[patch 7/7] vfs: mountinfo: show dominating group id

Show peer group ID of nearest dominating group that has intersection
with the mount's namespace.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 7 insertions, 2 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index c807b8d5f891..0505fb61aa74 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -850,8 +850,13 @@ static int show_mountinfo(struct seq_file *m, void *v)
         /* Tagged fields ("foo:X" or "bar") */
         if (IS_MNT_SHARED(mnt))
                 seq_printf(m, " shared:%i", mnt->mnt_group_id);
-        if (IS_MNT_SLAVE(mnt))
-                seq_printf(m, " master:%i", mnt->mnt_master->mnt_group_id);
+        if (IS_MNT_SLAVE(mnt)) {
+                int master = mnt->mnt_master->mnt_group_id;
+                int dom = get_dominating_id(mnt, &p->root);
+                seq_printf(m, " master:%i", master);
+                if (dom && dom != master)
+                        seq_printf(m, " propagate_from:%i", dom);
+        }
         if (IS_MNT_UNBINDABLE(mnt))
                 seq_puts(m, " unbindable");