On Mon, Mar 23, 2020 at 12:44:58PM -0400, Sasha Levin wrote:
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.
Ah, I thought this was backported, as "simple" grep shows it showing up in 4.14.110, but that was just a reference to the short git commit id.
I need to fix my scripts to always expand it to the full sha1 to prevent that from catching.
thanks,
greg k-h