The patch below does not apply to the 4.4-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 e19182c0fff451e3744c1107d98f072e7ca377a0 Mon Sep 17 00:00:00 2001

From: Jeff Mahoney jeffm@suse.com Date: Mon, 4 Dec 2017 13:11:45 -0500 Subject: [PATCH] btrfs: fix missing error return in btrfs_drop_snapshot

If btrfs_del_root fails in btrfs_drop_snapshot, we'll pick up the error but then return 0 anyway due to mixing err and ret.

Fixes: 79787eaab4612 ("btrfs: replace many BUG_ONs with proper error handling") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Jeff Mahoney jeffm@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 784d41e95ed9..16e46ee3cd16 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -9220,6 +9220,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, ret = btrfs_del_root(trans, fs_info, &root->root_key); if (ret) { btrfs_abort_transaction(trans, ret); + err = ret; goto out_end_trans; }