On 14.11.18 г. 9:24 ч., Lu Fengqi wrote:
> =============================
> WARNING: suspicious RCU usage
> 4.20.0-rc2+ #23 Tainted: G O
> -----------------------------
> fs/btrfs/volumes.c:886 suspicious rcu_dereference_check() usage!
>
> Use btrfs_info_in_rcu instead of pr_info for the required lock/unlock of
> RCU string.
>
> Fixes: 1f265fc6f58b ("btrfs: harden agaist duplicate fsid on scanned devices")
> Signed-off-by: Lu Fengqi <lufq.fnst@xxxxxxxxxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/volumes.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 2186300bab91..6039ae5c549e 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -873,15 +873,15 @@ static noinline struct btrfs_device *device_list_add(const char *path,
> if (device->bdev != path_bdev) {
> bdput(path_bdev);
> mutex_unlock(&fs_devices->device_list_mutex);
> - pr_warn(
> - "BTRFS: duplicate device fsid:devid for %pU:%llu old:%s new:%s\n",
> + btrfs_warn_in_rcu(device->fs_info,
> + "duplicate device fsid:devid for %pU:%llu old:%s new:%s\n",
> disk_super->fsid, devid,
> rcu_str_deref(device->name), path);
> return ERR_PTR(-EEXIST);
> }
> bdput(path_bdev);
> - pr_info(
> - "BTRFS: device fsid %pU devid %llu moved old:%s new:%s\n",
> + btrfs_info_in_rcu(device->fs_info,
> + "device fsid %pU devid %llu moved old:%s new:%s\n",
> disk_super->fsid, devid,
> rcu_str_deref(device->name), path);
> }
>
