Btrfs: bail out gracefully rather than BUG_ON (56a0e706) · Commits · 戴 / test

If a file's DIR_ITEM key is invalid (due to memory errors) and gets written to disk, a future lookup_path can end up with kernel panic due to BUG_ON(). This gets rid of the BUG_ON(), meanwhile output the corrupted key and return ENOENT if it's invalid. Signed-off-by:

Liu Bo <bo.li.liu@oracle.com> Reported-by:

Guillaume Bouchard <bouchard@mercs-eng.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -5445,6 +5445,14 @@ static int btrfs_inode_by_name(struct inode dir, struct dentry dentry,
		goto out_err;

		btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
		if (location->type != BTRFS_INODE_ITEM_KEY &&
		location->type != BTRFS_ROOT_ITEM_KEY) {
		btrfs_warn(root->fs_info,
		"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
		__func__, name, btrfs_ino(BTRFS_I(dir)),
		location->objectid, location->type, location->offset);
		goto out_err;
		}
		out:
		btrfs_free_path(path);
		return ret;
		@@ -5761,8 +5769,6 @@ struct inode btrfs_lookup_dentry(struct inode dir, struct dentry *dentry)
		return inode;
		}

		BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);

		index = srcu_read_lock(&fs_info->subvol_srcu);
		ret = fixup_tree_root_location(fs_info, dir, dentry,
		&location, &sub_root);

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