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>
39 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
40 unsigned int from, unsigned int to)
42 struct buffer_head *head = page_buffers(page);
43 unsigned int bsize = head->b_size;
44 struct buffer_head *bh;
45 unsigned int start, end;
47 for (bh = head, start = 0; bh != head || !start;
48 bh = bh->b_this_page, start = end) {
50 if (end <= from || start >= to)
52 if (gfs2_is_jdata(ip))
53 set_buffer_uptodate(bh);
54 gfs2_trans_add_bh(ip->i_gl, bh, 0);
59 * gfs2_get_block_noalloc - Fills in a buffer head with details about a block
61 * @lblock: The block number to look up
62 * @bh_result: The buffer head to return the result in
63 * @create: Non-zero if we may add block to the file
68 static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock,
69 struct buffer_head *bh_result, int create)
73 error = gfs2_block_map(inode, lblock, bh_result, 0);
76 if (!buffer_mapped(bh_result))
81 static int gfs2_get_block_direct(struct inode *inode, sector_t lblock,
82 struct buffer_head *bh_result, int create)
84 return gfs2_block_map(inode, lblock, bh_result, 0);
88 * gfs2_writepage_common - Common bits of writepage
89 * @page: The page to be written
90 * @wbc: The writeback control
92 * Returns: 1 if writepage is ok, otherwise an error code or zero if no error.
95 static int gfs2_writepage_common(struct page *page,
96 struct writeback_control *wbc)
98 struct inode *inode = page->mapping->host;
99 struct gfs2_inode *ip = GFS2_I(inode);
100 struct gfs2_sbd *sdp = GFS2_SB(inode);
101 loff_t i_size = i_size_read(inode);
102 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
105 if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl)))
107 if (current->journal_info)
109 /* Is the page fully outside i_size? (truncate in progress) */
110 offset = i_size & (PAGE_CACHE_SIZE-1);
111 if (page->index > end_index || (page->index == end_index && !offset)) {
112 page->mapping->a_ops->invalidatepage(page, 0);
117 redirty_page_for_writepage(wbc, page);
124 * gfs2_writeback_writepage - Write page for writeback mappings
126 * @wbc: The writeback control
130 static int gfs2_writeback_writepage(struct page *page,
131 struct writeback_control *wbc)
135 ret = gfs2_writepage_common(page, wbc);
139 ret = mpage_writepage(page, gfs2_get_block_noalloc, wbc);
141 ret = block_write_full_page(page, gfs2_get_block_noalloc, wbc);
146 * gfs2_ordered_writepage - Write page for ordered data files
147 * @page: The page to write
148 * @wbc: The writeback control
152 static int gfs2_ordered_writepage(struct page *page,
153 struct writeback_control *wbc)
155 struct inode *inode = page->mapping->host;
156 struct gfs2_inode *ip = GFS2_I(inode);
159 ret = gfs2_writepage_common(page, wbc);
163 if (!page_has_buffers(page)) {
164 create_empty_buffers(page, inode->i_sb->s_blocksize,
165 (1 << BH_Dirty)|(1 << BH_Uptodate));
167 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1);
168 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
172 * __gfs2_jdata_writepage - The core of jdata writepage
173 * @page: The page to write
174 * @wbc: The writeback control
176 * This is shared between writepage and writepages and implements the
177 * core of the writepage operation. If a transaction is required then
178 * PageChecked will have been set and the transaction will have
179 * already been started before this is called.
182 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
184 struct inode *inode = page->mapping->host;
185 struct gfs2_inode *ip = GFS2_I(inode);
186 struct gfs2_sbd *sdp = GFS2_SB(inode);
188 if (PageChecked(page)) {
189 ClearPageChecked(page);
190 if (!page_has_buffers(page)) {
191 create_empty_buffers(page, inode->i_sb->s_blocksize,
192 (1 << BH_Dirty)|(1 << BH_Uptodate));
194 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
196 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
200 * gfs2_jdata_writepage - Write complete page
201 * @page: Page to write
207 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
209 struct inode *inode = page->mapping->host;
210 struct gfs2_sbd *sdp = GFS2_SB(inode);
214 if (PageChecked(page)) {
215 if (wbc->sync_mode != WB_SYNC_ALL)
217 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
222 ret = gfs2_writepage_common(page, wbc);
224 ret = __gfs2_jdata_writepage(page, wbc);
230 redirty_page_for_writepage(wbc, page);
236 * gfs2_writeback_writepages - Write a bunch of dirty pages back to disk
237 * @mapping: The mapping to write
238 * @wbc: Write-back control
240 * For the data=writeback case we can already ignore buffer heads
241 * and write whole extents at once. This is a big reduction in the
242 * number of I/O requests we send and the bmap calls we make in this case.
244 static int gfs2_writeback_writepages(struct address_space *mapping,
245 struct writeback_control *wbc)
247 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
251 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
252 * @mapping: The mapping
253 * @wbc: The writeback control
254 * @writepage: The writepage function to call for each page
255 * @pvec: The vector of pages
256 * @nr_pages: The number of pages to write
258 * Returns: non-zero if loop should terminate, zero otherwise
261 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
262 struct writeback_control *wbc,
263 struct pagevec *pvec,
264 int nr_pages, pgoff_t end)
266 struct inode *inode = mapping->host;
267 struct gfs2_sbd *sdp = GFS2_SB(inode);
268 loff_t i_size = i_size_read(inode);
269 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
270 unsigned offset = i_size & (PAGE_CACHE_SIZE-1);
271 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
275 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
279 for(i = 0; i < nr_pages; i++) {
280 struct page *page = pvec->pages[i];
284 if (unlikely(page->mapping != mapping)) {
289 if (!wbc->range_cyclic && page->index > end) {
295 if (wbc->sync_mode != WB_SYNC_NONE)
296 wait_on_page_writeback(page);
298 if (PageWriteback(page) ||
299 !clear_page_dirty_for_io(page)) {
304 /* Is the page fully outside i_size? (truncate in progress) */
305 if (page->index > end_index || (page->index == end_index && !offset)) {
306 page->mapping->a_ops->invalidatepage(page, 0);
311 ret = __gfs2_jdata_writepage(page, wbc);
313 if (ret || (--(wbc->nr_to_write) <= 0))
321 * gfs2_write_cache_jdata - Like write_cache_pages but different
322 * @mapping: The mapping to write
323 * @wbc: The writeback control
324 * @writepage: The writepage function to call
325 * @data: The data to pass to writepage
327 * The reason that we use our own function here is that we need to
328 * start transactions before we grab page locks. This allows us
329 * to get the ordering right.
332 static int gfs2_write_cache_jdata(struct address_space *mapping,
333 struct writeback_control *wbc)
344 pagevec_init(&pvec, 0);
345 if (wbc->range_cyclic) {
346 index = mapping->writeback_index; /* Start from prev offset */
349 index = wbc->range_start >> PAGE_CACHE_SHIFT;
350 end = wbc->range_end >> PAGE_CACHE_SHIFT;
351 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
357 while (!done && (index <= end) &&
358 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
360 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
362 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end);
368 pagevec_release(&pvec);
372 if (!scanned && !done) {
374 * We hit the last page and there is more work to be done: wrap
375 * back to the start of the file
382 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
383 mapping->writeback_index = index;
389 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
390 * @mapping: The mapping to write
391 * @wbc: The writeback control
395 static int gfs2_jdata_writepages(struct address_space *mapping,
396 struct writeback_control *wbc)
398 struct gfs2_inode *ip = GFS2_I(mapping->host);
399 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
402 ret = gfs2_write_cache_jdata(mapping, wbc);
403 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
404 gfs2_log_flush(sdp, ip->i_gl);
405 ret = gfs2_write_cache_jdata(mapping, wbc);
411 * stuffed_readpage - Fill in a Linux page with stuffed file data
418 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
420 struct buffer_head *dibh;
421 u64 dsize = i_size_read(&ip->i_inode);
426 * Due to the order of unstuffing files and ->fault(), we can be
427 * asked for a zero page in the case of a stuffed file being extended,
428 * so we need to supply one here. It doesn't happen often.
430 if (unlikely(page->index)) {
431 zero_user(page, 0, PAGE_CACHE_SIZE);
432 SetPageUptodate(page);
436 error = gfs2_meta_inode_buffer(ip, &dibh);
440 kaddr = kmap_atomic(page, KM_USER0);
441 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
442 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
443 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
444 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
445 kunmap_atomic(kaddr, KM_USER0);
446 flush_dcache_page(page);
448 SetPageUptodate(page);
455 * __gfs2_readpage - readpage
456 * @file: The file to read a page for
457 * @page: The page to read
459 * This is the core of gfs2's readpage. Its used by the internal file
460 * reading code as in that case we already hold the glock. Also its
461 * called by gfs2_readpage() once the required lock has been granted.
465 static int __gfs2_readpage(void *file, struct page *page)
467 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
468 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
471 if (gfs2_is_stuffed(ip)) {
472 error = stuffed_readpage(ip, page);
475 error = mpage_readpage(page, gfs2_block_map);
478 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
485 * gfs2_readpage - read a page of a file
486 * @file: The file to read
487 * @page: The page of the file
489 * This deals with the locking required. We have to unlock and
490 * relock the page in order to get the locking in the right
494 static int gfs2_readpage(struct file *file, struct page *page)
496 struct address_space *mapping = page->mapping;
497 struct gfs2_inode *ip = GFS2_I(mapping->host);
498 struct gfs2_holder gh;
502 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
503 error = gfs2_glock_nq(&gh);
506 error = AOP_TRUNCATED_PAGE;
508 if (page->mapping == mapping && !PageUptodate(page))
509 error = __gfs2_readpage(file, page);
514 gfs2_holder_uninit(&gh);
515 if (error && error != AOP_TRUNCATED_PAGE)
521 * gfs2_internal_read - read an internal file
522 * @ip: The gfs2 inode
523 * @ra_state: The readahead state (or NULL for no readahead)
524 * @buf: The buffer to fill
525 * @pos: The file position
526 * @size: The amount to read
530 int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
531 char *buf, loff_t *pos, unsigned size)
533 struct address_space *mapping = ip->i_inode.i_mapping;
534 unsigned long index = *pos / PAGE_CACHE_SIZE;
535 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
543 if (offset + size > PAGE_CACHE_SIZE)
544 amt = PAGE_CACHE_SIZE - offset;
545 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
547 return PTR_ERR(page);
548 p = kmap_atomic(page, KM_USER0);
549 memcpy(buf + copied, p + offset, amt);
550 kunmap_atomic(p, KM_USER0);
551 mark_page_accessed(page);
552 page_cache_release(page);
556 } while(copied < size);
562 * gfs2_readpages - Read a bunch of pages at once
565 * 1. This is only for readahead, so we can simply ignore any things
566 * which are slightly inconvenient (such as locking conflicts between
567 * the page lock and the glock) and return having done no I/O. Its
568 * obviously not something we'd want to do on too regular a basis.
569 * Any I/O we ignore at this time will be done via readpage later.
570 * 2. We don't handle stuffed files here we let readpage do the honours.
571 * 3. mpage_readpages() does most of the heavy lifting in the common case.
572 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
575 static int gfs2_readpages(struct file *file, struct address_space *mapping,
576 struct list_head *pages, unsigned nr_pages)
578 struct inode *inode = mapping->host;
579 struct gfs2_inode *ip = GFS2_I(inode);
580 struct gfs2_sbd *sdp = GFS2_SB(inode);
581 struct gfs2_holder gh;
584 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
585 ret = gfs2_glock_nq(&gh);
588 if (!gfs2_is_stuffed(ip))
589 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
592 gfs2_holder_uninit(&gh);
593 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
599 * gfs2_write_begin - Begin to write to a file
600 * @file: The file to write to
601 * @mapping: The mapping in which to write
602 * @pos: The file offset at which to start writing
603 * @len: Length of the write
604 * @flags: Various flags
605 * @pagep: Pointer to return the page
606 * @fsdata: Pointer to return fs data (unused by GFS2)
611 static int gfs2_write_begin(struct file *file, struct address_space *mapping,
612 loff_t pos, unsigned len, unsigned flags,
613 struct page **pagep, void **fsdata)
615 struct gfs2_inode *ip = GFS2_I(mapping->host);
616 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
617 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
618 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
621 struct gfs2_alloc *al;
622 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
623 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
624 unsigned to = from + len;
627 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
628 error = gfs2_glock_nq(&ip->i_gh);
631 if (&ip->i_inode == sdp->sd_rindex) {
632 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
633 GL_NOCACHE, &m_ip->i_gh);
634 if (unlikely(error)) {
635 gfs2_glock_dq(&ip->i_gh);
640 error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
644 if (alloc_required || gfs2_is_jdata(ip))
645 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
647 if (alloc_required) {
648 al = gfs2_alloc_get(ip);
654 error = gfs2_quota_lock_check(ip);
658 al->al_requested = data_blocks + ind_blocks;
659 error = gfs2_inplace_reserve(ip);
664 rblocks = RES_DINODE + ind_blocks;
665 if (gfs2_is_jdata(ip))
666 rblocks += data_blocks ? data_blocks : 1;
667 if (ind_blocks || data_blocks)
668 rblocks += RES_STATFS + RES_QUOTA;
669 if (&ip->i_inode == sdp->sd_rindex)
670 rblocks += 2 * RES_STATFS;
672 error = gfs2_trans_begin(sdp, rblocks,
673 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
678 flags |= AOP_FLAG_NOFS;
679 page = grab_cache_page_write_begin(mapping, index, flags);
684 if (gfs2_is_stuffed(ip)) {
686 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
687 error = gfs2_unstuff_dinode(ip, page);
690 } else if (!PageUptodate(page)) {
691 error = stuffed_readpage(ip, page);
697 error = block_prepare_write(page, from, to, gfs2_block_map);
702 page_cache_release(page);
705 * XXX(hch): the call below should probably be replaced with
706 * a call to the gfs2-specific truncate blocks helper to actually
707 * release disk blocks..
709 if (pos + len > ip->i_inode.i_size)
710 simple_setsize(&ip->i_inode, ip->i_inode.i_size);
714 if (alloc_required) {
715 gfs2_inplace_release(ip);
717 gfs2_quota_unlock(ip);
722 if (&ip->i_inode == sdp->sd_rindex) {
723 gfs2_glock_dq(&m_ip->i_gh);
724 gfs2_holder_uninit(&m_ip->i_gh);
726 gfs2_glock_dq(&ip->i_gh);
728 gfs2_holder_uninit(&ip->i_gh);
733 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
734 * @inode: the rindex inode
736 static void adjust_fs_space(struct inode *inode)
738 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
739 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
740 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
741 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
742 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
743 struct buffer_head *m_bh, *l_bh;
744 u64 fs_total, new_free;
746 /* Total up the file system space, according to the latest rindex. */
747 fs_total = gfs2_ri_total(sdp);
748 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
751 spin_lock(&sdp->sd_statfs_spin);
752 gfs2_statfs_change_in(m_sc, m_bh->b_data +
753 sizeof(struct gfs2_dinode));
754 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
755 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
758 spin_unlock(&sdp->sd_statfs_spin);
759 fs_warn(sdp, "File system extended by %llu blocks.\n",
760 (unsigned long long)new_free);
761 gfs2_statfs_change(sdp, new_free, new_free, 0);
763 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
765 update_statfs(sdp, m_bh, l_bh);
772 * gfs2_stuffed_write_end - Write end for stuffed files
774 * @dibh: The buffer_head containing the on-disk inode
775 * @pos: The file position
776 * @len: The length of the write
777 * @copied: How much was actually copied by the VFS
780 * This copies the data from the page into the inode block after
781 * the inode data structure itself.
785 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
786 loff_t pos, unsigned len, unsigned copied,
789 struct gfs2_inode *ip = GFS2_I(inode);
790 struct gfs2_sbd *sdp = GFS2_SB(inode);
791 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
792 u64 to = pos + copied;
794 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
795 struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
797 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
798 kaddr = kmap_atomic(page, KM_USER0);
799 memcpy(buf + pos, kaddr + pos, copied);
800 memset(kaddr + pos + copied, 0, len - copied);
801 flush_dcache_page(page);
802 kunmap_atomic(kaddr, KM_USER0);
804 if (!PageUptodate(page))
805 SetPageUptodate(page);
807 page_cache_release(page);
810 if (inode->i_size < to) {
811 i_size_write(inode, to);
812 ip->i_disksize = inode->i_size;
814 gfs2_dinode_out(ip, di);
815 mark_inode_dirty(inode);
818 if (inode == sdp->sd_rindex) {
819 adjust_fs_space(inode);
820 ip->i_gh.gh_flags |= GL_NOCACHE;
825 if (inode == sdp->sd_rindex) {
826 gfs2_glock_dq(&m_ip->i_gh);
827 gfs2_holder_uninit(&m_ip->i_gh);
829 gfs2_glock_dq(&ip->i_gh);
830 gfs2_holder_uninit(&ip->i_gh);
836 * @file: The file to write to
837 * @mapping: The address space to write to
838 * @pos: The file position
839 * @len: The length of the data
841 * @page: The page that has been written
842 * @fsdata: The fsdata (unused in GFS2)
844 * The main write_end function for GFS2. We have a separate one for
845 * stuffed files as they are slightly different, otherwise we just
846 * put our locking around the VFS provided functions.
851 static int gfs2_write_end(struct file *file, struct address_space *mapping,
852 loff_t pos, unsigned len, unsigned copied,
853 struct page *page, void *fsdata)
855 struct inode *inode = page->mapping->host;
856 struct gfs2_inode *ip = GFS2_I(inode);
857 struct gfs2_sbd *sdp = GFS2_SB(inode);
858 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
859 struct buffer_head *dibh;
860 struct gfs2_alloc *al = ip->i_alloc;
861 unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
862 unsigned int to = from + len;
865 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
867 ret = gfs2_meta_inode_buffer(ip, &dibh);
870 page_cache_release(page);
874 gfs2_trans_add_bh(ip->i_gl, dibh, 1);
876 if (gfs2_is_stuffed(ip))
877 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
879 if (!gfs2_is_writeback(ip))
880 gfs2_page_add_databufs(ip, page, from, to);
882 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
884 if (inode->i_size > ip->i_disksize)
885 ip->i_disksize = inode->i_size;
886 gfs2_dinode_out(ip, dibh->b_data);
887 mark_inode_dirty(inode);
890 if (inode == sdp->sd_rindex) {
891 adjust_fs_space(inode);
892 ip->i_gh.gh_flags |= GL_NOCACHE;
899 gfs2_inplace_release(ip);
900 gfs2_quota_unlock(ip);
903 if (inode == sdp->sd_rindex) {
904 gfs2_glock_dq(&m_ip->i_gh);
905 gfs2_holder_uninit(&m_ip->i_gh);
907 gfs2_glock_dq(&ip->i_gh);
908 gfs2_holder_uninit(&ip->i_gh);
913 * gfs2_set_page_dirty - Page dirtying function
914 * @page: The page to dirty
916 * Returns: 1 if it dirtyed the page, or 0 otherwise
919 static int gfs2_set_page_dirty(struct page *page)
921 SetPageChecked(page);
922 return __set_page_dirty_buffers(page);
926 * gfs2_bmap - Block map function
927 * @mapping: Address space info
928 * @lblock: The block to map
930 * Returns: The disk address for the block or 0 on hole or error
933 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
935 struct gfs2_inode *ip = GFS2_I(mapping->host);
936 struct gfs2_holder i_gh;
940 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
944 if (!gfs2_is_stuffed(ip))
945 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
947 gfs2_glock_dq_uninit(&i_gh);
952 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
954 struct gfs2_bufdata *bd;
958 clear_buffer_dirty(bh);
961 if (!list_empty(&bd->bd_le.le_list) && !buffer_pinned(bh))
962 list_del_init(&bd->bd_le.le_list);
964 gfs2_remove_from_journal(bh, current->journal_info, 0);
967 clear_buffer_mapped(bh);
968 clear_buffer_req(bh);
969 clear_buffer_new(bh);
970 gfs2_log_unlock(sdp);
974 static void gfs2_invalidatepage(struct page *page, unsigned long offset)
976 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
977 struct buffer_head *bh, *head;
978 unsigned long pos = 0;
980 BUG_ON(!PageLocked(page));
982 ClearPageChecked(page);
983 if (!page_has_buffers(page))
986 bh = head = page_buffers(page);
989 gfs2_discard(sdp, bh);
991 bh = bh->b_this_page;
992 } while (bh != head);
995 try_to_release_page(page, 0);
999 * gfs2_ok_for_dio - check that dio is valid on this file
1001 * @rw: READ or WRITE
1002 * @offset: The offset at which we are reading or writing
1004 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
1005 * 1 (to accept the i/o request)
1007 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
1010 * Should we return an error here? I can't see that O_DIRECT for
1011 * a stuffed file makes any sense. For now we'll silently fall
1012 * back to buffered I/O
1014 if (gfs2_is_stuffed(ip))
1017 if (offset >= i_size_read(&ip->i_inode))
1024 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
1025 const struct iovec *iov, loff_t offset,
1026 unsigned long nr_segs)
1028 struct file *file = iocb->ki_filp;
1029 struct inode *inode = file->f_mapping->host;
1030 struct gfs2_inode *ip = GFS2_I(inode);
1031 struct gfs2_holder gh;
1035 * Deferred lock, even if its a write, since we do no allocation
1036 * on this path. All we need change is atime, and this lock mode
1037 * ensures that other nodes have flushed their buffered read caches
1038 * (i.e. their page cache entries for this inode). We do not,
1039 * unfortunately have the option of only flushing a range like
1042 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1043 rv = gfs2_glock_nq(&gh);
1046 rv = gfs2_ok_for_dio(ip, rw, offset);
1048 goto out; /* dio not valid, fall back to buffered i/o */
1050 rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev,
1051 iov, offset, nr_segs,
1052 gfs2_get_block_direct, NULL);
1054 gfs2_glock_dq_m(1, &gh);
1055 gfs2_holder_uninit(&gh);
1060 * gfs2_releasepage - free the metadata associated with a page
1061 * @page: the page that's being released
1062 * @gfp_mask: passed from Linux VFS, ignored by us
1064 * Call try_to_free_buffers() if the buffers in this page can be
1070 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1072 struct address_space *mapping = page->mapping;
1073 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1074 struct buffer_head *bh, *head;
1075 struct gfs2_bufdata *bd;
1077 if (!page_has_buffers(page))
1081 head = bh = page_buffers(page);
1083 if (atomic_read(&bh->b_count))
1084 goto cannot_release;
1086 if (bd && bd->bd_ail)
1087 goto cannot_release;
1088 gfs2_assert_warn(sdp, !buffer_pinned(bh));
1089 gfs2_assert_warn(sdp, !buffer_dirty(bh));
1090 bh = bh->b_this_page;
1091 } while(bh != head);
1092 gfs2_log_unlock(sdp);
1094 head = bh = page_buffers(page);
1099 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1100 gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
1101 if (!list_empty(&bd->bd_le.le_list)) {
1102 if (!buffer_pinned(bh))
1103 list_del_init(&bd->bd_le.le_list);
1109 bh->b_private = NULL;
1111 gfs2_log_unlock(sdp);
1113 kmem_cache_free(gfs2_bufdata_cachep, bd);
1115 bh = bh->b_this_page;
1116 } while (bh != head);
1118 return try_to_free_buffers(page);
1120 gfs2_log_unlock(sdp);
1124 static const struct address_space_operations gfs2_writeback_aops = {
1125 .writepage = gfs2_writeback_writepage,
1126 .writepages = gfs2_writeback_writepages,
1127 .readpage = gfs2_readpage,
1128 .readpages = gfs2_readpages,
1129 .sync_page = block_sync_page,
1130 .write_begin = gfs2_write_begin,
1131 .write_end = gfs2_write_end,
1133 .invalidatepage = gfs2_invalidatepage,
1134 .releasepage = gfs2_releasepage,
1135 .direct_IO = gfs2_direct_IO,
1136 .migratepage = buffer_migrate_page,
1137 .is_partially_uptodate = block_is_partially_uptodate,
1138 .error_remove_page = generic_error_remove_page,
1141 static const struct address_space_operations gfs2_ordered_aops = {
1142 .writepage = gfs2_ordered_writepage,
1143 .readpage = gfs2_readpage,
1144 .readpages = gfs2_readpages,
1145 .sync_page = block_sync_page,
1146 .write_begin = gfs2_write_begin,
1147 .write_end = gfs2_write_end,
1148 .set_page_dirty = gfs2_set_page_dirty,
1150 .invalidatepage = gfs2_invalidatepage,
1151 .releasepage = gfs2_releasepage,
1152 .direct_IO = gfs2_direct_IO,
1153 .migratepage = buffer_migrate_page,
1154 .is_partially_uptodate = block_is_partially_uptodate,
1155 .error_remove_page = generic_error_remove_page,
1158 static const struct address_space_operations gfs2_jdata_aops = {
1159 .writepage = gfs2_jdata_writepage,
1160 .writepages = gfs2_jdata_writepages,
1161 .readpage = gfs2_readpage,
1162 .readpages = gfs2_readpages,
1163 .sync_page = block_sync_page,
1164 .write_begin = gfs2_write_begin,
1165 .write_end = gfs2_write_end,
1166 .set_page_dirty = gfs2_set_page_dirty,
1168 .invalidatepage = gfs2_invalidatepage,
1169 .releasepage = gfs2_releasepage,
1170 .is_partially_uptodate = block_is_partially_uptodate,
1171 .error_remove_page = generic_error_remove_page,
1174 void gfs2_set_aops(struct inode *inode)
1176 struct gfs2_inode *ip = GFS2_I(inode);
1178 if (gfs2_is_writeback(ip))
1179 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1180 else if (gfs2_is_ordered(ip))
1181 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1182 else if (gfs2_is_jdata(ip))
1183 inode->i_mapping->a_ops = &gfs2_jdata_aops;