On Tue, Apr 26, 2016 at 3:32 PM, David Sterba <dste...@suse.com> wrote:
> If the label setting ioctl races with sysfs label handler, we could get
> mixed result in the output, part old part new. We should either get the
> old or new label. The chances to hit this race are low.
>
> Signed-off-by: David Sterba <dste...@suse.com>
> ---
> fs/btrfs/sysfs.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
> index 3d14618ce54b..7b0da1dcb6df 100644
> --- a/fs/btrfs/sysfs.c
> +++ b/fs/btrfs/sysfs.c
> @@ -367,7 +367,12 @@ static ssize_t btrfs_label_show(struct kobject *kobj,
> {
> struct btrfs_fs_info *fs_info = to_fs_info(kobj);
> char *label = fs_info->super_copy->label;
> - return snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
> +
> + spin_lock(&fs_info->super_lock);
> + snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
> + spin_unlock(&fs_info->super_lock);
> +
> + return buf;
We should return a ssize_t value, not a char *. I.e. return what
snprintf returns. This should make gcc emit a warning.
> }
>
> static ssize_t btrfs_label_store(struct kobject *kobj,
> --
> 2.7.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Filipe David Manana,
"Reasonable men adapt themselves to the world.
Unreasonable men adapt the world to themselves.
That's why all progress depends on unreasonable men."
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
