mkfs.xfs: print std info if agcount makes agsize out of bounds

When specifying a too-small agcount with stripe geometry,
mkfs.xfs can fail with a somewhat unexpected message:

$ mkfs.xfs -f -d file,name=fsfile,size=9764864000b,agcount=31,su=512k,sw=20
Allocation group size (314995613) is not a multiple of the stripe unit (128)

This strikes me as especially odd because normally, mkfs.xfs
tries to fix up the agsize to be a stripe multiple.  The only way
we get to the above error message is if ag _size_ is out of bounds;
exiting with an error about alignment rather than about size
seems odd.

Maybe below is too clever, but if by the time we've decided that
agsize is out of bounds after rounding it both up and down,
as necessary, to get to a stripe-width multiple, calling
validate_ag_geometry() will give us the same standard message as
if we had specified no stripe geometry:

$ mkfs/mkfs.xfs -f -d file,name=fsfile,size=9764864000b,agcount=31,su=512k,sw=20
agsize (314995613b) too big, maximum is 268435455 blocks
Usage: mkfs.xfs
...

$ mkfs/mkfs.xfs -f -d file,name=fsfile,size=9764864000b,agcount=31
agsize (314995613b) too big, maximum is 268435455 blocks
Usage: mkfs.xfs
...

Also, tidy up error message to explicitly state "blocks" not "b"

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 5445b6f0af5d76ee27e152ec442bd315c253c429..d636549e27513eacd14a09da3423382fda9a1695 100644 (file)
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -707,7 +707,7 @@ validate_ag_geometry(
 {
        if (agsize < XFS_AG_MIN_BLOCKS(blocklog)) {
                fprintf(stderr,
-       _("agsize (%lldb) too small, need at least %lld blocks\n"),
+       _("agsize (%lld blocks) too small, need at least %lld blocks\n"),
                        (long long)agsize,
                        (long long)XFS_AG_MIN_BLOCKS(blocklog));
                usage();
@@ -715,7 +715,7 @@ validate_ag_geometry(
 
        if (agsize > XFS_AG_MAX_BLOCKS(blocklog)) {
                fprintf(stderr,
-       _("agsize (%lldb) too big, maximum is %lld blocks\n"),
+       _("agsize (%lld blocks) too big, maximum is %lld blocks\n"),
                        (long long)agsize,
                        (long long)XFS_AG_MAX_BLOCKS(blocklog));
                usage();
@@ -723,7 +723,7 @@ validate_ag_geometry(
 
        if (agsize > dblocks) {
                fprintf(stderr,
-       _("agsize (%lldb) too big, data area is %lld blocks\n"),
+       _("agsize (%lld blocks) too big, data area is %lld blocks\n"),
                        (long long)agsize, (long long)dblocks);
                        usage();
        }
@@ -2174,9 +2174,12 @@ _("size %s specified for log subvolume is too large, maximum is %lld blocks\n"),
                                if (nodsflag) {
                                        dsunit = dswidth = 0;
                                } else {
-                                       fprintf(stderr,
-_("Allocation group size (%lld) is not a multiple of the stripe unit (%d)\n"),
-                                               (long long)agsize, dsunit);
+                                       /*
+                                        * agsize is out of bounds, this will
+                                        * print nice details & exit.
+                                        */
+                                       validate_ag_geometry(blocklog, dblocks,
+                                                           agsize, agcount);
                                        exit(1);
                                }
                        }