Multi Session CD Patch

[Brandon Mercer <nomercy_(_at_)_eutonian_(_dot_)_com>]

Hello,
I've been working on getting multisession CD support to work in a 
somewhat usable fashion.  What I've come up with is to add a flag to 
mount_cd9660 to allow the user to specify the address of the session 
they'd like to mount.  This can be found by using cdrecord -toc or some 
other method.  By default it mounts the last session on the disk.  If 
the incorrect session is given it gives the user an error.  I have 
tested this only on i386, but it should work well in other archs.

My plan was also to set up a userland tool to display the track # and 
allow the user to put that into mount rather than the address.  Let me 
know what you think of that idea.  It seemed a bit like a cludge to do 
that in mount_cd9660... I'm open to ideas.  Thanks,
Brandon Mercer

Index: src/sys/sys/mount.h
===================================================================
RCS file: /cvs/src/sys/sys/mount.h,v
retrieving revision 1.68
diff -u -r1.68 mount.h
--- src/sys/sys/mount.h 31 Mar 2006 13:05:23 -0000      1.68
+++ src/sys/sys/mount.h 4 Apr 2006 17:33:41 -0000
@@ -94,11 +94,13 @@
      char    *fspec;                 /* block special device to mount */
      struct  export_args export_info;/* network export info */
      int     flags;                  /* mounting flags, see below */
+       u_int32_t     sessaddr;           /* address of session to mount */
};
#define        ISOFSMNT_NORRIP 0x00000001      /* disable Rock Ridge Ext.*/
#define        ISOFSMNT_GENS   0x00000002      /* enable generation 
numbers */
#define        ISOFSMNT_EXTATT 0x00000004      /* enable extended 
attributes */
#define        ISOFSMNT_NOJOLIET 0x00000008    /* disable Joliet Ext.*/
+#define        ISOFSMNT_USESESS  0x00000010   /* enable session address */

/*
* Arguments to mount NFS

# cvs diff -u src/sys/isofs/cd9660/cd9660_vfsops.c

Index: src/sys/isofs/cd9660/cd9660_vfsops.c
===================================================================
RCS file: /cvs/src/sys/isofs/cd9660/cd9660_vfsops.c,v
retrieving revision 1.38
diff -u -r1.38 cd9660_vfsops.c
--- src/sys/isofs/cd9660/cd9660_vfsops.c        22 Jan 2006 00:40:02 
-0000      1.38
+++ src/sys/isofs/cd9660/cd9660_vfsops.c        4 Apr 2006 17:34:58 -0000
@@ -265,9 +265,16 @@
       */
      iso_bsize = ISO_DEFAULT_BLOCK_SIZE;

-       error = VOP_IOCTL(devvp, CDIOREADMSADDR, (caddr_t)&sess, 0, 
FSCRED, p);
-       if (error)
+       /* check to see if the user sent a session address */
+       if (argp->flags & ISOFSMNT_USESESS) {
+           sess = argp->sessaddr;
+       } else {
+           error = VOP_IOCTL(devvp, CDIOREADMSADDR, (caddr_t)&sess, 0, 
FSCRED, p);
+           if (error)
              sess = 0;
+
+       }
+

      joliet_level = 0;
      for (iso_blknum = 16; iso_blknum < 100; iso_blknum++) {

# cvs diff -u src/sbin/mount_cd9660/mount_cd9660.c
Index: src/sbin/mount_cd9660/mount_cd9660.c
===================================================================
RCS file: /cvs/src/sbin/mount_cd9660/mount_cd9660.c,v
retrieving revision 1.17
diff -u -r1.17 mount_cd9660.c
--- src/sbin/mount_cd9660/mount_cd9660.c        8 Apr 2005 20:09:36 
-0000       1.17
+++ src/sbin/mount_cd9660/mount_cd9660.c        4 Apr 2006 17:35:44 -0000
@@ -76,9 +77,10 @@
      struct iso_args args;
      int ch, mntflags, opts;
      char *dev, dir[MAXPATHLEN];
+       const char *errstr;

      mntflags = opts = 0;
-       while ((ch = getopt(argc, argv, "egjo:R")) != -1)
+       while ((ch = getopt(argc, argv, "egjo:s:R")) != -1)
              switch (ch) {
              case 'e':
                      opts |= ISOFSMNT_EXTATT;
@@ -92,6 +94,12 @@
              case 'o':
                      getmntopts(optarg, mopts, &mntflags);
                      break;
+               case 's':
+                       opts |= ISOFSMNT_USESESS;
+                       args.sessaddr = strtonum(optarg, 0, UINT_MAX, 
&errstr);
+                       if (errstr)
+                           errx(1, "address %s: %s", errstr, optarg);
+                       break;
              case 'R':
                      opts |= ISOFSMNT_NORRIP;
                      break;
@@ -135,6 +143,6 @@
usage(void)
{
      (void)fprintf(stderr,
-               "usage: mount_cd9660 [-egjR] [-o options] special node\n");
+               "usage: mount_cd9660 [-egjR] [-o options] [-s 
sessionaddr] special node\n");
      exit(1);
}