From 8bf9725c29f2589237dd696d06a204230add0ba3 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 18 Oct 2007 23:40:02 -0700 Subject: pid namespaces: introduce MS_KERNMOUNT flag This flag tells the .get_sb callback that this is a kern_mount() call so that it can trust *data pointer to be valid in-kernel one. If this flag is passed from the user process, it is cleared since the *data pointer is not a valid kernel object. Running a few steps forward - this will be needed for proc to create the superblock and store a valid pid namespace on it during the namespace creation. The reason, why the namespace cannot live without proc mount is described in the appropriate patch. Signed-off-by: Pavel Emelyanov Cc: Oleg Nesterov Cc: Sukadev Bhattiprolu Cc: Paul Menage Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/namespace.c | 2 +- fs/super.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 07daa7972591..860752998fb3 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1411,7 +1411,7 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, mnt_flags |= MNT_RELATIME; flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | - MS_NOATIME | MS_NODIRATIME | MS_RELATIME); + MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT); /* ... and get the mountpoint */ retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd); diff --git a/fs/super.c b/fs/super.c index feaae7eeaffd..d28fde7e1cfb 100644 --- a/fs/super.c +++ b/fs/super.c @@ -944,9 +944,9 @@ do_kern_mount(const char *fstype, int flags, const char *name, void *data) return mnt; } -struct vfsmount *kern_mount(struct file_system_type *type) +struct vfsmount *kern_mount_data(struct file_system_type *type, void *data) { - return vfs_kern_mount(type, 0, type->name, NULL); + return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data); } -EXPORT_SYMBOL(kern_mount); +EXPORT_SYMBOL_GPL(kern_mount_data); -- cgit v1.2.3