Re: [PATCH] fs: btrfs: block-group.c: Fix suspicious RCU usage warning

From: David Sterba
Date: Fri Mar 06 2020 - 14:37:56 EST


On Fri, Mar 06, 2020 at 12:22:43PM +0530, madhuparnabhowmik10@xxxxxxxxx wrote:
> From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
>
> The space_info list is rcu protected.
> Hence, it should be traversed with rcu_read_lock held.
>
> Warning:
> [ 29.104591] =============================
> [ 29.104756] WARNING: suspicious RCU usage
> [ 29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted
> [ 29.105231] -----------------------------
> [ 29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!!
>
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>

I've updated the changelog based on comments from the mail thread and
applied the patch. Thanks.