1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
4 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
23 #include <linux/slab.h>
24 #include <linux/highmem.h>
25 #include <linux/pagemap.h>
26 #include <asm/byteorder.h>
27 #include <linux/swap.h>
28 #include <linux/pipe_fs_i.h>
29 #include <linux/mpage.h>
30 #include <linux/quotaops.h>
32 #define MLOG_MASK_PREFIX ML_FILE_IO
33 #include <cluster/masklog.h>
40 #include "extent_map.h"
47 #include "refcounttree.h"
49 #include "buffer_head_io.h"
51 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
52 struct buffer_head *bh_result, int create)
56 struct ocfs2_dinode *fe = NULL;
57 struct buffer_head *bh = NULL;
58 struct buffer_head *buffer_cache_bh = NULL;
59 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
62 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
63 (unsigned long long)iblock, bh_result, create);
65 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
67 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
68 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
69 (unsigned long long)iblock);
73 status = ocfs2_read_inode_block(inode, &bh);
78 fe = (struct ocfs2_dinode *) bh->b_data;
80 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
81 le32_to_cpu(fe->i_clusters))) {
82 mlog(ML_ERROR, "block offset is outside the allocated size: "
83 "%llu\n", (unsigned long long)iblock);
87 /* We don't use the page cache to create symlink data, so if
88 * need be, copy it over from the buffer cache. */
89 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
90 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
92 buffer_cache_bh = sb_getblk(osb->sb, blkno);
93 if (!buffer_cache_bh) {
94 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
98 /* we haven't locked out transactions, so a commit
99 * could've happened. Since we've got a reference on
100 * the bh, even if it commits while we're doing the
101 * copy, the data is still good. */
102 if (buffer_jbd(buffer_cache_bh)
103 && ocfs2_inode_is_new(inode)) {
104 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
106 mlog(ML_ERROR, "couldn't kmap!\n");
109 memcpy(kaddr + (bh_result->b_size * iblock),
110 buffer_cache_bh->b_data,
112 kunmap_atomic(kaddr, KM_USER0);
113 set_buffer_uptodate(bh_result);
115 brelse(buffer_cache_bh);
118 map_bh(bh_result, inode->i_sb,
119 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
130 int ocfs2_get_block(struct inode *inode, sector_t iblock,
131 struct buffer_head *bh_result, int create)
134 unsigned int ext_flags;
135 u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
136 u64 p_blkno, count, past_eof;
137 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
139 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
140 (unsigned long long)iblock, bh_result, create);
142 if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
143 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
144 inode, inode->i_ino);
146 if (S_ISLNK(inode->i_mode)) {
147 /* this always does I/O for some reason. */
148 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
152 err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
155 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
156 "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
157 (unsigned long long)p_blkno);
161 if (max_blocks < count)
165 * ocfs2 never allocates in this function - the only time we
166 * need to use BH_New is when we're extending i_size on a file
167 * system which doesn't support holes, in which case BH_New
168 * allows block_prepare_write() to zero.
170 * If we see this on a sparse file system, then a truncate has
171 * raced us and removed the cluster. In this case, we clear
172 * the buffers dirty and uptodate bits and let the buffer code
173 * ignore it as a hole.
175 if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
176 clear_buffer_dirty(bh_result);
177 clear_buffer_uptodate(bh_result);
181 /* Treat the unwritten extent as a hole for zeroing purposes. */
182 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
183 map_bh(bh_result, inode->i_sb, p_blkno);
185 bh_result->b_size = count << inode->i_blkbits;
187 if (!ocfs2_sparse_alloc(osb)) {
191 "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
192 (unsigned long long)iblock,
193 (unsigned long long)p_blkno,
194 (unsigned long long)OCFS2_I(inode)->ip_blkno);
195 mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
200 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
201 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
202 (unsigned long long)past_eof);
204 if (create && (iblock >= past_eof))
205 set_buffer_new(bh_result);
216 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
217 struct buffer_head *di_bh)
221 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
223 if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
224 ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
225 (unsigned long long)OCFS2_I(inode)->ip_blkno);
229 size = i_size_read(inode);
231 if (size > PAGE_CACHE_SIZE ||
232 size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
233 ocfs2_error(inode->i_sb,
234 "Inode %llu has with inline data has bad size: %Lu",
235 (unsigned long long)OCFS2_I(inode)->ip_blkno,
236 (unsigned long long)size);
240 kaddr = kmap_atomic(page, KM_USER0);
242 memcpy(kaddr, di->id2.i_data.id_data, size);
243 /* Clear the remaining part of the page */
244 memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
245 flush_dcache_page(page);
246 kunmap_atomic(kaddr, KM_USER0);
248 SetPageUptodate(page);
253 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
256 struct buffer_head *di_bh = NULL;
258 BUG_ON(!PageLocked(page));
259 BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
261 ret = ocfs2_read_inode_block(inode, &di_bh);
267 ret = ocfs2_read_inline_data(inode, page, di_bh);
275 static int ocfs2_readpage(struct file *file, struct page *page)
277 struct inode *inode = page->mapping->host;
278 struct ocfs2_inode_info *oi = OCFS2_I(inode);
279 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
282 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
284 ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
286 if (ret == AOP_TRUNCATED_PAGE)
292 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
293 ret = AOP_TRUNCATED_PAGE;
294 goto out_inode_unlock;
298 * i_size might have just been updated as we grabed the meta lock. We
299 * might now be discovering a truncate that hit on another node.
300 * block_read_full_page->get_block freaks out if it is asked to read
301 * beyond the end of a file, so we check here. Callers
302 * (generic_file_read, vm_ops->fault) are clever enough to check i_size
303 * and notice that the page they just read isn't needed.
305 * XXX sys_readahead() seems to get that wrong?
307 if (start >= i_size_read(inode)) {
308 zero_user(page, 0, PAGE_SIZE);
309 SetPageUptodate(page);
314 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
315 ret = ocfs2_readpage_inline(inode, page);
317 ret = block_read_full_page(page, ocfs2_get_block);
321 up_read(&OCFS2_I(inode)->ip_alloc_sem);
323 ocfs2_inode_unlock(inode, 0);
332 * This is used only for read-ahead. Failures or difficult to handle
333 * situations are safe to ignore.
335 * Right now, we don't bother with BH_Boundary - in-inode extent lists
336 * are quite large (243 extents on 4k blocks), so most inodes don't
337 * grow out to a tree. If need be, detecting boundary extents could
338 * trivially be added in a future version of ocfs2_get_block().
340 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
341 struct list_head *pages, unsigned nr_pages)
344 struct inode *inode = mapping->host;
345 struct ocfs2_inode_info *oi = OCFS2_I(inode);
350 * Use the nonblocking flag for the dlm code to avoid page
351 * lock inversion, but don't bother with retrying.
353 ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
357 if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
358 ocfs2_inode_unlock(inode, 0);
363 * Don't bother with inline-data. There isn't anything
364 * to read-ahead in that case anyway...
366 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
370 * Check whether a remote node truncated this file - we just
371 * drop out in that case as it's not worth handling here.
373 last = list_entry(pages->prev, struct page, lru);
374 start = (loff_t)last->index << PAGE_CACHE_SHIFT;
375 if (start >= i_size_read(inode))
378 err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
381 up_read(&oi->ip_alloc_sem);
382 ocfs2_inode_unlock(inode, 0);
387 /* Note: Because we don't support holes, our allocation has
388 * already happened (allocation writes zeros to the file data)
389 * so we don't have to worry about ordered writes in
392 * ->writepage is called during the process of invalidating the page cache
393 * during blocked lock processing. It can't block on any cluster locks
394 * to during block mapping. It's relying on the fact that the block
395 * mapping can't have disappeared under the dirty pages that it is
396 * being asked to write back.
398 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
402 mlog_entry("(0x%p)\n", page);
404 ret = block_write_full_page(page, ocfs2_get_block, wbc);
412 * This is called from ocfs2_write_zero_page() which has handled it's
413 * own cluster locking and has ensured allocation exists for those
414 * blocks to be written.
416 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
417 unsigned from, unsigned to)
421 ret = block_prepare_write(page, from, to, ocfs2_get_block);
426 /* Taken from ext3. We don't necessarily need the full blown
427 * functionality yet, but IMHO it's better to cut and paste the whole
428 * thing so we can avoid introducing our own bugs (and easily pick up
429 * their fixes when they happen) --Mark */
430 int walk_page_buffers( handle_t *handle,
431 struct buffer_head *head,
435 int (*fn)( handle_t *handle,
436 struct buffer_head *bh))
438 struct buffer_head *bh;
439 unsigned block_start, block_end;
440 unsigned blocksize = head->b_size;
442 struct buffer_head *next;
444 for ( bh = head, block_start = 0;
445 ret == 0 && (bh != head || !block_start);
446 block_start = block_end, bh = next)
448 next = bh->b_this_page;
449 block_end = block_start + blocksize;
450 if (block_end <= from || block_start >= to) {
451 if (partial && !buffer_uptodate(bh))
455 err = (*fn)(handle, bh);
462 handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
467 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
471 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
472 if (IS_ERR(handle)) {
478 if (ocfs2_should_order_data(inode)) {
479 ret = ocfs2_jbd2_file_inode(handle, inode);
486 ocfs2_commit_trans(osb, handle);
487 handle = ERR_PTR(ret);
492 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
497 struct inode *inode = mapping->host;
499 mlog_entry("(block = %llu)\n", (unsigned long long)block);
501 /* We don't need to lock journal system files, since they aren't
502 * accessed concurrently from multiple nodes.
504 if (!INODE_JOURNAL(inode)) {
505 err = ocfs2_inode_lock(inode, NULL, 0);
511 down_read(&OCFS2_I(inode)->ip_alloc_sem);
514 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
515 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
518 if (!INODE_JOURNAL(inode)) {
519 up_read(&OCFS2_I(inode)->ip_alloc_sem);
520 ocfs2_inode_unlock(inode, 0);
524 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
525 (unsigned long long)block);
531 status = err ? 0 : p_blkno;
533 mlog_exit((int)status);
539 * TODO: Make this into a generic get_blocks function.
541 * From do_direct_io in direct-io.c:
542 * "So what we do is to permit the ->get_blocks function to populate
543 * bh.b_size with the size of IO which is permitted at this offset and
546 * This function is called directly from get_more_blocks in direct-io.c.
548 * called like this: dio->get_blocks(dio->inode, fs_startblk,
549 * fs_count, map_bh, dio->rw == WRITE);
551 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
552 struct buffer_head *bh_result, int create)
555 u64 p_blkno, inode_blocks, contig_blocks;
556 unsigned int ext_flags;
557 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
558 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
560 /* This function won't even be called if the request isn't all
561 * nicely aligned and of the right size, so there's no need
562 * for us to check any of that. */
564 inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
567 * Any write past EOF is not allowed because we'd be extending.
569 if (create && (iblock + max_blocks) > inode_blocks) {
574 /* This figures out the size of the next contiguous block, and
575 * our logical offset */
576 ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
577 &contig_blocks, &ext_flags);
579 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
580 (unsigned long long)iblock);
585 if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno && create) {
586 ocfs2_error(inode->i_sb,
587 "Inode %llu has a hole at block %llu\n",
588 (unsigned long long)OCFS2_I(inode)->ip_blkno,
589 (unsigned long long)iblock);
594 /* We should already CoW the refcounted extent. */
595 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
597 * get_more_blocks() expects us to describe a hole by clearing
598 * the mapped bit on bh_result().
600 * Consider an unwritten extent as a hole.
602 if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
603 map_bh(bh_result, inode->i_sb, p_blkno);
606 * ocfs2_prepare_inode_for_write() should have caught
607 * the case where we'd be filling a hole and triggered
608 * a buffered write instead.
616 clear_buffer_mapped(bh_result);
619 /* make sure we don't map more than max_blocks blocks here as
620 that's all the kernel will handle at this point. */
621 if (max_blocks < contig_blocks)
622 contig_blocks = max_blocks;
623 bh_result->b_size = contig_blocks << blocksize_bits;
629 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
630 * particularly interested in the aio/dio case. Like the core uses
631 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
632 * truncation on another.
634 static void ocfs2_dio_end_io(struct kiocb *iocb,
639 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
642 /* this io's submitter should not have unlocked this before we could */
643 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
645 ocfs2_iocb_clear_rw_locked(iocb);
647 level = ocfs2_iocb_rw_locked_level(iocb);
649 up_read(&inode->i_alloc_sem);
650 ocfs2_rw_unlock(inode, level);
654 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
655 * from ext3. PageChecked() bits have been removed as OCFS2 does not
656 * do journalled data.
658 static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
660 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
662 jbd2_journal_invalidatepage(journal, page, offset);
665 static int ocfs2_releasepage(struct page *page, gfp_t wait)
667 journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
669 if (!page_has_buffers(page))
671 return jbd2_journal_try_to_free_buffers(journal, page, wait);
674 static ssize_t ocfs2_direct_IO(int rw,
676 const struct iovec *iov,
678 unsigned long nr_segs)
680 struct file *file = iocb->ki_filp;
681 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
687 * Fallback to buffered I/O if we see an inode without
690 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
693 /* Fallback to buffered I/O if we are appending. */
694 if (i_size_read(inode) <= offset)
697 ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
698 inode->i_sb->s_bdev, iov, offset,
700 ocfs2_direct_IO_get_blocks,
707 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
712 unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
714 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
717 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
719 cluster_start = cpos % cpp;
720 cluster_start = cluster_start << osb->s_clustersize_bits;
722 cluster_end = cluster_start + osb->s_clustersize;
725 BUG_ON(cluster_start > PAGE_SIZE);
726 BUG_ON(cluster_end > PAGE_SIZE);
729 *start = cluster_start;
735 * 'from' and 'to' are the region in the page to avoid zeroing.
737 * If pagesize > clustersize, this function will avoid zeroing outside
738 * of the cluster boundary.
740 * from == to == 0 is code for "zero the entire cluster region"
742 static void ocfs2_clear_page_regions(struct page *page,
743 struct ocfs2_super *osb, u32 cpos,
744 unsigned from, unsigned to)
747 unsigned int cluster_start, cluster_end;
749 ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
751 kaddr = kmap_atomic(page, KM_USER0);
754 if (from > cluster_start)
755 memset(kaddr + cluster_start, 0, from - cluster_start);
756 if (to < cluster_end)
757 memset(kaddr + to, 0, cluster_end - to);
759 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
762 kunmap_atomic(kaddr, KM_USER0);
766 * Nonsparse file systems fully allocate before we get to the write
767 * code. This prevents ocfs2_write() from tagging the write as an
768 * allocating one, which means ocfs2_map_page_blocks() might try to
769 * read-in the blocks at the tail of our file. Avoid reading them by
770 * testing i_size against each block offset.
772 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
773 unsigned int block_start)
775 u64 offset = page_offset(page) + block_start;
777 if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
780 if (i_size_read(inode) > offset)
787 * Some of this taken from block_prepare_write(). We already have our
788 * mapping by now though, and the entire write will be allocating or
789 * it won't, so not much need to use BH_New.
791 * This will also skip zeroing, which is handled externally.
793 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
794 struct inode *inode, unsigned int from,
795 unsigned int to, int new)
798 struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
799 unsigned int block_end, block_start;
800 unsigned int bsize = 1 << inode->i_blkbits;
802 if (!page_has_buffers(page))
803 create_empty_buffers(page, bsize, 0);
805 head = page_buffers(page);
806 for (bh = head, block_start = 0; bh != head || !block_start;
807 bh = bh->b_this_page, block_start += bsize) {
808 block_end = block_start + bsize;
810 clear_buffer_new(bh);
813 * Ignore blocks outside of our i/o range -
814 * they may belong to unallocated clusters.
816 if (block_start >= to || block_end <= from) {
817 if (PageUptodate(page))
818 set_buffer_uptodate(bh);
823 * For an allocating write with cluster size >= page
824 * size, we always write the entire page.
829 if (!buffer_mapped(bh)) {
830 map_bh(bh, inode->i_sb, *p_blkno);
831 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
834 if (PageUptodate(page)) {
835 if (!buffer_uptodate(bh))
836 set_buffer_uptodate(bh);
837 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
839 ocfs2_should_read_blk(inode, page, block_start) &&
840 (block_start < from || block_end > to)) {
841 ll_rw_block(READ, 1, &bh);
845 *p_blkno = *p_blkno + 1;
849 * If we issued read requests - let them complete.
851 while(wait_bh > wait) {
852 wait_on_buffer(*--wait_bh);
853 if (!buffer_uptodate(*wait_bh))
857 if (ret == 0 || !new)
861 * If we get -EIO above, zero out any newly allocated blocks
862 * to avoid exposing stale data.
867 block_end = block_start + bsize;
868 if (block_end <= from)
870 if (block_start >= to)
873 zero_user(page, block_start, bh->b_size);
874 set_buffer_uptodate(bh);
875 mark_buffer_dirty(bh);
878 block_start = block_end;
879 bh = bh->b_this_page;
880 } while (bh != head);
885 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
886 #define OCFS2_MAX_CTXT_PAGES 1
888 #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
891 #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
894 * Describe the state of a single cluster to be written to.
896 struct ocfs2_write_cluster_desc {
900 * Give this a unique field because c_phys eventually gets
904 unsigned c_unwritten;
905 unsigned c_needs_zero;
908 struct ocfs2_write_ctxt {
909 /* Logical cluster position / len of write */
913 /* First cluster allocated in a nonsparse extend */
914 u32 w_first_new_cpos;
916 struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
919 * This is true if page_size > cluster_size.
921 * It triggers a set of special cases during write which might
922 * have to deal with allocating writes to partial pages.
924 unsigned int w_large_pages;
927 * Pages involved in this write.
929 * w_target_page is the page being written to by the user.
931 * w_pages is an array of pages which always contains
932 * w_target_page, and in the case of an allocating write with
933 * page_size < cluster size, it will contain zero'd and mapped
934 * pages adjacent to w_target_page which need to be written
935 * out in so that future reads from that region will get
938 struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
939 unsigned int w_num_pages;
940 struct page *w_target_page;
943 * ocfs2_write_end() uses this to know what the real range to
944 * write in the target should be.
946 unsigned int w_target_from;
947 unsigned int w_target_to;
950 * We could use journal_current_handle() but this is cleaner,
955 struct buffer_head *w_di_bh;
957 struct ocfs2_cached_dealloc_ctxt w_dealloc;
960 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
964 for(i = 0; i < num_pages; i++) {
966 unlock_page(pages[i]);
967 mark_page_accessed(pages[i]);
968 page_cache_release(pages[i]);
973 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
975 ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
981 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
982 struct ocfs2_super *osb, loff_t pos,
983 unsigned len, struct buffer_head *di_bh)
986 struct ocfs2_write_ctxt *wc;
988 wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
992 wc->w_cpos = pos >> osb->s_clustersize_bits;
993 wc->w_first_new_cpos = UINT_MAX;
994 cend = (pos + len - 1) >> osb->s_clustersize_bits;
995 wc->w_clen = cend - wc->w_cpos + 1;
999 if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
1000 wc->w_large_pages = 1;
1002 wc->w_large_pages = 0;
1004 ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
1012 * If a page has any new buffers, zero them out here, and mark them uptodate
1013 * and dirty so they'll be written out (in order to prevent uninitialised
1014 * block data from leaking). And clear the new bit.
1016 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
1018 unsigned int block_start, block_end;
1019 struct buffer_head *head, *bh;
1021 BUG_ON(!PageLocked(page));
1022 if (!page_has_buffers(page))
1025 bh = head = page_buffers(page);
1028 block_end = block_start + bh->b_size;
1030 if (buffer_new(bh)) {
1031 if (block_end > from && block_start < to) {
1032 if (!PageUptodate(page)) {
1033 unsigned start, end;
1035 start = max(from, block_start);
1036 end = min(to, block_end);
1038 zero_user_segment(page, start, end);
1039 set_buffer_uptodate(bh);
1042 clear_buffer_new(bh);
1043 mark_buffer_dirty(bh);
1047 block_start = block_end;
1048 bh = bh->b_this_page;
1049 } while (bh != head);
1053 * Only called when we have a failure during allocating write to write
1054 * zero's to the newly allocated region.
1056 static void ocfs2_write_failure(struct inode *inode,
1057 struct ocfs2_write_ctxt *wc,
1058 loff_t user_pos, unsigned user_len)
1061 unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
1062 to = user_pos + user_len;
1063 struct page *tmppage;
1065 ocfs2_zero_new_buffers(wc->w_target_page, from, to);
1067 for(i = 0; i < wc->w_num_pages; i++) {
1068 tmppage = wc->w_pages[i];
1070 if (page_has_buffers(tmppage)) {
1071 if (ocfs2_should_order_data(inode))
1072 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1074 block_commit_write(tmppage, from, to);
1079 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1080 struct ocfs2_write_ctxt *wc,
1081 struct page *page, u32 cpos,
1082 loff_t user_pos, unsigned user_len,
1086 unsigned int map_from = 0, map_to = 0;
1087 unsigned int cluster_start, cluster_end;
1088 unsigned int user_data_from = 0, user_data_to = 0;
1090 ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1091 &cluster_start, &cluster_end);
1093 if (page == wc->w_target_page) {
1094 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1095 map_to = map_from + user_len;
1098 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1099 cluster_start, cluster_end,
1102 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1103 map_from, map_to, new);
1109 user_data_from = map_from;
1110 user_data_to = map_to;
1112 map_from = cluster_start;
1113 map_to = cluster_end;
1117 * If we haven't allocated the new page yet, we
1118 * shouldn't be writing it out without copying user
1119 * data. This is likely a math error from the caller.
1123 map_from = cluster_start;
1124 map_to = cluster_end;
1126 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1127 cluster_start, cluster_end, new);
1135 * Parts of newly allocated pages need to be zero'd.
1137 * Above, we have also rewritten 'to' and 'from' - as far as
1138 * the rest of the function is concerned, the entire cluster
1139 * range inside of a page needs to be written.
1141 * We can skip this if the page is up to date - it's already
1142 * been zero'd from being read in as a hole.
1144 if (new && !PageUptodate(page))
1145 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1146 cpos, user_data_from, user_data_to);
1148 flush_dcache_page(page);
1155 * This function will only grab one clusters worth of pages.
1157 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1158 struct ocfs2_write_ctxt *wc,
1159 u32 cpos, loff_t user_pos, int new,
1160 struct page *mmap_page)
1163 unsigned long start, target_index, index;
1164 struct inode *inode = mapping->host;
1166 target_index = user_pos >> PAGE_CACHE_SHIFT;
1169 * Figure out how many pages we'll be manipulating here. For
1170 * non allocating write, we just change the one
1171 * page. Otherwise, we'll need a whole clusters worth.
1174 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1175 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1177 wc->w_num_pages = 1;
1178 start = target_index;
1181 for(i = 0; i < wc->w_num_pages; i++) {
1184 if (index == target_index && mmap_page) {
1186 * ocfs2_pagemkwrite() is a little different
1187 * and wants us to directly use the page
1190 lock_page(mmap_page);
1192 if (mmap_page->mapping != mapping) {
1193 unlock_page(mmap_page);
1195 * Sanity check - the locking in
1196 * ocfs2_pagemkwrite() should ensure
1197 * that this code doesn't trigger.
1204 page_cache_get(mmap_page);
1205 wc->w_pages[i] = mmap_page;
1207 wc->w_pages[i] = find_or_create_page(mapping, index,
1209 if (!wc->w_pages[i]) {
1216 if (index == target_index)
1217 wc->w_target_page = wc->w_pages[i];
1224 * Prepare a single cluster for write one cluster into the file.
1226 static int ocfs2_write_cluster(struct address_space *mapping,
1227 u32 phys, unsigned int unwritten,
1228 unsigned int should_zero,
1229 struct ocfs2_alloc_context *data_ac,
1230 struct ocfs2_alloc_context *meta_ac,
1231 struct ocfs2_write_ctxt *wc, u32 cpos,
1232 loff_t user_pos, unsigned user_len)
1235 u64 v_blkno, p_blkno;
1236 struct inode *inode = mapping->host;
1237 struct ocfs2_extent_tree et;
1239 new = phys == 0 ? 1 : 0;
1244 * This is safe to call with the page locks - it won't take
1245 * any additional semaphores or cluster locks.
1248 ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1249 &tmp_pos, 1, 0, wc->w_di_bh,
1250 wc->w_handle, data_ac,
1253 * This shouldn't happen because we must have already
1254 * calculated the correct meta data allocation required. The
1255 * internal tree allocation code should know how to increase
1256 * transaction credits itself.
1258 * If need be, we could handle -EAGAIN for a
1259 * RESTART_TRANS here.
1261 mlog_bug_on_msg(ret == -EAGAIN,
1262 "Inode %llu: EAGAIN return during allocation.\n",
1263 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1268 } else if (unwritten) {
1269 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1271 ret = ocfs2_mark_extent_written(inode, &et,
1272 wc->w_handle, cpos, 1, phys,
1273 meta_ac, &wc->w_dealloc);
1281 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1283 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1286 * The only reason this should fail is due to an inability to
1287 * find the extent added.
1289 ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1292 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1293 "at logical block %llu",
1294 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1295 (unsigned long long)v_blkno);
1299 BUG_ON(p_blkno == 0);
1301 for(i = 0; i < wc->w_num_pages; i++) {
1304 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1305 wc->w_pages[i], cpos,
1316 * We only have cleanup to do in case of allocating write.
1319 ocfs2_write_failure(inode, wc, user_pos, user_len);
1326 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1327 struct ocfs2_alloc_context *data_ac,
1328 struct ocfs2_alloc_context *meta_ac,
1329 struct ocfs2_write_ctxt *wc,
1330 loff_t pos, unsigned len)
1334 unsigned int local_len = len;
1335 struct ocfs2_write_cluster_desc *desc;
1336 struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1338 for (i = 0; i < wc->w_clen; i++) {
1339 desc = &wc->w_desc[i];
1342 * We have to make sure that the total write passed in
1343 * doesn't extend past a single cluster.
1346 cluster_off = pos & (osb->s_clustersize - 1);
1347 if ((cluster_off + local_len) > osb->s_clustersize)
1348 local_len = osb->s_clustersize - cluster_off;
1350 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1354 wc, desc->c_cpos, pos, local_len);
1370 * ocfs2_write_end() wants to know which parts of the target page it
1371 * should complete the write on. It's easiest to compute them ahead of
1372 * time when a more complete view of the write is available.
1374 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1375 struct ocfs2_write_ctxt *wc,
1376 loff_t pos, unsigned len, int alloc)
1378 struct ocfs2_write_cluster_desc *desc;
1380 wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1381 wc->w_target_to = wc->w_target_from + len;
1387 * Allocating write - we may have different boundaries based
1388 * on page size and cluster size.
1390 * NOTE: We can no longer compute one value from the other as
1391 * the actual write length and user provided length may be
1395 if (wc->w_large_pages) {
1397 * We only care about the 1st and last cluster within
1398 * our range and whether they should be zero'd or not. Either
1399 * value may be extended out to the start/end of a
1400 * newly allocated cluster.
1402 desc = &wc->w_desc[0];
1403 if (desc->c_needs_zero)
1404 ocfs2_figure_cluster_boundaries(osb,
1409 desc = &wc->w_desc[wc->w_clen - 1];
1410 if (desc->c_needs_zero)
1411 ocfs2_figure_cluster_boundaries(osb,
1416 wc->w_target_from = 0;
1417 wc->w_target_to = PAGE_CACHE_SIZE;
1422 * Populate each single-cluster write descriptor in the write context
1423 * with information about the i/o to be done.
1425 * Returns the number of clusters that will have to be allocated, as
1426 * well as a worst case estimate of the number of extent records that
1427 * would have to be created during a write to an unwritten region.
1429 static int ocfs2_populate_write_desc(struct inode *inode,
1430 struct ocfs2_write_ctxt *wc,
1431 unsigned int *clusters_to_alloc,
1432 unsigned int *extents_to_split)
1435 struct ocfs2_write_cluster_desc *desc;
1436 unsigned int num_clusters = 0;
1437 unsigned int ext_flags = 0;
1441 *clusters_to_alloc = 0;
1442 *extents_to_split = 0;
1444 for (i = 0; i < wc->w_clen; i++) {
1445 desc = &wc->w_desc[i];
1446 desc->c_cpos = wc->w_cpos + i;
1448 if (num_clusters == 0) {
1450 * Need to look up the next extent record.
1452 ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1453 &num_clusters, &ext_flags);
1459 /* We should already CoW the refcountd extent. */
1460 BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1463 * Assume worst case - that we're writing in
1464 * the middle of the extent.
1466 * We can assume that the write proceeds from
1467 * left to right, in which case the extent
1468 * insert code is smart enough to coalesce the
1469 * next splits into the previous records created.
1471 if (ext_flags & OCFS2_EXT_UNWRITTEN)
1472 *extents_to_split = *extents_to_split + 2;
1475 * Only increment phys if it doesn't describe
1482 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1483 * file that got extended. w_first_new_cpos tells us
1484 * where the newly allocated clusters are so we can
1487 if (desc->c_cpos >= wc->w_first_new_cpos) {
1489 desc->c_needs_zero = 1;
1492 desc->c_phys = phys;
1495 desc->c_needs_zero = 1;
1496 *clusters_to_alloc = *clusters_to_alloc + 1;
1499 if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1500 desc->c_unwritten = 1;
1501 desc->c_needs_zero = 1;
1512 static int ocfs2_write_begin_inline(struct address_space *mapping,
1513 struct inode *inode,
1514 struct ocfs2_write_ctxt *wc)
1517 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1520 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1522 page = find_or_create_page(mapping, 0, GFP_NOFS);
1529 * If we don't set w_num_pages then this page won't get unlocked
1530 * and freed on cleanup of the write context.
1532 wc->w_pages[0] = wc->w_target_page = page;
1533 wc->w_num_pages = 1;
1535 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1536 if (IS_ERR(handle)) {
1537 ret = PTR_ERR(handle);
1542 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1543 OCFS2_JOURNAL_ACCESS_WRITE);
1545 ocfs2_commit_trans(osb, handle);
1551 if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1552 ocfs2_set_inode_data_inline(inode, di);
1554 if (!PageUptodate(page)) {
1555 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1557 ocfs2_commit_trans(osb, handle);
1563 wc->w_handle = handle;
1568 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1570 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1572 if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1577 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1578 struct inode *inode, loff_t pos,
1579 unsigned len, struct page *mmap_page,
1580 struct ocfs2_write_ctxt *wc)
1582 int ret, written = 0;
1583 loff_t end = pos + len;
1584 struct ocfs2_inode_info *oi = OCFS2_I(inode);
1585 struct ocfs2_dinode *di = NULL;
1587 mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n",
1588 (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos,
1589 oi->ip_dyn_features);
1592 * Handle inodes which already have inline data 1st.
1594 if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1595 if (mmap_page == NULL &&
1596 ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1597 goto do_inline_write;
1600 * The write won't fit - we have to give this inode an
1601 * inline extent list now.
1603 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1610 * Check whether the inode can accept inline data.
1612 if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1616 * Check whether the write can fit.
1618 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1620 end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1624 ret = ocfs2_write_begin_inline(mapping, inode, wc);
1631 * This signals to the caller that the data can be written
1636 return written ? written : ret;
1640 * This function only does anything for file systems which can't
1641 * handle sparse files.
1643 * What we want to do here is fill in any hole between the current end
1644 * of allocation and the end of our write. That way the rest of the
1645 * write path can treat it as an non-allocating write, which has no
1646 * special case code for sparse/nonsparse files.
1648 static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,
1650 struct ocfs2_write_ctxt *wc)
1653 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1654 loff_t newsize = pos + len;
1656 if (ocfs2_sparse_alloc(osb))
1659 if (newsize <= i_size_read(inode))
1662 ret = ocfs2_extend_no_holes(inode, newsize, pos);
1666 wc->w_first_new_cpos =
1667 ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1672 int ocfs2_write_begin_nolock(struct address_space *mapping,
1673 loff_t pos, unsigned len, unsigned flags,
1674 struct page **pagep, void **fsdata,
1675 struct buffer_head *di_bh, struct page *mmap_page)
1677 int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1678 unsigned int clusters_to_alloc, extents_to_split;
1679 struct ocfs2_write_ctxt *wc;
1680 struct inode *inode = mapping->host;
1681 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1682 struct ocfs2_dinode *di;
1683 struct ocfs2_alloc_context *data_ac = NULL;
1684 struct ocfs2_alloc_context *meta_ac = NULL;
1686 struct ocfs2_extent_tree et;
1688 ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1694 if (ocfs2_supports_inline_data(osb)) {
1695 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1707 ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);
1713 ret = ocfs2_check_range_for_refcount(inode, pos, len);
1717 } else if (ret == 1) {
1718 ret = ocfs2_refcount_cow(inode, di_bh,
1719 wc->w_cpos, wc->w_clen, UINT_MAX);
1726 ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1733 di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1736 * We set w_target_from, w_target_to here so that
1737 * ocfs2_write_end() knows which range in the target page to
1738 * write out. An allocation requires that we write the entire
1741 if (clusters_to_alloc || extents_to_split) {
1743 * XXX: We are stretching the limits of
1744 * ocfs2_lock_allocators(). It greatly over-estimates
1745 * the work to be done.
1747 mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u,"
1748 " clusters_to_add = %u, extents_to_split = %u\n",
1749 (unsigned long long)OCFS2_I(inode)->ip_blkno,
1750 (long long)i_size_read(inode), le32_to_cpu(di->i_clusters),
1751 clusters_to_alloc, extents_to_split);
1753 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1755 ret = ocfs2_lock_allocators(inode, &et,
1756 clusters_to_alloc, extents_to_split,
1757 &data_ac, &meta_ac);
1763 credits = ocfs2_calc_extend_credits(inode->i_sb,
1770 * We have to zero sparse allocated clusters, unwritten extent clusters,
1771 * and non-sparse clusters we just extended. For non-sparse writes,
1772 * we know zeros will only be needed in the first and/or last cluster.
1774 if (clusters_to_alloc || extents_to_split ||
1775 (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1776 wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1777 cluster_of_pages = 1;
1779 cluster_of_pages = 0;
1781 ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1783 handle = ocfs2_start_trans(osb, credits);
1784 if (IS_ERR(handle)) {
1785 ret = PTR_ERR(handle);
1790 wc->w_handle = handle;
1792 if (clusters_to_alloc && vfs_dq_alloc_space_nodirty(inode,
1793 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc))) {
1798 * We don't want this to fail in ocfs2_write_end(), so do it
1801 ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1802 OCFS2_JOURNAL_ACCESS_WRITE);
1809 * Fill our page array first. That way we've grabbed enough so
1810 * that we can zero and flush if we error after adding the
1813 ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
1814 cluster_of_pages, mmap_page);
1820 ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1828 ocfs2_free_alloc_context(data_ac);
1830 ocfs2_free_alloc_context(meta_ac);
1833 *pagep = wc->w_target_page;
1837 if (clusters_to_alloc)
1838 vfs_dq_free_space(inode,
1839 ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1841 ocfs2_commit_trans(osb, handle);
1844 ocfs2_free_write_ctxt(wc);
1847 ocfs2_free_alloc_context(data_ac);
1849 ocfs2_free_alloc_context(meta_ac);
1853 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1854 loff_t pos, unsigned len, unsigned flags,
1855 struct page **pagep, void **fsdata)
1858 struct buffer_head *di_bh = NULL;
1859 struct inode *inode = mapping->host;
1861 ret = ocfs2_inode_lock(inode, &di_bh, 1);
1868 * Take alloc sem here to prevent concurrent lookups. That way
1869 * the mapping, zeroing and tree manipulation within
1870 * ocfs2_write() will be safe against ->readpage(). This
1871 * should also serve to lock out allocation from a shared
1874 down_write(&OCFS2_I(inode)->ip_alloc_sem);
1876 ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
1877 fsdata, di_bh, NULL);
1888 up_write(&OCFS2_I(inode)->ip_alloc_sem);
1891 ocfs2_inode_unlock(inode, 1);
1896 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1897 unsigned len, unsigned *copied,
1898 struct ocfs2_dinode *di,
1899 struct ocfs2_write_ctxt *wc)
1903 if (unlikely(*copied < len)) {
1904 if (!PageUptodate(wc->w_target_page)) {
1910 kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
1911 memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1912 kunmap_atomic(kaddr, KM_USER0);
1914 mlog(0, "Data written to inode at offset %llu. "
1915 "id_count = %u, copied = %u, i_dyn_features = 0x%x\n",
1916 (unsigned long long)pos, *copied,
1917 le16_to_cpu(di->id2.i_data.id_count),
1918 le16_to_cpu(di->i_dyn_features));
1921 int ocfs2_write_end_nolock(struct address_space *mapping,
1922 loff_t pos, unsigned len, unsigned copied,
1923 struct page *page, void *fsdata)
1926 unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1927 struct inode *inode = mapping->host;
1928 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1929 struct ocfs2_write_ctxt *wc = fsdata;
1930 struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1931 handle_t *handle = wc->w_handle;
1932 struct page *tmppage;
1934 if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1935 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1936 goto out_write_size;
1939 if (unlikely(copied < len)) {
1940 if (!PageUptodate(wc->w_target_page))
1943 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1946 flush_dcache_page(wc->w_target_page);
1948 for(i = 0; i < wc->w_num_pages; i++) {
1949 tmppage = wc->w_pages[i];
1951 if (tmppage == wc->w_target_page) {
1952 from = wc->w_target_from;
1953 to = wc->w_target_to;
1955 BUG_ON(from > PAGE_CACHE_SIZE ||
1956 to > PAGE_CACHE_SIZE ||
1960 * Pages adjacent to the target (if any) imply
1961 * a hole-filling write in which case we want
1962 * to flush their entire range.
1965 to = PAGE_CACHE_SIZE;
1968 if (page_has_buffers(tmppage)) {
1969 if (ocfs2_should_order_data(inode))
1970 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1971 block_commit_write(tmppage, from, to);
1977 if (pos > inode->i_size) {
1978 i_size_write(inode, pos);
1979 mark_inode_dirty(inode);
1981 inode->i_blocks = ocfs2_inode_sector_count(inode);
1982 di->i_size = cpu_to_le64((u64)i_size_read(inode));
1983 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1984 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
1985 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
1986 ocfs2_journal_dirty(handle, wc->w_di_bh);
1988 ocfs2_commit_trans(osb, handle);
1990 ocfs2_run_deallocs(osb, &wc->w_dealloc);
1992 ocfs2_free_write_ctxt(wc);
1997 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
1998 loff_t pos, unsigned len, unsigned copied,
1999 struct page *page, void *fsdata)
2002 struct inode *inode = mapping->host;
2004 ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
2006 up_write(&OCFS2_I(inode)->ip_alloc_sem);
2007 ocfs2_inode_unlock(inode, 1);
2012 const struct address_space_operations ocfs2_aops = {
2013 .readpage = ocfs2_readpage,
2014 .readpages = ocfs2_readpages,
2015 .writepage = ocfs2_writepage,
2016 .write_begin = ocfs2_write_begin,
2017 .write_end = ocfs2_write_end,
2019 .sync_page = block_sync_page,
2020 .direct_IO = ocfs2_direct_IO,
2021 .invalidatepage = ocfs2_invalidatepage,
2022 .releasepage = ocfs2_releasepage,
2023 .migratepage = buffer_migrate_page,
2024 .is_partially_uptodate = block_is_partially_uptodate,
2025 .error_remove_page = generic_error_remove_page,