On Thu, Apr 02, 2020 at 06:57:18AM -0400, Brian Foster wrote:
> Qian Cai reports seemingly random buffer read verifier errors during
> filesystem writeback. This was isolated to a recent patch that
> factored out some inode cluster freeing code and happened to cast an
> unsigned inode number type to a signed value. If the inode number
> value overflows, we can skip marking in-core inodes associated with
> the underlying buffer stale at the time the physical inodes are
> freed. If such an inode happens to be dirty, xfsaild will eventually
> attempt to write it back over non-inode blocks. The invalidation of
> the underlying inode buffer causes writeback to read the buffer from
> disk. This fails the read verifier (preventing eventual corruption)
> if the buffer no longer looks like an inode cluster. Analysis by
> Dave Chinner.
>
> Fix up the helper to use the proper type for inode number values.
>
> Fixes: 5806165a6663 ("xfs: factor inode lookup from xfs_ifree_cluster")
> Reported-by: Qian Cai <cai@xxxxxx>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
> ---
>
> Fixes the problem described here[1]. I wasn't sure if we planned on
> fixing the original patch in for-next or wanted a separate patch. Feel
> free to commit standalone or fold into the original...
>
> Brian
>
> [1] https://lore.kernel.org/linux-xfs/990EDC4E-1A4E-4AC3-84D9-078ACF5EB9CC@xxxxxx/
Looks ok, I'll probably just attach it to the end rather than rebase
for-next at this super late point...
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
>
> fs/xfs/xfs_inode.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 0cac0d37e3ae..ae86c870da92 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -2511,7 +2511,7 @@ static struct xfs_inode *
> xfs_ifree_get_one_inode(
> struct xfs_perag *pag,
> struct xfs_inode *free_ip,
> - int inum)
> + xfs_ino_t inum)
> {
> struct xfs_mount *mp = pag->pag_mount;
> struct xfs_inode *ip;
> --
> 2.21.1
>
