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authorRob Landley <rob@landley.net>2013-09-12 01:26:06 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-12 02:59:36 +0400
commit137fdcc18a5979b53c0a1379b25fc68724e98a45 (patch)
tree4578399c35a509933e38e2951f46efe167012785
parent5e4c0d974139a98741b829b27cf38dc8f9284490 (diff)
downloadlinux-137fdcc18a5979b53c0a1379b25fc68724e98a45.tar.xz
initmpfs: replace MS_NOUSER in initramfs
Mounting MS_NOUSER prevents --bind mounts from rootfs. Prevent new rootfs mounts with a different mechanism that doesn't affect bind mounts. Signed-off-by: Rob Landley <rob@landley.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ramfs/inode.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index c24f1e10b946..8f7fe323e049 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -247,7 +247,12 @@ struct dentry *ramfs_mount(struct file_system_type *fs_type,
static struct dentry *rootfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- return mount_nodev(fs_type, flags|MS_NOUSER, data, ramfs_fill_super);
+ static unsigned long once;
+
+ if (test_and_set_bit(1, &once))
+ return ERR_PTR(-ENODEV);
+
+ return mount_nodev(fs_type, flags, data, ramfs_fill_super);
}
static void ramfs_kill_sb(struct super_block *sb)