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| author | Valerie Aurora <vaurora@redhat.com> | 2010-01-26 14:20:47 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-03-03 14:07:55 -0500 |
| commit | 495d6c9c6595ec7b37910dfd42634839431d21fd (patch) | |
| tree | 375a2ea9803a91c5df34df80d7e08119d9772240 | |
| parent | 2ecdc82ef0b03e67ce5ecee79d0d108177a704df (diff) | |
| download | lwn-495d6c9c6595ec7b37910dfd42634839431d21fd.tar.gz lwn-495d6c9c6595ec7b37910dfd42634839431d21fd.zip | |
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 <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namespace.c | 2 | ||||
| -rw-r--r-- | fs/pnode.h | 2 | ||||
| -rw-r--r-- | include/linux/mount.h | 11 |
3 files changed, 12 insertions, 3 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 25c1dcf9e9eb..d25d4602ab50 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1538,7 +1538,7 @@ static int do_remount(struct path *path, int flags, int mnt_flags, err = do_remount_sb(sb, flags, data, 0); if (!err) { spin_lock(&vfsmount_lock); - mnt_flags |= path->mnt->mnt_flags & MNT_PNODE_MASK; + mnt_flags |= path->mnt->mnt_flags & MNT_PROPAGATION_MASK; path->mnt->mnt_flags = mnt_flags; spin_unlock(&vfsmount_lock); } diff --git a/fs/pnode.h b/fs/pnode.h index 6c7ef3252a26..1ea4ae1efcd3 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -25,7 +25,7 @@ static inline void set_mnt_shared(struct vfsmount *mnt) { - mnt->mnt_flags &= ~MNT_PNODE_MASK; + mnt->mnt_flags &= ~MNT_SHARED_MASK; mnt->mnt_flags |= MNT_SHARED; } diff --git a/include/linux/mount.h b/include/linux/mount.h index 5d5275364867..375d43a5d802 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; |