btrfs: do not delete mismatched root refs (423a716c) · Commits · 戴 / test

btrfs_del_root_ref() will simply WARN_ON() if the ref doesn't match in any way, and then continue to delete the reference. This shouldn't happen, we have these values because there's more to the reference than the original root and the sub root. If any of these checks fail, return -ENOENT. CC: stable@vger.kernel.org # 4.4+ Signed-off-by:

Josef Bacik <josef@toxicpanda.com> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/root-tree.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -376,11 +376,13 @@ again:
		leaf = path->nodes[0];
		ref = btrfs_item_ptr(leaf, path->slots[0],
		struct btrfs_root_ref);

		WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
		WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
		ptr = (unsigned long)(ref + 1);
		WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
		if ((btrfs_root_ref_dirid(leaf, ref) != dirid) \|\|
		(btrfs_root_ref_name_len(leaf, ref) != name_len) \|\|
		memcmp_extent_buffer(leaf, name, ptr, name_len)) {
		err = -ENOENT;
		goto out;
		}
		*sequence = btrfs_root_ref_sequence(leaf, ref);

		ret = btrfs_del_item(trans, tree_root, path);

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