Commit 9e3aa805 authored Sep 03, 2020 by Josef Bacik Committed by David Sterba Sep 07, 2020

btrfs: free data reloc tree on failed mount



While testing a weird problem with -o degraded, I noticed I was getting
leaked root errors

  BTRFS warning (device loop0): writable mount is not allowed due to too many missing devices
  BTRFS error (device loop0): open_ctree failed
  BTRFS error (device loop0): leaked root -9-0 refcount 1

This is the DATA_RELOC root, which gets read before the other fs roots,
but is included in the fs roots radix tree.  Handle this by adding a
btrfs_drop_and_free_fs_root() on the data reloc root if it exists.  This
is ok to do here if we fail further up because we will only drop the ref
if we delete the root from the radix tree, and all other cleanup won't
be duplicated.

CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent ea57788e

fs/btrfs/disk-io.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3441,6 +3441,8 @@ fail_block_groups:
		btrfs_put_block_group_cache(fs_info);

		fail_tree_roots:
		if (fs_info->data_reloc_root)
		btrfs_drop_and_free_fs_root(fs_info, fs_info->data_reloc_root);
		free_root_pointers(fs_info, true);
		invalidate_inode_pages2(fs_info->btree_inode->i_mapping);

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