From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 24 Jan 2020 09:32:30 -0500
Git-commit: 02162a0265eb56742442ef42c58db8739ddd9b94
Patch-mainline: 5.7-rc1
References: bsc#1176019
Subject: [PATCH] btrfs: hold a ref on the root in __btrfs_run_defrag_inode

We are looking up an arbitrary inode, we need to hold a ref on the root
while we're doing this.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/file.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 1bc7665f8ff0..27237bbaad65 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -292,11 +292,16 @@ static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
 		ret = PTR_ERR(inode_root);
 		goto cleanup;
 	}
+	if (!btrfs_grab_fs_root(inode_root)) {
+		ret = -ENOENT;
+		goto cleanup;
+	}
 
 	key.objectid = defrag->ino;
 	key.type = BTRFS_INODE_ITEM_KEY;
 	key.offset = 0;
 	inode = btrfs_iget(fs_info->sb, &key, inode_root);
+	btrfs_put_fs_root(inode_root);
 	if (IS_ERR(inode)) {
 		ret = PTR_ERR(inode);
 		goto cleanup;
-- 
2.26.2