2 files changed, 31 insertions, 6 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index c7cb8a526c05..7829eab0b706 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1361,6 +1361,36 @@ enum umount_tree_flags {
         UMOUNT_PROPAGATE = 2,
         UMOUNT_CONNECTED = 4,
 };
+
+static bool disconnect_mount(struct mount *mnt, enum umount_tree_flags how)
+{
+        /* Leaving mounts connected is only valid for lazy umounts */
+        if (how & UMOUNT_SYNC)
+                return true;
+
+        /* A mount without a parent has nothing to be connected to */
+        if (!mnt_has_parent(mnt))
+                return true;
+
+        /* Because the reference counting rules change when mounts are
+         * unmounted and connected, umounted mounts may not be
+         * connected to mounted mounts.
+         */
+        if (!(mnt->mnt_parent->mnt.mnt_flags & MNT_UMOUNT))
+                return true;
+
+        /* Has it been requested that the mount remain connected? */
+        if (how & UMOUNT_CONNECTED)
+                return false;
+
+        /* Is the mount locked such that it needs to remain connected? */
+        if (IS_MNT_LOCKED(mnt))
+                return false;
+
+        /* By default disconnect the mount */
+        return true;
+}
+
 /*
  * mount_lock must be held
  * namespace_sem must be held for write
@@ -1398,10 +1428,7 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
                 if (how & UMOUNT_SYNC)
                         p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
 
-                disconnect = !(((how & UMOUNT_CONNECTED) &&
-                                mnt_has_parent(p) &&
-                                (p->mnt_parent->mnt.mnt_flags & MNT_UMOUNT)) ||
-                               IS_MNT_LOCKED_AND_LAZY(p));
+                disconnect = disconnect_mount(p, how);
 
                 pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt,
                                  disconnect ? &unmounted : NULL);
diff --git a/fs/pnode.h b/fs/pnode.h
index 7114ce6e6b9e..0fcdbe7ca648 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -20,8 +20,6 @@
 #define SET_MNT_MARK(m) ((m)->mnt.mnt_flags |= MNT_MARKED)
 #define CLEAR_MNT_MARK(m) ((m)->mnt.mnt_flags &= ~MNT_MARKED)
 #define IS_MNT_LOCKED(m) ((m)->mnt.mnt_flags & MNT_LOCKED)
-#define IS_MNT_LOCKED_AND_LAZY(m) \
-        (((m)->mnt.mnt_flags & (MNT_LOCKED|MNT_SYNC_UMOUNT)) == MNT_LOCKED)
 
 #define CL_EXPIRE               0x01
 #define CL_SLAVE                0x02