[PATCH] beginning of the shared-subtree proper
A private mount does not forward or receive propagation. This patch
provides user the ability to convert any mount to private.
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>
diff --git a/fs/namespace.c b/fs/namespace.c
index 4abee9a..3782923 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -24,6 +24,7 @@
#include <linux/mount.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
+#include "pnode.h"
extern int __init init_rootfs(void);
@@ -663,6 +664,27 @@
}
/*
+ * recursively change the type of the mountpoint.
+ */
+static int do_change_type(struct nameidata *nd, int flag)
+{
+ struct vfsmount *m, *mnt = nd->mnt;
+ int recurse = flag & MS_REC;
+ int type = flag & ~MS_REC;
+
+ if (nd->dentry != nd->mnt->mnt_root)
+ return -EINVAL;
+
+ down_write(&namespace_sem);
+ spin_lock(&vfsmount_lock);
+ for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))
+ change_mnt_propagation(m, type);
+ spin_unlock(&vfsmount_lock);
+ up_write(&namespace_sem);
+ return 0;
+}
+
+/*
* do loopback mount.
*/
static int do_loopback(struct nameidata *nd, char *old_name, int recurse)
@@ -1091,6 +1113,8 @@
data_page);
else if (flags & MS_BIND)
retval = do_loopback(&nd, dev_name, flags & MS_REC);
+ else if (flags & MS_PRIVATE)
+ retval = do_change_type(&nd, flags);
else if (flags & MS_MOVE)
retval = do_move_mount(&nd, dev_name);
else