[PATCH v2] mkfs: test that -l su is a multiple of block size

[Jan Tulak <jtulak@xxxxxxxxxx>]

lsunit was already tested, but lsu was not. So a thing like -l su=4097 was
possible. This commit adds a check to catch this, and moves the entire
lsu/lsunit block size testing to calc_stripe_factors(), where already is some
logic w.r.t. lsu/lsunit.

Signed-off-by: Jan Tulak <jtulak@xxxxxxxxxx>
---
UPDATE:
Moving the checks to calc_stripe_factors().

An example of previously failing options:
 mkfs.xfs -f -dfile,name=fsfile,size=128m -l su=16385
---
 mkfs/xfs_mkfs.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 6059d91..b8f6b89 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -726,6 +726,9 @@ struct opt_params mopts = {
  */
 #define WHACK_SIZE (128 * 1024)
 
+/*
+ * Convert lsu to lsunit for 512 bytes blocks and check validity of the values.
+ */
 static void
 calc_stripe_factors(
        int             dsu,
@@ -775,6 +778,20 @@ calc_stripe_factors(
 
        if (lsu)
                *lsunit = (int)BTOBBT(lsu);
+
+       /* verify if lsu/lsunit is a multiple block size */
+       if (lsu % blocksize != 0) {
+               fprintf(stderr,
+_("log stripe unit (%d) must be a multiple of the block size (%d)\n"),
+               lsu, blocksize);
+               exit(1);
+       }
+       if ((BBTOB(*lsunit) % blocksize != 0)) {
+               fprintf(stderr,
+_("log stripe unit (%d) must be a multiple of the block size (%d)\n"),
+               BBTOB(*lsunit), blocksize);
+               exit(1);
+       }
 }
 
 /*
@@ -2862,12 +2879,6 @@ an AG size that is one stripe unit smaller, for example 
%llu.\n"),
         */
 
        if (lsunit) {
-               if ((BBTOB(lsunit) % blocksize != 0)) {
-                       fprintf(stderr,
-       _("log stripe unit (%d) must be a multiple of the block size (%d)\n"),
-                       BBTOB(lsunit), blocksize);
-                       exit(1);
-               }
                /* convert from 512 byte blocks to fs blocks */
                lsunit = DTOBT(lsunit);
        } else if (sb_feat.log_version == 2 && loginternal && dsunit) {
-- 
2.5.5