[PATCH review 05/18] mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.

Eric W. Biederman
2014-12-12T22:51:35Z

Clear MNT_LOCKED in the callers of copy_tree except copy_mnt_ns, and
collect_mounts. In copy_mnt_ns it is necessary to create an exact
copy of a mount tree, so not clearing MNT_LOCKED is important.
Similarly collect_mounts is used to take a snapshot of the mount tree
for audit logging purposes and auditing using a faithful copy of the
tree is important.

This becomes particularly significant when we start setting MNT_LOCKED
on rootfs to prevent it from being unmounted.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/namespace.c | 1 -
fs/pnode.c | 1 +
2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index 15d0328bd035..e8d1ffa7f132 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1613,7 +1613,6 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
if (IS_ERR(q))
return q;

- q->mnt.mnt_flags &= ~MNT_LOCKED;
q->mnt_mountpoint = mnt->mnt_mountpoint;

p = mnt;
diff --git a/fs/pnode.c b/fs/pnode.c
index aae331a5d03b..260ac8f898a4 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -242,6 +242,7 @@ static int propagate_one(struct mount *m)
child = copy_tree(last_source, last_source->mnt.mnt_root, type);
if (IS_ERR(child))
return PTR_ERR(child);
+ child->mnt.mnt_flags &= ~MNT_LOCKED;
mnt_set_mountpoint(m, mp, child);
last_dest = m;
last_source = child;
--
1.9.1