Re: [PATCH 2/2] xfs: validate allocated inode number

[Christoph Hellwig <hch@infradead.org>]

On Tue, Apr 17, 2018 at 04:39:16PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> When we have corrupted free inode btrees, we can attempt to
> allocate inodes that we know are already allocated. Catch allocation
> of these inodes and report corruption as early as possible to
> prevent corruption propagation or deadlocks.
> 
> Signed-Off-By: Dave Chinner <dchinner@redhat.com>
> ---
>  fs/xfs/xfs_inode.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 7b764f746ff2..12e6c1aec386 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -790,6 +790,19 @@ xfs_ialloc(
>  	}
>  	ASSERT(*ialloc_context == NULL);
>  
> +	/*
> +	 * Protect against obviously corrupt allocation btree records. Later
> +	 * xfs_iget checks will catch re-allocation of other active in-memory
> +	 * and on-disk inodes. If we don't catch reallocating the parent inode
> +	 * here we will deadlock in xfs_iget() so we have to do these checks
> +	 * first.
> +	 */
> +	if ((pip && ino == pip->i_ino) ||
> +	    !xfs_verify_dir_ino(mp, ino)) {

Seems like the whole conditional would fit onto a single line.

Otherwise looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>