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| author | WeiWei Wang <wangww631@huawei.com> | 2015-09-05 00:44:23 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-05 01:54:41 +0200 |
| commit | 6ab855a99b735c227ad1e0deda636833f41c5b87 (patch) | |
| tree | 236c00bd664c7557378b2a03f1a55de4e9e0498c | |
| parent | ocfs2: clear the rest of the buffers on error (diff) | |
| download | linux-6ab855a99b735c227ad1e0deda636833f41c5b87.tar.xz linux-6ab855a99b735c227ad1e0deda636833f41c5b87.zip | |
ocfs2: add ip_alloc_sem in direct IO to protect allocation changes
In ocfs2, ip_alloc_sem is used to protect allocation changes on the
node. In direct IO, we add ip_alloc_sem to protect date consistent
between direct-io and ocfs2_truncate_file race (buffer io use
ip_alloc_sem already). Although inode->i_mutex lock is used to avoid
concurrency of above situation, i think ip_alloc_sem is still needed
because protect allocation changes is significant.
Other filesystem like ext4 also uses rw_semaphore to protect data
consistent between get_block-vs-truncate race by other means, So
ip_alloc_sem in ocfs2 direct io is needed.
Signed-off-by: Weiwei Wang <wangww631@huawei.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ocfs2/aops.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index b36dcad3a140..a7ab145e2901 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -533,10 +533,14 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); + down_read(&OCFS2_I(inode)->ip_alloc_sem); + /* This figures out the size of the next contiguous block, and * our logical offset */ ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &contig_blocks, &ext_flags); + up_read(&OCFS2_I(inode)->ip_alloc_sem); + if (ret) { mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", (unsigned long long)iblock); @@ -557,6 +561,8 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, alloc_locked = 1; + down_write(&OCFS2_I(inode)->ip_alloc_sem); + /* fill hole, allocate blocks can't be larger than the size * of the hole */ clusters_to_alloc = ocfs2_clusters_for_bytes(inode->i_sb, len); @@ -569,6 +575,7 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, ret = ocfs2_extend_allocation(inode, cpos, clusters_to_alloc, 0); if (ret < 0) { + up_write(&OCFS2_I(inode)->ip_alloc_sem); mlog_errno(ret); goto bail; } @@ -576,11 +583,13 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &contig_blocks, &ext_flags); if (ret < 0) { + up_write(&OCFS2_I(inode)->ip_alloc_sem); mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", (unsigned long long)iblock); ret = -EIO; goto bail; } + up_write(&OCFS2_I(inode)->ip_alloc_sem); } /* @@ -835,12 +844,17 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb, /* zeroing out the previously allocated cluster tail * that but not zeroed */ - if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) + if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) { + down_read(&OCFS2_I(inode)->ip_alloc_sem); ret = ocfs2_direct_IO_zero_extend(osb, inode, offset, zero_len_tail, cluster_align_tail); - else + up_read(&OCFS2_I(inode)->ip_alloc_sem); + } else { + down_write(&OCFS2_I(inode)->ip_alloc_sem); ret = ocfs2_direct_IO_extend_no_holes(osb, inode, offset); + up_write(&OCFS2_I(inode)->ip_alloc_sem); + } if (ret < 0) { mlog_errno(ret); ocfs2_inode_unlock(inode, 1); |