x86/mm/pat: Don't report PAT on CPUs that don't support it
[linux/fpc-iii.git] / fs / gfs2 / aops.c
blobed7a2e252ad802bf587006b00939696ea2cbe9eb
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 to)
44 struct buffer_head *head = page_buffers(page);
45 unsigned int bsize = head->b_size;
46 struct buffer_head *bh;
47 unsigned int start, end;
49 for (bh = head, start = 0; bh != head || !start;
50 bh = bh->b_this_page, start = end) {
51 end = start + bsize;
52 if (end <= from || start >= to)
53 continue;
54 if (gfs2_is_jdata(ip))
55 set_buffer_uptodate(bh);
56 gfs2_trans_add_data(ip->i_gl, bh);
60 /**
61 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
62 * @inode: The inode
63 * @lblock: The block number to look up
64 * @bh_result: The buffer head to return the result in
65 * @create: Non-zero if we may add block to the file
67 * Returns: errno
70 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
71 struct buffer_head *bh_result, int create)
73 int error;
75 error = gfs2_block_map(inode, lblock, bh_result, 0);
76 if (error)
77 return error;
78 if (!buffer_mapped(bh_result))
79 return -EIO;
80 return 0;
83 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
84 struct buffer_head *bh_result, int create)
86 return gfs2_block_map(inode, lblock, bh_result, 0);
89 /**
90 * gfs2_writepage_common - Common bits of writepage
91 * @page: The page to be written
92 * @wbc: The writeback control
94 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
97 static int gfs2_writepage_common(struct page *page,
98 struct writeback_control *wbc)
100 struct inode *inode = page->mapping->host;
101 struct gfs2_inode *ip = GFS2_I(inode);
102 struct gfs2_sbd *sdp = GFS2_SB(inode);
103 loff_t i_size = i_size_read(inode);
104 pgoff_t end_index = i_size >> PAGE_SHIFT;
105 unsigned offset;
107 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
108 goto out;
109 if (current->journal_info)
110 goto redirty;
111 /* Is the page fully outside i_size? (truncate in progress) */
112 offset = i_size & (PAGE_SIZE-1);
113 if (page->index > end_index || (page->index == end_index && !offset)) {
114 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
115 goto out;
117 return 1;
118 redirty:
119 redirty_page_for_writepage(wbc, page);
120 out:
121 unlock_page(page);
122 return 0;
126 * gfs2_writepage - Write page for writeback mappings
127 * @page: The page
128 * @wbc: The writeback control
132 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
134 int ret;
136 ret = gfs2_writepage_common(page, wbc);
137 if (ret <= 0)
138 return ret;
140 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
143 /* This is the same as calling block_write_full_page, but it also
144 * writes pages outside of i_size
146 static int gfs2_write_full_page(struct page *page, get_block_t *get_block,
147 struct writeback_control *wbc)
149 struct inode * const inode = page->mapping->host;
150 loff_t i_size = i_size_read(inode);
151 const pgoff_t end_index = i_size >> PAGE_SHIFT;
152 unsigned offset;
155 * The page straddles i_size. It must be zeroed out on each and every
156 * writepage invocation because it may be mmapped. "A file is mapped
157 * in multiples of the page size. For a file that is not a multiple of
158 * the page size, the remaining memory is zeroed when mapped, and
159 * writes to that region are not written out to the file."
161 offset = i_size & (PAGE_SIZE-1);
162 if (page->index == end_index && offset)
163 zero_user_segment(page, offset, PAGE_SIZE);
165 return __block_write_full_page(inode, page, get_block, wbc,
166 end_buffer_async_write);
170 * __gfs2_jdata_writepage - The core of jdata writepage
171 * @page: The page to write
172 * @wbc: The writeback control
174 * This is shared between writepage and writepages and implements the
175 * core of the writepage operation. If a transaction is required then
176 * PageChecked will have been set and the transaction will have
177 * already been started before this is called.
180 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
182 struct inode *inode = page->mapping->host;
183 struct gfs2_inode *ip = GFS2_I(inode);
184 struct gfs2_sbd *sdp = GFS2_SB(inode);
186 if (PageChecked(page)) {
187 ClearPageChecked(page);
188 if (!page_has_buffers(page)) {
189 create_empty_buffers(page, inode->i_sb->s_blocksize,
190 BIT(BH_Dirty)|BIT(BH_Uptodate));
192 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
194 return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
198 * gfs2_jdata_writepage - Write complete page
199 * @page: Page to write
200 * @wbc: The writeback control
202 * Returns: errno
206 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
208 struct inode *inode = page->mapping->host;
209 struct gfs2_inode *ip = GFS2_I(inode);
210 struct gfs2_sbd *sdp = GFS2_SB(inode);
211 int ret;
213 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
214 goto out;
215 if (PageChecked(page) || current->journal_info)
216 goto out_ignore;
217 ret = __gfs2_jdata_writepage(page, wbc);
218 return ret;
220 out_ignore:
221 redirty_page_for_writepage(wbc, page);
222 out:
223 unlock_page(page);
224 return 0;
228 * gfs2_writepages - Write a bunch of dirty pages back to disk
229 * @mapping: The mapping to write
230 * @wbc: Write-back control
232 * Used for both ordered and writeback modes.
234 static int gfs2_writepages(struct address_space *mapping,
235 struct writeback_control *wbc)
237 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
241 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
242 * @mapping: The mapping
243 * @wbc: The writeback control
244 * @pvec: The vector of pages
245 * @nr_pages: The number of pages to write
246 * @end: End position
247 * @done_index: Page index
249 * Returns: non-zero if loop should terminate, zero otherwise
252 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
253 struct writeback_control *wbc,
254 struct pagevec *pvec,
255 int nr_pages, pgoff_t end,
256 pgoff_t *done_index)
258 struct inode *inode = mapping->host;
259 struct gfs2_sbd *sdp = GFS2_SB(inode);
260 unsigned nrblocks = nr_pages * (PAGE_SIZE/inode->i_sb->s_blocksize);
261 int i;
262 int ret;
264 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
265 if (ret < 0)
266 return ret;
268 for(i = 0; i < nr_pages; i++) {
269 struct page *page = pvec->pages[i];
272 * At this point, the page may be truncated or
273 * invalidated (changing page->mapping to NULL), or
274 * even swizzled back from swapper_space to tmpfs file
275 * mapping. However, page->index will not change
276 * because we have a reference on the page.
278 if (page->index > end) {
280 * can't be range_cyclic (1st pass) because
281 * end == -1 in that case.
283 ret = 1;
284 break;
287 *done_index = page->index;
289 lock_page(page);
291 if (unlikely(page->mapping != mapping)) {
292 continue_unlock:
293 unlock_page(page);
294 continue;
297 if (!PageDirty(page)) {
298 /* someone wrote it for us */
299 goto continue_unlock;
302 if (PageWriteback(page)) {
303 if (wbc->sync_mode != WB_SYNC_NONE)
304 wait_on_page_writeback(page);
305 else
306 goto continue_unlock;
309 BUG_ON(PageWriteback(page));
310 if (!clear_page_dirty_for_io(page))
311 goto continue_unlock;
313 trace_wbc_writepage(wbc, inode_to_bdi(inode));
315 ret = __gfs2_jdata_writepage(page, wbc);
316 if (unlikely(ret)) {
317 if (ret == AOP_WRITEPAGE_ACTIVATE) {
318 unlock_page(page);
319 ret = 0;
320 } else {
323 * done_index is set past this page,
324 * so media errors will not choke
325 * background writeout for the entire
326 * file. This has consequences for
327 * range_cyclic semantics (ie. it may
328 * not be suitable for data integrity
329 * writeout).
331 *done_index = page->index + 1;
332 ret = 1;
333 break;
338 * We stop writing back only if we are not doing
339 * integrity sync. In case of integrity sync we have to
340 * keep going until we have written all the pages
341 * we tagged for writeback prior to entering this loop.
343 if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
344 ret = 1;
345 break;
349 gfs2_trans_end(sdp);
350 return ret;
354 * gfs2_write_cache_jdata - Like write_cache_pages but different
355 * @mapping: The mapping to write
356 * @wbc: The writeback control
358 * The reason that we use our own function here is that we need to
359 * start transactions before we grab page locks. This allows us
360 * to get the ordering right.
363 static int gfs2_write_cache_jdata(struct address_space *mapping,
364 struct writeback_control *wbc)
366 int ret = 0;
367 int done = 0;
368 struct pagevec pvec;
369 int nr_pages;
370 pgoff_t uninitialized_var(writeback_index);
371 pgoff_t index;
372 pgoff_t end;
373 pgoff_t done_index;
374 int cycled;
375 int range_whole = 0;
376 int tag;
378 pagevec_init(&pvec, 0);
379 if (wbc->range_cyclic) {
380 writeback_index = mapping->writeback_index; /* prev offset */
381 index = writeback_index;
382 if (index == 0)
383 cycled = 1;
384 else
385 cycled = 0;
386 end = -1;
387 } else {
388 index = wbc->range_start >> PAGE_SHIFT;
389 end = wbc->range_end >> PAGE_SHIFT;
390 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
391 range_whole = 1;
392 cycled = 1; /* ignore range_cyclic tests */
394 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
395 tag = PAGECACHE_TAG_TOWRITE;
396 else
397 tag = PAGECACHE_TAG_DIRTY;
399 retry:
400 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
401 tag_pages_for_writeback(mapping, index, end);
402 done_index = index;
403 while (!done && (index <= end)) {
404 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
405 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
406 if (nr_pages == 0)
407 break;
409 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end, &done_index);
410 if (ret)
411 done = 1;
412 if (ret > 0)
413 ret = 0;
414 pagevec_release(&pvec);
415 cond_resched();
418 if (!cycled && !done) {
420 * range_cyclic:
421 * We hit the last page and there is more work to be done: wrap
422 * back to the start of the file
424 cycled = 1;
425 index = 0;
426 end = writeback_index - 1;
427 goto retry;
430 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
431 mapping->writeback_index = done_index;
433 return ret;
438 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
439 * @mapping: The mapping to write
440 * @wbc: The writeback control
444 static int gfs2_jdata_writepages(struct address_space *mapping,
445 struct writeback_control *wbc)
447 struct gfs2_inode *ip = GFS2_I(mapping->host);
448 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
449 int ret;
451 ret = gfs2_write_cache_jdata(mapping, wbc);
452 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
453 gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
454 ret = gfs2_write_cache_jdata(mapping, wbc);
456 return ret;
460 * stuffed_readpage - Fill in a Linux page with stuffed file data
461 * @ip: the inode
462 * @page: the page
464 * Returns: errno
467 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
469 struct buffer_head *dibh;
470 u64 dsize = i_size_read(&ip->i_inode);
471 void *kaddr;
472 int error;
475 * Due to the order of unstuffing files and ->fault(), we can be
476 * asked for a zero page in the case of a stuffed file being extended,
477 * so we need to supply one here. It doesn't happen often.
479 if (unlikely(page->index)) {
480 zero_user(page, 0, PAGE_SIZE);
481 SetPageUptodate(page);
482 return 0;
485 error = gfs2_meta_inode_buffer(ip, &dibh);
486 if (error)
487 return error;
489 kaddr = kmap_atomic(page);
490 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
491 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
492 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
493 memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
494 kunmap_atomic(kaddr);
495 flush_dcache_page(page);
496 brelse(dibh);
497 SetPageUptodate(page);
499 return 0;
504 * __gfs2_readpage - readpage
505 * @file: The file to read a page for
506 * @page: The page to read
508 * This is the core of gfs2's readpage. Its used by the internal file
509 * reading code as in that case we already hold the glock. Also its
510 * called by gfs2_readpage() once the required lock has been granted.
514 static int __gfs2_readpage(void *file, struct page *page)
516 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
517 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
518 int error;
520 if (gfs2_is_stuffed(ip)) {
521 error = stuffed_readpage(ip, page);
522 unlock_page(page);
523 } else {
524 error = mpage_readpage(page, gfs2_block_map);
527 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
528 return -EIO;
530 return error;
534 * gfs2_readpage - read a page of a file
535 * @file: The file to read
536 * @page: The page of the file
538 * This deals with the locking required. We have to unlock and
539 * relock the page in order to get the locking in the right
540 * order.
543 static int gfs2_readpage(struct file *file, struct page *page)
545 struct address_space *mapping = page->mapping;
546 struct gfs2_inode *ip = GFS2_I(mapping->host);
547 struct gfs2_holder gh;
548 int error;
550 unlock_page(page);
551 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
552 error = gfs2_glock_nq(&gh);
553 if (unlikely(error))
554 goto out;
555 error = AOP_TRUNCATED_PAGE;
556 lock_page(page);
557 if (page->mapping == mapping && !PageUptodate(page))
558 error = __gfs2_readpage(file, page);
559 else
560 unlock_page(page);
561 gfs2_glock_dq(&gh);
562 out:
563 gfs2_holder_uninit(&gh);
564 if (error && error != AOP_TRUNCATED_PAGE)
565 lock_page(page);
566 return error;
570 * gfs2_internal_read - read an internal file
571 * @ip: The gfs2 inode
572 * @buf: The buffer to fill
573 * @pos: The file position
574 * @size: The amount to read
578 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
579 unsigned size)
581 struct address_space *mapping = ip->i_inode.i_mapping;
582 unsigned long index = *pos / PAGE_SIZE;
583 unsigned offset = *pos & (PAGE_SIZE - 1);
584 unsigned copied = 0;
585 unsigned amt;
586 struct page *page;
587 void *p;
589 do {
590 amt = size - copied;
591 if (offset + size > PAGE_SIZE)
592 amt = PAGE_SIZE - offset;
593 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
594 if (IS_ERR(page))
595 return PTR_ERR(page);
596 p = kmap_atomic(page);
597 memcpy(buf + copied, p + offset, amt);
598 kunmap_atomic(p);
599 put_page(page);
600 copied += amt;
601 index++;
602 offset = 0;
603 } while(copied < size);
604 (*pos) += size;
605 return size;
609 * gfs2_readpages - Read a bunch of pages at once
610 * @file: The file to read from
611 * @mapping: Address space info
612 * @pages: List of pages to read
613 * @nr_pages: Number of pages to read
615 * Some notes:
616 * 1. This is only for readahead, so we can simply ignore any things
617 * which are slightly inconvenient (such as locking conflicts between
618 * the page lock and the glock) and return having done no I/O. Its
619 * obviously not something we'd want to do on too regular a basis.
620 * Any I/O we ignore at this time will be done via readpage later.
621 * 2. We don't handle stuffed files here we let readpage do the honours.
622 * 3. mpage_readpages() does most of the heavy lifting in the common case.
623 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
626 static int gfs2_readpages(struct file *file, struct address_space *mapping,
627 struct list_head *pages, unsigned nr_pages)
629 struct inode *inode = mapping->host;
630 struct gfs2_inode *ip = GFS2_I(inode);
631 struct gfs2_sbd *sdp = GFS2_SB(inode);
632 struct gfs2_holder gh;
633 int ret;
635 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
636 ret = gfs2_glock_nq(&gh);
637 if (unlikely(ret))
638 goto out_uninit;
639 if (!gfs2_is_stuffed(ip))
640 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
641 gfs2_glock_dq(&gh);
642 out_uninit:
643 gfs2_holder_uninit(&gh);
644 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
645 ret = -EIO;
646 return ret;
650 * gfs2_write_begin - Begin to write to a file
651 * @file: The file to write to
652 * @mapping: The mapping in which to write
653 * @pos: The file offset at which to start writing
654 * @len: Length of the write
655 * @flags: Various flags
656 * @pagep: Pointer to return the page
657 * @fsdata: Pointer to return fs data (unused by GFS2)
659 * Returns: errno
662 static int gfs2_write_begin(struct file *file, struct address_space *mapping,
663 loff_t pos, unsigned len, unsigned flags,
664 struct page **pagep, void **fsdata)
666 struct gfs2_inode *ip = GFS2_I(mapping->host);
667 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
668 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
669 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
670 unsigned requested = 0;
671 int alloc_required;
672 int error = 0;
673 pgoff_t index = pos >> PAGE_SHIFT;
674 unsigned from = pos & (PAGE_SIZE - 1);
675 struct page *page;
677 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
678 error = gfs2_glock_nq(&ip->i_gh);
679 if (unlikely(error))
680 goto out_uninit;
681 if (&ip->i_inode == sdp->sd_rindex) {
682 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
683 GL_NOCACHE, &m_ip->i_gh);
684 if (unlikely(error)) {
685 gfs2_glock_dq(&ip->i_gh);
686 goto out_uninit;
690 alloc_required = gfs2_write_alloc_required(ip, pos, len);
692 if (alloc_required || gfs2_is_jdata(ip))
693 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
695 if (alloc_required) {
696 struct gfs2_alloc_parms ap = { .aflags = 0, };
697 requested = data_blocks + ind_blocks;
698 ap.target = requested;
699 error = gfs2_quota_lock_check(ip, &ap);
700 if (error)
701 goto out_unlock;
703 error = gfs2_inplace_reserve(ip, &ap);
704 if (error)
705 goto out_qunlock;
708 rblocks = RES_DINODE + ind_blocks;
709 if (gfs2_is_jdata(ip))
710 rblocks += data_blocks ? data_blocks : 1;
711 if (ind_blocks || data_blocks)
712 rblocks += RES_STATFS + RES_QUOTA;
713 if (&ip->i_inode == sdp->sd_rindex)
714 rblocks += 2 * RES_STATFS;
715 if (alloc_required)
716 rblocks += gfs2_rg_blocks(ip, requested);
718 error = gfs2_trans_begin(sdp, rblocks,
719 PAGE_SIZE/sdp->sd_sb.sb_bsize);
720 if (error)
721 goto out_trans_fail;
723 error = -ENOMEM;
724 flags |= AOP_FLAG_NOFS;
725 page = grab_cache_page_write_begin(mapping, index, flags);
726 *pagep = page;
727 if (unlikely(!page))
728 goto out_endtrans;
730 if (gfs2_is_stuffed(ip)) {
731 error = 0;
732 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
733 error = gfs2_unstuff_dinode(ip, page);
734 if (error == 0)
735 goto prepare_write;
736 } else if (!PageUptodate(page)) {
737 error = stuffed_readpage(ip, page);
739 goto out;
742 prepare_write:
743 error = __block_write_begin(page, from, len, gfs2_block_map);
744 out:
745 if (error == 0)
746 return 0;
748 unlock_page(page);
749 put_page(page);
751 gfs2_trans_end(sdp);
752 if (pos + len > ip->i_inode.i_size)
753 gfs2_trim_blocks(&ip->i_inode);
754 goto out_trans_fail;
756 out_endtrans:
757 gfs2_trans_end(sdp);
758 out_trans_fail:
759 if (alloc_required) {
760 gfs2_inplace_release(ip);
761 out_qunlock:
762 gfs2_quota_unlock(ip);
764 out_unlock:
765 if (&ip->i_inode == sdp->sd_rindex) {
766 gfs2_glock_dq(&m_ip->i_gh);
767 gfs2_holder_uninit(&m_ip->i_gh);
769 gfs2_glock_dq(&ip->i_gh);
770 out_uninit:
771 gfs2_holder_uninit(&ip->i_gh);
772 return error;
776 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
777 * @inode: the rindex inode
779 static void adjust_fs_space(struct inode *inode)
781 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
782 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
783 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
784 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
785 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
786 struct buffer_head *m_bh, *l_bh;
787 u64 fs_total, new_free;
789 /* Total up the file system space, according to the latest rindex. */
790 fs_total = gfs2_ri_total(sdp);
791 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
792 return;
794 spin_lock(&sdp->sd_statfs_spin);
795 gfs2_statfs_change_in(m_sc, m_bh->b_data +
796 sizeof(struct gfs2_dinode));
797 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
798 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
799 else
800 new_free = 0;
801 spin_unlock(&sdp->sd_statfs_spin);
802 fs_warn(sdp, "File system extended by %llu blocks.\n",
803 (unsigned long long)new_free);
804 gfs2_statfs_change(sdp, new_free, new_free, 0);
806 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
807 goto out;
808 update_statfs(sdp, m_bh, l_bh);
809 brelse(l_bh);
810 out:
811 brelse(m_bh);
815 * gfs2_stuffed_write_end - Write end for stuffed files
816 * @inode: The inode
817 * @dibh: The buffer_head containing the on-disk inode
818 * @pos: The file position
819 * @len: The length of the write
820 * @copied: How much was actually copied by the VFS
821 * @page: The page
823 * This copies the data from the page into the inode block after
824 * the inode data structure itself.
826 * Returns: errno
828 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
829 loff_t pos, unsigned len, unsigned copied,
830 struct page *page)
832 struct gfs2_inode *ip = GFS2_I(inode);
833 struct gfs2_sbd *sdp = GFS2_SB(inode);
834 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
835 u64 to = pos + copied;
836 void *kaddr;
837 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
839 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
840 kaddr = kmap_atomic(page);
841 memcpy(buf + pos, kaddr + pos, copied);
842 flush_dcache_page(page);
843 kunmap_atomic(kaddr);
845 WARN_ON(!PageUptodate(page));
846 unlock_page(page);
847 put_page(page);
849 if (copied) {
850 if (inode->i_size < to)
851 i_size_write(inode, to);
852 mark_inode_dirty(inode);
855 if (inode == sdp->sd_rindex) {
856 adjust_fs_space(inode);
857 sdp->sd_rindex_uptodate = 0;
860 brelse(dibh);
861 gfs2_trans_end(sdp);
862 if (inode == sdp->sd_rindex) {
863 gfs2_glock_dq(&m_ip->i_gh);
864 gfs2_holder_uninit(&m_ip->i_gh);
866 gfs2_glock_dq(&ip->i_gh);
867 gfs2_holder_uninit(&ip->i_gh);
868 return copied;
872 * gfs2_write_end
873 * @file: The file to write to
874 * @mapping: The address space to write to
875 * @pos: The file position
876 * @len: The length of the data
877 * @copied: How much was actually copied by the VFS
878 * @page: The page that has been written
879 * @fsdata: The fsdata (unused in GFS2)
881 * The main write_end function for GFS2. We have a separate one for
882 * stuffed files as they are slightly different, otherwise we just
883 * put our locking around the VFS provided functions.
885 * Returns: errno
888 static int gfs2_write_end(struct file *file, struct address_space *mapping,
889 loff_t pos, unsigned len, unsigned copied,
890 struct page *page, void *fsdata)
892 struct inode *inode = page->mapping->host;
893 struct gfs2_inode *ip = GFS2_I(inode);
894 struct gfs2_sbd *sdp = GFS2_SB(inode);
895 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
896 struct buffer_head *dibh;
897 unsigned int from = pos & (PAGE_SIZE - 1);
898 unsigned int to = from + len;
899 int ret;
900 struct gfs2_trans *tr = current->journal_info;
901 BUG_ON(!tr);
903 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
905 ret = gfs2_meta_inode_buffer(ip, &dibh);
906 if (unlikely(ret)) {
907 unlock_page(page);
908 put_page(page);
909 goto failed;
912 if (gfs2_is_stuffed(ip))
913 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
915 if (!gfs2_is_writeback(ip))
916 gfs2_page_add_databufs(ip, page, from, to);
918 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
919 if (tr->tr_num_buf_new)
920 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
921 else
922 gfs2_trans_add_meta(ip->i_gl, dibh);
925 if (inode == sdp->sd_rindex) {
926 adjust_fs_space(inode);
927 sdp->sd_rindex_uptodate = 0;
930 brelse(dibh);
931 failed:
932 gfs2_trans_end(sdp);
933 gfs2_inplace_release(ip);
934 if (ip->i_qadata && ip->i_qadata->qa_qd_num)
935 gfs2_quota_unlock(ip);
936 if (inode == sdp->sd_rindex) {
937 gfs2_glock_dq(&m_ip->i_gh);
938 gfs2_holder_uninit(&m_ip->i_gh);
940 gfs2_glock_dq(&ip->i_gh);
941 gfs2_holder_uninit(&ip->i_gh);
942 return ret;
946 * gfs2_set_page_dirty - Page dirtying function
947 * @page: The page to dirty
949 * Returns: 1 if it dirtyed the page, or 0 otherwise
952 static int gfs2_set_page_dirty(struct page *page)
954 SetPageChecked(page);
955 return __set_page_dirty_buffers(page);
959 * gfs2_bmap - Block map function
960 * @mapping: Address space info
961 * @lblock: The block to map
963 * Returns: The disk address for the block or 0 on hole or error
966 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
968 struct gfs2_inode *ip = GFS2_I(mapping->host);
969 struct gfs2_holder i_gh;
970 sector_t dblock = 0;
971 int error;
973 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
974 if (error)
975 return 0;
977 if (!gfs2_is_stuffed(ip))
978 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
980 gfs2_glock_dq_uninit(&i_gh);
982 return dblock;
985 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
987 struct gfs2_bufdata *bd;
989 lock_buffer(bh);
990 gfs2_log_lock(sdp);
991 clear_buffer_dirty(bh);
992 bd = bh->b_private;
993 if (bd) {
994 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
995 list_del_init(&bd->bd_list);
996 else
997 gfs2_remove_from_journal(bh, REMOVE_JDATA);
999 bh->b_bdev = NULL;
1000 clear_buffer_mapped(bh);
1001 clear_buffer_req(bh);
1002 clear_buffer_new(bh);
1003 gfs2_log_unlock(sdp);
1004 unlock_buffer(bh);
1007 static void gfs2_invalidatepage(struct page *page, unsigned int offset,
1008 unsigned int length)
1010 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
1011 unsigned int stop = offset + length;
1012 int partial_page = (offset || length < PAGE_SIZE);
1013 struct buffer_head *bh, *head;
1014 unsigned long pos = 0;
1016 BUG_ON(!PageLocked(page));
1017 if (!partial_page)
1018 ClearPageChecked(page);
1019 if (!page_has_buffers(page))
1020 goto out;
1022 bh = head = page_buffers(page);
1023 do {
1024 if (pos + bh->b_size > stop)
1025 return;
1027 if (offset <= pos)
1028 gfs2_discard(sdp, bh);
1029 pos += bh->b_size;
1030 bh = bh->b_this_page;
1031 } while (bh != head);
1032 out:
1033 if (!partial_page)
1034 try_to_release_page(page, 0);
1038 * gfs2_ok_for_dio - check that dio is valid on this file
1039 * @ip: The inode
1040 * @offset: The offset at which we are reading or writing
1042 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
1043 * 1 (to accept the i/o request)
1045 static int gfs2_ok_for_dio(struct gfs2_inode *ip, loff_t offset)
1048 * Should we return an error here? I can't see that O_DIRECT for
1049 * a stuffed file makes any sense. For now we'll silently fall
1050 * back to buffered I/O
1052 if (gfs2_is_stuffed(ip))
1053 return 0;
1055 if (offset >= i_size_read(&ip->i_inode))
1056 return 0;
1057 return 1;
1062 static ssize_t gfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1064 struct file *file = iocb->ki_filp;
1065 struct inode *inode = file->f_mapping->host;
1066 struct address_space *mapping = inode->i_mapping;
1067 struct gfs2_inode *ip = GFS2_I(inode);
1068 loff_t offset = iocb->ki_pos;
1069 struct gfs2_holder gh;
1070 int rv;
1073 * Deferred lock, even if its a write, since we do no allocation
1074 * on this path. All we need change is atime, and this lock mode
1075 * ensures that other nodes have flushed their buffered read caches
1076 * (i.e. their page cache entries for this inode). We do not,
1077 * unfortunately have the option of only flushing a range like
1078 * the VFS does.
1080 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1081 rv = gfs2_glock_nq(&gh);
1082 if (rv)
1083 goto out_uninit;
1084 rv = gfs2_ok_for_dio(ip, offset);
1085 if (rv != 1)
1086 goto out; /* dio not valid, fall back to buffered i/o */
1089 * Now since we are holding a deferred (CW) lock at this point, you
1090 * might be wondering why this is ever needed. There is a case however
1091 * where we've granted a deferred local lock against a cached exclusive
1092 * glock. That is ok provided all granted local locks are deferred, but
1093 * it also means that it is possible to encounter pages which are
1094 * cached and possibly also mapped. So here we check for that and sort
1095 * them out ahead of the dio. The glock state machine will take care of
1096 * everything else.
1098 * If in fact the cached glock state (gl->gl_state) is deferred (CW) in
1099 * the first place, mapping->nr_pages will always be zero.
1101 if (mapping->nrpages) {
1102 loff_t lstart = offset & ~(PAGE_SIZE - 1);
1103 loff_t len = iov_iter_count(iter);
1104 loff_t end = PAGE_ALIGN(offset + len) - 1;
1106 rv = 0;
1107 if (len == 0)
1108 goto out;
1109 if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))
1110 unmap_shared_mapping_range(ip->i_inode.i_mapping, offset, len);
1111 rv = filemap_write_and_wait_range(mapping, lstart, end);
1112 if (rv)
1113 goto out;
1114 if (iov_iter_rw(iter) == WRITE)
1115 truncate_inode_pages_range(mapping, lstart, end);
1118 rv = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
1119 gfs2_get_block_direct, NULL, NULL, 0);
1120 out:
1121 gfs2_glock_dq(&gh);
1122 out_uninit:
1123 gfs2_holder_uninit(&gh);
1124 return rv;
1128 * gfs2_releasepage - free the metadata associated with a page
1129 * @page: the page that's being released
1130 * @gfp_mask: passed from Linux VFS, ignored by us
1132 * Call try_to_free_buffers() if the buffers in this page can be
1133 * released.
1135 * Returns: 0
1138 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1140 struct address_space *mapping = page->mapping;
1141 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1142 struct buffer_head *bh, *head;
1143 struct gfs2_bufdata *bd;
1145 if (!page_has_buffers(page))
1146 return 0;
1149 * From xfs_vm_releasepage: mm accommodates an old ext3 case where
1150 * clean pages might not have had the dirty bit cleared. Thus, it can
1151 * send actual dirty pages to ->releasepage() via shrink_active_list().
1153 * As a workaround, we skip pages that contain dirty buffers below.
1154 * Once ->releasepage isn't called on dirty pages anymore, we can warn
1155 * on dirty buffers like we used to here again.
1158 gfs2_log_lock(sdp);
1159 spin_lock(&sdp->sd_ail_lock);
1160 head = bh = page_buffers(page);
1161 do {
1162 if (atomic_read(&bh->b_count))
1163 goto cannot_release;
1164 bd = bh->b_private;
1165 if (bd && bd->bd_tr)
1166 goto cannot_release;
1167 if (buffer_dirty(bh) || WARN_ON(buffer_pinned(bh)))
1168 goto cannot_release;
1169 bh = bh->b_this_page;
1170 } while(bh != head);
1171 spin_unlock(&sdp->sd_ail_lock);
1173 head = bh = page_buffers(page);
1174 do {
1175 bd = bh->b_private;
1176 if (bd) {
1177 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1178 if (!list_empty(&bd->bd_list))
1179 list_del_init(&bd->bd_list);
1180 bd->bd_bh = NULL;
1181 bh->b_private = NULL;
1182 kmem_cache_free(gfs2_bufdata_cachep, bd);
1185 bh = bh->b_this_page;
1186 } while (bh != head);
1187 gfs2_log_unlock(sdp);
1189 return try_to_free_buffers(page);
1191 cannot_release:
1192 spin_unlock(&sdp->sd_ail_lock);
1193 gfs2_log_unlock(sdp);
1194 return 0;
1197 static const struct address_space_operations gfs2_writeback_aops = {
1198 .writepage = gfs2_writepage,
1199 .writepages = gfs2_writepages,
1200 .readpage = gfs2_readpage,
1201 .readpages = gfs2_readpages,
1202 .write_begin = gfs2_write_begin,
1203 .write_end = gfs2_write_end,
1204 .bmap = gfs2_bmap,
1205 .invalidatepage = gfs2_invalidatepage,
1206 .releasepage = gfs2_releasepage,
1207 .direct_IO = gfs2_direct_IO,
1208 .migratepage = buffer_migrate_page,
1209 .is_partially_uptodate = block_is_partially_uptodate,
1210 .error_remove_page = generic_error_remove_page,
1213 static const struct address_space_operations gfs2_ordered_aops = {
1214 .writepage = gfs2_writepage,
1215 .writepages = gfs2_writepages,
1216 .readpage = gfs2_readpage,
1217 .readpages = gfs2_readpages,
1218 .write_begin = gfs2_write_begin,
1219 .write_end = gfs2_write_end,
1220 .set_page_dirty = gfs2_set_page_dirty,
1221 .bmap = gfs2_bmap,
1222 .invalidatepage = gfs2_invalidatepage,
1223 .releasepage = gfs2_releasepage,
1224 .direct_IO = gfs2_direct_IO,
1225 .migratepage = buffer_migrate_page,
1226 .is_partially_uptodate = block_is_partially_uptodate,
1227 .error_remove_page = generic_error_remove_page,
1230 static const struct address_space_operations gfs2_jdata_aops = {
1231 .writepage = gfs2_jdata_writepage,
1232 .writepages = gfs2_jdata_writepages,
1233 .readpage = gfs2_readpage,
1234 .readpages = gfs2_readpages,
1235 .write_begin = gfs2_write_begin,
1236 .write_end = gfs2_write_end,
1237 .set_page_dirty = gfs2_set_page_dirty,
1238 .bmap = gfs2_bmap,
1239 .invalidatepage = gfs2_invalidatepage,
1240 .releasepage = gfs2_releasepage,
1241 .is_partially_uptodate = block_is_partially_uptodate,
1242 .error_remove_page = generic_error_remove_page,
1245 void gfs2_set_aops(struct inode *inode)
1247 struct gfs2_inode *ip = GFS2_I(inode);
1249 if (gfs2_is_writeback(ip))
1250 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1251 else if (gfs2_is_ordered(ip))
1252 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1253 else if (gfs2_is_jdata(ip))
1254 inode->i_mapping->a_ops = &gfs2_jdata_aops;
1255 else
1256 BUG();