From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 24 Jan 2020 09:32:47 -0500
Git-commit: fd79d43b347e12b3f7ededaadf6437c6538247c7
Patch-mainline: 5.7-rc1
References: bsc#1176019
Subject: [PATCH] btrfs: hold a ref on the root in scrub_print_warning_inode

We look up the root for the bytenr that is failing, so we need to hold a
ref on the root for that operation.

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/scrub.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 7e18dde5dcb0..158a661ad2b0 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -658,6 +658,10 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 		ret = PTR_ERR(local_root);
 		goto err;
 	}
+	if (!btrfs_grab_fs_root(local_root)) {
+		ret = -ENOENT;
+		goto err;
+	}
 
 	/*
 	 * this makes the path point to (inum INODE_ITEM ioff)
@@ -668,6 +672,7 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 
 	ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
 	if (ret) {
+		btrfs_put_fs_root(local_root);
 		btrfs_release_path(swarn->path);
 		goto err;
 	}
@@ -688,6 +693,7 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 	ipath = init_ipath(4096, local_root, swarn->path);
 	memalloc_nofs_restore(nofs_flag);
 	if (IS_ERR(ipath)) {
+		btrfs_put_fs_root(local_root);
 		ret = PTR_ERR(ipath);
 		ipath = NULL;
 		goto err;
@@ -711,6 +717,7 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 				  min(isize - offset, (u64)PAGE_SIZE), nlink,
 				  (char *)(unsigned long)ipath->fspath->val[i]);
 
+	btrfs_put_fs_root(local_root);
 	free_ipath(ipath);
 	return 0;
 
-- 
2.26.2