This is a note to let you know that I've just added the patch titled
Treat writes as new when holes span across page boundaries
to the 2.6.38-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
treat-writes-as-new-when-holes-span-across-page-boundaries.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 272b62c1f0f6f742046e45b50b6fec98860208a0 Mon Sep 17 00:00:00 2001
From: Goldwyn Rodrigues <[email protected]>
Date: Thu, 17 Feb 2011 09:44:40 -0600
Subject: Treat writes as new when holes span across page boundaries
From: Goldwyn Rodrigues <[email protected]>
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 <[email protected]>
Signed-off-by: jlbec <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/ocfs2/aops.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1026,6 +1026,12 @@ static int ocfs2_prepare_page_for_write(
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;
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.38/treat-writes-as-new-when-holes-span-across-page-boundaries.patch
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