[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, 1 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 3782923d6d4d..f6861a5487df 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -68,6 +68,7 @@ struct vfsmount *alloc_vfsmnt(const char *name)
                 INIT_LIST_HEAD(&mnt->mnt_mounts);
                 INIT_LIST_HEAD(&mnt->mnt_list);
                 INIT_LIST_HEAD(&mnt->mnt_expire);
+                INIT_LIST_HEAD(&mnt->mnt_share);
                 if (name) {
                         int size = strlen(name) + 1;
                         char *newname = kmalloc(size, GFP_KERNEL);
@@ -1113,7 +1114,7 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
                                     data_page);
         else if (flags & MS_BIND)
                 retval = do_loopback(&nd, dev_name, flags & MS_REC);
-        else if (flags & MS_PRIVATE)
+        else if (flags & (MS_SHARED | MS_PRIVATE))
                 retval = do_change_type(&nd, flags);
         else if (flags & MS_MOVE)
                 retval = do_move_mount(&nd, dev_name);