SUNRPC: hold current network namespace while pipefs superblock is active

We want to be sure that network namespace is still alive while we have pipefs
mounted.
This will be required later, when RPC pipefs will be mounting only from
user-space context.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index e32e6b8c006d641d3b3b0772f64645ad2d75515e..f628b0f48a87c04f6cf384356148e6d9f5029c35 100644 (file)
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -27,6 +27,9 @@
 #include <linux/workqueue.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/sunrpc/cache.h>
+#include <linux/nsproxy.h>
+
+#include "netns.h"
 
 static struct vfsmount *rpc_mnt __read_mostly;
 static int rpc_mount_count;
@@ -1011,6 +1014,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
        }
        if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
                return -ENOMEM;
+       sb->s_fs_info = get_net(net);
        return 0;
 }
 
@@ -1021,11 +1025,19 @@ rpc_mount(struct file_system_type *fs_type,
        return mount_ns(fs_type, flags, current->nsproxy->net_ns, rpc_fill_super);
 }
 
+void rpc_kill_sb(struct super_block *sb)
+{
+       struct net *net = sb->s_fs_info;
+
+       put_net(net);
+       kill_litter_super(sb);
+}
+
 static struct file_system_type rpc_pipe_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "rpc_pipefs",
        .mount          = rpc_mount,
-       .kill_sb        = kill_litter_super,
+       .kill_sb        = rpc_kill_sb,
 };
 
 static void