stable/btrfs: fix backport bug in d819d97 ("btrfs: honor path->skip_l…

…ocking in backref code")

Upstream commit 38e3eeb ("btrfs: honor path->skip_locking in
backref code") was incorrectly backported to 4.14.y . It misses removal
of two lines from original commit, what cause deadlock.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203993
Reported-by: Olivier Mazouffre <olivier.mazouffre@ims-bordeaux.fr>
Fixes: d819d97 ("btrfs: honor path->skip_locking in backref code")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/btrfs/backref.c

@@ -1290,8 +1290,6 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 					ret = -EIO;
 					goto out;
 				}
-				btrfs_tree_read_lock(eb);
-				btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
 				if (!path->skip_locking) {
 					btrfs_tree_read_lock(eb);
 					btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);