Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / fs / gfs2 / aops.c
blob2f725b4a386b38321e0031687fce3db1807ddc2c
1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
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/uio.h>
24 #include <trace/events/writeback.h>
26 #include "gfs2.h"
27 #include "incore.h"
28 #include "bmap.h"
29 #include "glock.h"
30 #include "inode.h"
31 #include "log.h"
32 #include "meta_io.h"
33 #include "quota.h"
34 #include "trans.h"
35 #include "rgrp.h"
36 #include "super.h"
37 #include "util.h"
38 #include "glops.h"
41 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
42 unsigned int from, unsigned int len)
44 struct buffer_head *head = page_buffers(page);
45 unsigned int bsize = head->b_size;
46 struct buffer_head *bh;
47 unsigned int to = from + len;
48 unsigned int start, end;
50 for (bh = head, start = 0; bh != head || !start;
51 bh = bh->b_this_page, start = end) {
52 end = start + bsize;
53 if (end <= from)
54 continue;
55 if (start >= to)
56 break;
57 if (gfs2_is_jdata(ip))
58 set_buffer_uptodate(bh);
59 gfs2_trans_add_data(ip->i_gl, bh);
63 /**
64 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
65 * @inode: The inode
66 * @lblock: The block number to look up
67 * @bh_result: The buffer head to return the result in
68 * @create: Non-zero if we may add block to the file
70 * Returns: errno
73 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
74 struct buffer_head *bh_result, int create)
76 int error;
78 error = gfs2_block_map(inode, lblock, bh_result, 0);
79 if (error)
80 return error;
81 if (!buffer_mapped(bh_result))
82 return -EIO;
83 return 0;
86 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
87 struct buffer_head *bh_result, int create)
89 return gfs2_block_map(inode, lblock, bh_result, 0);
92 /**
93 * gfs2_writepage_common - Common bits of writepage
94 * @page: The page to be written
95 * @wbc: The writeback control
97 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
100 static int gfs2_writepage_common(struct page *page,
101 struct writeback_control *wbc)
103 struct inode *inode = page->mapping->host;
104 struct gfs2_inode *ip = GFS2_I(inode);
105 struct gfs2_sbd *sdp = GFS2_SB(inode);
106 loff_t i_size = i_size_read(inode);
107 pgoff_t end_index = i_size >> PAGE_SHIFT;
108 unsigned offset;
110 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
111 goto out;
112 if (current->journal_info)
113 goto redirty;
114 /* Is the page fully outside i_size? (truncate in progress) */
115 offset = i_size & (PAGE_SIZE-1);
116 if (page->index > end_index || (page->index == end_index && !offset)) {
117 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
118 goto out;
120 return 1;
121 redirty:
122 redirty_page_for_writepage(wbc, page);
123 out:
124 unlock_page(page);
125 return 0;
129 * gfs2_writepage - Write page for writeback mappings
130 * @page: The page
131 * @wbc: The writeback control
135 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
137 int ret;
139 ret = gfs2_writepage_common(page, wbc);
140 if (ret <= 0)
141 return ret;
143 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
146 /* This is the same as calling block_write_full_page, but it also
147 * writes pages outside of i_size
149 static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
150 struct writeback_control *wbc)
152 struct inode * const inode = page->mapping->host;
153 loff_t i_size = i_size_read(inode);
154 const pgoff_t end_index = i_size >> PAGE_SHIFT;
155 unsigned offset;
158 * The page straddles i_size. It must be zeroed out on each and every
159 * writepage invocation because it may be mmapped. "A file is mapped
160 * in multiples of the page size. For a file that is not a multiple of
161 * the page size, the remaining memory is zeroed when mapped, and
162 * writes to that region are not written out to the file."
164 offset = i_size & (PAGE_SIZE-1);
165 if (page->index == end_index && offset)
166 zero_user_segment(page, offset, PAGE_SIZE);
168 return __block_write_full_page(inode, page, get_block, wbc,
169 end_buffer_async_write);
173 * __gfs2_jdata_writepage - The core of jdata writepage
174 * @page: The page to write
175 * @wbc: The writeback control
177 * This is shared between writepage and writepages and implements the
178 * core of the writepage operation. If a transaction is required then
179 * PageChecked will have been set and the transaction will have
180 * already been started before this is called.
183 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
185 struct inode *inode = page->mapping->host;
186 struct gfs2_inode *ip = GFS2_I(inode);
187 struct gfs2_sbd *sdp = GFS2_SB(inode);
189 if (PageChecked(page)) {
190 ClearPageChecked(page);
191 if (!page_has_buffers(page)) {
192 create_empty_buffers(page, inode->i_sb->s_blocksize,
193 BIT(BH_Dirty)|BIT(BH_Uptodate));
195 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
197 return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
201 * gfs2_jdata_writepage - Write complete page
202 * @page: Page to write
203 * @wbc: The writeback control
205 * Returns: errno
209 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
211 struct inode *inode = page->mapping->host;
212 struct gfs2_inode *ip = GFS2_I(inode);
213 struct gfs2_sbd *sdp = GFS2_SB(inode);
214 int ret;
216 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
217 goto out;
218 if (PageChecked(page) || current->journal_info)
219 goto out_ignore;
220 ret = __gfs2_jdata_writepage(page, wbc);
221 return ret;
223 out_ignore:
224 redirty_page_for_writepage(wbc, page);
225 out:
226 unlock_page(page);
227 return 0;
231 * gfs2_writepages - Write a bunch of dirty pages back to disk
232 * @mapping: The mapping to write
233 * @wbc: Write-back control
235 * Used for both ordered and writeback modes.
237 static int gfs2_writepages(struct address_space *mapping,
238 struct writeback_control *wbc)
240 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
241 int ret = mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
244 * Even if we didn't write any pages here, we might still be holding
245 * dirty pages in the ail. We forcibly flush the ail because we don't
246 * want balance_dirty_pages() to loop indefinitely trying to write out
247 * pages held in the ail that it can't find.
249 if (ret == 0)
250 set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
252 return ret;
256 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
257 * @mapping: The mapping
258 * @wbc: The writeback control
259 * @pvec: The vector of pages
260 * @nr_pages: The number of pages to write
261 * @done_index: Page index
263 * Returns: non-zero if loop should terminate, zero otherwise
266 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
267 struct writeback_control *wbc,
268 struct pagevec *pvec,
269 int nr_pages,
270 pgoff_t *done_index)
272 struct inode *inode = mapping->host;
273 struct gfs2_sbd *sdp = GFS2_SB(inode);
274 unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
275 int i;
276 int ret;
278 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
279 if (ret < 0)
280 return ret;
282 for(i = 0; i < nr_pages; i++) {
283 struct page *page = pvec->pages[i];
285 *done_index = page->index;
287 lock_page(page);
289 if (unlikely(page->mapping != mapping)) {
290 continue_unlock:
291 unlock_page(page);
292 continue;
295 if (!PageDirty(page)) {
296 /* someone wrote it for us */
297 goto continue_unlock;
300 if (PageWriteback(page)) {
301 if (wbc->sync_mode != WB_SYNC_NONE)
302 wait_on_page_writeback(page);
303 else
304 goto continue_unlock;
307 BUG_ON(PageWriteback(page));
308 if (!clear_page_dirty_for_io(page))
309 goto continue_unlock;
311 trace_wbc_writepage(wbc, inode_to_bdi(inode));
313 ret = __gfs2_jdata_writepage(page, wbc);
314 if (unlikely(ret)) {
315 if (ret == AOP_WRITEPAGE_ACTIVATE) {
316 unlock_page(page);
317 ret = 0;
318 } else {
321 * done_index is set past this page,
322 * so media errors will not choke
323 * background writeout for the entire
324 * file. This has consequences for
325 * range_cyclic semantics (ie. it may
326 * not be suitable for data integrity
327 * writeout).
329 *done_index = page->index + 1;
330 ret = 1;
331 break;
336 * We stop writing back only if we are not doing
337 * integrity sync. In case of integrity sync we have to
338 * keep going until we have written all the pages
339 * we tagged for writeback prior to entering this loop.
341 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
342 ret = 1;
343 break;
347 gfs2_trans_end(sdp);
348 return ret;
352 * gfs2_write_cache_jdata - Like write_cache_pages but different
353 * @mapping: The mapping to write
354 * @wbc: The writeback control
356 * The reason that we use our own function here is that we need to
357 * start transactions before we grab page locks. This allows us
358 * to get the ordering right.
361 static int gfs2_write_cache_jdata(struct address_space *mapping,
362 struct writeback_control *wbc)
364 int ret = 0;
365 int done = 0;
366 struct pagevec pvec;
367 int nr_pages;
368 pgoff_t uninitialized_var(writeback_index);
369 pgoff_t index;
370 pgoff_t end;
371 pgoff_t done_index;
372 int cycled;
373 int range_whole = 0;
374 int tag;
376 pagevec_init(&pvec);
377 if (wbc->range_cyclic) {
378 writeback_index = mapping->writeback_index; /* prev offset */
379 index = writeback_index;
380 if (index == 0)
381 cycled = 1;
382 else
383 cycled = 0;
384 end = -1;
385 } else {
386 index = wbc->range_start >> PAGE_SHIFT;
387 end = wbc->range_end >> PAGE_SHIFT;
388 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
389 range_whole = 1;
390 cycled = 1; /* ignore range_cyclic tests */
392 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
393 tag = PAGECACHE_TAG_TOWRITE;
394 else
395 tag = PAGECACHE_TAG_DIRTY;
397 retry:
398 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
399 tag_pages_for_writeback(mapping, index, end);
400 done_index = index;
401 while (!done && (index <= end)) {
402 nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
403 tag);
404 if (nr_pages == 0)
405 break;
407 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, &done_index);
408 if (ret)
409 done = 1;
410 if (ret > 0)
411 ret = 0;
412 pagevec_release(&pvec);
413 cond_resched();
416 if (!cycled && !done) {
418 * range_cyclic:
419 * We hit the last page and there is more work to be done: wrap
420 * back to the start of the file
422 cycled = 1;
423 index = 0;
424 end = writeback_index - 1;
425 goto retry;
428 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
429 mapping->writeback_index = done_index;
431 return ret;
436 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
437 * @mapping: The mapping to write
438 * @wbc: The writeback control
442 static int gfs2_jdata_writepages(struct address_space *mapping,
443 struct writeback_control *wbc)
445 struct gfs2_inode *ip = GFS2_I(mapping->host);
446 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
447 int ret;
449 ret = gfs2_write_cache_jdata(mapping, wbc);
450 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
451 gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
452 GFS2_LFC_JDATA_WPAGES);
453 ret = gfs2_write_cache_jdata(mapping, wbc);
455 return ret;
459 * stuffed_readpage - Fill in a Linux page with stuffed file data
460 * @ip: the inode
461 * @page: the page
463 * Returns: errno
466 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
468 struct buffer_head *dibh;
469 u64 dsize = i_size_read(&ip->i_inode);
470 void *kaddr;
471 int error;
474 * Due to the order of unstuffing files and ->fault(), we can be
475 * asked for a zero page in the case of a stuffed file being extended,
476 * so we need to supply one here. It doesn't happen often.
478 if (unlikely(page->index)) {
479 zero_user(page, 0, PAGE_SIZE);
480 SetPageUptodate(page);
481 return 0;
484 error = gfs2_meta_inode_buffer(ip, &dibh);
485 if (error)
486 return error;
488 kaddr = kmap_atomic(page);
489 if (dsize > gfs2_max_stuffed_size(ip))
490 dsize = gfs2_max_stuffed_size(ip);
491 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
492 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
493 kunmap_atomic(kaddr);
494 flush_dcache_page(page);
495 brelse(dibh);
496 SetPageUptodate(page);
498 return 0;
503 * __gfs2_readpage - readpage
504 * @file: The file to read a page for
505 * @page: The page to read
507 * This is the core of gfs2's readpage. It's used by the internal file
508 * reading code as in that case we already hold the glock. Also it's
509 * called by gfs2_readpage() once the required lock has been granted.
512 static int __gfs2_readpage(void *file, struct page *page)
514 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
515 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
516 int error;
518 if (gfs2_is_stuffed(ip)) {
519 error = stuffed_readpage(ip, page);
520 unlock_page(page);
521 } else {
522 error = mpage_readpage(page, gfs2_block_map);
525 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
526 return -EIO;
528 return error;
532 * gfs2_readpage - read a page of a file
533 * @file: The file to read
534 * @page: The page of the file
536 * This deals with the locking required. We have to unlock and
537 * relock the page in order to get the locking in the right
538 * order.
541 static int gfs2_readpage(struct file *file, struct page *page)
543 struct address_space *mapping = page->mapping;
544 struct gfs2_inode *ip = GFS2_I(mapping->host);
545 struct gfs2_holder gh;
546 int error;
548 unlock_page(page);
549 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
550 error = gfs2_glock_nq(&gh);
551 if (unlikely(error))
552 goto out;
553 error = AOP_TRUNCATED_PAGE;
554 lock_page(page);
555 if (page->mapping == mapping && !PageUptodate(page))
556 error = __gfs2_readpage(file, page);
557 else
558 unlock_page(page);
559 gfs2_glock_dq(&gh);
560 out:
561 gfs2_holder_uninit(&gh);
562 if (error && error != AOP_TRUNCATED_PAGE)
563 lock_page(page);
564 return error;
568 * gfs2_internal_read - read an internal file
569 * @ip: The gfs2 inode
570 * @buf: The buffer to fill
571 * @pos: The file position
572 * @size: The amount to read
576 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
577 unsigned size)
579 struct address_space *mapping = ip->i_inode.i_mapping;
580 unsigned long index = *pos / PAGE_SIZE;
581 unsigned offset = *pos & (PAGE_SIZE - 1);
582 unsigned copied = 0;
583 unsigned amt;
584 struct page *page;
585 void *p;
587 do {
588 amt = size - copied;
589 if (offset + size > PAGE_SIZE)
590 amt = PAGE_SIZE - offset;
591 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
592 if (IS_ERR(page))
593 return PTR_ERR(page);
594 p = kmap_atomic(page);
595 memcpy(buf + copied, p + offset, amt);
596 kunmap_atomic(p);
597 put_page(page);
598 copied += amt;
599 index++;
600 offset = 0;
601 } while(copied < size);
602 (*pos) += size;
603 return size;
607 * gfs2_readpages - Read a bunch of pages at once
608 * @file: The file to read from
609 * @mapping: Address space info
610 * @pages: List of pages to read
611 * @nr_pages: Number of pages to read
613 * Some notes:
614 * 1. This is only for readahead, so we can simply ignore any things
615 * which are slightly inconvenient (such as locking conflicts between
616 * the page lock and the glock) and return having done no I/O. Its
617 * obviously not something we'd want to do on too regular a basis.
618 * Any I/O we ignore at this time will be done via readpage later.
619 * 2. We don't handle stuffed files here we let readpage do the honours.
620 * 3. mpage_readpages() does most of the heavy lifting in the common case.
621 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
624 static int gfs2_readpages(struct file *file, struct address_space *mapping,
625 struct list_head *pages, unsigned nr_pages)
627 struct inode *inode = mapping->host;
628 struct gfs2_inode *ip = GFS2_I(inode);
629 struct gfs2_sbd *sdp = GFS2_SB(inode);
630 struct gfs2_holder gh;
631 int ret;
633 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
634 ret = gfs2_glock_nq(&gh);
635 if (unlikely(ret))
636 goto out_uninit;
637 if (!gfs2_is_stuffed(ip))
638 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
639 gfs2_glock_dq(&gh);
640 out_uninit:
641 gfs2_holder_uninit(&gh);
642 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
643 ret = -EIO;
644 return ret;
648 * gfs2_write_begin - Begin to write to a file
649 * @file: The file to write to
650 * @mapping: The mapping in which to write
651 * @pos: The file offset at which to start writing
652 * @len: Length of the write
653 * @flags: Various flags
654 * @pagep: Pointer to return the page
655 * @fsdata: Pointer to return fs data (unused by GFS2)
657 * Returns: errno
660 static int gfs2_write_begin(struct file *file, struct address_space *mapping,
661 loff_t pos, unsigned len, unsigned flags,
662 struct page **pagep, void **fsdata)
664 struct gfs2_inode *ip = GFS2_I(mapping->host);
665 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
666 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
667 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
668 unsigned requested = 0;
669 int alloc_required;
670 int error = 0;
671 pgoff_t index = pos >> PAGE_SHIFT;
672 unsigned from = pos & (PAGE_SIZE - 1);
673 struct page *page;
675 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
676 error = gfs2_glock_nq(&ip->i_gh);
677 if (unlikely(error))
678 goto out_uninit;
679 if (&ip->i_inode == sdp->sd_rindex) {
680 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
681 GL_NOCACHE, &m_ip->i_gh);
682 if (unlikely(error)) {
683 gfs2_glock_dq(&ip->i_gh);
684 goto out_uninit;
688 alloc_required = gfs2_write_alloc_required(ip, pos, len);
690 if (alloc_required || gfs2_is_jdata(ip))
691 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
693 if (alloc_required) {
694 struct gfs2_alloc_parms ap = { .aflags = 0, };
695 requested = data_blocks + ind_blocks;
696 ap.target = requested;
697 error = gfs2_quota_lock_check(ip, &ap);
698 if (error)
699 goto out_unlock;
701 error = gfs2_inplace_reserve(ip, &ap);
702 if (error)
703 goto out_qunlock;
706 rblocks = RES_DINODE + ind_blocks;
707 if (gfs2_is_jdata(ip))
708 rblocks += data_blocks ? data_blocks : 1;
709 if (ind_blocks || data_blocks)
710 rblocks += RES_STATFS + RES_QUOTA;
711 if (&ip->i_inode == sdp->sd_rindex)
712 rblocks += 2 * RES_STATFS;
713 if (alloc_required)
714 rblocks += gfs2_rg_blocks(ip, requested);
716 error = gfs2_trans_begin(sdp, rblocks,
717 PAGE_SIZE/sdp->sd_sb.sb_bsize);
718 if (error)
719 goto out_trans_fail;
721 error = -ENOMEM;
722 flags |= AOP_FLAG_NOFS;
723 page = grab_cache_page_write_begin(mapping, index, flags);
724 *pagep = page;
725 if (unlikely(!page))
726 goto out_endtrans;
728 if (gfs2_is_stuffed(ip)) {
729 error = 0;
730 if (pos + len > gfs2_max_stuffed_size(ip)) {
731 error = gfs2_unstuff_dinode(ip, page);
732 if (error == 0)
733 goto prepare_write;
734 } else if (!PageUptodate(page)) {
735 error = stuffed_readpage(ip, page);
737 goto out;
740 prepare_write:
741 error = __block_write_begin(page, from, len, gfs2_block_map);
742 out:
743 if (error == 0)
744 return 0;
746 unlock_page(page);
747 put_page(page);
749 gfs2_trans_end(sdp);
750 if (pos + len > ip->i_inode.i_size)
751 gfs2_trim_blocks(&ip->i_inode);
752 goto out_trans_fail;
754 out_endtrans:
755 gfs2_trans_end(sdp);
756 out_trans_fail:
757 if (alloc_required) {
758 gfs2_inplace_release(ip);
759 out_qunlock:
760 gfs2_quota_unlock(ip);
762 out_unlock:
763 if (&ip->i_inode == sdp->sd_rindex) {
764 gfs2_glock_dq(&m_ip->i_gh);
765 gfs2_holder_uninit(&m_ip->i_gh);
767 gfs2_glock_dq(&ip->i_gh);
768 out_uninit:
769 gfs2_holder_uninit(&ip->i_gh);
770 return error;
774 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
775 * @inode: the rindex inode
777 static void adjust_fs_space(struct inode *inode)
779 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
780 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
781 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
782 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
783 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
784 struct buffer_head *m_bh, *l_bh;
785 u64 fs_total, new_free;
787 /* Total up the file system space, according to the latest rindex. */
788 fs_total = gfs2_ri_total(sdp);
789 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
790 return;
792 spin_lock(&sdp->sd_statfs_spin);
793 gfs2_statfs_change_in(m_sc, m_bh->b_data +
794 sizeof(struct gfs2_dinode));
795 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
796 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
797 else
798 new_free = 0;
799 spin_unlock(&sdp->sd_statfs_spin);
800 fs_warn(sdp, "File system extended by %llu blocks.\n",
801 (unsigned long long)new_free);
802 gfs2_statfs_change(sdp, new_free, new_free, 0);
804 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
805 goto out;
806 update_statfs(sdp, m_bh, l_bh);
807 brelse(l_bh);
808 out:
809 brelse(m_bh);
813 * gfs2_stuffed_write_end - Write end for stuffed files
814 * @inode: The inode
815 * @dibh: The buffer_head containing the on-disk inode
816 * @pos: The file position
817 * @len: The length of the write
818 * @copied: How much was actually copied by the VFS
819 * @page: The page
821 * This copies the data from the page into the inode block after
822 * the inode data structure itself.
824 * Returns: errno
826 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
827 loff_t pos, unsigned len, unsigned copied,
828 struct page *page)
830 struct gfs2_inode *ip = GFS2_I(inode);
831 struct gfs2_sbd *sdp = GFS2_SB(inode);
832 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
833 u64 to = pos + copied;
834 void *kaddr;
835 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
837 BUG_ON(pos + len > gfs2_max_stuffed_size(ip));
839 kaddr = kmap_atomic(page);
840 memcpy(buf + pos, kaddr + pos, copied);
841 flush_dcache_page(page);
842 kunmap_atomic(kaddr);
844 WARN_ON(!PageUptodate(page));
845 unlock_page(page);
846 put_page(page);
848 if (copied) {
849 if (inode->i_size < to)
850 i_size_write(inode, to);
851 mark_inode_dirty(inode);
854 if (inode == sdp->sd_rindex) {
855 adjust_fs_space(inode);
856 sdp->sd_rindex_uptodate = 0;
859 brelse(dibh);
860 gfs2_trans_end(sdp);
861 if (inode == sdp->sd_rindex) {
862 gfs2_glock_dq(&m_ip->i_gh);
863 gfs2_holder_uninit(&m_ip->i_gh);
865 gfs2_glock_dq(&ip->i_gh);
866 gfs2_holder_uninit(&ip->i_gh);
867 return copied;
871 * gfs2_write_end
872 * @file: The file to write to
873 * @mapping: The address space to write to
874 * @pos: The file position
875 * @len: The length of the data
876 * @copied: How much was actually copied by the VFS
877 * @page: The page that has been written
878 * @fsdata: The fsdata (unused in GFS2)
880 * The main write_end function for GFS2. We have a separate one for
881 * stuffed files as they are slightly different, otherwise we just
882 * put our locking around the VFS provided functions.
884 * Returns: errno
887 static int gfs2_write_end(struct file *file, struct address_space *mapping,
888 loff_t pos, unsigned len, unsigned copied,
889 struct page *page, void *fsdata)
891 struct inode *inode = page->mapping->host;
892 struct gfs2_inode *ip = GFS2_I(inode);
893 struct gfs2_sbd *sdp = GFS2_SB(inode);
894 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
895 struct buffer_head *dibh;
896 int ret;
897 struct gfs2_trans *tr = current->journal_info;
898 BUG_ON(!tr);
900 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
902 ret = gfs2_meta_inode_buffer(ip, &dibh);
903 if (unlikely(ret)) {
904 unlock_page(page);
905 put_page(page);
906 goto failed;
909 if (gfs2_is_stuffed(ip))
910 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
912 if (!gfs2_is_writeback(ip))
913 gfs2_page_add_databufs(ip, page, pos & ~PAGE_MASK, len);
915 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
916 if (tr->tr_num_buf_new)
917 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
918 else
919 gfs2_trans_add_meta(ip->i_gl, dibh);
922 if (inode == sdp->sd_rindex) {
923 adjust_fs_space(inode);
924 sdp->sd_rindex_uptodate = 0;
927 brelse(dibh);
928 failed:
929 gfs2_trans_end(sdp);
930 gfs2_inplace_release(ip);
931 if (ip->i_qadata && ip->i_qadata->qa_qd_num)
932 gfs2_quota_unlock(ip);
933 if (inode == sdp->sd_rindex) {
934 gfs2_glock_dq(&m_ip->i_gh);
935 gfs2_holder_uninit(&m_ip->i_gh);
937 gfs2_glock_dq(&ip->i_gh);
938 gfs2_holder_uninit(&ip->i_gh);
939 return ret;
943 * gfs2_set_page_dirty - Page dirtying function
944 * @page: The page to dirty
946 * Returns: 1 if it dirtyed the page, or 0 otherwise
949 static int gfs2_set_page_dirty(struct page *page)
951 SetPageChecked(page);
952 return __set_page_dirty_buffers(page);
956 * gfs2_bmap - Block map function
957 * @mapping: Address space info
958 * @lblock: The block to map
960 * Returns: The disk address for the block or 0 on hole or error
963 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
965 struct gfs2_inode *ip = GFS2_I(mapping->host);
966 struct gfs2_holder i_gh;
967 sector_t dblock = 0;
968 int error;
970 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
971 if (error)
972 return 0;
974 if (!gfs2_is_stuffed(ip))
975 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
977 gfs2_glock_dq_uninit(&i_gh);
979 return dblock;
982 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
984 struct gfs2_bufdata *bd;
986 lock_buffer(bh);
987 gfs2_log_lock(sdp);
988 clear_buffer_dirty(bh);
989 bd = bh->b_private;
990 if (bd) {
991 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
992 list_del_init(&bd->bd_list);
993 else
994 gfs2_remove_from_journal(bh, REMOVE_JDATA);
996 bh->b_bdev = NULL;
997 clear_buffer_mapped(bh);
998 clear_buffer_req(bh);
999 clear_buffer_new(bh);
1000 gfs2_log_unlock(sdp);
1001 unlock_buffer(bh);
1004 static void gfs2_invalidatepage(struct page *page, unsigned int offset,
1005 unsigned int length)
1007 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
1008 unsigned int stop = offset + length;
1009 int partial_page = (offset || length < PAGE_SIZE);
1010 struct buffer_head *bh, *head;
1011 unsigned long pos = 0;
1013 BUG_ON(!PageLocked(page));
1014 if (!partial_page)
1015 ClearPageChecked(page);
1016 if (!page_has_buffers(page))
1017 goto out;
1019 bh = head = page_buffers(page);
1020 do {
1021 if (pos + bh->b_size > stop)
1022 return;
1024 if (offset <= pos)
1025 gfs2_discard(sdp, bh);
1026 pos += bh->b_size;
1027 bh = bh->b_this_page;
1028 } while (bh != head);
1029 out:
1030 if (!partial_page)
1031 try_to_release_page(page, 0);
1035 * gfs2_ok_for_dio - check that dio is valid on this file
1036 * @ip: The inode
1037 * @offset: The offset at which we are reading or writing
1039 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
1040 * 1 (to accept the i/o request)
1042 static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset)
1045 * Should we return an error here? I can't see that O_DIRECT for
1046 * a stuffed file makes any sense. For now we'll silently fall
1047 * back to buffered I/O
1049 if (gfs2_is_stuffed(ip))
1050 return 0;
1052 if (offset >= i_size_read(&ip->i_inode))
1053 return 0;
1054 return 1;
1059 static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1061 struct file *file = iocb->ki_filp;
1062 struct inode *inode = file->f_mapping->host;
1063 struct address_space *mapping = inode->i_mapping;
1064 struct gfs2_inode *ip = GFS2_I(inode);
1065 loff_t offset = iocb->ki_pos;
1066 struct gfs2_holder gh;
1067 int rv;
1070 * Deferred lock, even if its a write, since we do no allocation
1071 * on this path. All we need change is atime, and this lock mode
1072 * ensures that other nodes have flushed their buffered read caches
1073 * (i.e. their page cache entries for this inode). We do not,
1074 * unfortunately have the option of only flushing a range like
1075 * the VFS does.
1077 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1078 rv = gfs2_glock_nq(&gh);
1079 if (rv)
1080 goto out_uninit;
1081 rv = gfs2_ok_for_dio(ip, offset);
1082 if (rv != 1)
1083 goto out; /* dio not valid, fall back to buffered i/o */
1086 * Now since we are holding a deferred (CW) lock at this point, you
1087 * might be wondering why this is ever needed. There is a case however
1088 * where we've granted a deferred local lock against a cached exclusive
1089 * glock. That is ok provided all granted local locks are deferred, but
1090 * it also means that it is possible to encounter pages which are
1091 * cached and possibly also mapped. So here we check for that and sort
1092 * them out ahead of the dio. The glock state machine will take care of
1093 * everything else.
1095 * If in fact the cached glock state (gl->gl_state) is deferred (CW) in
1096 * the first place, mapping->nr_pages will always be zero.
1098 if (mapping->nrpages) {
1099 loff_t lstart = offset & ~(PAGE_SIZE - 1);
1100 loff_t len = iov_iter_count(iter);
1101 loff_t end = PAGE_ALIGN(offset + len) - 1;
1103 rv = 0;
1104 if (len == 0)
1105 goto out;
1106 if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
1107 unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
1108 rv = filemap_write_and_wait_range(mapping, lstart, end);
1109 if (rv)
1110 goto out;
1111 if (iov_iter_rw(iter) == WRITE)
1112 truncate_inode_pages_range(mapping, lstart, end);
1115 rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
1116 gfs2_get_block_direct, NULL, NULL, 0);
1117 out:
1118 gfs2_glock_dq(&gh);
1119 out_uninit:
1120 gfs2_holder_uninit(&gh);
1121 return rv;
1125 * gfs2_releasepage - free the metadata associated with a page
1126 * @page: the page that's being released
1127 * @gfp_mask: passed from Linux VFS, ignored by us
1129 * Call try_to_free_buffers() if the buffers in this page can be
1130 * released.
1132 * Returns: 0
1135 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1137 struct address_space *mapping = page->mapping;
1138 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1139 struct buffer_head *bh, *head;
1140 struct gfs2_bufdata *bd;
1142 if (!page_has_buffers(page))
1143 return 0;
1146 * From xfs_vm_releasepage: mm accommodates an old ext3 case where
1147 * clean pages might not have had the dirty bit cleared. Thus, it can
1148 * send actual dirty pages to ->releasepage() via shrink_active_list().
1150 * As a workaround, we skip pages that contain dirty buffers below.
1151 * Once ->releasepage isn't called on dirty pages anymore, we can warn
1152 * on dirty buffers like we used to here again.
1155 gfs2_log_lock(sdp);
1156 spin_lock(&sdp->sd_ail_lock);
1157 head = bh = page_buffers(page);
1158 do {
1159 if (atomic_read(&bh->b_count))
1160 goto cannot_release;
1161 bd = bh->b_private;
1162 if (bd && bd->bd_tr)
1163 goto cannot_release;
1164 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
1165 goto cannot_release;
1166 bh = bh->b_this_page;
1167 } while(bh != head);
1168 spin_unlock(&sdp->sd_ail_lock);
1170 head = bh = page_buffers(page);
1171 do {
1172 bd = bh->b_private;
1173 if (bd) {
1174 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1175 if (!list_empty(&bd->bd_list))
1176 list_del_init(&bd->bd_list);
1177 bd->bd_bh = NULL;
1178 bh->b_private = NULL;
1179 kmem_cache_free(gfs2_bufdata_cachep, bd);
1182 bh = bh->b_this_page;
1183 } while (bh != head);
1184 gfs2_log_unlock(sdp);
1186 return try_to_free_buffers(page);
1188 cannot_release:
1189 spin_unlock(&sdp->sd_ail_lock);
1190 gfs2_log_unlock(sdp);
1191 return 0;
1194 static const struct address_space_operations gfs2_writeback_aops = {
1195 .writepage = gfs2_writepage,
1196 .writepages = gfs2_writepages,
1197 .readpage = gfs2_readpage,
1198 .readpages = gfs2_readpages,
1199 .write_begin = gfs2_write_begin,
1200 .write_end = gfs2_write_end,
1201 .bmap = gfs2_bmap,
1202 .invalidatepage = gfs2_invalidatepage,
1203 .releasepage = gfs2_releasepage,
1204 .direct_IO = gfs2_direct_IO,
1205 .migratepage = buffer_migrate_page,
1206 .is_partially_uptodate = block_is_partially_uptodate,
1207 .error_remove_page = generic_error_remove_page,
1210 static const struct address_space_operations gfs2_ordered_aops = {
1211 .writepage = gfs2_writepage,
1212 .writepages = gfs2_writepages,
1213 .readpage = gfs2_readpage,
1214 .readpages = gfs2_readpages,
1215 .write_begin = gfs2_write_begin,
1216 .write_end = gfs2_write_end,
1217 .set_page_dirty = gfs2_set_page_dirty,
1218 .bmap = gfs2_bmap,
1219 .invalidatepage = gfs2_invalidatepage,
1220 .releasepage = gfs2_releasepage,
1221 .direct_IO = gfs2_direct_IO,
1222 .migratepage = buffer_migrate_page,
1223 .is_partially_uptodate = block_is_partially_uptodate,
1224 .error_remove_page = generic_error_remove_page,
1227 static const struct address_space_operations gfs2_jdata_aops = {
1228 .writepage = gfs2_jdata_writepage,
1229 .writepages = gfs2_jdata_writepages,
1230 .readpage = gfs2_readpage,
1231 .readpages = gfs2_readpages,
1232 .write_begin = gfs2_write_begin,
1233 .write_end = gfs2_write_end,
1234 .set_page_dirty = gfs2_set_page_dirty,
1235 .bmap = gfs2_bmap,
1236 .invalidatepage = gfs2_invalidatepage,
1237 .releasepage = gfs2_releasepage,
1238 .is_partially_uptodate = block_is_partially_uptodate,
1239 .error_remove_page = generic_error_remove_page,
1242 void gfs2_set_aops(struct inode *inode)
1244 struct gfs2_inode *ip = GFS2_I(inode);
1246 if (gfs2_is_writeback(ip))
1247 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1248 else if (gfs2_is_ordered(ip))
1249 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1250 else if (gfs2_is_jdata(ip))
1251 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1252 else
1253 BUG();