[src/trunk]: src/sbin/newfs_msdos Use the same defaults for cluster sizes as ...

[mlelstv <mlelstv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/97524e400fc8
branches:  trunk
changeset: 814674:97524e400fc8
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Apr 03 11:00:13 2016 +0000

description:
Use the same defaults for cluster sizes as Windows.

diffstat:

 sbin/newfs_msdos/mkfs_msdos.c |  34 ++++++++++++++++++++++------------
 1 files changed, 22 insertions(+), 12 deletions(-)

diffs (55 lines):

diff -r d78e3a2dbcd6 -r 97524e400fc8 sbin/newfs_msdos/mkfs_msdos.c
--- a/sbin/newfs_msdos/mkfs_msdos.c     Sun Apr 03 10:36:00 2016 +0000
+++ b/sbin/newfs_msdos/mkfs_msdos.c     Sun Apr 03 11:00:13 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mkfs_msdos.c,v 1.9 2014/01/05 12:52:39 martin Exp $    */
+/*     $NetBSD: mkfs_msdos.c,v 1.10 2016/04/03 11:00:13 mlelstv Exp $  */
 
 /*
  * Copyright (c) 1998 Robert Nordier
@@ -37,7 +37,7 @@
 static const char rcsid[] =
   "$FreeBSD: src/sbin/newfs_msdos/newfs_msdos.c,v 1.15 2000/10/10 01:49:37 wollman Exp $";
 #else
-__RCSID("$NetBSD: mkfs_msdos.c,v 1.9 2014/01/05 12:52:39 martin Exp $");
+__RCSID("$NetBSD: mkfs_msdos.c,v 1.10 2016/04/03 11:00:13 mlelstv Exp $");
 #endif
 #endif /* not lint */
 
@@ -335,16 +335,26 @@
            return -1;
        bpb.bsec -= (o.offset / bpb.bps);
        if (bpb.spc == 0) {     /* set defaults */
-           if (bpb.bsec <= 6000)       /* about 3MB -> 512 bytes */
-               bpb.spc = 1;
-           else if (bpb.bsec <= (1<<17)) /* 64M -> 4k */
-               bpb.spc = 8;
-           else if (bpb.bsec <= (1<<19)) /* 256M -> 8k */
-               bpb.spc = 16;
-           else if (bpb.bsec <= (1<<21)) /* 1G -> 16k */
-               bpb.spc = 32;
-           else
-               bpb.spc = 64;           /* otherwise 32k */
+           /* minimum cluster size */
+           switch (o.fat_type) {
+           case 12:
+               bpb.spc = 1;            /* use 512 bytes */
+               x = 2;                  /* up to 2MB */
+               break;
+           case 16:
+               bpb.spc = 1;            /* use 512 bytes */
+               x = 32;                 /* up to 32MB */
+               break;
+           default:
+               bpb.spc = 8;            /* use 4k */
+               x = 8192;               /* up to 8GB */
+               break;
+           }
+           x1 = howmany(bpb.bsec, (1048576 / 512)); /* -> MB */
+           while (bpb.spc < 128 && x < x1) {
+               x *= 2;
+               bpb.spc *= 2;
+           }
        }
     }