--- util-linux-2.13-pre6/mount/mount.8.subtree	2006-06-12 09:18:26.000000000 +0200

+++ util-linux-2.13-pre6/mount/mount.8	2006-06-12 09:19:43.000000000 +0200

@@ -131,6 +131,41 @@

 .B "mount --move olddir newdir"

 .RE

+Since Linux 2.6.15 it is possible to mark a mount and its submounts as shared,

+private, slave or unbindable. A shared mount provides ability to create mirrors

+of that mount such that mounts and umounts within any of the mirrors propagate

+to the other mirror. A slave mount receives propagation from its master, but

+any not vice-versa.  A private mount carries no propagation abilities.  A

+unbindable mount is a private mount which cannot cloned through a bind

+operation. Detailed semantics is documented in Documentation/sharedsubtree.txt

+file in the kernel source tree.

+.RS

+.br

+.B "mount --make-shared mountpoint"

+.br

+.B "mount --make-slave mountpoint"

+.br

+.B "mount --make-private mountpoint"

+.br

+.B "mount --make-unbindable mountpoint"

+.br

+.RE

+

+The following commands allows one to recursively change the type of all the

+mounts under a given mountpoint.

+.RS

+.br

+.B "mount --make-rshared mountpoint"

+.br

+.B "mount --make-rslave mountpoint"

+.br

+.B "mount --make-rprivate mountpoint"

+.br

+.B

+"mount --make-runbindable mountpoint"

+.br

+.RE

+

 The

 .I proc

 file system is not associated with a special device, and when

--- util-linux-2.13-pre6/mount/mount_constants.h.subtree	2002-11-01 01:24:36.000000000 +0100

+++ util-linux-2.13-pre6/mount/mount_constants.h	2006-06-12 09:19:43.000000000 +0200

@@ -57,6 +57,18 @@

 #ifndef MS_VERBOSE

 #define MS_VERBOSE	0x8000	/* 32768 */

 #endif

+#ifndef MS_UNBINDABLE

+#define MS_UNBINDABLE	(1<<17)	/* 131072 unbindable*/

+#endif

+#ifndef MS_PRIVATE

+#define MS_PRIVATE	(1<<18)	/* 262144 Private*/

+#endif

+#ifndef MS_SLAVE

+#define MS_SLAVE	(1<<19)	/* 524288 Slave*/

+#endif

+#ifndef MS_SHARED

+#define MS_SHARED	(1<<20)	/* 1048576 Shared*/

+#endif

 /*

  * Magic mount flag number. Had to be or-ed to the flag values.

  */

--- util-linux-2.13-pre6/mount/mount.c.subtree	2006-06-12 09:18:26.000000000 +0200

+++ util-linux-2.13-pre6/mount/mount.c	2006-06-12 09:19:43.000000000 +0200

@@ -74,7 +74,9 @@

 /* Add volumelabel in a listing of mounted devices (-l). */

 static int list_with_volumelabel = 0;

-/* Nonzero for mount {--bind|--replace|--before|--after|--over|--move} */

+/* Nonzero for mount {--bind|--replace|--before|--after|--over|--move|

+ * 		       make-shared|make-private|make-unbindable|make-slave}

+ */

 static int mounttype = 0;

 /* True if ruid != euid.  */

@@ -109,6 +111,8 @@

 /* Options that we keep from appearing in the options field in the mtab.  */

 #define MS_NOMTAB	(MS_REMOUNT|MS_NOAUTO|MS_USERS|MS_USER|MS_PAMCONSOLE)

+#define MS_PROPAGATION  (MS_SHARED|MS_SLAVE|MS_UNBINDABLE|MS_PRIVATE)

+

 /* Options that we make ordinary users have by default.  */

 #define MS_SECURE	(MS_NOEXEC|MS_NOSUID|MS_NODEV)

@@ -346,6 +350,9 @@

 		*flags |= MS_RDONLY;

 	if (readwrite)

 		*flags &= ~MS_RDONLY;

+

+	if (mounttype & MS_PROPAGATION)

+		*flags &= ~MS_BIND;

 	*flags |= mounttype;

 }

@@ -916,13 +923,15 @@

       if (loop)

 	  opt_loopdev = loopdev;

-      update_mtab_entry(loop ? loopfile : spec,

+      if (!(mounttype & MS_PROPAGATION)) {

+	      update_mtab_entry(loop ? loopfile : spec,

 			node,

 			types ? types : "unknown",

 			fix_opts_string (flags & ~MS_NOMTAB, extra_opts, user),

 			flags,

 			freq,

 			pass);

+      }

       block_signals (SIG_UNBLOCK);

       res = 0;

@@ -1461,6 +1470,14 @@

 	{ "move", 0, 0, 133 },

 	{ "guess-fstype", 1, 0, 134 },

 	{ "rbind", 0, 0, 135 },

+	{ "make-shared", 0, 0, 136 },

+	{ "make-slave", 0, 0, 137 },

+	{ "make-private", 0, 0, 138 },

+	{ "make-unbindable", 0, 0, 139 },

+	{ "make-rshared", 0, 0, 140 },

+	{ "make-rslave", 0, 0, 141 },

+	{ "make-rprivate", 0, 0, 142 },

+	{ "make-runbindable", 0, 0, 143 },

 	{ "internal-only", 0, 0, 'i' },

 	{ NULL, 0, 0, 0 }

 };

@@ -1487,6 +1504,17 @@

 	  "       mount --bind olddir newdir\n"

 	  "or move a subtree:\n"

 	  "       mount --move olddir newdir\n"

+	  "One can change the type of mount containing the directory dir:\n"

+	  "       mount --make-shared dir\n"

+	  "       mount --make-slave dir\n"

+	  "       mount --make-private dir\n"

+	  "       mount --make-unbindable dir\n"

+	  "One can change the type of all the mounts in a mount subtree\n"

+	  "containing the directory dir:\n"

+	  "       mount --make-rshared dir\n"

+	  "       mount --make-rslave dir\n"

+	  "       mount --make-rprivate dir\n"

+	  "       mount --make-runbindable dir\n"

 	  "A device can be given by name, say /dev/hda1 or /dev/cdrom,\n"

 	  "or by label, using  -L label  or by uuid, using  -U uuid .\n"

 	  "Other options: [-nfFrsvw] [-o options] [-p passwdfd].\n"

@@ -1638,6 +1666,39 @@

 		case 135:

 			mounttype = (MS_BIND | MS_REC);

 			break;

+

+		case 136:

+			mounttype = MS_SHARED;

+			break;

+

+		case 137:

+			mounttype = MS_SLAVE;

+			break;

+

+		case 138:

+			mounttype = MS_PRIVATE;

+			break;

+

+		case 139:

+			mounttype = MS_UNBINDABLE;

+			break;

+

+		case 140:

+			mounttype = (MS_SHARED | MS_REC);

+			break;

+

+		case 141:

+			mounttype = (MS_SLAVE | MS_REC);

+			break;

+

+		case 142:

+			mounttype = (MS_PRIVATE | MS_REC);

+			break;

+

+		case 143:

+			mounttype = (MS_UNBINDABLE | MS_REC);

+			break;

+

 		case '?':

 		default:

 			usage (stderr, EX_USAGE);