Re: [PATCH] btrfs: initialize variable cancel

From: Filipe Manana
Date: Fri Jan 21 2022 - 10:41:06 EST


On Fri, Jan 21, 2022 at 05:45:22AM -0800, trix@xxxxxxxxxx wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
>
> Clang static analysis reports this problem
> ioctl.c:3333:8: warning: 3rd function call argument is an
> uninitialized value
> ret = exclop_start_or_cancel_reloc(fs_info,
>
> cancel is only set in one branch of an if-check and is
> always used. So initialize to false.
>
> Fixes: 1a15eb724aae ("btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls")
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>

Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>

Could use a more precise subject like for example:

"btrfs: fix use of uninitialized variable at rm device ioctl"

Anyway, it looks good.
Thanks.

> ---
> fs/btrfs/ioctl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 190ad8af4f45a..26e82379747f8 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3308,7 +3308,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
> struct block_device *bdev = NULL;
> fmode_t mode;
> int ret;
> - bool cancel;
> + bool cancel = false;
>
> if (!capable(CAP_SYS_ADMIN))
> return -EPERM;
> --
> 2.26.3
>