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

["Darrick J. Wong" <darrick.wong@oracle.com>]

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>
---
 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"));
 }