Re: [PATCH] btrfs: correct zstd workspace manager lock to use spin_lock_bh()

From: David Sterba
Date: Tue May 21 2019 - 05:02:37 EST


On Fri, May 17, 2019 at 07:16:26PM -0400, Dennis Zhou wrote:
> The btrfs zstd workspace manager uses a background timer to reclaim
> not recently used workspaces. I dumbly call spin_lock() from this
> context which I should have caught with lockdep but.. This deadlock was
> reported in [1]. The fix is to switch the zstd wsm lock to use
> spin_lock_bh().
>
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=203517
>
> Signed-off-by: Dennis Zhou <dennis@xxxxxxxxxx>

Reviewed-by: David Sterba <dsterba@xxxxxxxx>

Added to 5.2-rc queue, thanks.