[PATCH] introduce shared mounts

This creates shared mounts.  A shared mount when bind-mounted to some
mountpoint, propagates mount/umount events to each other.  All the
shared mounts that propagate events to each other belong to the same
peer-group.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mount.h b/include/linux/mount.h
index 8eadd3b65899..2582559718fc 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -20,6 +20,7 @@
 #define MNT_NOSUID      0x01
 #define MNT_NODEV       0x02
 #define MNT_NOEXEC      0x04
+#define MNT_SHARED      0x10    /* if the vfsmount is a shared mount */
 #define MNT_PNODE_MASK  0x30    /* propogation flag mask */
 
 struct vfsmount {
@@ -36,6 +37,7 @@ struct vfsmount {
         char *mnt_devname;              /* Name of device e.g. /dev/dsk/hda1 */
         struct list_head mnt_list;
         struct list_head mnt_expire;    /* link in fs-specific expiry list */
+        struct list_head mnt_share;     /* circular list of shared mounts */
         struct namespace *mnt_namespace; /* containing namespace */
         int mnt_pinned;
 };