Re: [PATCH 5/6] xfs_repair: use libxfs function to calculate root inode location

[Brian Foster <bfoster@redhat.com>]

On Wed, Dec 04, 2019 at 09:04:56AM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Use libxfs_ialloc_calc_rootino to compute the location of the root
> inode, and improve the function comments while we're at it.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

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

>  repair/globals.c    |    5 ---
>  repair/globals.h    |    5 ---
>  repair/xfs_repair.c |   78 +++++++--------------------------------------------
>  3 files changed, 10 insertions(+), 78 deletions(-)
> 
> 
> diff --git a/repair/globals.c b/repair/globals.c
> index 8a60e706..299bacd1 100644
> --- a/repair/globals.c
> +++ b/repair/globals.c
> @@ -72,11 +72,6 @@ int	lost_uquotino;
>  int	lost_gquotino;
>  int	lost_pquotino;
>  
> -xfs_agino_t	first_prealloc_ino;
> -xfs_agblock_t	bnobt_root;
> -xfs_agblock_t	bcntbt_root;
> -xfs_agblock_t	inobt_root;
> -
>  /* configuration vars -- fs geometry dependent */
>  
>  int		inodes_per_block;
> diff --git a/repair/globals.h b/repair/globals.h
> index 2ed5c894..953e3dfb 100644
> --- a/repair/globals.h
> +++ b/repair/globals.h
> @@ -113,11 +113,6 @@ extern int		lost_uquotino;
>  extern int		lost_gquotino;
>  extern int		lost_pquotino;
>  
> -extern xfs_agino_t	first_prealloc_ino;
> -extern xfs_agblock_t	bnobt_root;
> -extern xfs_agblock_t	bcntbt_root;
> -extern xfs_agblock_t	inobt_root;
> -
>  /* configuration vars -- fs geometry dependent */
>  
>  extern int		inodes_per_block;
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index 94673750..abd568c9 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -426,79 +426,21 @@ _("would reset superblock %s inode pointer to %"PRIu64"\n"),
>  	*ino = expected_ino;
>  }
>  
> +/*
> + * Make sure that the first 3 inodes in the filesystem are the root directory,
> + * the realtime bitmap, and the realtime summary, in that order.
> + */
>  static void
> -calc_mkfs(xfs_mount_t *mp)
> +calc_mkfs(
> +	struct xfs_mount	*mp)
>  {
> -	xfs_agblock_t	fino_bno;
> -	int		do_inoalign;
> -
> -	do_inoalign = M_IGEO(mp)->ialloc_align;
> -
> -	/*
> -	 * Pre-calculate the geometry of ag 0. We know what it looks like
> -	 * because we know what mkfs does: 2 allocation btree roots (by block
> -	 * and by size), the inode allocation btree root, the free inode
> -	 * allocation btree root (if enabled) and some number of blocks to
> -	 * prefill the agfl.
> -	 *
> -	 * Because the current shape of the btrees may differ from the current
> -	 * shape, we open code the mkfs freelist block count here. mkfs creates
> -	 * single level trees, so the calculation is pertty straight forward for
> -	 * the trees that use the AGFL.
> -	 */
> -	bnobt_root = howmany(4 * mp->m_sb.sb_sectsize, mp->m_sb.sb_blocksize);
> -	bcntbt_root = bnobt_root + 1;
> -	inobt_root = bnobt_root + 2;
> -	fino_bno = inobt_root + (2 * min(2, mp->m_ag_maxlevels)) + 1;
> -	if (xfs_sb_version_hasfinobt(&mp->m_sb))
> -		fino_bno++;
> -	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
> -		fino_bno += min(2, mp->m_rmap_maxlevels); /* agfl blocks */
> -		fino_bno++;
> -	}
> -	if (xfs_sb_version_hasreflink(&mp->m_sb))
> -		fino_bno++;
> -
> -	/*
> -	 * If the log is allocated in the first allocation group we need to
> -	 * add the number of blocks used by the log to the above calculation.
> -	 *
> -	 * This can happens with filesystems that only have a single
> -	 * allocation group, or very odd geometries created by old mkfs
> -	 * versions on very small filesystems.
> -	 */
> -	if (mp->m_sb.sb_logstart &&
> -	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == 0) {
> -
> -		/*
> -		 * XXX(hch): verify that sb_logstart makes sense?
> -		 */
> -		 fino_bno += mp->m_sb.sb_logblocks;
> -	}
> -
> -	/*
> -	 * ditto the location of the first inode chunks in the fs ('/')
> -	 */
> -	if (xfs_sb_version_hasdalign(&mp->m_sb) && do_inoalign)  {
> -		first_prealloc_ino = XFS_AGB_TO_AGINO(mp, roundup(fino_bno,
> -					mp->m_sb.sb_unit));
> -	} else if (xfs_sb_version_hasalign(&mp->m_sb) &&
> -					mp->m_sb.sb_inoalignmt > 1)  {
> -		first_prealloc_ino = XFS_AGB_TO_AGINO(mp,
> -					roundup(fino_bno,
> -						mp->m_sb.sb_inoalignmt));
> -	} else  {
> -		first_prealloc_ino = XFS_AGB_TO_AGINO(mp, fino_bno);
> -	}
> +	xfs_ino_t		rootino = libxfs_ialloc_calc_rootino(mp, -1);
>  
> -	/*
> -	 * now the first 3 inodes in the system
> -	 */
> -	ensure_fixed_ino(&mp->m_sb.sb_rootino, first_prealloc_ino,
> +	ensure_fixed_ino(&mp->m_sb.sb_rootino, rootino,
>  			_("root"));
> -	ensure_fixed_ino(&mp->m_sb.sb_rbmino, first_prealloc_ino + 1,
> +	ensure_fixed_ino(&mp->m_sb.sb_rbmino, rootino + 1,
>  			_("realtime bitmap"));
> -	ensure_fixed_ino(&mp->m_sb.sb_rsumino, first_prealloc_ino + 2,
> +	ensure_fixed_ino(&mp->m_sb.sb_rsumino, rootino + 2,
>  			_("realtime summary"));
>  }
>  
>