From b2442afc5b28389aa21f50ca8e828261bb9325a8 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Wed, 10 Jun 2009 09:37:43 +0200
Subject: [PATCH] mount: move MS_{PROPAGATION,BIND,MOVE} detection

The previous commit does not properly fix the problem with "none"
fstype and MS_{PROPAGATION,BIND,MOVE} flags. The real fstype has to
be replaced with "none" before we try to use /sbin/mount.<type>
helper.

Old version:

	# grep test /proc/self/mountinfo
	16 18 0:19 / /mnt/test rw,relatime - tmpfs tmpfs rw

	# ./mount -v -v -v --make-private /mnt/test
	mount: fstab path: "/etc/fstab"
	mount: mtab path:  "/etc/mtab"
	mount: lock path:  "/etc/mtab~"
	mount: temp path:  "/etc/mtab.tmp"
	mount: UID:        0
	mount: eUID:       0
	mount: spec:  "tmpfs"
	mount: node:  "/mnt/test"
	mount: types: "tmpfs"
	mount: opts:  "rw"
	mount: external mount: argv[0] = "/sbin/mount.tmpfs"
	mount: external mount: argv[1] = "tmpfs"
	mount: external mount: argv[2] = "/mnt/test"
	mount: external mount: argv[3] = "-v"
	mount: external mount: argv[4] = "-o"
	mount: external mount: argv[5] = "rw"
	tmpfs on /mnt/test type tmpfs (rw)

	# grep test /proc/self/mountinfo
	16 18 0:19 / /mnt/test rw,relatime - tmpfs tmpfs rw
	17 16 0:20 / /mnt/test rw,relatime - tmpfs tmpfs rw

Fixed version:

	# grep test /proc/self/mountinfo
	16 18 0:19 / /mnt/test rw,relatime - tmpfs tmpfs rw

	# ./mount -v -v -v --make-private /mnt/test
	mount: fstab path: "/etc/fstab"
	mount: mtab path:  "/etc/mtab"
	mount: lock path:  "/etc/mtab~"
	mount: temp path:  "/etc/mtab.tmp"
	mount: UID:        0
	mount: eUID:       0
	mount: spec:  "tmpfs"
	mount: node:  "/mnt/test"
	mount: types: "tmpfs"
	mount: opts:  "rw"
	mount: mount(2) syscall: source: "tmpfs", target: "/mnt/test",
	filesystemtype: "none", mountflags: 262144, data: (null)

	# grep test /proc/self/mountinfo
	16 18 0:19 / /mnt/test rw,relatime - tmpfs tmpfs rw

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 mount/mount.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mount/mount.c b/mount/mount.c
index e002ebbb..c636e9dc 100644
--- a/mount/mount.c
+++ b/mount/mount.c
@@ -895,9 +895,6 @@ guess_fstype_and_mount(const char *spec, const char *node, const char **types,
    if (*types && strcasecmp (*types, "auto") == 0)
       *types = NULL;
 
-   if (flags & (MS_BIND | MS_MOVE | MS_PROPAGATION))
-      *types = "none";
-
    if (!*types && !(flags & MS_REMOUNT)) {
       *types = guess_fstype_by_devname(spec);
       if (*types) {
@@ -1302,6 +1299,9 @@ try_mount_one (const char *spec0, const char *node0, const char *types0,
   if (loop)
       opt_loopdev = loopdev;
 
+  if (flags & (MS_BIND | MS_MOVE | MS_PROPAGATION))
+      types = "none";
+
   /*
    * Call mount.TYPE for types that require a separate mount program.
    * For the moment these types are ncpfs and smbfs. Maybe also vxfs.
-- 
2.39.5