 kmem_cache_destroy(metapage_cache);
231}
232
233static 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
245
246
247static 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 }
268
269 return lblock;
270}
271
272static void last_read_complete(struct page *page)
273{
274 if (!PageError(page))
275 SetPageUptodate(page);
276 unlock_page(page);
277}
278
279static void metapage_read_end_io(struct bio *bio, int err)
280{
281 struct page *page = bio->bi_private;
282
283 if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
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
292static void remove_from_logsync(struct metapage *mp)
293{
294 struct jfs_log *log = mp->log;
295 unsigned long flags;
296
297
298
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
314static void last_write_complete(struct page *page)
315{
316 struct metapage *mp;
317 unsigned int offset;
318
319 for (offset = 0; offset < PAGE_CACHE_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
328
329
330 }
331 end_page_writeback(page);
332}
333
334static void metapage_write_end_io(struct bio *bio, int err)
335{
336 struct page *page = bio->bi_private;
337
338 BUG_ON(!PagePrivate(page));
339
340 if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
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
348static int metapage_writepage(struct page *page, struct writeback_control *wbc)
349{
350 struct bio *bio = NULL;
351 int block_offset;
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_CACHE_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_CACHE_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
384
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
398 len = min(xlen, blocks_per_mp);
399 xlen -= len;
400 bio_bytes += len << inode->i_blkbits;
401 continue;
402 }
403
404 if (bio_add_page(bio, page, bio_bytes, bio_offset) <
405 bio_bytes)
406 goto add_failed;
407
408
409
410
411 inc_io(page);
412 if (!bio->bi_iter.bi_size)
413 goto dump_bio;
414 submit_bio(WRITE, bio);
415 nr_underway++;
416 bio = NULL;
417 } else
418 inc_io(page);
419 xlen = (PAGE_CACHE_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
425
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->bi_bdev = 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
438
439 bio_offset = offset;
440 bio_bytes = len << inode->i_blkbits;
441
442 xlen -= len;
443 next_block = lblock + len;
444 }
445 if (bio) {
446 if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
447 goto add_failed;
448 if (!bio->bi_iter.bi_size)
449 goto dump_bio;
450
451 submit_bio(WRITE, bio);
452 nr_underway++;
453 }
454 if (redirty)
455 redirty_page_for_writepage(wbc, page);
456
457 unlock_page(page);
458
459 if (bad_blocks)
460 goto err_out;
461
462 if (nr_underway == 0)
463 end_page_writeback(page);
464
465 return 0;
466add_failed:
467
468 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
469 goto skip;
470dump_bio:
471 print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16,
472 4, bio, sizeof(*bio), 0);
473skip:
474 bio_put(bio);
475 unlock_page(page);
476 dec_io(page, last_write_complete);
477err_out:
478 while (bad_blocks--)
479 dec_io(page, last_write_complete);
480 return -EIO;
481}
482
483static int metapage_readpage(struct file *fp, struct page *page)
484{
485 struct inode *inode = page->mapping->host;
486 struct bio *bio = NULL;
487 int block_offset;
488 int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
489 sector_t page_start;
490 sector_t pblock;
491 int xlen;
492 unsigned int len;
493 int offset;
494
495 BUG_ON(!PageLocked(page));
496 page_start = (sector_t)page->index <<
497 (PAGE_CACHE_SHIFT - inode->i_blkbits);
498
499 block_offset = 0;
500 while (block_offset < blocks_per_page) {
501 xlen = blocks_per_page - block_offset;
502 pblock = metapage_get_blocks(inode, page_start + block_offset,
503 &xlen);
504 if (pblock) {
505 if (!PagePrivate(page))
506 insert_metapage(page, NULL);
507 inc_io(page);
508 if (bio)
509 submit_bio(READ, bio);
510
511 bio = bio_alloc(GFP_NOFS, 1);
512 bio->bi_bdev = inode->i_sb->s_bdev;
513 bio->bi_iter.bi_sector =
514 pblock << (inode->i_blkbits - 9);
515 bio->bi_end_io = metapage_read_end_io;
516 bio->bi_private = page;
517 len = xlen << inode->i_blkbits;
518 offset = block_offset << inode->i_blkbits;
519 if (bio_add_page(bio, page, len, offset) < len)
520 goto add_failed;
521 block_offset += xlen;
522 } else
523 block_offset++;
524 }
525 if (bio)
526 submit_bio(READ, bio);
527 else
528 unlock_page(page);
529
530 return 0;
531
532add_failed:
533 printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
534 bio_put(bio);
535 dec_io(page, last_read_complete);
536 return -EIO;
537}
538
539static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
540{
541 struct metapage *mp;
542 int ret = 1;
543 int offset;
544
545 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
546 mp = page_to_mp(page, offset);
547
548 if (!mp)
549 continue;
550
551 jfs_info("metapage_releasepage: mp = 0x%p", mp);
552 if (mp->count || mp->nohomeok ||
553 test_bit(META_dirty, &mp->flag)) {
554 jfs_info("count = %ld, nohomeok = %d", mp->count,
555 mp->nohomeok);
556 ret = 0;
557 continue;
558 }
559 if (mp->lsn)
560 remove_from_logsync(mp);
561 remove_metapage(page, mp);
562 INCREMENT(mpStat.pagefree);
563 free_metapage(mp);
564 }
565 return ret;
566}
567
568static void metapage_invalidatepage(struct page *page, unsigned int offset,
569 unsigned int length)
570{
571 BUG_ON(offset || length < PAGE_CACHE_SIZE);
572
573 BUG_ON(PageWriteback(page));
574
575 metapage_releasepage(page, 0);
576}
577
578const struct address_space_operations jfs_metapage_aops = {
579 .readpage = metapage_readpage,
580 .writepage = metapage_writepage,
581 .releasepage = metapage_releasepage,
582 .invalidatepage = metapage_invalidatepage,
583 .set_page_dirty = __set_page_dirty_nobuffers,
584};
585
586struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
587 unsigned int size, int absolute,
588 unsigned long new)
589{
590 int l2BlocksPerPage;
591 int l2bsize;
592 struct address_space *mapping;
593 struct metapage *mp = NULL;
594 struct page *page;
595 unsigned long page_index;
596 unsigned long page_offset;
597
598 jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
599 inode->i_ino, lblock, absolute);
600
601 l2bsize = inode->i_blkbits;
602 l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
603 page_index = lblock >> l2BlocksPerPage;
604 page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
605 if ((page_offset + size) > PAGE_CACHE_SIZE) {
606 jfs_err("MetaData crosses page boundary!!");
607 jfs_err("lblock = %lx, size = %d", lblock, size);
608 dump_stack();
609 return NULL;
610 }
611 if (absolute)
612 mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
613 else {
614
615
616
617
618
619 if ((lblock << inode->i_blkbits) >= inode->i_size)
620 return NULL;
621 mapping = inode->i_mapping;
622 }
623
624 if (new && (PSIZE == PAGE_CACHE_SIZE)) {
625 page = grab_cache_page(mapping, page_index);
626 if (!page) {
627 jfs_err("grab_cache_page failed!");
628 return NULL;
629 }
630 SetPageUptodate(page);
631 } else {
632 page = read_mapping_page(mapping, page_index, NULL);
633 if (IS_ERR(page) || !PageUptodate(page)) {
634 jfs_err("read_mapping_page failed!");
635 return NULL;
636 }
637 lock_page(page);
638 }
639
640 mp = page_to_mp(page, page_offset);
641 if (mp) {
642 if (mp->logical_size != size) {
643 jfs_error(inode->i_sb,
644 "get_mp->logical_size != size\n");
645 jfs_err("logical_size = %d, size = %d",
646 mp->logical_size, size);
647 dump_stack();
648 goto unlock;
649 }
650 mp->count++;
651 lock_metapage(mp);
652 if (test_bit(META_discard, &mp->flag)) {
653 if (!new) {
654 jfs_error(inode->i_sb,
655 "using a discarded metapage\n");
656 discard_metapage(mp);
657 goto unlock;
658 }
659 clear_bit(META_discard, &mp->flag);
660 }
661 } else {
662 INCREMENT(mpStat.pagealloc);
663 mp = alloc_metapage(GFP_NOFS);
664 mp->page = page;
665 mp->flag = 0;
666 mp->xflag = COMMIT_PAGE;
667 mp->count = 1;
668 mp->nohomeok = 0;
669 mp->logical_size = size;
670 mp->data = page_address(page) + page_offset;
671 mp->index = lblock;
672 if (unlikely(insert_metapage(page, mp))) {
673 free_metapage(mp);
674 goto unlock;
675 }
676 lock_metapage(mp);
677 }
678
679 if (new) {
680 jfs_info("zeroing mp = 0x%p", mp);
681 memset(mp->data, 0, PSIZE);
682 }
683
684 unlock_page(page);
685 jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
686 return mp;
687
688unlock:
689 unlock_page(page);
690 return NULL;
691}
692
693void grab_metapage(struct metapage * mp)
694{
695 jfs_info("grab_metapage: mp = 0x%p", mp);
696 page_cache_get(mp->page);
697 lock_page(mp->page);
698 mp->count++;
699 lock_metapage(mp);
700 unlock_page(mp->page);
701}
702
703void force_metapage(struct metapage *mp)
704{
705 struct page *page = mp->page;
706 jfs_info("force_metapage: mp = 0x%p", mp);
707 set_bit(META_forcewrite, &mp->flag);
708 clear_bit(META_sync, &mp->flag);
709 page_cache_get(page);
710 lock_page(page);
711 set_page_dirty(page);
712 write_one_page(page, 1);
713 clear_bit(META_forcewrite, &mp->flag);
714 page_cache_release(page);
715}
716
717void hold_metapage(struct metapage *mp)
718{
719 lock_page(mp->page);
720}
721
722void put_metapage(struct metapage *mp)
723{
724 if (mp->count || mp->nohomeok) {
725
726 unlock_page(mp->page);
727 return;
728 }
729 page_cache_get(mp->page);
730 mp->count++;
731 lock_metapage(mp);
732 unlock_page(mp->page);
733 release_metapage(mp);
734}
735
736void release_metapage(struct metapage * mp)
737{
738 struct page *page = mp->page;
739 jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
740
741 BUG_ON(!page);
742
743 lock_page(page);
744 unlock_metapage(mp);
745
746 assert(mp->count);
747 if (--mp->count || mp->nohomeok) {
748 unlock_page(page);
749 page_cache_release(page);
750 return;
751 }
752
753 if (test_bit(META_dirty, &mp->flag)) {
754 set_page_dirty(page);
755 if (test_bit(META_sync, &mp->flag)) {
756 clear_bit(META_sync, &mp->flag);
757 write_one_page(page, 1);
758 lock_page(page);
759 }
760 } else if (mp->lsn)
761 remove_from_logsync(mp);
762
763
764 drop_metapage(page, mp);
765
766 unlock_page(page);
767 page_cache_release(page);
768}
769
770void __invalidate_metapages(struct inode *ip, s64 addr, int len)
771{
772 sector_t lblock;
773 int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
774 int BlocksPerPage = 1 << l2BlocksPerPage;
775
776 struct address_space *mapping =
777 JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
778 struct metapage *mp;
779 struct page *page;
780 unsigned int offset;
781
782
783
784
785
786 for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
787 lblock += BlocksPerPage) {
788 page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
789 if (!page)
790 continue;
791 for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
792 mp = page_to_mp(page, offset);
793 if (!mp)
794 continue;
795 if (mp->index < addr)
796 continue;
797 if (mp->index >= addr + len)
798 break;
799
800 clear_bit(META_dirty, &mp->flag);
801 set_bit(META_discard, &mp->flag);
802 if (mp->lsn)
803 remove_from_logsync(mp);
804 }
805 unlock_page(page);
806 page_cache_release(page);
807 }
808}
809
810#ifdef CONFIG_JFS_STATISTICS
811static int jfs_mpstat_proc_show(struct seq_file *m, void *v)
812{
813 seq_printf(m,
814 "JFS Metapage statistics\n"
815 "=======================\n"
816 "page allocations = %d\n"
817 "page frees = %d\n"
818 "lock waits = %d\n",
819 mpStat.pagealloc,
820 mpStat.pagefree,
821 mpStat.lockwait);
822 return 0;
823}
824
825static int jfs_mpstat_proc_open(struct inode *inode, struct file *file)
826{
827 return single_open(file, jfs_mpstat_proc_show, NULL);
828}
829
830const struct file_operations jfs_mpstat_proc_fops = {
831 .owner = THIS_MODULE,
832 .open = jfs_mpstat_proc_open,
833 .read = seq_read,
834 .llseek = seq_lseek,
835 .release = single_release,
836};
837#endif
838
