Btrfs: csum_verify_file_block locking fix

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index e7510ac5559d..2c98b620c594 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -110,6 +110,7 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
         file_key.offset = offset;
         file_key.flags = 0;
         btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+        mutex_lock(&root->fs_info->fs_mutex);
         ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
         if (ret)
                 goto fail;
@@ -123,6 +124,7 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root,
 fail:
         btrfs_release_path(root, path);
         btrfs_free_path(path);
+        mutex_unlock(&root->fs_info->fs_mutex);
         return ret;
 }