Re: [PATCH, RFC] fix attr fit checking for filesystems which have lost their attr2

[Eric Sandeen <sandeen@sandeen.net>]

Timothy Shimmin wrote:
> Eric,
> 
> So probably need something like this for xfs_bmap_compute_maxlevels()...

Yep, I think that looks good.  I had forgotten that you could mount with
"noattr2" to change the default behavior... so this isn't only a bug
w.r.t. bad_features2, is it.

Thanks,

-Eric

> 
> --Tim
> 
> ===========================================================================
> Index: fs/xfs/xfs_bmap.c
> ===========================================================================
> 
> --- a/fs/xfs/xfs_bmap.c	2008-03-31 16:32:24.000000000 +1000
> +++ b/fs/xfs/xfs_bmap.c	2008-03-31 16:21:11.439806073 +1000
> @@ -4154,16 +4154,21 @@ xfs_bmap_compute_maxlevels(
>   	 * number of leaf entries, is controlled by the type of di_nextents
>   	 * (a signed 32-bit number, xfs_extnum_t), or by di_anextents
>   	 * (a signed 16-bit number, xfs_aextnum_t).
> +	 *
> +	 * Note that we can no longer assume that if we are in ATTR1 that
> +	 * the fork offset of all the inodes will be (m_attroffset >> 3)
> +	 * because we could have mounted with ATTR2 and then mounted back
> +	 * with ATTR1, keeping the di_forkoff's fixed but probably at
> +	 * various positions. Therefore, for both ATTR1 and ATTR2
> +	 * we have to assume the worst case scenario of a minimum size
> +	 * available.
>   	 */
>   	if (whichfork == XFS_DATA_FORK) {
>   		maxleafents = MAXEXTNUM;
> -		sz = (mp->m_flags & XFS_MOUNT_ATTR2) ?
> -			XFS_BMDR_SPACE_CALC(MINDBTPTRS) : mp->m_attroffset;
> +		sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
>   	} else {
>   		maxleafents = MAXAEXTNUM;
> -		sz = (mp->m_flags & XFS_MOUNT_ATTR2) ?
> -			XFS_BMDR_SPACE_CALC(MINABTPTRS) :
> -			mp->m_sb.sb_inodesize - mp->m_attroffset;
> +		sz = XFS_BMDR_SPACE_CALC(MINABTPTRS);
>   	}
>   	maxrootrecs = (int)XFS_BTREE_BLOCK_MAXRECS(sz, xfs_bmdr, 0);
>   	minleafrecs = mp->m_bmap_dmnr[0];
>