bin/121182: newfs_msdos should supports devices without CHS characteristics

[Andriy Gapon]

>Number:         121182
>Category:       bin
>Synopsis:       newfs_msdos should supports devices without CHS characteristics
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Feb 28 19:40:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Andriy Gapon
>Release:        FreeBSD 7.0-RC1 i386
>Organization:
>Environment:
System: FreeBSD 7.0-RC1 i386


	
>Description:
Currently newfs_msdos strictly requires that a device provides CHS characteristics.
And this is the case even if a user provided values for those parameters via
command line options.
First, in a modern world CHS requirements are no longer valid.
Second, user-provided overrides should be honored and undoubted.

>How-To-Repeat:
Try to format a DVD-RAM disk to FAT, e.g. FAT32:
newfs_msdos -F 32 /dev/acd1

>Fix:
The logic for faking CHS parameters is borrowed from bsdlabel code.

--- newfs-chs.patch begins here ---
--- newfs_msdos.c.orig	2008-02-21 21:35:00.000000000 +0200
+++ newfs_msdos.c	2008-02-21 21:56:13.000000000 +0200
@@ -739,13 +739,25 @@
     /* Maybe it's a fixed drive */
     if (lp == NULL) {
 	if (ioctl(fd, DIOCGDINFO, &dlp) == -1) {
-	    if (ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
+	    if (bpb->bps == 0 && ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
 		errx(1, "Cannot get sector size, %s", strerror(errno));
-	    if (ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1)
-		errx(1, "Cannot get number of sectors, %s", strerror(errno));
-	    if (ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks)== -1)
-		errx(1, "Cannot get number of heads, %s", strerror(errno));
+
+	    /* XXX Should we use bpb->bps if it's set? */
 	    dlp.d_secperunit = ms / dlp.d_secsize;
+
+	    if (bpb->spt == 0 && ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1) {
+		warnx("Cannot get number of sectors per track, %s", strerror(errno));
+		dlp.d_nsectors = 63;
+	    }
+	    if (bpb->hds == 0 && ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
+		warnx("Cannot get number of heads, %s", strerror(errno));
+		if (dlp.d_secperunit <= 63*1*1024)
+		    dlp.d_ntracks = 1;
+		else if (dlp.d_secperunit <= 63*16*1024)
+		    dlp.d_ntracks = 16;
+		else
+		    dlp.d_ntracks = 255;
+	    }
 	}
 
 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
--- newfs-chs.patch ends here ---


>Release-Note:
>Audit-Trail:
>Unformatted: