[PATCH] ceph: fix uninitialized return code

[PATCH] ceph: fix uninitialized return code

[Arnd Bergmann]

clang points out a -Wsometimed-uninitized bug in the modified
ceph_real_mount() function:

fs/ceph/super.c:850:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
        if (!fsc->sb->s_root) {
            ^~~~~~~~~~~~~~~~
fs/ceph/super.c:885:9: note: uninitialized use occurs here
        return err;
               ^~~
fs/ceph/super.c:850:2: note: remove the 'if' if its condition is always true
        if (!fsc->sb->s_root) {
        ^~~~~~~~~~~~~~~~~~~~~~
fs/ceph/super.c:843:9: note: initialize the variable 'err' to silence this warning
        int err;
               ^
                = 0

Set it to zero if the condition is false.

Fixes: 108f95bfaa56 ("vfs: Convert ceph to use the new mount API")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/ceph/super.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 0d23903ddfa5..d663aa1286f6 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -876,6 +876,8 @@ static int ceph_real_mount(struct fs_context *fc, struct ceph_fs_client *fsc)
 			goto out;
 		}
 		fsc->sb->s_root = root;
+	} else {
+		err = 0;
 	}
 
 	fc->root = dget(fsc->sb->s_root);
-- 
2.20.0

Re: [PATCH] ceph: fix uninitialized return code

[Nathan Chancellor]

On Mon, Jul 08, 2019 at 03:48:08PM +0200, Arnd Bergmann wrote:
> clang points out a -Wsometimed-uninitized bug in the modified
> ceph_real_mount() function:
> 
> fs/ceph/super.c:850:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>         if (!fsc->sb->s_root) {
>             ^~~~~~~~~~~~~~~~
> fs/ceph/super.c:885:9: note: uninitialized use occurs here
>         return err;
>                ^~~
> fs/ceph/super.c:850:2: note: remove the 'if' if its condition is always true
>         if (!fsc->sb->s_root) {
>         ^~~~~~~~~~~~~~~~~~~~~~
> fs/ceph/super.c:843:9: note: initialize the variable 'err' to silence this warning
>         int err;
>                ^
>                 = 0
> 
> Set it to zero if the condition is false.
> 
> Fixes: 108f95bfaa56 ("vfs: Convert ceph to use the new mount API")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for the patch!

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

Re: [PATCH] ceph: fix uninitialized return code

[Jeff Layton]

On Mon, 2019-07-08 at 15:48 +0200, Arnd Bergmann wrote:
> clang points out a -Wsometimed-uninitized bug in the modified
> ceph_real_mount() function:
> 
> fs/ceph/super.c:850:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>         if (!fsc->sb->s_root) {
>             ^~~~~~~~~~~~~~~~
> fs/ceph/super.c:885:9: note: uninitialized use occurs here
>         return err;
>                ^~~
> fs/ceph/super.c:850:2: note: remove the 'if' if its condition is always true
>         if (!fsc->sb->s_root) {
>         ^~~~~~~~~~~~~~~~~~~~~~
> fs/ceph/super.c:843:9: note: initialize the variable 'err' to silence this warning
>         int err;
>                ^
>                 = 0
> 
> Set it to zero if the condition is false.
> 
> Fixes: 108f95bfaa56 ("vfs: Convert ceph to use the new mount API")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  fs/ceph/super.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index 0d23903ddfa5..d663aa1286f6 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -876,6 +876,8 @@ static int ceph_real_mount(struct fs_context *fc, struct ceph_fs_client *fsc)
>  			goto out;
>  		}
>  		fsc->sb->s_root = root;
> +	} else {
> +		err = 0;
>  	}
>  
>  	fc->root = dget(fsc->sb->s_root);

I see 108f95bfaa56 linux-next, but this hasn't been merged into the ceph
kclient tree yet. It'd be ideal if Al just squashed this in before
sending the PR to Linus.

In any case, patch looks fine:

Reviewed-by: Jeff Layton <jlayton@kernel.org>