[PATCH v3] btrfs: reflink: Initialize return value to 0 in btrfs_extent_same()

[PATCH v3] btrfs: reflink: Initialize return value to 0 in btrfs_extent_same()

[Sidong Yang]

This patch fixes a warning reported by smatch. It reported that ret
could be returned without initialized. 0 would be proper value for
initializing ret. Because dedupe operations are supposed to to return
0 for a 0 length range.

Signed-off-by: Sidong Yang <realwakka@gmail.com>
---
v2:
 - Removed assert and added initializing ret
v3:
 - Changed initializing value to 0
---
 fs/btrfs/reflink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index 9b0814318e72..c71e49782e86 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -649,7 +649,7 @@ static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 			     struct inode *dst, u64 dst_loff)
 {
-	int ret;
+	int ret = 0;
 	u64 i, tail_len, chunk_count;
 	struct btrfs_root *root_dst = BTRFS_I(dst)->root;
 
-- 
2.25.1

Re: [PATCH v3] btrfs: reflink: Initialize return value to 0 in btrfs_extent_same()

[Filipe Manana]

On Thu, Aug 26, 2021 at 3:44 PM Sidong Yang <realwakka@gmail.com> wrote:
>
> This patch fixes a warning reported by smatch. It reported that ret
> could be returned without initialized. 0 would be proper value for
> initializing ret. Because dedupe operations are supposed to to return
> 0 for a 0 length range.
>
> Signed-off-by: Sidong Yang <realwakka@gmail.com>

Reviewed-by: Filipe Manana <fdmanana@suse.com>

Looks good, thanks.

> ---
> v2:
>  - Removed assert and added initializing ret
> v3:
>  - Changed initializing value to 0
> ---
>  fs/btrfs/reflink.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
> index 9b0814318e72..c71e49782e86 100644
> --- a/fs/btrfs/reflink.c
> +++ b/fs/btrfs/reflink.c
> @@ -649,7 +649,7 @@ static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
>  static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
>                              struct inode *dst, u64 dst_loff)
>  {
> -       int ret;
> +       int ret = 0;
>         u64 i, tail_len, chunk_count;
>         struct btrfs_root *root_dst = BTRFS_I(dst)->root;
>
> --
> 2.25.1
>


-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”

Re: [PATCH v3] btrfs: reflink: Initialize return value to 0 in btrfs_extent_same()

[David Sterba]

On Thu, Aug 26, 2021 at 02:44:36PM +0000, Sidong Yang wrote:
> This patch fixes a warning reported by smatch. It reported that ret
> could be returned without initialized. 0 would be proper value for
> initializing ret. Because dedupe operations are supposed to to return
> 0 for a 0 length range.
> 
> Signed-off-by: Sidong Yang <realwakka@gmail.com>
> ---
> v2:
>  - Removed assert and added initializing ret
> v3:
>  - Changed initializing value to 0

I've slightly rephrased the changelog, added to misc-next, thanks.