[PATCH] xfs: only validate summary counts on primary superblock

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

From: Darrick J. Wong <darrick.wong@oracle.com>

Skip the summary counter checks for secondary superblocks because
userspace has always written the secondary supers with zeroed counters.
mkfs.xfs fails immediately without this patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_sb.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index ca1b3a7a9171..47e1dd4a5009 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -148,6 +148,7 @@ xfs_validate_sb_read(
 STATIC int
 xfs_validate_sb_write(
 	struct xfs_mount	*mp,
+	struct xfs_buf		*bp,
 	struct xfs_sb		*sbp)
 {
 	/*
@@ -155,10 +156,13 @@ xfs_validate_sb_write(
 	 * the superblock.  We skip this in the read validator because there
 	 * could be newer superblocks in the log and if the values are garbage
 	 * even after replay we'll recalculate them at the end of log mount.
+	 * We only check the primary superblock to allow userspace tools to
+	 * write secondary superblocks with zeroed counters.
 	 */
-	if (sbp->sb_fdblocks > sbp->sb_dblocks ||
-	    !xfs_verify_icount(mp, sbp->sb_icount) ||
-	    sbp->sb_ifree > sbp->sb_icount) {
+	if (XFS_BUF_ADDR(bp) == XFS_SB_DADDR &&
+	    (sbp->sb_fdblocks > sbp->sb_dblocks ||
+	     !xfs_verify_icount(mp, sbp->sb_icount) ||
+	     sbp->sb_ifree > sbp->sb_icount)) {
 		xfs_warn(mp, "SB summary counter sanity check failed");
 		return -EFSCORRUPTED;
 	}
@@ -756,7 +760,7 @@ xfs_sb_write_verify(
 	error = xfs_validate_sb_common(mp, bp, &sb);
 	if (error)
 		goto out_error;
-	error = xfs_validate_sb_write(mp, &sb);
+	error = xfs_validate_sb_write(mp, bp, &sb);
 	if (error)
 		goto out_error;