From 746d40a73162f942f63f6a2f612f491d107b9824 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Thu, 20 Jul 2017 10:51:34 -0500
Subject: [PATCH] mkfs.xfs: allow specification of 0 data stripe width & unit

The "noalign" option works for this too, but it seems reasonable
to allow explicit specification of stripe unit and stripe width
to 0; today, doing so today makes the code think it's unspecified,
and so it goes ahead and detects stripe geometry and sets it in the
superblock.  That's unexpected and surprising.

Create a new flag that tracks whtether a geometry option has been
specified, and if it's set along with 0 values, treat it the
same as if "noalign" had been specified.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---
 mkfs/xfs_mkfs.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: xfsprogs-rhel7.5/mkfs/xfs_mkfs.c
===================================================================
--- xfsprogs-rhel7.5.orig/mkfs/xfs_mkfs.c
+++ xfsprogs-rhel7.5/mkfs/xfs_mkfs.c
@@ -909,6 +909,7 @@ main(
 	int			dsw;
 	int			dsunit;
 	int			dswidth;
+	int			dsflag;
 	int			force_overwrite;
 	struct fsxattr		fsx;
 	int			iaflag;
@@ -1012,7 +1013,7 @@ main(
 	dfile = logfile = rtfile = NULL;
 	dsize = logsize = rtsize = rtextsize = protofile = NULL;
 	dsu = dsw = dsunit = dswidth = lalign = lsu = lsunit = 0;
-	nodsflag = norsflag = 0;
+	dsflag = nodsflag = norsflag = 0;
 	force_overwrite = 0;
 	worst_freelist = 0;
 	lazy_sb_counters = 1;
@@ -1137,6 +1138,7 @@ main(
 						exit(1);
 					}
 					dsunit = cvtnum(0, 0, value);
+					dsflag = 1;
 					break;
 				case D_SWIDTH:
 					if (!value || *value == '\0')
@@ -1153,6 +1155,7 @@ main(
 						exit(1);
 					}
 					dswidth = cvtnum(0, 0, value);
+					dsflag = 1;
 					break;
 				case D_SU:
 					if (!value || *value == '\0')
@@ -1164,6 +1167,7 @@ main(
 							 D_SU);
 					dsu = cvtnum(
 						blocksize, sectorsize, value);
+					dsflag = 1;
 					break;
 				case D_SW:
 					if (!value || *value == '\0')
@@ -1180,6 +1184,7 @@ main(
 						exit(1);
 					}
 					dsw = cvtnum(0, 0, value);
+					dsflag = 1;
 					break;
 				case D_NOALIGN:
 					if (dsu)
@@ -2078,6 +2083,10 @@ _("warning: sparse inodes not supported 
 	calc_stripe_factors(dsu, dsw, sectorsize, lsu, lsectorsize,
 				&dsunit, &dswidth, &lsunit);
 
+	/* If sunit & swidth were manually specified as 0, same as noalign */
+	if (dsflag && !dsunit && !dswidth)
+		nodsflag = 1;
+
 	xi.setblksize = sectorsize;
 
 	/*