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10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/pagemap.h>
16#include <linux/pagevec.h>
17#include <linux/mpage.h>
18#include <linux/fs.h>
19#include <linux/writeback.h>
20#include <linux/swap.h>
21#include <linux/gfs2_ondisk.h>
22#include <linux/backing-dev.h>
23#include <linux/aio.h>
24
25#include "gfs2.h"
26#include "incore.h"
27#include "bmap.h"
28#include "glock.h"
29#include "inode.h"
30#include "log.h"
31#include "meta_io.h"
32#include "quota.h"
33#include "trans.h"
34#include "rgrp.h"
35#include "super.h"
36#include "util.h"
37#include "glops.h"
38
39
40static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
41 unsigned int from, unsigned int to)
42{
43 struct buffer_head *head = page_buffers(page);
44 unsigned int bsize = head->b_size;
45 struct buffer_head *bh;
46 unsigned int start, end;
47
48 for (bh = head, start = 0; bh != head || !start;
49 bh = bh->b_this_page, start = end) {
50 end = start + bsize;
51 if (end <= from || start >= to)
52 continue;
53 if (gfs2_is_jdata(ip))
54 set_buffer_uptodate(bh);
55 gfs2_trans_add_data(ip->i_gl, bh);
56 }
57}
58
59
60
61
62
63
64
65
66
67
68
69static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
70 struct buffer_head *bh_result, int create)
71{
72 int error;
73
74 error = gfs2_block_map(inode, lblock, bh_result, 0);
75 if (error)
76 return error;
77 if (!buffer_mapped(bh_result))
78 return -EIO;
79 return 0;
80}
81
82static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
83 struct buffer_head *bh_result, int create)
84{
85 return gfs2_block_map(inode, lblock, bh_result, 0);
86}
87
88
89
90
91
92
93
94
95
96static int gfs2_writepage_common(struct page *page,
97 struct writeback_control *wbc)
98{
99 struct inode *inode = page->mapping->host;
100 struct gfs2_inode *ip = GFS2_I(inode);
101 struct gfs2_sbd *sdp = GFS2_SB(inode);
102 loff_t i_size = i_size_read(inode);
103 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
104 unsigned offset;
105
106 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
107 goto out;
108 if (current->journal_info)
109 goto redirty;
110
111 offset = i_size & (PAGE_CACHE_SIZE-1);
112 if (page->index > end_index || (page->index == end_index && !offset)) {
113 page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
114 goto out;
115 }
116 return 1;
117redirty:
118 redirty_page_for_writepage(wbc, page);
119out:
120 unlock_page(page);
121 return 0;
122}
123
124
125
126
127
128
129
130
131static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
132{
133 int ret;
134
135 ret = gfs2_writepage_common(page, wbc);
136 if (ret <= 0)
137 return ret;
138
139 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
140}
141
142
143
144
145
146
147
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150
151
152
153static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
154{
155 struct inode *inode = page->mapping->host;
156 struct gfs2_inode *ip = GFS2_I(inode);
157 struct gfs2_sbd *sdp = GFS2_SB(inode);
158
159 if (PageChecked(page)) {
160 ClearPageChecked(page);
161 if (!page_has_buffers(page)) {
162 create_empty_buffers(page, inode->i_sb->s_blocksize,
163 (1 << BH_Dirty)|(1 << BH_Uptodate));
164 }
165 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
166 }
167 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
168}
169
170
171
172
173
174
175
176
177
178static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
179{
180 struct inode *inode = page->mapping->host;
181 struct gfs2_sbd *sdp = GFS2_SB(inode);
182 int ret;
183 int done_trans = 0;
184
185 if (PageChecked(page)) {
186 if (wbc->sync_mode != WB_SYNC_ALL)
187 goto out_ignore;
188 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
189 if (ret)
190 goto out_ignore;
191 done_trans = 1;
192 }
193 ret = gfs2_writepage_common(page, wbc);
194 if (ret > 0)
195 ret = __gfs2_jdata_writepage(page, wbc);
196 if (done_trans)
197 gfs2_trans_end(sdp);
198 return ret;
199
200out_ignore:
201 redirty_page_for_writepage(wbc, page);
202 unlock_page(page);
203 return 0;
204}
205
206
207
208
209
210
211
212
213static int gfs2_writepages(struct address_space *mapping,
214 struct writeback_control *wbc)
215{
216 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
217}
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228
229
230static int gfs2_write_jdata_pagevec(struct address_space *mapping,
231 struct writeback_control *wbc,
232 struct pagevec *pvec,
233 int nr_pages, pgoff_t end)
234{
235 struct inode *inode = mapping->host;
236 struct gfs2_sbd *sdp = GFS2_SB(inode);
237 loff_t i_size = i_size_read(inode);
238 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
239 unsigned offset = i_size & (PAGE_CACHE_SIZE-1);
240 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
241 int i;
242 int ret;
243
244 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
245 if (ret < 0)
246 return ret;
247
248 for(i = 0; i < nr_pages; i++) {
249 struct page *page = pvec->pages[i];
250
251 lock_page(page);
252
253 if (unlikely(page->mapping != mapping)) {
254 unlock_page(page);
255 continue;
256 }
257
258 if (!wbc->range_cyclic && page->index > end) {
259 ret = 1;
260 unlock_page(page);
261 continue;
262 }
263
264 if (wbc->sync_mode != WB_SYNC_NONE)
265 wait_on_page_writeback(page);
266
267 if (PageWriteback(page) ||
268 !clear_page_dirty_for_io(page)) {
269 unlock_page(page);
270 continue;
271 }
272
273
274 if (page->index > end_index || (page->index == end_index && !offset)) {
275 page->mapping->a_ops->invalidatepage(page, 0,
276 PAGE_CACHE_SIZE);
277 unlock_page(page);
278 continue;
279 }
280
281 ret = __gfs2_jdata_writepage(page, wbc);
282
283 if (ret || (--(wbc->nr_to_write) <= 0))
284 ret = 1;
285 }
286 gfs2_trans_end(sdp);
287 return ret;
288}
289
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294
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296
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299
300
301
302static int gfs2_write_cache_jdata(struct address_space *mapping,
303 struct writeback_control *wbc)
304{
305 int ret = 0;
306 int done = 0;
307 struct pagevec pvec;
308 int nr_pages;
309 pgoff_t index;
310 pgoff_t end;
311 int scanned = 0;
312 int range_whole = 0;
313
314 pagevec_init(&pvec, 0);
315 if (wbc->range_cyclic) {
316 index = mapping->writeback_index;
317 end = -1;
318 } else {
319 index = wbc->range_start >> PAGE_CACHE_SHIFT;
320 end = wbc->range_end >> PAGE_CACHE_SHIFT;
321 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
322 range_whole = 1;
323 scanned = 1;
324 }
325
326retry:
327 while (!done && (index <= end) &&
328 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
329 PAGECACHE_TAG_DIRTY,
330 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
331 scanned = 1;
332 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end);
333 if (ret)
334 done = 1;
335 if (ret > 0)
336 ret = 0;
337
338 pagevec_release(&pvec);
339 cond_resched();
340 }
341
342 if (!scanned && !done) {
343
344
345
346
347 scanned = 1;
348 index = 0;
349 goto retry;
350 }
351
352 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
353 mapping->writeback_index = index;
354 return ret;
355}
356
357
358
359
360
361
362
363
364
365static int gfs2_jdata_writepages(struct address_space *mapping,
366 struct writeback_control *wbc)
367{
368 struct gfs2_inode *ip = GFS2_I(mapping->host);
369 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
370 int ret;
371
372 ret = gfs2_write_cache_jdata(mapping, wbc);
373 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
374 gfs2_log_flush(sdp, ip->i_gl);
375 ret = gfs2_write_cache_jdata(mapping, wbc);
376 }
377 return ret;
378}
379
380
381
382
383
384
385
386
387
388static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
389{
390 struct buffer_head *dibh;
391 u64 dsize = i_size_read(&ip->i_inode);
392 void *kaddr;
393 int error;
394
395
396
397
398
399
400 if (unlikely(page->index)) {
401 zero_user(page, 0, PAGE_CACHE_SIZE);
402 SetPageUptodate(page);
403 return 0;
404 }
405
406 error = gfs2_meta_inode_buffer(ip, &dibh);
407 if (error)
408 return error;
409
410 kaddr = kmap_atomic(page);
411 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
412 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
413 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
414 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
415 kunmap_atomic(kaddr);
416 flush_dcache_page(page);
417 brelse(dibh);
418 SetPageUptodate(page);
419
420 return 0;
421}
422
423
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427
428
429
430
431
432
433
434
435static int __gfs2_readpage(void *file, struct page *page)
436{
437 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
438 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
439 int error;
440
441 if (gfs2_is_stuffed(ip)) {
442 error = stuffed_readpage(ip, page);
443 unlock_page(page);
444 } else {
445 error = mpage_readpage(page, gfs2_block_map);
446 }
447
448 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
449 return -EIO;
450
451 return error;
452}
453
454
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457
458
459
460
461
462
463
464static int gfs2_readpage(struct file *file, struct page *page)
465{
466 struct address_space *mapping = page->mapping;
467 struct gfs2_inode *ip = GFS2_I(mapping->host);
468 struct gfs2_holder gh;
469 int error;
470
471 unlock_page(page);
472 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
473 error = gfs2_glock_nq(&gh);
474 if (unlikely(error))
475 goto out;
476 error = AOP_TRUNCATED_PAGE;
477 lock_page(page);
478 if (page->mapping == mapping && !PageUptodate(page))
479 error = __gfs2_readpage(file, page);
480 else
481 unlock_page(page);
482 gfs2_glock_dq(&gh);
483out:
484 gfs2_holder_uninit(&gh);
485 if (error && error != AOP_TRUNCATED_PAGE)
486 lock_page(page);
487 return error;
488}
489
490
491
492
493
494
495
496
497
498
499int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
500 unsigned size)
501{
502 struct address_space *mapping = ip->i_inode.i_mapping;
503 unsigned long index = *pos / PAGE_CACHE_SIZE;
504 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
505 unsigned copied = 0;
506 unsigned amt;
507 struct page *page;
508 void *p;
509
510 do {
511 amt = size - copied;
512 if (offset + size > PAGE_CACHE_SIZE)
513 amt = PAGE_CACHE_SIZE - offset;
514 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
515 if (IS_ERR(page))
516 return PTR_ERR(page);
517 p = kmap_atomic(page);
518 memcpy(buf + copied, p + offset, amt);
519 kunmap_atomic(p);
520 mark_page_accessed(page);
521 page_cache_release(page);
522 copied += amt;
523 index++;
524 offset = 0;
525 } while(copied < size);
526 (*pos) += size;
527 return size;
528}
529
530
531
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537
538
539
540
541
542
543
544static int gfs2_readpages(struct file *file, struct address_space *mapping,
545 struct list_head *pages, unsigned nr_pages)
546{
547 struct inode *inode = mapping->host;
548 struct gfs2_inode *ip = GFS2_I(inode);
549 struct gfs2_sbd *sdp = GFS2_SB(inode);
550 struct gfs2_holder gh;
551 int ret;
552
553 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
554 ret = gfs2_glock_nq(&gh);
555 if (unlikely(ret))
556 goto out_uninit;
557 if (!gfs2_is_stuffed(ip))
558 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
559 gfs2_glock_dq(&gh);
560out_uninit:
561 gfs2_holder_uninit(&gh);
562 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
563 ret = -EIO;
564 return ret;
565}
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580static int gfs2_write_begin(struct file *file, struct address_space *mapping,
581 loff_t pos, unsigned len, unsigned flags,
582 struct page **pagep, void **fsdata)
583{
584 struct gfs2_inode *ip = GFS2_I(mapping->host);
585 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
586 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
587 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
588 unsigned requested = 0;
589 int alloc_required;
590 int error = 0;
591 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
592 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
593 struct page *page;
594
595 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
596 error = gfs2_glock_nq(&ip->i_gh);
597 if (unlikely(error))
598 goto out_uninit;
599 if (&ip->i_inode == sdp->sd_rindex) {
600 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
601 GL_NOCACHE, &m_ip->i_gh);
602 if (unlikely(error)) {
603 gfs2_glock_dq(&ip->i_gh);
604 goto out_uninit;
605 }
606 }
607
608 alloc_required = gfs2_write_alloc_required(ip, pos, len);
609
610 if (alloc_required || gfs2_is_jdata(ip))
611 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
612
613 if (alloc_required) {
614 struct gfs2_alloc_parms ap = { .aflags = 0, };
615 error = gfs2_quota_lock_check(ip);
616 if (error)
617 goto out_unlock;
618
619 requested = data_blocks + ind_blocks;
620 ap.target = requested;
621 error = gfs2_inplace_reserve(ip, &ap);
622 if (error)
623 goto out_qunlock;
624 }
625
626 rblocks = RES_DINODE + ind_blocks;
627 if (gfs2_is_jdata(ip))
628 rblocks += data_blocks ? data_blocks : 1;
629 if (ind_blocks || data_blocks)
630 rblocks += RES_STATFS + RES_QUOTA;
631 if (&ip->i_inode == sdp->sd_rindex)
632 rblocks += 2 * RES_STATFS;
633 if (alloc_required)
634 rblocks += gfs2_rg_blocks(ip, requested);
635
636 error = gfs2_trans_begin(sdp, rblocks,
637 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
638 if (error)
639 goto out_trans_fail;
640
641 error = -ENOMEM;
642 flags |= AOP_FLAG_NOFS;
643 page = grab_cache_page_write_begin(mapping, index, flags);
644 *pagep = page;
645 if (unlikely(!page))
646 goto out_endtrans;
647
648 if (gfs2_is_stuffed(ip)) {
649 error = 0;
650 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
651 error = gfs2_unstuff_dinode(ip, page);
652 if (error == 0)
653 goto prepare_write;
654 } else if (!PageUptodate(page)) {
655 error = stuffed_readpage(ip, page);
656 }
657 goto out;
658 }
659
660prepare_write:
661 error = __block_write_begin(page, from, len, gfs2_block_map);
662out:
663 if (error == 0)
664 return 0;
665
666 unlock_page(page);
667 page_cache_release(page);
668
669 gfs2_trans_end(sdp);
670 if (pos + len > ip->i_inode.i_size)
671 gfs2_trim_blocks(&ip->i_inode);
672 goto out_trans_fail;
673
674out_endtrans:
675 gfs2_trans_end(sdp);
676out_trans_fail:
677 if (alloc_required) {
678 gfs2_inplace_release(ip);
679out_qunlock:
680 gfs2_quota_unlock(ip);
681 }
682out_unlock:
683 if (&ip->i_inode == sdp->sd_rindex) {
684 gfs2_glock_dq(&m_ip->i_gh);
685 gfs2_holder_uninit(&m_ip->i_gh);
686 }
687 gfs2_glock_dq(&ip->i_gh);
688out_uninit:
689 gfs2_holder_uninit(&ip->i_gh);
690 return error;
691}
692
693
694
695
696
697static void adjust_fs_space(struct inode *inode)
698{
699 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
700 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
701 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
702 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
703 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
704 struct buffer_head *m_bh, *l_bh;
705 u64 fs_total, new_free;
706
707
708 fs_total = gfs2_ri_total(sdp);
709 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
710 return;
711
712 spin_lock(&sdp->sd_statfs_spin);
713 gfs2_statfs_change_in(m_sc, m_bh->b_data +
714 sizeof(struct gfs2_dinode));
715 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
716 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
717 else
718 new_free = 0;
719 spin_unlock(&sdp->sd_statfs_spin);
720 fs_warn(sdp, "File system extended by %llu blocks.\n",
721 (unsigned long long)new_free);
722 gfs2_statfs_change(sdp, new_free, new_free, 0);
723
724 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
725 goto out;
726 update_statfs(sdp, m_bh, l_bh);
727 brelse(l_bh);
728out:
729 brelse(m_bh);
730}
731
732
733
734
735
736
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738
739
740
741
742
743
744
745
746static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
747 loff_t pos, unsigned len, unsigned copied,
748 struct page *page)
749{
750 struct gfs2_inode *ip = GFS2_I(inode);
751 struct gfs2_sbd *sdp = GFS2_SB(inode);
752 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
753 u64 to = pos + copied;
754 void *kaddr;
755 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
756
757 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
758 kaddr = kmap_atomic(page);
759 memcpy(buf + pos, kaddr + pos, copied);
760 memset(kaddr + pos + copied, 0, len - copied);
761 flush_dcache_page(page);
762 kunmap_atomic(kaddr);
763
764 if (!PageUptodate(page))
765 SetPageUptodate(page);
766 unlock_page(page);
767 page_cache_release(page);
768
769 if (copied) {
770 if (inode->i_size < to)
771 i_size_write(inode, to);
772 mark_inode_dirty(inode);
773 }
774
775 if (inode == sdp->sd_rindex) {
776 adjust_fs_space(inode);
777 sdp->sd_rindex_uptodate = 0;
778 }
779
780 brelse(dibh);
781 gfs2_trans_end(sdp);
782 if (inode == sdp->sd_rindex) {
783 gfs2_glock_dq(&m_ip->i_gh);
784 gfs2_holder_uninit(&m_ip->i_gh);
785 }
786 gfs2_glock_dq(&ip->i_gh);
787 gfs2_holder_uninit(&ip->i_gh);
788 return copied;
789}
790
791
792
793
794
795
796
797
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799
800
801
802
803
804
805
806
807
808static int gfs2_write_end(struct file *file, struct address_space *mapping,
809 loff_t pos, unsigned len, unsigned copied,
810 struct page *page, void *fsdata)
811{
812 struct inode *inode = page->mapping->host;
813 struct gfs2_inode *ip = GFS2_I(inode);
814 struct gfs2_sbd *sdp = GFS2_SB(inode);
815 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
816 struct buffer_head *dibh;
817 unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
818 unsigned int to = from + len;
819 int ret;
820 struct gfs2_trans *tr = current->journal_info;
821 BUG_ON(!tr);
822
823 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
824
825 ret = gfs2_meta_inode_buffer(ip, &dibh);
826 if (unlikely(ret)) {
827 unlock_page(page);
828 page_cache_release(page);
829 goto failed;
830 }
831
832 if (gfs2_is_stuffed(ip))
833 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
834
835 if (!gfs2_is_writeback(ip))
836 gfs2_page_add_databufs(ip, page, from, to);
837
838 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
839 if (tr->tr_num_buf_new)
840 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
841 else
842 gfs2_trans_add_meta(ip->i_gl, dibh);
843
844
845 if (inode == sdp->sd_rindex) {
846 adjust_fs_space(inode);
847 sdp->sd_rindex_uptodate = 0;
848 }
849
850 brelse(dibh);
851failed:
852 gfs2_trans_end(sdp);
853 gfs2_inplace_release(ip);
854 if (ip->i_res->rs_qa_qd_num)
855 gfs2_quota_unlock(ip);
856 if (inode == sdp->sd_rindex) {
857 gfs2_glock_dq(&m_ip->i_gh);
858 gfs2_holder_uninit(&m_ip->i_gh);
859 }
860 gfs2_glock_dq(&ip->i_gh);
861 gfs2_holder_uninit(&ip->i_gh);
862 return ret;
863}
864
865
866
867
868
869
870
871
872static int gfs2_set_page_dirty(struct page *page)
873{
874 SetPageChecked(page);
875 return __set_page_dirty_buffers(page);
876}
877
878
879
880
881
882
883
884
885
886static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
887{
888 struct gfs2_inode *ip = GFS2_I(mapping->host);
889 struct gfs2_holder i_gh;
890 sector_t dblock = 0;
891 int error;
892
893 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
894 if (error)
895 return 0;
896
897 if (!gfs2_is_stuffed(ip))
898 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
899
900 gfs2_glock_dq_uninit(&i_gh);
901
902 return dblock;
903}
904
905static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
906{
907 struct gfs2_bufdata *bd;
908
909 lock_buffer(bh);
910 gfs2_log_lock(sdp);
911 clear_buffer_dirty(bh);
912 bd = bh->b_private;
913 if (bd) {
914 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
915 list_del_init(&bd->bd_list);
916 else
917 gfs2_remove_from_journal(bh, current->journal_info, 0);
918 }
919 bh->b_bdev = NULL;
920 clear_buffer_mapped(bh);
921 clear_buffer_req(bh);
922 clear_buffer_new(bh);
923 gfs2_log_unlock(sdp);
924 unlock_buffer(bh);
925}
926
927static void gfs2_invalidatepage(struct page *page, unsigned int offset,
928 unsigned int length)
929{
930 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
931 unsigned int stop = offset + length;
932 int partial_page = (offset || length < PAGE_CACHE_SIZE);
933 struct buffer_head *bh, *head;
934 unsigned long pos = 0;
935
936 BUG_ON(!PageLocked(page));
937 if (!partial_page)
938 ClearPageChecked(page);
939 if (!page_has_buffers(page))
940 goto out;
941
942 bh = head = page_buffers(page);
943 do {
944 if (pos + bh->b_size > stop)
945 return;
946
947 if (offset <= pos)
948 gfs2_discard(sdp, bh);
949 pos += bh->b_size;
950 bh = bh->b_this_page;
951 } while (bh != head);
952out:
953 if (!partial_page)
954 try_to_release_page(page, 0);
955}
956
957
958
959
960
961
962
963
964
965
966static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
967{
968
969
970
971
972
973 if (gfs2_is_stuffed(ip))
974 return 0;
975
976 if (offset >= i_size_read(&ip->i_inode))
977 return 0;
978 return 1;
979}
980
981
982
983static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
984 const struct iovec *iov, loff_t offset,
985 unsigned long nr_segs)
986{
987 struct file *file = iocb->ki_filp;
988 struct inode *inode = file->f_mapping->host;
989 struct address_space *mapping = inode->i_mapping;
990 struct gfs2_inode *ip = GFS2_I(inode);
991 struct gfs2_holder gh;
992 int rv;
993
994
995
996
997
998
999
1000
1001
1002 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1003 rv = gfs2_glock_nq(&gh);
1004 if (rv)
1005 return rv;
1006 rv = gfs2_ok_for_dio(ip, rw, offset);
1007 if (rv != 1)
1008 goto out;
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023 if (mapping->nrpages) {
1024 loff_t lstart = offset & (PAGE_CACHE_SIZE - 1);
1025 loff_t len = iov_length(iov, nr_segs);
1026 loff_t end = PAGE_ALIGN(offset + len) - 1;
1027
1028 rv = 0;
1029 if (len == 0)
1030 goto out;
1031 if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
1032 unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
1033 rv = filemap_write_and_wait_range(mapping, lstart, end);
1034 if (rv)
1035 return rv;
1036 truncate_inode_pages_range(mapping, lstart, end);
1037 }
1038
1039 rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1040 offset, nr_segs, gfs2_get_block_direct,
1041 NULL, NULL, 0);
1042out:
1043 gfs2_glock_dq(&gh);
1044 gfs2_holder_uninit(&gh);
1045 return rv;
1046}
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1060{
1061 struct address_space *mapping = page->mapping;
1062 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1063 struct buffer_head *bh, *head;
1064 struct gfs2_bufdata *bd;
1065
1066 if (!page_has_buffers(page))
1067 return 0;
1068
1069 gfs2_log_lock(sdp);
1070 spin_lock(&sdp->sd_ail_lock);
1071 head = bh = page_buffers(page);
1072 do {
1073 if (atomic_read(&bh->b_count))
1074 goto cannot_release;
1075 bd = bh->b_private;
1076 if (bd && bd->bd_tr)
1077 goto cannot_release;
1078 if (buffer_pinned(bh) || buffer_dirty(bh))
1079 goto not_possible;
1080 bh = bh->b_this_page;
1081 } while(bh != head);
1082 spin_unlock(&sdp->sd_ail_lock);
1083 gfs2_log_unlock(sdp);
1084
1085 head = bh = page_buffers(page);
1086 do {
1087 gfs2_log_lock(sdp);
1088 bd = bh->b_private;
1089 if (bd) {
1090 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1091 if (!list_empty(&bd->bd_list)) {
1092 if (!buffer_pinned(bh))
1093 list_del_init(&bd->bd_list);
1094 else
1095 bd = NULL;
1096 }
1097 if (bd)
1098 bd->bd_bh = NULL;
1099 bh->b_private = NULL;
1100 }
1101 gfs2_log_unlock(sdp);
1102 if (bd)
1103 kmem_cache_free(gfs2_bufdata_cachep, bd);
1104
1105 bh = bh->b_this_page;
1106 } while (bh != head);
1107
1108 return try_to_free_buffers(page);
1109
1110not_possible:
1111 WARN_ON(buffer_dirty(bh));
1112 WARN_ON(buffer_pinned(bh));
1113cannot_release:
1114 spin_unlock(&sdp->sd_ail_lock);
1115 gfs2_log_unlock(sdp);
1116 return 0;
1117}
1118
1119static const struct address_space_operations gfs2_writeback_aops = {
1120 .writepage = gfs2_writepage,
1121 .writepages = gfs2_writepages,
1122 .readpage = gfs2_readpage,
1123 .readpages = gfs2_readpages,
1124 .write_begin = gfs2_write_begin,
1125 .write_end = gfs2_write_end,
1126 .bmap = gfs2_bmap,
1127 .invalidatepage = gfs2_invalidatepage,
1128 .releasepage = gfs2_releasepage,
1129 .direct_IO = gfs2_direct_IO,
1130 .migratepage = buffer_migrate_page,
1131 .is_partially_uptodate = block_is_partially_uptodate,
1132 .error_remove_page = generic_error_remove_page,
1133};
1134
1135static const struct address_space_operations gfs2_ordered_aops = {
1136 .writepage = gfs2_writepage,
1137 .writepages = gfs2_writepages,
1138 .readpage = gfs2_readpage,
1139 .readpages = gfs2_readpages,
1140 .write_begin = gfs2_write_begin,
1141 .write_end = gfs2_write_end,
1142 .set_page_dirty = gfs2_set_page_dirty,
1143 .bmap = gfs2_bmap,
1144 .invalidatepage = gfs2_invalidatepage,
1145 .releasepage = gfs2_releasepage,
1146 .direct_IO = gfs2_direct_IO,
1147 .migratepage = buffer_migrate_page,
1148 .is_partially_uptodate = block_is_partially_uptodate,
1149 .error_remove_page = generic_error_remove_page,
1150};
1151
1152static const struct address_space_operations gfs2_jdata_aops = {
1153 .writepage = gfs2_jdata_writepage,
1154 .writepages = gfs2_jdata_writepages,
1155 .readpage = gfs2_readpage,
1156 .readpages = gfs2_readpages,
1157 .write_begin = gfs2_write_begin,
1158 .write_end = gfs2_write_end,
1159 .set_page_dirty = gfs2_set_page_dirty,
1160 .bmap = gfs2_bmap,
1161 .invalidatepage = gfs2_invalidatepage,
1162 .releasepage = gfs2_releasepage,
1163 .is_partially_uptodate = block_is_partially_uptodate,
1164 .error_remove_page = generic_error_remove_page,
1165};
1166
1167void gfs2_set_aops(struct inode *inode)
1168{
1169 struct gfs2_inode *ip = GFS2_I(inode);
1170
1171 if (gfs2_is_writeback(ip))
1172 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1173 else if (gfs2_is_ordered(ip))
1174 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1175 else if (gfs2_is_jdata(ip))
1176 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1177 else
1178 BUG();
1179}
1180
1181