[34/44] btrfs: hold a ref on the root in get_subvol_name_from_objectid
diff mbox series

Message ID 20191206144538.168112-35-josef@toxicpanda.com
State New
Headers show
Series
  • Cleanup how we handle root refs, part 1
Related show

Commit Message

Josef Bacik Dec. 6, 2019, 2:45 p.m. UTC
We lookup the name of a subvol which means we'll cross into different
roots.  Hold a ref while we're doing the look ups in the fs_root we're
searching.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/super.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch
diff mbox series

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index e387ca1ac0e5..9c50bee71de9 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1082,6 +1082,10 @@  static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 			ret = PTR_ERR(fs_root);
 			goto err;
 		}
+		if (!btrfs_grab_fs_root(fs_root)) {
+			ret = -ENOENT;
+			goto err;
+		}
 
 		/*
 		 * Walk up the filesystem tree by inode refs until we hit the
@@ -1094,13 +1098,16 @@  static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 
 			ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
 			if (ret < 0) {
+				btrfs_put_fs_root(fs_root);
 				goto err;
 			} else if (ret > 0) {
 				ret = btrfs_previous_item(fs_root, path, dirid,
 							  BTRFS_INODE_REF_KEY);
 				if (ret < 0) {
+					btrfs_put_fs_root(fs_root);
 					goto err;
 				} else if (ret > 0) {
+					btrfs_put_fs_root(fs_root);
 					ret = -ENOENT;
 					goto err;
 				}
@@ -1117,6 +1124,7 @@  static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 			ptr -= len + 1;
 			if (ptr < name) {
 				ret = -ENAMETOOLONG;
+				btrfs_put_fs_root(fs_root);
 				goto err;
 			}
 			read_extent_buffer(path->nodes[0], ptr + 1,
@@ -1124,6 +1132,7 @@  static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 			ptr[0] = '/';
 			btrfs_release_path(path);
 		}
+		btrfs_put_fs_root(fs_root);
 	}
 
 	btrfs_free_path(path);