diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2015-01-03 05:39:35 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2015-04-02 20:34:19 -0500 |
| commit | 5d88457eb5b86b475422dc882f089203faaeedb5 (patch) | |
| tree | 19d4a52f225092dfa2875dcb073d129151e910cf /fs/pnode.c | |
| parent | 411a938b5abc9cb126c41cccf5975ae464fe0f3e (diff) | |
| download | linux-5d88457eb5b86b475422dc882f089203faaeedb5.tar.bz2 | |
mnt: On an unmount propagate clearing of MNT_LOCKED
A prerequisite of calling umount_tree is that the point where the tree
is mounted at is valid to unmount.
If we are propagating the effect of the unmount clear MNT_LOCKED in
every instance where the same filesystem is mounted on the same
mountpoint in the mount tree, as we know (by virtue of the fact
that umount_tree was called) that it is safe to reveal what
is at that mountpoint.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/pnode.c')
| -rw-r--r-- | fs/pnode.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/fs/pnode.c b/fs/pnode.c index c27ae38ee250..89890293dd0a 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -362,6 +362,26 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) } /* + * Clear MNT_LOCKED when it can be shown to be safe. + * + * mount_lock lock must be held for write + */ +void propagate_mount_unlock(struct mount *mnt) +{ + struct mount *parent = mnt->mnt_parent; + struct mount *m, *child; + + BUG_ON(parent == mnt); + + for (m = propagation_next(parent, parent); m; + m = propagation_next(m, parent)) { + child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint); + if (child) + child->mnt.mnt_flags &= ~MNT_LOCKED; + } +} + +/* * NOTE: unmounting 'mnt' naturally propagates to all other mounts its * parent propagates to. */ |