[PATCH] pivot_root() circular reference fix

Fix http://bugzilla.kernel.org/show_bug.cgi?id=4857

When pivot_root is called from an init script in an initramfs environment,
it causes a circular reference in the mount tree.

The cause of this is that pivot_root() is not prepared to handle pivoting
an unattached mount.  In an initramfs environment, rootfs is the root of
the namespace, and so it is not attached.

This patch fixes this and related problems, by returning -EINVAL if either
the current root or the new root is detached.

Signed-off-by: Miklos Szeredi <[email protected]>
Acked-by: Al Viro <[email protected]>
Cc: <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions