[PATCH 21/38] vfs: Convert rpc_pipefs to fs_context

[David Howells <dhowells@xxxxxxxxxx>]

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx>
cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: linux-nfs@xxxxxxxxxxxxxxx
---

 net/sunrpc/rpc_pipe.c |   34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 69663681bf9d..2d697861d49a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -13,6 +13,7 @@
 #include <linux/string.h>
 #include <linux/pagemap.h>
 #include <linux/mount.h>
+#include <linux/fs_context.h>
 #include <linux/namei.h>
 #include <linux/fsnotify.h>
 #include <linux/kernel.h>
@@ -1354,11 +1355,11 @@ rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
 }
 
 static int
-rpc_fill_super(struct super_block *sb, void *data, int silent)
+rpc_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct inode *inode;
 	struct dentry *root, *gssd_dentry;
-	struct net *net = get_net(sb->s_fs_info);
+	struct net *net = sb->s_fs_info;
 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 	int err;
 
@@ -1415,12 +1416,29 @@ gssd_running(struct net *net)
 }
 EXPORT_SYMBOL_GPL(gssd_running);
 
-static struct dentry *
-rpc_mount(struct file_system_type *fs_type,
-		int flags, const char *dev_name, void *data)
+static int rpc_fs_get_tree(struct fs_context *fc)
+{
+	fc->s_fs_info = get_net(fc->net_ns);
+	return vfs_get_super(fc, vfs_get_keyed_super, rpc_fill_super);
+}
+
+static void rpc_fs_free_fc(struct fs_context *fc)
 {
-	struct net *net = current->nsproxy->net_ns;
-	return mount_ns(fs_type, flags, data, net, net->user_ns, rpc_fill_super);
+	if (fc->s_fs_info)
+		put_net(fc->s_fs_info);
+}
+
+static const struct fs_context_operations rpc_fs_context_ops = {
+	.free		= rpc_fs_free_fc,
+	.get_tree	= rpc_fs_get_tree,
+};
+
+static int rpc_init_fs_context(struct fs_context *fc)
+{
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
+	fc->ops = &rpc_fs_context_ops;
+	return 0;
 }
 
 static void rpc_kill_sb(struct super_block *sb)
@@ -1448,7 +1466,7 @@ static void rpc_kill_sb(struct super_block *sb)
 static struct file_system_type rpc_pipe_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "rpc_pipefs",
-	.mount		= rpc_mount,
+	.init_fs_context = rpc_init_fs_context,
 	.kill_sb	= rpc_kill_sb,
 };
 MODULE_ALIAS_FS("rpc_pipefs");