[PATCH 4/10] Debian patch: add an option to not update mtab for smbmount

[Steve Langasek]

On Wed, May 30, 2007 at 10:34:00PM +0200, Christian Perrier wrote:
> The attached patch is currently used in Debian.

> It adds a "-n" option to smbmount so that it does not update
> /etc/mtab. I can't find a real evidence of why this was needed.

> Please note that the patch adds the option but does not update the
> manpage.

samba (2.2.3a-7) unstable; urgency=medium

  [...]
  * Applied patch from Urban Widmark <urban at teststation.com>
    (smbfs upstream maintainer) to add a '-n' option to smbmount
    that does the same as mount's '-n'. (Closes: #139590)
  [...]

The original bug report was that smbfs could not be used when the root
filesystem was mounted read-only, which is a valid use and supported by
mount when using other fs types that don't do their own writing to
/etc/mtab.  I don't know why Urban never included this upstream though.

-- 
Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
vorlon at debian.org                                   http://www.debian.org/

> Goal: Add an option to not update mtab
> 
> Fixes: ?
> 
> Status wrt upstream: Should be forwarded
> 
> Note: Part of no-longer maintained smbfs stuff?
>       The manpages are not modified
> 
> Index: samba-3.0.25a/source/client/smbmnt.c
> ===================================================================
> --- samba-3.0.25a.orig/source/client/smbmnt.c	2007-05-26 07:46:33.492644419 +0200
> +++ samba-3.0.25a/source/client/smbmnt.c	2007-05-26 07:46:33.848647257 +0200
> @@ -44,6 +44,7 @@
>  static uid_t mount_uid;
>  static gid_t mount_gid;
>  static int mount_ro;
> +static int no_mtab;
>  static unsigned mount_fmask;
>  static unsigned mount_dmask;
>  static int user_mount;
> @@ -56,6 +57,7 @@
>          printf("Usage: smbmnt mount-point [options]\n");
>  	printf("Version %s\n\n",SAMBA_VERSION_STRING);
>          printf("-s share       share name on server\n"
> +               "-n             don't update /etc/mtab\n"
>                 "-r             mount read-only\n"
>                 "-u uid         mount as uid\n"
>                 "-g gid         mount as gid\n"
> @@ -70,7 +72,7 @@
>  {
>          int opt;
>  
> -        while ((opt = getopt (argc, argv, "s:u:g:rf:d:o:")) != EOF)
> +        while ((opt = getopt (argc, argv, "s:u:g:nrf:d:o:")) != EOF)
>  	{
>                  switch (opt)
>  		{
> @@ -87,6 +89,9 @@
>  				mount_gid = strtol(optarg, NULL, 0);
>  			}
>                          break;
> +		case 'n':
> +			no_mtab = 1;
> +			break;
>                  case 'r':
>                          mount_ro = 1;
>                          break;
> @@ -291,36 +296,38 @@
>  		return -1;
>  	}
>  	
> -        if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1)
> -        {
> -                fprintf(stderr, "Can't get "MOUNTED"~ lock file");
> -                return 1;
> -        }
> -        close(fd);
> +	if (!no_mtab) {
> +		if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1)
> +		{
> +			fprintf(stderr, "Can't get "MOUNTED"~ lock file");
> +			return 1;
> +		}
> +		close(fd);
>  	
> -        if ((mtab = setmntent(MOUNTED, "a+")) == NULL)
> -        {
> -                fprintf(stderr, "Can't open " MOUNTED);
> -                return 1;
> -        }
> +		if ((mtab = setmntent(MOUNTED, "a+")) == NULL)
> +		{
> +			fprintf(stderr, "Can't open " MOUNTED);
> +			return 1;
> +		}
>  
> -        if (addmntent(mtab, &ment) == 1)
> -        {
> -                fprintf(stderr, "Can't write mount entry");
> -                return 1;
> -        }
> -        if (fchmod(fileno(mtab), 0644) == -1)
> -        {
> -                fprintf(stderr, "Can't set perms on "MOUNTED);
> -                return 1;
> -        }
> -        endmntent(mtab);
> +		if (addmntent(mtab, &ment) == 1)
> +		{
> +			fprintf(stderr, "Can't write mount entry");
> +			return 1;
> +		}
> +		if (fchmod(fileno(mtab), 0644) == -1)
> +		{
> +			fprintf(stderr, "Can't set perms on "MOUNTED);
> +			return 1;
> +		}
> +		endmntent(mtab);
>  
> -        if (unlink(MOUNTED"~") == -1)
> -        {
> -                fprintf(stderr, "Can't remove "MOUNTED"~");
> -                return 1;
> -        }
> +		if (unlink(MOUNTED"~") == -1)
> +		{
> +			fprintf(stderr, "Can't remove "MOUNTED"~");
> +			return 1;
> +		}
> +	}
>  
>  	return 0;
>  }	
> Index: samba-3.0.25a/source/client/smbmount.c
> ===================================================================
> --- samba-3.0.25a.orig/source/client/smbmount.c	2007-05-26 07:46:32.692638041 +0200
> +++ samba-3.0.25a/source/client/smbmount.c	2007-05-26 07:46:33.884647544 +0200
> @@ -48,6 +48,7 @@
>  static int mount_ro;
>  static unsigned mount_fmask;
>  static unsigned mount_dmask;
> +static BOOL no_mtab = False;
>  static BOOL use_kerberos;
>  /* TODO: Add code to detect smbfs version in kernel */
>  static BOOL status32_smbfs = False;
> @@ -273,6 +274,9 @@
>                  return;
>          }
>  
> +	if (no_mtab)
> +		return;
> +
>          if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1) {
>                  DEBUG(0,("%d: Can't get "MOUNTED"~ lock file", sys_getpid()));
>                  return;
> @@ -470,6 +474,9 @@
>  	args[i++] = "-s";
>  	args[i++] = svc2;
>  
> +	if (no_mtab) {
> +		args[i++] = "-n";
> +	}
>  	if (mount_ro) {
>  		args[i++] = "-r";
>  	}
> @@ -665,7 +672,7 @@
>  ****************************************************************************/
>  static void usage(void)
>  {
> -	printf("Usage: mount.smbfs service mountpoint [-o options,...]\n");
> +	printf("Usage: mount.smbfs service mountpoint [-n] [-o options,...]\n");
>  
>  	printf("Version %s\n\n",SAMBA_VERSION_STRING);
>  
> @@ -742,8 +749,13 @@
>  	argc -= 2;
>  	argv += 2;
>  
> -	opt = getopt(argc, argv, "o:");
> -	if(opt != 'o') {
> +	opt = getopt(argc, argv, "no:");
> +	if (opt == 'n') {
> +		DEBUG(3,("No mtab!\n"));
> +		no_mtab = True;
> +		opt = getopt(argc, argv, "o:");
> +	}
> +	if (opt != 'o') {
>  		return;
>  	}
>