From 495d6c9c6595ec7b37910dfd42634839431d21fd Mon Sep 17 00:00:00 2001 From: Valerie Aurora Date: Tue, 26 Jan 2010 14:20:47 -0500 Subject: VFS: Clean up shared mount flag propagation The handling of mount flags in set_mnt_shared() got a little tangled up during previous cleanups, with the following problems: * MNT_PNODE_MASK is defined as a literal constant when it should be a bitwise xor of other MNT_* flags * set_mnt_shared() clears and then sets MNT_SHARED (part of MNT_PNODE_MASK) * MNT_PNODE_MASK could use a comment in mount.h * MNT_PNODE_MASK is a terrible name, change to MNT_SHARED_MASK This patch fixes these problems. Signed-off-by: Al Viro --- include/linux/mount.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/mount.h b/include/linux/mount.h index 5d527536486..375d43a5d80 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -34,7 +34,16 @@ struct mnt_namespace; #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ -#define MNT_PNODE_MASK 0x3000 /* propagation flag mask */ +/* + * MNT_SHARED_MASK is the set of flags that should be cleared when a + * mount becomes shared. Currently, this is only the flag that says a + * mount cannot be bind mounted, since this is how we create a mount + * that shares events with another mount. If you add a new MNT_* + * flag, consider how it interacts with shared mounts. + */ +#define MNT_SHARED_MASK (MNT_UNBINDABLE) +#define MNT_PROPAGATION_MASK (MNT_SHARED | MNT_UNBINDABLE) + struct vfsmount { struct list_head mnt_hash; -- cgit v1.2.3