Re: FAILED: patch "[PATCH] btrfs: fix log context list corruption after rename whiteout" failed to apply to 4.14-stable tree

[Sasha Levin <sashal@kernel.org>]

On Mon, Mar 23, 2020 at 03:43:02PM +0100, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.14-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 236ebc20d9afc5e9ff52f3cf3f365a91583aac10 Mon Sep 17 00:00:00 2001
>From: Filipe Manana <fdmanana@suse.com>
>Date: Tue, 10 Mar 2020 12:13:53 +0000
>Subject: [PATCH] btrfs: fix log context list corruption after rename whiteout
> error
>
>During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
>we can end up returning from btrfs_rename() with the log context object
>still in the root's log context list - this happens if 'sync_log' was
>set to true before we called btrfs_whiteout_for_rename() and it is
>dangerous because we end up with a corrupt linked list (root->log_ctxs)
>as the log context object was allocated on the stack.
>
>After btrfs_rename() returns, any task that is running btrfs_sync_log()
>concurrently can end up crashing because that linked list is traversed by
>btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
>the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list
>corruption after rename exchange operation") fixed.
>
>Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name")
>CC: stable@vger.kernel.org # 4.19+
>Signed-off-by: Filipe Manana <fdmanana@suse.com>
>Signed-off-by: David Sterba <dsterba@suse.com>

Greg, I'm not sure why you tried this for 4.14 - it's tagged 4.19+ and
we don't have d4682ba03ef618 in 4.14 either.

-- 
Thanks,
Sasha