Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / fs / pnode.c

diff --git a/kernel/fs/pnode.c b/kernel/fs/pnode.c
index 6367e1e..9989970 100644 (file)
--- a/kernel/fs/pnode.c
+++ b/kernel/fs/pnode.c
@@ -198,10 +198,15 @@ static struct mount *next_group(struct mount *m, struct mount *origin)
 
 /* all accesses are serialized by namespace_sem */
 static struct user_namespace *user_ns;
-static struct mount *last_dest, *last_source, *dest_master;
+static struct mount *last_dest, *first_source, *last_source, *dest_master;
 static struct mountpoint *mp;
 static struct hlist_head *list;
 
+static inline bool peers(struct mount *m1, struct mount *m2)
+{
+       return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id;
+}
+
 static int propagate_one(struct mount *m)
 {
        struct mount *child;
@@ -212,24 +217,26 @@ static int propagate_one(struct mount *m)
        /* skip if mountpoint isn't covered by it */
        if (!is_subdir(mp->m_dentry, m->mnt.mnt_root))
                return 0;
-       if (m->mnt_group_id == last_dest->mnt_group_id) {
+       if (peers(m, last_dest)) {
                type = CL_MAKE_SHARED;
        } else {
                struct mount *n, *p;
+               bool done;
                for (n = m; ; n = p) {
                        p = n->mnt_master;
-                       if (p == dest_master || IS_MNT_MARKED(p)) {
-                               while (last_dest->mnt_master != p) {
-                                       last_source = last_source->mnt_master;
-                                       last_dest = last_source->mnt_parent;
-                               }
-                               if (n->mnt_group_id != last_dest->mnt_group_id) {
-                                       last_source = last_source->mnt_master;
-                                       last_dest = last_source->mnt_parent;
-                               }
+                       if (p == dest_master || IS_MNT_MARKED(p))
                                break;
-                       }
                }
+               do {
+                       struct mount *parent = last_source->mnt_parent;
+                       if (last_source == first_source)
+                               break;
+                       done = parent->mnt_master == p;
+                       if (done && peers(n, parent))
+                               break;
+                       last_source = last_source->mnt_master;
+               } while (!done);
+
                type = CL_SLAVE;
                /* beginning of peer group among the slaves? */
                if (IS_MNT_SHARED(m))
@@ -281,6 +288,7 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp,
         */
        user_ns = current->nsproxy->mnt_ns->user_ns;
        last_dest = dest_mnt;
+       first_source = source_mnt;
        last_source = source_mnt;
        mp = dest_mp;
        list = tree_list;