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.
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>
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>
40 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
41 unsigned int from, unsigned int to)
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;
48 for (bh = head, start = 0; bh != head || !start;
49 bh = bh->b_this_page, start = end) {
51 if (end <= from || start >= to)
53 if (gfs2_is_jdata(ip))
54 set_buffer_uptodate(bh);
55 gfs2_trans_add_data(ip->i_gl, bh);
60 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
62 * @lblock: The block number to look up
63 * @bh_result: The buffer head to return the result in
64 * @create: Non-zero if we may add block to the file
69 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
70 struct buffer_head *bh_result, int create)
74 error = gfs2_block_map(inode, lblock, bh_result, 0);
77 if (!buffer_mapped(bh_result))
82 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
83 struct buffer_head *bh_result, int create)
85 return gfs2_block_map(inode, lblock, bh_result, 0);
89 * gfs2_writepage_common - Common bits of writepage
90 * @page: The page to be written
91 * @wbc: The writeback control
93 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
96 static int gfs2_writepage_common(struct page *page,
97 struct writeback_control *wbc)
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;
106 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
108 if (current->journal_info)
110 /* Is the page fully outside i_size? (truncate in progress) */
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);
118 redirty_page_for_writepage(wbc, page);
125 * gfs2_writeback_writepage - Write page for writeback mappings
127 * @wbc: The writeback control
131 static int gfs2_writeback_writepage(struct page *page,
132 struct writeback_control *wbc)
136 ret = gfs2_writepage_common(page, wbc);
140 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
144 * gfs2_ordered_writepage - Write page for ordered data files
145 * @page: The page to write
146 * @wbc: The writeback control
150 static int gfs2_ordered_writepage(struct page *page,
151 struct writeback_control *wbc)
153 struct inode *inode = page->mapping->host;
154 struct gfs2_inode *ip = GFS2_I(inode);
157 ret = gfs2_writepage_common(page, wbc);
161 if (!page_has_buffers(page)) {
162 create_empty_buffers(page, inode->i_sb->s_blocksize,
163 (1 << BH_Dirty)|(1 << BH_Uptodate));
165 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1);
166 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
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 (1 << BH_Dirty)|(1 << BH_Uptodate));
192 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
194 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
198 * gfs2_jdata_writepage - Write complete page
199 * @page: Page to write
205 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
207 struct inode *inode = page->mapping->host;
208 struct gfs2_sbd *sdp = GFS2_SB(inode);
212 if (PageChecked(page)) {
213 if (wbc->sync_mode != WB_SYNC_ALL)
215 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
220 ret = gfs2_writepage_common(page, wbc);
222 ret = __gfs2_jdata_writepage(page, wbc);
228 redirty_page_for_writepage(wbc, page);
234 * gfs2_writepages - Write a bunch of dirty pages back to disk
235 * @mapping: The mapping to write
236 * @wbc: Write-back control
238 * Used for both ordered and writeback modes.
240 static int gfs2_writepages(struct address_space *mapping,
241 struct writeback_control *wbc)
243 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
247 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
248 * @mapping: The mapping
249 * @wbc: The writeback control
250 * @writepage: The writepage function to call for each page
251 * @pvec: The vector of pages
252 * @nr_pages: The number of pages to write
254 * Returns: non-zero if loop should terminate, zero otherwise
257 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
258 struct writeback_control *wbc,
259 struct pagevec *pvec,
260 int nr_pages, pgoff_t end)
262 struct inode *inode = mapping->host;
263 struct gfs2_sbd *sdp = GFS2_SB(inode);
264 loff_t i_size = i_size_read(inode);
265 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
266 unsigned offset = i_size & (PAGE_CACHE_SIZE-1);
267 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
271 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
275 for(i = 0; i < nr_pages; i++) {
276 struct page *page = pvec->pages[i];
280 if (unlikely(page->mapping != mapping)) {
285 if (!wbc->range_cyclic && page->index > end) {
291 if (wbc->sync_mode != WB_SYNC_NONE)
292 wait_on_page_writeback(page);
294 if (PageWriteback(page) ||
295 !clear_page_dirty_for_io(page)) {
300 /* Is the page fully outside i_size? (truncate in progress) */
301 if (page->index > end_index || (page->index == end_index && !offset)) {
302 page->mapping->a_ops->invalidatepage(page, 0,
308 ret = __gfs2_jdata_writepage(page, wbc);
310 if (ret || (--(wbc->nr_to_write) <= 0))
318 * gfs2_write_cache_jdata - Like write_cache_pages but different
319 * @mapping: The mapping to write
320 * @wbc: The writeback control
321 * @writepage: The writepage function to call
322 * @data: The data to pass to writepage
324 * The reason that we use our own function here is that we need to
325 * start transactions before we grab page locks. This allows us
326 * to get the ordering right.
329 static int gfs2_write_cache_jdata(struct address_space *mapping,
330 struct writeback_control *wbc)
341 pagevec_init(&pvec, 0);
342 if (wbc->range_cyclic) {
343 index = mapping->writeback_index; /* Start from prev offset */
346 index = wbc->range_start >> PAGE_CACHE_SHIFT;
347 end = wbc->range_end >> PAGE_CACHE_SHIFT;
348 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
354 while (!done && (index <= end) &&
355 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
357 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
359 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end);
365 pagevec_release(&pvec);
369 if (!scanned && !done) {
371 * We hit the last page and there is more work to be done: wrap
372 * back to the start of the file
379 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
380 mapping->writeback_index = index;
386 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
387 * @mapping: The mapping to write
388 * @wbc: The writeback control
392 static int gfs2_jdata_writepages(struct address_space *mapping,
393 struct writeback_control *wbc)
395 struct gfs2_inode *ip = GFS2_I(mapping->host);
396 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
399 ret = gfs2_write_cache_jdata(mapping, wbc);
400 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
401 gfs2_log_flush(sdp, ip->i_gl);
402 ret = gfs2_write_cache_jdata(mapping, wbc);
408 * stuffed_readpage - Fill in a Linux page with stuffed file data
415 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
417 struct buffer_head *dibh;
418 u64 dsize = i_size_read(&ip->i_inode);
423 * Due to the order of unstuffing files and ->fault(), we can be
424 * asked for a zero page in the case of a stuffed file being extended,
425 * so we need to supply one here. It doesn't happen often.
427 if (unlikely(page->index)) {
428 zero_user(page, 0, PAGE_CACHE_SIZE);
429 SetPageUptodate(page);
433 error = gfs2_meta_inode_buffer(ip, &dibh);
437 kaddr = kmap_atomic(page);
438 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
439 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
440 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
441 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
442 kunmap_atomic(kaddr);
443 flush_dcache_page(page);
445 SetPageUptodate(page);
452 * __gfs2_readpage - readpage
453 * @file: The file to read a page for
454 * @page: The page to read
456 * This is the core of gfs2's readpage. Its used by the internal file
457 * reading code as in that case we already hold the glock. Also its
458 * called by gfs2_readpage() once the required lock has been granted.
462 static int __gfs2_readpage(void *file, struct page *page)
464 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
465 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
468 if (gfs2_is_stuffed(ip)) {
469 error = stuffed_readpage(ip, page);
472 error = mpage_readpage(page, gfs2_block_map);
475 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
482 * gfs2_readpage - read a page of a file
483 * @file: The file to read
484 * @page: The page of the file
486 * This deals with the locking required. We have to unlock and
487 * relock the page in order to get the locking in the right
491 static int gfs2_readpage(struct file *file, struct page *page)
493 struct address_space *mapping = page->mapping;
494 struct gfs2_inode *ip = GFS2_I(mapping->host);
495 struct gfs2_holder gh;
499 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
500 error = gfs2_glock_nq(&gh);
503 error = AOP_TRUNCATED_PAGE;
505 if (page->mapping == mapping && !PageUptodate(page))
506 error = __gfs2_readpage(file, page);
511 gfs2_holder_uninit(&gh);
512 if (error && error != AOP_TRUNCATED_PAGE)
518 * gfs2_internal_read - read an internal file
519 * @ip: The gfs2 inode
520 * @buf: The buffer to fill
521 * @pos: The file position
522 * @size: The amount to read
526 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
529 struct address_space *mapping = ip->i_inode.i_mapping;
530 unsigned long index = *pos / PAGE_CACHE_SIZE;
531 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
539 if (offset + size > PAGE_CACHE_SIZE)
540 amt = PAGE_CACHE_SIZE - offset;
541 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
543 return PTR_ERR(page);
544 p = kmap_atomic(page);
545 memcpy(buf + copied, p + offset, amt);
547 mark_page_accessed(page);
548 page_cache_release(page);
552 } while(copied < size);
558 * gfs2_readpages - Read a bunch of pages at once
561 * 1. This is only for readahead, so we can simply ignore any things
562 * which are slightly inconvenient (such as locking conflicts between
563 * the page lock and the glock) and return having done no I/O. Its
564 * obviously not something we'd want to do on too regular a basis.
565 * Any I/O we ignore at this time will be done via readpage later.
566 * 2. We don't handle stuffed files here we let readpage do the honours.
567 * 3. mpage_readpages() does most of the heavy lifting in the common case.
568 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
571 static int gfs2_readpages(struct file *file, struct address_space *mapping,
572 struct list_head *pages, unsigned nr_pages)
574 struct inode *inode = mapping->host;
575 struct gfs2_inode *ip = GFS2_I(inode);
576 struct gfs2_sbd *sdp = GFS2_SB(inode);
577 struct gfs2_holder gh;
580 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
581 ret = gfs2_glock_nq(&gh);
584 if (!gfs2_is_stuffed(ip))
585 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
588 gfs2_holder_uninit(&gh);
589 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
595 * gfs2_write_begin - Begin to write to a file
596 * @file: The file to write to
597 * @mapping: The mapping in which to write
598 * @pos: The file offset at which to start writing
599 * @len: Length of the write
600 * @flags: Various flags
601 * @pagep: Pointer to return the page
602 * @fsdata: Pointer to return fs data (unused by GFS2)
607 static int gfs2_write_begin(struct file *file, struct address_space *mapping,
608 loff_t pos, unsigned len, unsigned flags,
609 struct page **pagep, void **fsdata)
611 struct gfs2_inode *ip = GFS2_I(mapping->host);
612 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
613 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
614 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
615 unsigned requested = 0;
618 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
619 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
622 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
623 error = gfs2_glock_nq(&ip->i_gh);
626 if (&ip->i_inode == sdp->sd_rindex) {
627 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
628 GL_NOCACHE, &m_ip->i_gh);
629 if (unlikely(error)) {
630 gfs2_glock_dq(&ip->i_gh);
635 alloc_required = gfs2_write_alloc_required(ip, pos, len);
637 if (alloc_required || gfs2_is_jdata(ip))
638 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
640 if (alloc_required) {
641 error = gfs2_quota_lock_check(ip);
645 requested = data_blocks + ind_blocks;
646 error = gfs2_inplace_reserve(ip, requested, 0);
651 rblocks = RES_DINODE + ind_blocks;
652 if (gfs2_is_jdata(ip))
653 rblocks += data_blocks ? data_blocks : 1;
654 if (ind_blocks || data_blocks)
655 rblocks += RES_STATFS + RES_QUOTA;
656 if (&ip->i_inode == sdp->sd_rindex)
657 rblocks += 2 * RES_STATFS;
659 rblocks += gfs2_rg_blocks(ip, requested);
661 error = gfs2_trans_begin(sdp, rblocks,
662 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
667 flags |= AOP_FLAG_NOFS;
668 page = grab_cache_page_write_begin(mapping, index, flags);
673 if (gfs2_is_stuffed(ip)) {
675 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
676 error = gfs2_unstuff_dinode(ip, page);
679 } else if (!PageUptodate(page)) {
680 error = stuffed_readpage(ip, page);
686 error = __block_write_begin(page, from, len, gfs2_block_map);
692 page_cache_release(page);
695 if (pos + len > ip->i_inode.i_size)
696 gfs2_trim_blocks(&ip->i_inode);
702 if (alloc_required) {
703 gfs2_inplace_release(ip);
705 gfs2_quota_unlock(ip);
708 if (&ip->i_inode == sdp->sd_rindex) {
709 gfs2_glock_dq(&m_ip->i_gh);
710 gfs2_holder_uninit(&m_ip->i_gh);
712 gfs2_glock_dq(&ip->i_gh);
714 gfs2_holder_uninit(&ip->i_gh);
719 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
720 * @inode: the rindex inode
722 static void adjust_fs_space(struct inode *inode)
724 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
725 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
726 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
727 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
728 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
729 struct buffer_head *m_bh, *l_bh;
730 u64 fs_total, new_free;
732 /* Total up the file system space, according to the latest rindex. */
733 fs_total = gfs2_ri_total(sdp);
734 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
737 spin_lock(&sdp->sd_statfs_spin);
738 gfs2_statfs_change_in(m_sc, m_bh->b_data +
739 sizeof(struct gfs2_dinode));
740 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
741 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
744 spin_unlock(&sdp->sd_statfs_spin);
745 fs_warn(sdp, "File system extended by %llu blocks.\n",
746 (unsigned long long)new_free);
747 gfs2_statfs_change(sdp, new_free, new_free, 0);
749 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
751 update_statfs(sdp, m_bh, l_bh);
758 * gfs2_stuffed_write_end - Write end for stuffed files
760 * @dibh: The buffer_head containing the on-disk inode
761 * @pos: The file position
762 * @len: The length of the write
763 * @copied: How much was actually copied by the VFS
766 * This copies the data from the page into the inode block after
767 * the inode data structure itself.
771 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
772 loff_t pos, unsigned len, unsigned copied,
775 struct gfs2_inode *ip = GFS2_I(inode);
776 struct gfs2_sbd *sdp = GFS2_SB(inode);
777 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
778 u64 to = pos + copied;
780 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
782 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
783 kaddr = kmap_atomic(page);
784 memcpy(buf + pos, kaddr + pos, copied);
785 memset(kaddr + pos + copied, 0, len - copied);
786 flush_dcache_page(page);
787 kunmap_atomic(kaddr);
789 if (!PageUptodate(page))
790 SetPageUptodate(page);
792 page_cache_release(page);
795 if (inode->i_size < to)
796 i_size_write(inode, to);
797 mark_inode_dirty(inode);
800 if (inode == sdp->sd_rindex) {
801 adjust_fs_space(inode);
802 sdp->sd_rindex_uptodate = 0;
807 if (inode == sdp->sd_rindex) {
808 gfs2_glock_dq(&m_ip->i_gh);
809 gfs2_holder_uninit(&m_ip->i_gh);
811 gfs2_glock_dq(&ip->i_gh);
812 gfs2_holder_uninit(&ip->i_gh);
818 * @file: The file to write to
819 * @mapping: The address space to write to
820 * @pos: The file position
821 * @len: The length of the data
823 * @page: The page that has been written
824 * @fsdata: The fsdata (unused in GFS2)
826 * The main write_end function for GFS2. We have a separate one for
827 * stuffed files as they are slightly different, otherwise we just
828 * put our locking around the VFS provided functions.
833 static int gfs2_write_end(struct file *file, struct address_space *mapping,
834 loff_t pos, unsigned len, unsigned copied,
835 struct page *page, void *fsdata)
837 struct inode *inode = page->mapping->host;
838 struct gfs2_inode *ip = GFS2_I(inode);
839 struct gfs2_sbd *sdp = GFS2_SB(inode);
840 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
841 struct buffer_head *dibh;
842 unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
843 unsigned int to = from + len;
846 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
848 ret = gfs2_meta_inode_buffer(ip, &dibh);
851 page_cache_release(page);
855 gfs2_trans_add_meta(ip->i_gl, dibh);
857 if (gfs2_is_stuffed(ip))
858 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
860 if (!gfs2_is_writeback(ip))
861 gfs2_page_add_databufs(ip, page, from, to);
863 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
865 if (inode == sdp->sd_rindex) {
866 adjust_fs_space(inode);
867 sdp->sd_rindex_uptodate = 0;
873 gfs2_inplace_release(ip);
874 if (ip->i_res->rs_qa_qd_num)
875 gfs2_quota_unlock(ip);
876 if (inode == sdp->sd_rindex) {
877 gfs2_glock_dq(&m_ip->i_gh);
878 gfs2_holder_uninit(&m_ip->i_gh);
880 gfs2_glock_dq(&ip->i_gh);
881 gfs2_holder_uninit(&ip->i_gh);
886 * gfs2_set_page_dirty - Page dirtying function
887 * @page: The page to dirty
889 * Returns: 1 if it dirtyed the page, or 0 otherwise
892 static int gfs2_set_page_dirty(struct page *page)
894 SetPageChecked(page);
895 return __set_page_dirty_buffers(page);
899 * gfs2_bmap - Block map function
900 * @mapping: Address space info
901 * @lblock: The block to map
903 * Returns: The disk address for the block or 0 on hole or error
906 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
908 struct gfs2_inode *ip = GFS2_I(mapping->host);
909 struct gfs2_holder i_gh;
913 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
917 if (!gfs2_is_stuffed(ip))
918 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
920 gfs2_glock_dq_uninit(&i_gh);
925 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
927 struct gfs2_bufdata *bd;
931 clear_buffer_dirty(bh);
934 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
935 list_del_init(&bd->bd_list);
937 gfs2_remove_from_journal(bh, current->journal_info, 0);
940 clear_buffer_mapped(bh);
941 clear_buffer_req(bh);
942 clear_buffer_new(bh);
943 gfs2_log_unlock(sdp);
947 static void gfs2_invalidatepage(struct page *page, unsigned int offset,
950 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
951 unsigned int stop = offset + length;
952 int partial_page = (offset || length < PAGE_CACHE_SIZE);
953 struct buffer_head *bh, *head;
954 unsigned long pos = 0;
956 BUG_ON(!PageLocked(page));
958 ClearPageChecked(page);
959 if (!page_has_buffers(page))
962 bh = head = page_buffers(page);
964 if (pos + bh->b_size > stop)
968 gfs2_discard(sdp, bh);
970 bh = bh->b_this_page;
971 } while (bh != head);
974 try_to_release_page(page, 0);
978 * gfs2_ok_for_dio - check that dio is valid on this file
981 * @offset: The offset at which we are reading or writing
983 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
984 * 1 (to accept the i/o request)
986 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
989 * Should we return an error here? I can't see that O_DIRECT for
990 * a stuffed file makes any sense. For now we'll silently fall
991 * back to buffered I/O
993 if (gfs2_is_stuffed(ip))
996 if (offset >= i_size_read(&ip->i_inode))
1003 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
1004 const struct iovec *iov, loff_t offset,
1005 unsigned long nr_segs)
1007 struct file *file = iocb->ki_filp;
1008 struct inode *inode = file->f_mapping->host;
1009 struct gfs2_inode *ip = GFS2_I(inode);
1010 struct gfs2_holder gh;
1014 * Deferred lock, even if its a write, since we do no allocation
1015 * on this path. All we need change is atime, and this lock mode
1016 * ensures that other nodes have flushed their buffered read caches
1017 * (i.e. their page cache entries for this inode). We do not,
1018 * unfortunately have the option of only flushing a range like
1021 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1022 rv = gfs2_glock_nq(&gh);
1025 rv = gfs2_ok_for_dio(ip, rw, offset);
1027 goto out; /* dio not valid, fall back to buffered i/o */
1029 rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1030 offset, nr_segs, gfs2_get_block_direct,
1034 gfs2_holder_uninit(&gh);
1039 * gfs2_releasepage - free the metadata associated with a page
1040 * @page: the page that's being released
1041 * @gfp_mask: passed from Linux VFS, ignored by us
1043 * Call try_to_free_buffers() if the buffers in this page can be
1049 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1051 struct address_space *mapping = page->mapping;
1052 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1053 struct buffer_head *bh, *head;
1054 struct gfs2_bufdata *bd;
1056 if (!page_has_buffers(page))
1060 spin_lock(&sdp->sd_ail_lock);
1061 head = bh = page_buffers(page);
1063 if (atomic_read(&bh->b_count))
1064 goto cannot_release;
1066 if (bd && bd->bd_tr)
1067 goto cannot_release;
1068 if (buffer_pinned(bh) || buffer_dirty(bh))
1070 bh = bh->b_this_page;
1071 } while(bh != head);
1072 spin_unlock(&sdp->sd_ail_lock);
1073 gfs2_log_unlock(sdp);
1075 head = bh = page_buffers(page);
1080 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1081 if (!list_empty(&bd->bd_list)) {
1082 if (!buffer_pinned(bh))
1083 list_del_init(&bd->bd_list);
1089 bh->b_private = NULL;
1091 gfs2_log_unlock(sdp);
1093 kmem_cache_free(gfs2_bufdata_cachep, bd);
1095 bh = bh->b_this_page;
1096 } while (bh != head);
1098 return try_to_free_buffers(page);
1100 not_possible: /* Should never happen */
1101 WARN_ON(buffer_dirty(bh));
1102 WARN_ON(buffer_pinned(bh));
1104 spin_unlock(&sdp->sd_ail_lock);
1105 gfs2_log_unlock(sdp);
1109 static const struct address_space_operations gfs2_writeback_aops = {
1110 .writepage = gfs2_writeback_writepage,
1111 .writepages = gfs2_writepages,
1112 .readpage = gfs2_readpage,
1113 .readpages = gfs2_readpages,
1114 .write_begin = gfs2_write_begin,
1115 .write_end = gfs2_write_end,
1117 .invalidatepage = gfs2_invalidatepage,
1118 .releasepage = gfs2_releasepage,
1119 .direct_IO = gfs2_direct_IO,
1120 .migratepage = buffer_migrate_page,
1121 .is_partially_uptodate = block_is_partially_uptodate,
1122 .error_remove_page = generic_error_remove_page,
1125 static const struct address_space_operations gfs2_ordered_aops = {
1126 .writepage = gfs2_ordered_writepage,
1127 .writepages = gfs2_writepages,
1128 .readpage = gfs2_readpage,
1129 .readpages = gfs2_readpages,
1130 .write_begin = gfs2_write_begin,
1131 .write_end = gfs2_write_end,
1132 .set_page_dirty = gfs2_set_page_dirty,
1134 .invalidatepage = gfs2_invalidatepage,
1135 .releasepage = gfs2_releasepage,
1136 .direct_IO = gfs2_direct_IO,
1137 .migratepage = buffer_migrate_page,
1138 .is_partially_uptodate = block_is_partially_uptodate,
1139 .error_remove_page = generic_error_remove_page,
1142 static const struct address_space_operations gfs2_jdata_aops = {
1143 .writepage = gfs2_jdata_writepage,
1144 .writepages = gfs2_jdata_writepages,
1145 .readpage = gfs2_readpage,
1146 .readpages = gfs2_readpages,
1147 .write_begin = gfs2_write_begin,
1148 .write_end = gfs2_write_end,
1149 .set_page_dirty = gfs2_set_page_dirty,
1151 .invalidatepage = gfs2_invalidatepage,
1152 .releasepage = gfs2_releasepage,
1153 .is_partially_uptodate = block_is_partially_uptodate,
1154 .error_remove_page = generic_error_remove_page,
1157 void gfs2_set_aops(struct inode *inode)
1159 struct gfs2_inode *ip = GFS2_I(inode);
1161 if (gfs2_is_writeback(ip))
1162 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1163 else if (gfs2_is_ordered(ip))
1164 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1165 else if (gfs2_is_jdata(ip))
1166 inode->i_mapping->a_ops = &gfs2_jdata_aops;