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_data(ip->i_gl, bh);
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 return nobh_writepage(page, gfs2_get_block_noalloc, wbc);
143 * gfs2_ordered_writepage - Write page for ordered data files
144 * @page: The page to write
145 * @wbc: The writeback control
149 static int gfs2_ordered_writepage(struct page *page,
150 struct writeback_control *wbc)
152 struct inode *inode = page->mapping->host;
153 struct gfs2_inode *ip = GFS2_I(inode);
156 ret = gfs2_writepage_common(page, wbc);
160 if (!page_has_buffers(page)) {
161 create_empty_buffers(page, inode->i_sb->s_blocksize,
162 (1 << BH_Dirty)|(1 << BH_Uptodate));
164 gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1);
165 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
169 * __gfs2_jdata_writepage - The core of jdata writepage
170 * @page: The page to write
171 * @wbc: The writeback control
173 * This is shared between writepage and writepages and implements the
174 * core of the writepage operation. If a transaction is required then
175 * PageChecked will have been set and the transaction will have
176 * already been started before this is called.
179 static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
181 struct inode *inode = page->mapping->host;
182 struct gfs2_inode *ip = GFS2_I(inode);
183 struct gfs2_sbd *sdp = GFS2_SB(inode);
185 if (PageChecked(page)) {
186 ClearPageChecked(page);
187 if (!page_has_buffers(page)) {
188 create_empty_buffers(page, inode->i_sb->s_blocksize,
189 (1 << BH_Dirty)|(1 << BH_Uptodate));
191 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
193 return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
197 * gfs2_jdata_writepage - Write complete page
198 * @page: Page to write
204 static int gfs2_jdata_writepage(struct page *page, struct writeback_control *wbc)
206 struct inode *inode = page->mapping->host;
207 struct gfs2_sbd *sdp = GFS2_SB(inode);
211 if (PageChecked(page)) {
212 if (wbc->sync_mode != WB_SYNC_ALL)
214 ret = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
219 ret = gfs2_writepage_common(page, wbc);
221 ret = __gfs2_jdata_writepage(page, wbc);
227 redirty_page_for_writepage(wbc, page);
233 * gfs2_writepages - Write a bunch of dirty pages back to disk
234 * @mapping: The mapping to write
235 * @wbc: Write-back control
237 * Used for both ordered and writeback modes.
239 static int gfs2_writepages(struct address_space *mapping,
240 struct writeback_control *wbc)
242 return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc);
246 * gfs2_write_jdata_pagevec - Write back a pagevec's worth of pages
247 * @mapping: The mapping
248 * @wbc: The writeback control
249 * @writepage: The writepage function to call for each page
250 * @pvec: The vector of pages
251 * @nr_pages: The number of pages to write
253 * Returns: non-zero if loop should terminate, zero otherwise
256 static int gfs2_write_jdata_pagevec(struct address_space *mapping,
257 struct writeback_control *wbc,
258 struct pagevec *pvec,
259 int nr_pages, pgoff_t end)
261 struct inode *inode = mapping->host;
262 struct gfs2_sbd *sdp = GFS2_SB(inode);
263 loff_t i_size = i_size_read(inode);
264 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
265 unsigned offset = i_size & (PAGE_CACHE_SIZE-1);
266 unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
270 ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
274 for(i = 0; i < nr_pages; i++) {
275 struct page *page = pvec->pages[i];
279 if (unlikely(page->mapping != mapping)) {
284 if (!wbc->range_cyclic && page->index > end) {
290 if (wbc->sync_mode != WB_SYNC_NONE)
291 wait_on_page_writeback(page);
293 if (PageWriteback(page) ||
294 !clear_page_dirty_for_io(page)) {
299 /* Is the page fully outside i_size? (truncate in progress) */
300 if (page->index > end_index || (page->index == end_index && !offset)) {
301 page->mapping->a_ops->invalidatepage(page, 0);
306 ret = __gfs2_jdata_writepage(page, wbc);
308 if (ret || (--(wbc->nr_to_write) <= 0))
316 * gfs2_write_cache_jdata - Like write_cache_pages but different
317 * @mapping: The mapping to write
318 * @wbc: The writeback control
319 * @writepage: The writepage function to call
320 * @data: The data to pass to writepage
322 * The reason that we use our own function here is that we need to
323 * start transactions before we grab page locks. This allows us
324 * to get the ordering right.
327 static int gfs2_write_cache_jdata(struct address_space *mapping,
328 struct writeback_control *wbc)
339 pagevec_init(&pvec, 0);
340 if (wbc->range_cyclic) {
341 index = mapping->writeback_index; /* Start from prev offset */
344 index = wbc->range_start >> PAGE_CACHE_SHIFT;
345 end = wbc->range_end >> PAGE_CACHE_SHIFT;
346 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
352 while (!done && (index <= end) &&
353 (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
355 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) {
357 ret = gfs2_write_jdata_pagevec(mapping, wbc, &pvec, nr_pages, end);
363 pagevec_release(&pvec);
367 if (!scanned && !done) {
369 * We hit the last page and there is more work to be done: wrap
370 * back to the start of the file
377 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
378 mapping->writeback_index = index;
384 * gfs2_jdata_writepages - Write a bunch of dirty pages back to disk
385 * @mapping: The mapping to write
386 * @wbc: The writeback control
390 static int gfs2_jdata_writepages(struct address_space *mapping,
391 struct writeback_control *wbc)
393 struct gfs2_inode *ip = GFS2_I(mapping->host);
394 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
397 ret = gfs2_write_cache_jdata(mapping, wbc);
398 if (ret == 0 && wbc->sync_mode == WB_SYNC_ALL) {
399 gfs2_log_flush(sdp, ip->i_gl);
400 ret = gfs2_write_cache_jdata(mapping, wbc);
406 * stuffed_readpage - Fill in a Linux page with stuffed file data
413 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
415 struct buffer_head *dibh;
416 u64 dsize = i_size_read(&ip->i_inode);
421 * Due to the order of unstuffing files and ->fault(), we can be
422 * asked for a zero page in the case of a stuffed file being extended,
423 * so we need to supply one here. It doesn't happen often.
425 if (unlikely(page->index)) {
426 zero_user(page, 0, PAGE_CACHE_SIZE);
427 SetPageUptodate(page);
431 error = gfs2_meta_inode_buffer(ip, &dibh);
435 kaddr = kmap_atomic(page);
436 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
437 dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
438 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
439 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
440 kunmap_atomic(kaddr);
441 flush_dcache_page(page);
443 SetPageUptodate(page);
450 * __gfs2_readpage - readpage
451 * @file: The file to read a page for
452 * @page: The page to read
454 * This is the core of gfs2's readpage. Its used by the internal file
455 * reading code as in that case we already hold the glock. Also its
456 * called by gfs2_readpage() once the required lock has been granted.
460 static int __gfs2_readpage(void *file, struct page *page)
462 struct gfs2_inode *ip = GFS2_I(page->mapping->host);
463 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
466 if (gfs2_is_stuffed(ip)) {
467 error = stuffed_readpage(ip, page);
470 error = mpage_readpage(page, gfs2_block_map);
473 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
480 * gfs2_readpage - read a page of a file
481 * @file: The file to read
482 * @page: The page of the file
484 * This deals with the locking required. We have to unlock and
485 * relock the page in order to get the locking in the right
489 static int gfs2_readpage(struct file *file, struct page *page)
491 struct address_space *mapping = page->mapping;
492 struct gfs2_inode *ip = GFS2_I(mapping->host);
493 struct gfs2_holder gh;
497 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
498 error = gfs2_glock_nq(&gh);
501 error = AOP_TRUNCATED_PAGE;
503 if (page->mapping == mapping && !PageUptodate(page))
504 error = __gfs2_readpage(file, page);
509 gfs2_holder_uninit(&gh);
510 if (error && error != AOP_TRUNCATED_PAGE)
516 * gfs2_internal_read - read an internal file
517 * @ip: The gfs2 inode
518 * @buf: The buffer to fill
519 * @pos: The file position
520 * @size: The amount to read
524 int gfs2_internal_read(struct gfs2_inode *ip, char *buf, loff_t *pos,
527 struct address_space *mapping = ip->i_inode.i_mapping;
528 unsigned long index = *pos / PAGE_CACHE_SIZE;
529 unsigned offset = *pos & (PAGE_CACHE_SIZE - 1);
537 if (offset + size > PAGE_CACHE_SIZE)
538 amt = PAGE_CACHE_SIZE - offset;
539 page = read_cache_page(mapping, index, __gfs2_readpage, NULL);
541 return PTR_ERR(page);
542 p = kmap_atomic(page);
543 memcpy(buf + copied, p + offset, amt);
545 mark_page_accessed(page);
546 page_cache_release(page);
550 } while(copied < size);
556 * gfs2_readpages - Read a bunch of pages at once
559 * 1. This is only for readahead, so we can simply ignore any things
560 * which are slightly inconvenient (such as locking conflicts between
561 * the page lock and the glock) and return having done no I/O. Its
562 * obviously not something we'd want to do on too regular a basis.
563 * Any I/O we ignore at this time will be done via readpage later.
564 * 2. We don't handle stuffed files here we let readpage do the honours.
565 * 3. mpage_readpages() does most of the heavy lifting in the common case.
566 * 4. gfs2_block_map() is relied upon to set BH_Boundary in the right places.
569 static int gfs2_readpages(struct file *file, struct address_space *mapping,
570 struct list_head *pages, unsigned nr_pages)
572 struct inode *inode = mapping->host;
573 struct gfs2_inode *ip = GFS2_I(inode);
574 struct gfs2_sbd *sdp = GFS2_SB(inode);
575 struct gfs2_holder gh;
578 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
579 ret = gfs2_glock_nq(&gh);
582 if (!gfs2_is_stuffed(ip))
583 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
586 gfs2_holder_uninit(&gh);
587 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
593 * gfs2_write_begin - Begin to write to a file
594 * @file: The file to write to
595 * @mapping: The mapping in which to write
596 * @pos: The file offset at which to start writing
597 * @len: Length of the write
598 * @flags: Various flags
599 * @pagep: Pointer to return the page
600 * @fsdata: Pointer to return fs data (unused by GFS2)
605 static int gfs2_write_begin(struct file *file, struct address_space *mapping,
606 loff_t pos, unsigned len, unsigned flags,
607 struct page **pagep, void **fsdata)
609 struct gfs2_inode *ip = GFS2_I(mapping->host);
610 struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
611 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
612 unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
613 unsigned requested = 0;
616 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
617 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
620 gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
621 error = gfs2_glock_nq(&ip->i_gh);
624 if (&ip->i_inode == sdp->sd_rindex) {
625 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
626 GL_NOCACHE, &m_ip->i_gh);
627 if (unlikely(error)) {
628 gfs2_glock_dq(&ip->i_gh);
633 alloc_required = gfs2_write_alloc_required(ip, pos, len);
635 if (alloc_required || gfs2_is_jdata(ip))
636 gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
638 if (alloc_required) {
639 error = gfs2_quota_lock_check(ip);
643 requested = data_blocks + ind_blocks;
644 error = gfs2_inplace_reserve(ip, requested, 0);
649 rblocks = RES_DINODE + ind_blocks;
650 if (gfs2_is_jdata(ip))
651 rblocks += data_blocks ? data_blocks : 1;
652 if (ind_blocks || data_blocks)
653 rblocks += RES_STATFS + RES_QUOTA;
654 if (&ip->i_inode == sdp->sd_rindex)
655 rblocks += 2 * RES_STATFS;
657 rblocks += gfs2_rg_blocks(ip, requested);
659 error = gfs2_trans_begin(sdp, rblocks,
660 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
665 flags |= AOP_FLAG_NOFS;
666 page = grab_cache_page_write_begin(mapping, index, flags);
671 if (gfs2_is_stuffed(ip)) {
673 if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
674 error = gfs2_unstuff_dinode(ip, page);
677 } else if (!PageUptodate(page)) {
678 error = stuffed_readpage(ip, page);
684 error = __block_write_begin(page, from, len, gfs2_block_map);
690 page_cache_release(page);
693 if (pos + len > ip->i_inode.i_size)
694 gfs2_trim_blocks(&ip->i_inode);
700 if (alloc_required) {
701 gfs2_inplace_release(ip);
703 gfs2_quota_unlock(ip);
706 if (&ip->i_inode == sdp->sd_rindex) {
707 gfs2_glock_dq(&m_ip->i_gh);
708 gfs2_holder_uninit(&m_ip->i_gh);
710 gfs2_glock_dq(&ip->i_gh);
712 gfs2_holder_uninit(&ip->i_gh);
717 * adjust_fs_space - Adjusts the free space available due to gfs2_grow
718 * @inode: the rindex inode
720 static void adjust_fs_space(struct inode *inode)
722 struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
723 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
724 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
725 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
726 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
727 struct buffer_head *m_bh, *l_bh;
728 u64 fs_total, new_free;
730 /* Total up the file system space, according to the latest rindex. */
731 fs_total = gfs2_ri_total(sdp);
732 if (gfs2_meta_inode_buffer(m_ip, &m_bh) != 0)
735 spin_lock(&sdp->sd_statfs_spin);
736 gfs2_statfs_change_in(m_sc, m_bh->b_data +
737 sizeof(struct gfs2_dinode));
738 if (fs_total > (m_sc->sc_total + l_sc->sc_total))
739 new_free = fs_total - (m_sc->sc_total + l_sc->sc_total);
742 spin_unlock(&sdp->sd_statfs_spin);
743 fs_warn(sdp, "File system extended by %llu blocks.\n",
744 (unsigned long long)new_free);
745 gfs2_statfs_change(sdp, new_free, new_free, 0);
747 if (gfs2_meta_inode_buffer(l_ip, &l_bh) != 0)
749 update_statfs(sdp, m_bh, l_bh);
756 * gfs2_stuffed_write_end - Write end for stuffed files
758 * @dibh: The buffer_head containing the on-disk inode
759 * @pos: The file position
760 * @len: The length of the write
761 * @copied: How much was actually copied by the VFS
764 * This copies the data from the page into the inode block after
765 * the inode data structure itself.
769 static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
770 loff_t pos, unsigned len, unsigned copied,
773 struct gfs2_inode *ip = GFS2_I(inode);
774 struct gfs2_sbd *sdp = GFS2_SB(inode);
775 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
776 u64 to = pos + copied;
778 unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
780 BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
781 kaddr = kmap_atomic(page);
782 memcpy(buf + pos, kaddr + pos, copied);
783 memset(kaddr + pos + copied, 0, len - copied);
784 flush_dcache_page(page);
785 kunmap_atomic(kaddr);
787 if (!PageUptodate(page))
788 SetPageUptodate(page);
790 page_cache_release(page);
793 if (inode->i_size < to)
794 i_size_write(inode, to);
795 mark_inode_dirty(inode);
798 if (inode == sdp->sd_rindex) {
799 adjust_fs_space(inode);
800 sdp->sd_rindex_uptodate = 0;
805 if (inode == sdp->sd_rindex) {
806 gfs2_glock_dq(&m_ip->i_gh);
807 gfs2_holder_uninit(&m_ip->i_gh);
809 gfs2_glock_dq(&ip->i_gh);
810 gfs2_holder_uninit(&ip->i_gh);
816 * @file: The file to write to
817 * @mapping: The address space to write to
818 * @pos: The file position
819 * @len: The length of the data
821 * @page: The page that has been written
822 * @fsdata: The fsdata (unused in GFS2)
824 * The main write_end function for GFS2. We have a separate one for
825 * stuffed files as they are slightly different, otherwise we just
826 * put our locking around the VFS provided functions.
831 static int gfs2_write_end(struct file *file, struct address_space *mapping,
832 loff_t pos, unsigned len, unsigned copied,
833 struct page *page, void *fsdata)
835 struct inode *inode = page->mapping->host;
836 struct gfs2_inode *ip = GFS2_I(inode);
837 struct gfs2_sbd *sdp = GFS2_SB(inode);
838 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
839 struct buffer_head *dibh;
840 unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
841 unsigned int to = from + len;
844 BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
846 ret = gfs2_meta_inode_buffer(ip, &dibh);
849 page_cache_release(page);
853 gfs2_trans_add_meta(ip->i_gl, dibh);
855 if (gfs2_is_stuffed(ip))
856 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
858 if (!gfs2_is_writeback(ip))
859 gfs2_page_add_databufs(ip, page, from, to);
861 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
863 if (inode == sdp->sd_rindex) {
864 adjust_fs_space(inode);
865 sdp->sd_rindex_uptodate = 0;
871 gfs2_inplace_release(ip);
872 if (ip->i_res->rs_qa_qd_num)
873 gfs2_quota_unlock(ip);
874 if (inode == sdp->sd_rindex) {
875 gfs2_glock_dq(&m_ip->i_gh);
876 gfs2_holder_uninit(&m_ip->i_gh);
878 gfs2_glock_dq(&ip->i_gh);
879 gfs2_holder_uninit(&ip->i_gh);
884 * gfs2_set_page_dirty - Page dirtying function
885 * @page: The page to dirty
887 * Returns: 1 if it dirtyed the page, or 0 otherwise
890 static int gfs2_set_page_dirty(struct page *page)
892 SetPageChecked(page);
893 return __set_page_dirty_buffers(page);
897 * gfs2_bmap - Block map function
898 * @mapping: Address space info
899 * @lblock: The block to map
901 * Returns: The disk address for the block or 0 on hole or error
904 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
906 struct gfs2_inode *ip = GFS2_I(mapping->host);
907 struct gfs2_holder i_gh;
911 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
915 if (!gfs2_is_stuffed(ip))
916 dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
918 gfs2_glock_dq_uninit(&i_gh);
923 static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
925 struct gfs2_bufdata *bd;
929 clear_buffer_dirty(bh);
932 if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
933 list_del_init(&bd->bd_list);
935 gfs2_remove_from_journal(bh, current->journal_info, 0);
938 clear_buffer_mapped(bh);
939 clear_buffer_req(bh);
940 clear_buffer_new(bh);
941 gfs2_log_unlock(sdp);
945 static void gfs2_invalidatepage(struct page *page, unsigned long offset)
947 struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
948 struct buffer_head *bh, *head;
949 unsigned long pos = 0;
951 BUG_ON(!PageLocked(page));
953 ClearPageChecked(page);
954 if (!page_has_buffers(page))
957 bh = head = page_buffers(page);
960 gfs2_discard(sdp, bh);
962 bh = bh->b_this_page;
963 } while (bh != head);
966 try_to_release_page(page, 0);
970 * gfs2_ok_for_dio - check that dio is valid on this file
973 * @offset: The offset at which we are reading or writing
975 * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o)
976 * 1 (to accept the i/o request)
978 static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
981 * Should we return an error here? I can't see that O_DIRECT for
982 * a stuffed file makes any sense. For now we'll silently fall
983 * back to buffered I/O
985 if (gfs2_is_stuffed(ip))
988 if (offset >= i_size_read(&ip->i_inode))
995 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
996 const struct iovec *iov, loff_t offset,
997 unsigned long nr_segs)
999 struct file *file = iocb->ki_filp;
1000 struct inode *inode = file->f_mapping->host;
1001 struct gfs2_inode *ip = GFS2_I(inode);
1002 struct gfs2_holder gh;
1006 * Deferred lock, even if its a write, since we do no allocation
1007 * on this path. All we need change is atime, and this lock mode
1008 * ensures that other nodes have flushed their buffered read caches
1009 * (i.e. their page cache entries for this inode). We do not,
1010 * unfortunately have the option of only flushing a range like
1013 gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
1014 rv = gfs2_glock_nq(&gh);
1017 rv = gfs2_ok_for_dio(ip, rw, offset);
1019 goto out; /* dio not valid, fall back to buffered i/o */
1021 rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1022 offset, nr_segs, gfs2_get_block_direct,
1026 gfs2_holder_uninit(&gh);
1031 * gfs2_releasepage - free the metadata associated with a page
1032 * @page: the page that's being released
1033 * @gfp_mask: passed from Linux VFS, ignored by us
1035 * Call try_to_free_buffers() if the buffers in this page can be
1041 int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
1043 struct address_space *mapping = page->mapping;
1044 struct gfs2_sbd *sdp = gfs2_mapping2sbd(mapping);
1045 struct buffer_head *bh, *head;
1046 struct gfs2_bufdata *bd;
1048 if (!page_has_buffers(page))
1052 spin_lock(&sdp->sd_ail_lock);
1053 head = bh = page_buffers(page);
1055 if (atomic_read(&bh->b_count))
1056 goto cannot_release;
1058 if (bd && bd->bd_ail)
1059 goto cannot_release;
1060 if (buffer_pinned(bh) || buffer_dirty(bh))
1062 bh = bh->b_this_page;
1063 } while(bh != head);
1064 spin_unlock(&sdp->sd_ail_lock);
1065 gfs2_log_unlock(sdp);
1067 head = bh = page_buffers(page);
1072 gfs2_assert_warn(sdp, bd->bd_bh == bh);
1073 if (!list_empty(&bd->bd_list)) {
1074 if (!buffer_pinned(bh))
1075 list_del_init(&bd->bd_list);
1081 bh->b_private = NULL;
1083 gfs2_log_unlock(sdp);
1085 kmem_cache_free(gfs2_bufdata_cachep, bd);
1087 bh = bh->b_this_page;
1088 } while (bh != head);
1090 return try_to_free_buffers(page);
1092 not_possible: /* Should never happen */
1093 WARN_ON(buffer_dirty(bh));
1094 WARN_ON(buffer_pinned(bh));
1096 spin_unlock(&sdp->sd_ail_lock);
1097 gfs2_log_unlock(sdp);
1101 static const struct address_space_operations gfs2_writeback_aops = {
1102 .writepage = gfs2_writeback_writepage,
1103 .writepages = gfs2_writepages,
1104 .readpage = gfs2_readpage,
1105 .readpages = gfs2_readpages,
1106 .write_begin = gfs2_write_begin,
1107 .write_end = gfs2_write_end,
1109 .invalidatepage = gfs2_invalidatepage,
1110 .releasepage = gfs2_releasepage,
1111 .direct_IO = gfs2_direct_IO,
1112 .migratepage = buffer_migrate_page,
1113 .is_partially_uptodate = block_is_partially_uptodate,
1114 .error_remove_page = generic_error_remove_page,
1117 static const struct address_space_operations gfs2_ordered_aops = {
1118 .writepage = gfs2_ordered_writepage,
1119 .writepages = gfs2_writepages,
1120 .readpage = gfs2_readpage,
1121 .readpages = gfs2_readpages,
1122 .write_begin = gfs2_write_begin,
1123 .write_end = gfs2_write_end,
1124 .set_page_dirty = gfs2_set_page_dirty,
1126 .invalidatepage = gfs2_invalidatepage,
1127 .releasepage = gfs2_releasepage,
1128 .direct_IO = gfs2_direct_IO,
1129 .migratepage = buffer_migrate_page,
1130 .is_partially_uptodate = block_is_partially_uptodate,
1131 .error_remove_page = generic_error_remove_page,
1134 static const struct address_space_operations gfs2_jdata_aops = {
1135 .writepage = gfs2_jdata_writepage,
1136 .writepages = gfs2_jdata_writepages,
1137 .readpage = gfs2_readpage,
1138 .readpages = gfs2_readpages,
1139 .write_begin = gfs2_write_begin,
1140 .write_end = gfs2_write_end,
1141 .set_page_dirty = gfs2_set_page_dirty,
1143 .invalidatepage = gfs2_invalidatepage,
1144 .releasepage = gfs2_releasepage,
1145 .is_partially_uptodate = block_is_partially_uptodate,
1146 .error_remove_page = generic_error_remove_page,
1149 void gfs2_set_aops(struct inode *inode)
1151 struct gfs2_inode *ip = GFS2_I(inode);
1153 if (gfs2_is_writeback(ip))
1154 inode->i_mapping->a_ops = &gfs2_writeback_aops;
1155 else if (gfs2_is_ordered(ip))
1156 inode->i_mapping->a_ops = &gfs2_ordered_aops;
1157 else if (gfs2_is_jdata(ip))
1158 inode->i_mapping->a_ops = &gfs2_jdata_aops;