On Wed, Nov 14, 2018 at 03:24:56PM +0800, 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")
Thanks for the fix.
Please note that the patch is still in the devel queue (misc-next) so
the commit id is unstable, and such fixups get folded to the patch.
You may also reply to the original mail with patch, but sending a bare
code change without a full changelog is also fine if the original patch
was sent long time ago and the fixup could get lost.
> Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com>
> ---
> 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",
The trailing newline is appended by all btrfs_* message helpers, removed
in the commit.
