[PATCH] btrfs: Fix the wrong condition judgment about subset extent map

[PATCH] btrfs: Fix the wrong condition judgment about subset extent map

[Qu Wenruo]

Previous commit: btrfs: Fix and enhance merge_extent_mapping() to insert
best fitted extent map
is using wrong condition to judgement whether the range is a subset of a
existing extent map.

This may cause bug in btrfs no-holes mode.

This patch will correct the judgment and fix the bug.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 fs/btrfs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8039021..a99ee9d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6527,7 +6527,7 @@ insert:
 		 * extent causing the -EEXIST.
 		 */
 		if (start >= extent_map_end(existing) ||
-		    start + len <= existing->start) {
+		    start <= existing->start) {
 			/*
 			 * The existing extent map is the one nearest to
 			 * the [start, start + len) range which overlaps
-- 
2.1.0

Re: [PATCH] btrfs: Fix the wrong condition judgment about subset extent map

[Miao Xie]

This patch and the previous one(The following patch) also fixed a oops, which can be reproduced
by LTP stress test(ltpstress.sh + fsstress).

[PATCH] btrfs: Fix and enhance merge_extent_mapping() to insert best fitted extent map

Thanks
Miao

On Mon, 22 Sep 2014 09:13:03 +0800, Qu Wenruo wrote:
> Previous commit: btrfs: Fix and enhance merge_extent_mapping() to insert
> best fitted extent map
> is using wrong condition to judgement whether the range is a subset of a
> existing extent map.
> 
> This may cause bug in btrfs no-holes mode.
> 
> This patch will correct the judgment and fix the bug.
> 
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>  fs/btrfs/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 8039021..a99ee9d 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -6527,7 +6527,7 @@ insert:
>  		 * extent causing the -EEXIST.
>  		 */
>  		if (start >= extent_map_end(existing) ||
> -		    start + len <= existing->start) {
> +		    start <= existing->start) {
>  			/*
>  			 * The existing extent map is the one nearest to
>  			 * the [start, start + len) range which overlaps
>