[PATCH 15/45] btrfs: grab a ref on the root in relink_extent_backref

[Josef Bacik <josef@xxxxxxxxxxxxxx>]

We're doing an arbitrary lookup on an fs_root, we need to hold a ref on
that root.

Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
 fs/btrfs/inode.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 88f3d6eace7a..d46e3ec6ba30 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2711,8 +2711,12 @@ static noinline int relink_extent_backref(struct btrfs_path *path,
 		return PTR_ERR(root);
 	}
 
+	if (!btrfs_grab_fs_root(root))
+		return 0;
+
 	if (btrfs_root_readonly(root)) {
 		srcu_read_unlock(&fs_info->subvol_srcu, index);
+		btrfs_put_fs_root(root);
 		return 0;
 	}
 
@@ -2722,6 +2726,7 @@ static noinline int relink_extent_backref(struct btrfs_path *path,
 	key.offset = 0;
 
 	inode = btrfs_iget(fs_info->sb, &key, root);
+	btrfs_put_fs_root(root);
 	if (IS_ERR(inode)) {
 		srcu_read_unlock(&fs_info->subvol_srcu, index);
 		return 0;
-- 
2.23.0