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| author | Goldwyn Rodrigues <rgoldwyn@gmail.com> | 2011-02-17 09:44:40 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-14 13:02:30 -0700 |
| commit | b8b602b32fb7533406880478b3872d1e1c6911dc (patch) | |
| tree | 3bc713b484de21cce113a760986ebb498cb94ecb | |
| parent | b2d10ef61c4f466e6f117045358cb48675d49734 (diff) | |
| download | lwn-b8b602b32fb7533406880478b3872d1e1c6911dc.tar.gz lwn-b8b602b32fb7533406880478b3872d1e1c6911dc.zip | |
Treat writes as new when holes span across page boundaries
commit 272b62c1f0f6f742046e45b50b6fec98860208a0 upstream.
When a hole spans across page boundaries, the next write forces
a read of the block. This could end up reading existing garbage
data from the disk in ocfs2_map_page_blocks. This leads to
non-zero holes. In order to avoid this, mark the writes as new
when the holes span across page boundaries.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: jlbec <jlbec@evilplan.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ocfs2/aops.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 1fbb0e20131b..bbba782cce26 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1026,6 +1026,12 @@ static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, &cluster_start, &cluster_end); + /* treat the write as new if the a hole/lseek spanned across + * the page boundary. + */ + new = new | ((i_size_read(inode) <= page_offset(page)) && + (page_offset(page) <= user_pos)); + if (page == wc->w_target_page) { map_from = user_pos & (PAGE_CACHE_SIZE - 1); map_to = map_from + user_len; |