Re: [PATCH] xfs: check sizes of XFS on-disk structures at compile time

Brian Foster
2016-01-12T14:01:24Z

On Mon, Jan 11, 2016 at 03:26:57PM -0800, Darrick J. Wong wrote:
> Check the sizes of XFS on-disk structures when compiling the kernel.
> Use this to catch inadvertent changes in structure size due to padding
> and alignment issues, etc.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

Seems reasonable to me:

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_format.h | 4 ++++
> fs/xfs/xfs_super.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 49 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index e2536bb..a589b47 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -1509,4 +1509,8 @@ struct xfs_acl {
> #define SGI_ACL_FILE_SIZE (sizeof(SGI_ACL_FILE)-1)
> #define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1)
>
> +#define XFS_CHECK_STRUCT_SIZE(structname, size) \
> + BUILD_BUG_ON_MSG(sizeof(structname) != (size), "XFS: sizeof(struct " \
> + #structname ") is wrong, expected " #size)
> +
> #endif /* __XFS_FORMAT_H__ */
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 36bd882..31b69d1 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1812,11 +1812,56 @@ xfs_destroy_workqueues(void)
> destroy_workqueue(xfs_alloc_wq);
> }
>
> +static void __init
> +xfs_check_ondisk_structs(void)
> +{
> + /* on-disk structures */
> + XFS_CHECK_STRUCT_SIZE(struct xfs_dsb, 264);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_agf, 224);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_agi, 336);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_agfl, 36);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_timestamp, 8);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_dinode, 176);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_disk_dquot, 104);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_dqblk, 136);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_dsymlink_hdr, 56);
> + XFS_CHECK_STRUCT_SIZE(xfs_alloc_rec_t, 8);
> + XFS_CHECK_STRUCT_SIZE(xfs_alloc_key_t, 8);
> + XFS_CHECK_STRUCT_SIZE(xfs_alloc_ptr_t, 4);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_rec, 16);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_inobt_key, 4);
> + XFS_CHECK_STRUCT_SIZE(xfs_inobt_ptr_t, 4);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_bmdr_block, 4);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_rec, 16);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_bmbt_key, 8);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_btree_block, 72);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_acl_entry, 12);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_acl, 4);
> +
> + /* log structures */
> + XFS_CHECK_STRUCT_SIZE(struct xfs_trans_header, 16);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_32, 52);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_inode_log_format_64, 56);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_ictimestamp, 8);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_icdinode, 176);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_extent_32, 12);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_extent_64, 16);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_32, 28);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_efi_log_format_64, 32);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_32, 28);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_efd_log_format_64, 32);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_dq_logformat, 24);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_qoff_logformat, 20);
> + XFS_CHECK_STRUCT_SIZE(struct xfs_icreate_log, 28);
> +}
> +
> STATIC int __init
> init_xfs_fs(void)
> {
> int error;
>
> + xfs_check_ondisk_structs();
> +
> printk(KERN_INFO XFS_VERSION_STRING " with "
> XFS_BUILD_OPTIONS " enabled\n");
>
>
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs