rpc_pipe: remove the clntXX dir if creating the pipe fails

[platform/adaptation/renesas_rcar/renesas_kernel.git] / net / sunrpc / rpc_pipe.c

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index bf04b30..0b74c61 100644 (file)
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -38,7 +38,7 @@
 #define NET_NAME(net)  ((net == &init_net) ? " (init_net)" : "")
 
 static struct file_system_type rpc_pipe_fs_type;
-
+static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
 
 static struct kmem_cache *rpc_inode_cachep __read_mostly;
 
@@ -216,14 +216,11 @@ rpc_destroy_inode(struct inode *inode)
 static int
 rpc_pipe_open(struct inode *inode, struct file *filp)
 {
-       struct net *net = inode->i_sb->s_fs_info;
-       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
        struct rpc_pipe *pipe;
        int first_open;
        int res = -ENXIO;
 
        mutex_lock(&inode->i_mutex);
-       sn->gssd_running = 1;
        pipe = RPC_I(inode)->pipe;
        if (pipe == NULL)
                goto out;
@@ -1159,6 +1156,7 @@ enum {
        RPCAUTH_nfsd4_cb,
        RPCAUTH_cache,
        RPCAUTH_nfsd,
+       RPCAUTH_gssd,
        RPCAUTH_RootEOF
 };
 
@@ -1195,6 +1193,10 @@ static const struct rpc_filelist files[] = {
                .name = "nfsd",
                .mode = S_IFDIR | S_IRUGO | S_IXUGO,
        },
+       [RPCAUTH_gssd] = {
+               .name = "gssd",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
 };
 
 /*
@@ -1208,13 +1210,24 @@ struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
 }
 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
 
-void rpc_pipefs_init_net(struct net *net)
+int rpc_pipefs_init_net(struct net *net)
 {
        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
+       sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
+       if (IS_ERR(sn->gssd_dummy))
+               return PTR_ERR(sn->gssd_dummy);
+
        mutex_init(&sn->pipefs_sb_lock);
-       sn->gssd_running = 1;
        sn->pipe_version = -1;
+       return 0;
+}
+
+void rpc_pipefs_exit_net(struct net *net)
+{
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+       rpc_destroy_pipe_data(sn->gssd_dummy);
 }
 
 /*
@@ -1244,11 +1257,75 @@ void rpc_put_sb_net(const struct net *net)
 }
 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
 
+static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
+       [0] = {
+               .name = "clntXX",
+               .mode = S_IFDIR | S_IRUGO | S_IXUGO,
+       },
+};
+
+static ssize_t
+dummy_downcall(struct file *filp, const char __user *src, size_t len)
+{
+       return -EINVAL;
+}
+
+static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
+       .upcall         = rpc_pipe_generic_upcall,
+       .downcall       = dummy_downcall,
+};
+
+/**
+ * rpc_gssd_dummy_populate - create a dummy gssd pipe
+ * @root:      root of the rpc_pipefs filesystem
+ * @pipe_data: pipe data created when netns is initialized
+ *
+ * Create a dummy set of directories and a pipe that gssd can hold open to
+ * indicate that it is up and running.
+ */
+static struct dentry *
+rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
+{
+       int ret = 0;
+       struct dentry *gssd_dentry;
+       struct dentry *clnt_dentry = NULL;
+       struct dentry *pipe_dentry = NULL;
+       struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
+                                 strlen(files[RPCAUTH_gssd].name));
+
+       /* We should never get this far if "gssd" doesn't exist */
+       gssd_dentry = d_hash_and_lookup(root, &q);
+       if (!gssd_dentry)
+               return ERR_PTR(-ENOENT);
+
+       ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
+       if (ret) {
+               pipe_dentry = ERR_PTR(ret);
+               goto out;
+       }
+
+       q.name = gssd_dummy_clnt_dir[0].name;
+       q.len = strlen(gssd_dummy_clnt_dir[0].name);
+       clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
+       if (!clnt_dentry) {
+               pipe_dentry = ERR_PTR(-ENOENT);
+               goto out;
+       }
+
+       pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
+       if (IS_ERR(pipe_dentry))
+               __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
+out:
+       dput(clnt_dentry);
+       dput(gssd_dentry);
+       return pipe_dentry;
+}
+
 static int
 rpc_fill_super(struct super_block *sb, void *data, int silent)
 {
        struct inode *inode;
-       struct dentry *root;
+       struct dentry *root, *gssd_dentry;
        struct net *net = data;
        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
        int err;
@@ -1266,6 +1343,13 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
                return -ENOMEM;
        if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
                return -ENOMEM;
+
+       gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
+       if (IS_ERR(gssd_dentry)) {
+               __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
+               return PTR_ERR(gssd_dentry);
+       }
+
        dprintk("RPC:       sending pipefs MOUNT notification for net %p%s\n",
                net, NET_NAME(net));
        mutex_lock(&sn->pipefs_sb_lock);
@@ -1280,6 +1364,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
        return 0;
 
 err_depopulate:
+       dput(gssd_dentry);
        blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
                                           RPC_PIPEFS_UMOUNT,
                                           sb);
@@ -1289,6 +1374,16 @@ err_depopulate:
        return err;
 }
 
+bool
+gssd_running(struct net *net)
+{
+       struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+       struct rpc_pipe *pipe = sn->gssd_dummy;
+
+       return pipe->nreaders || pipe->nwriters;
+}
+EXPORT_SYMBOL_GPL(gssd_running);
+
 static struct dentry *
 rpc_mount(struct file_system_type *fs_type,
                int flags, const char *dev_name, void *data)