SUNRPC: split SUNPRC PipeFS dentry and private pipe data creation

This patch is a final step towards to removing PipeFS inode references from
kernel code other than PipeFS itself. It makes all kernel SUNRPC PipeFS users
depends on pipe private data, which state depend on their specific operations,
etc.
This patch completes SUNRPC PipeFS preparations and allows to create pipe
private data and PipeFS dentries independently.
Next step will be making SUNPRC PipeFS dentries allocated by SUNRPC PipeFS
network namespace aware routines.

Signed-off-by: Stanislav Kinsbursky <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/blocklayout/blocklayout.c

···
 MODULE_AUTHOR("Andy Adamson <[e-mail]>");
 MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
 
-struct dentry *bl_device_pipe;
+struct rpc_pipe *bl_device_pipe;
 wait_queue_head_t bl_wq;
 
 static void print_page(struct page *page)
···
 	if (ret)
 		goto out_putrpc;
 
-	bl_device_pipe = rpc_mkpipe(path.dentry, "blocklayout", NULL,
-				    &bl_upcall_ops, 0);
+	bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
 	path_put(&path);
 	if (IS_ERR(bl_device_pipe)) {
 		ret = PTR_ERR(bl_device_pipe);
 		goto out_putrpc;
 	}
+	bl_device_pipe->dentry = rpc_mkpipe_dentry(path.dentry, "blocklayout",
+						   NULL, bl_device_pipe);
+	if (IS_ERR(bl_device_pipe->dentry)) {
+		ret = PTR_ERR(bl_device_pipe->dentry);
+		goto out_destroy_pipe;
+	}
 out:
 	return ret;
 
+out_destroy_pipe:
+	rpc_destroy_pipe_data(bl_device_pipe);
 out_putrpc:
 	rpc_put_mount();
 out_remove:
···
 	       __func__);
 
 	pnfs_unregister_layoutdriver(&blocklayout_type);
-	rpc_unlink(bl_device_pipe);
+	rpc_unlink(bl_device_pipe->dentry);
+	rpc_destroy_pipe_data(bl_device_pipe);
 	rpc_put_mount();
 }
 

fs/nfs/blocklayout/blocklayout.h

···
 	u16 totallen; /* length of entire message, including hdr itself */
 };
 
-extern struct dentry *bl_device_pipe;
+extern struct rpc_pipe *bl_device_pipe;
 extern wait_queue_head_t bl_wq;
 
 #define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */

fs/nfs/blocklayout/blocklayoutdev.c

···
 
 	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
 	add_wait_queue(&bl_wq, &wq);
-	rc = rpc_queue_upcall(RPC_I(bl_device_pipe->d_inode)->pipe, &msg);
+	rc = rpc_queue_upcall(bl_device_pipe, &msg);
 	if (rc < 0) {
 		remove_wait_queue(&bl_wq, &wq);
 		rv = ERR_PTR(rc);

fs/nfs/blocklayout/blocklayoutdm.c

···
 	msg.len = sizeof(bl_msg) + bl_msg.totallen;
 
 	add_wait_queue(&bl_wq, &wq);
-	if (rpc_queue_upcall(RPC_I(bl_device_pipe->d_inode)->pipe, &msg) < 0) {
+	if (rpc_queue_upcall(bl_device_pipe, &msg) < 0) {
 		remove_wait_queue(&bl_wq, &wq);
 		goto out;
 	}

fs/nfs/idmap.c

···
 };
 
 struct idmap {
-	struct dentry		*idmap_dentry;
+	struct rpc_pipe		*idmap_pipe;
 	wait_queue_head_t	idmap_wq;
 	struct idmap_msg	idmap_im;
 	struct mutex		idmap_lock;	/* Serializes upcalls */
···
 nfs_idmap_new(struct nfs_client *clp)
 {
 	struct idmap *idmap;
+	struct rpc_pipe *pipe;
 	int error;
 
 	BUG_ON(clp->cl_idmap != NULL);
···
 	if (idmap == NULL)
 		return -ENOMEM;
 
-	idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry,
-			"idmap", idmap, &idmap_upcall_ops, 0);
-	if (IS_ERR(idmap->idmap_dentry)) {
-		error = PTR_ERR(idmap->idmap_dentry);
+	pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
+	if (IS_ERR(pipe)) {
+		error = PTR_ERR(pipe);
 		kfree(idmap);
 		return error;
 	}
 
+	if (clp->cl_rpcclient->cl_path.dentry)
+		pipe->dentry = rpc_mkpipe_dentry(clp->cl_rpcclient->cl_path.dentry,
+				"idmap", idmap, pipe);
+	if (IS_ERR(pipe->dentry)) {
+		error = PTR_ERR(pipe->dentry);
+		rpc_destroy_pipe_data(pipe);
+		kfree(idmap);
+		return error;
+	}
+	idmap->idmap_pipe = pipe;
 	mutex_init(&idmap->idmap_lock);
 	mutex_init(&idmap->idmap_im_lock);
 	init_waitqueue_head(&idmap->idmap_wq);
···
 
 	if (!idmap)
 		return;
-	rpc_unlink(idmap->idmap_dentry);
+	if (idmap->idmap_pipe->dentry)
+		rpc_unlink(idmap->idmap_pipe->dentry);
+	rpc_destroy_pipe_data(idmap->idmap_pipe);
 	clp->cl_idmap = NULL;
 	kfree(idmap);
 }
···
 	msg.len = sizeof(*im);
 
 	add_wait_queue(&idmap->idmap_wq, &wq);
-	if (rpc_queue_upcall(RPC_I(idmap->idmap_dentry->d_inode)->pipe, &msg) < 0) {
+	if (rpc_queue_upcall(idmap->idmap_pipe, &msg) < 0) {
 		remove_wait_queue(&idmap->idmap_wq, &wq);
 		goto out;
 	}
···
 
 	add_wait_queue(&idmap->idmap_wq, &wq);
 
-	if (rpc_queue_upcall(RPC_I(idmap->idmap_dentry->d_inode)->pipe, &msg) < 0) {
+	if (rpc_queue_upcall(idmap->idmap_pipe, &msg) < 0) {
 		remove_wait_queue(&idmap->idmap_wq, &wq);
 		goto out;
 	}

include/linux/sunrpc/rpc_pipe_fs.h

···
 	struct delayed_work queue_timeout;
 	const struct rpc_pipe_ops *ops;
 	spinlock_t lock;
+	struct dentry *dentry;
 };
 
 struct rpc_inode {
···
 					   struct cache_detail *);
 extern void rpc_remove_cache_dir(struct dentry *);
 
-extern struct dentry *rpc_mkpipe(struct dentry *, const char *, void *,
-				 const struct rpc_pipe_ops *, int flags);
+struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags);
+void rpc_destroy_pipe_data(struct rpc_pipe *pipe);
+extern struct dentry *rpc_mkpipe_dentry(struct dentry *, const char *, void *,
+					struct rpc_pipe *);
 extern int rpc_unlink(struct dentry *);
 extern struct vfsmount *rpc_get_mount(void);
 extern void rpc_put_mount(void);

net/sunrpc/auth_gss/auth_gss.c

···
 	 * mechanism (for example, "krb5") and exists for
 	 * backwards-compatibility with older gssd's.
 	 */
-	struct dentry *dentry[2];
+	struct rpc_pipe *pipe[2];
 };
 
 /* pipe_version >= 0 if and only if someone has a pipe open. */
···
 		kfree(gss_msg);
 		return ERR_PTR(vers);
 	}
-	gss_msg->pipe = RPC_I(gss_auth->dentry[vers]->d_inode)->pipe;
+	gss_msg->pipe = gss_auth->pipe[vers];
 	INIT_LIST_HEAD(&gss_msg->list);
 	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 	init_waitqueue_head(&gss_msg->waitqueue);
···
 	 * that we supported only the old pipe.  So we instead create
 	 * the new pipe first.
 	 */
-	gss_auth->dentry[1] = rpc_mkpipe(clnt->cl_path.dentry,
-					 "gssd",
-					 clnt, &gss_upcall_ops_v1,
-					 RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry[1])) {
-		err = PTR_ERR(gss_auth->dentry[1]);
+	gss_auth->pipe[1] = rpc_mkpipe_data(&gss_upcall_ops_v1,
+					    RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->pipe[1])) {
+		err = PTR_ERR(gss_auth->pipe[1]);
 		goto err_put_mech;
 	}
 
-	gss_auth->dentry[0] = rpc_mkpipe(clnt->cl_path.dentry,
-					 gss_auth->mech->gm_name,
-					 clnt, &gss_upcall_ops_v0,
-					 RPC_PIPE_WAIT_FOR_OPEN);
-	if (IS_ERR(gss_auth->dentry[0])) {
-		err = PTR_ERR(gss_auth->dentry[0]);
+	gss_auth->pipe[0] = rpc_mkpipe_data(&gss_upcall_ops_v0,
+					    RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(gss_auth->pipe[0])) {
+		err = PTR_ERR(gss_auth->pipe[0]);
+		goto err_destroy_pipe_1;
+	}
+
+	gss_auth->pipe[1]->dentry = rpc_mkpipe_dentry(clnt->cl_path.dentry,
+						      "gssd",
+						      clnt, gss_auth->pipe[1]);
+	if (IS_ERR(gss_auth->pipe[1]->dentry)) {
+		err = PTR_ERR(gss_auth->pipe[1]->dentry);
+		goto err_destroy_pipe_0;
+	}
+
+	gss_auth->pipe[0]->dentry = rpc_mkpipe_dentry(clnt->cl_path.dentry,
+						      gss_auth->mech->gm_name,
+						      clnt, gss_auth->pipe[0]);
+	if (IS_ERR(gss_auth->pipe[0]->dentry)) {
+		err = PTR_ERR(gss_auth->pipe[0]->dentry);
 		goto err_unlink_pipe_1;
 	}
 	err = rpcauth_init_credcache(auth);
···
 
 	return auth;
 err_unlink_pipe_0:
-	rpc_unlink(gss_auth->dentry[0]);
+	rpc_unlink(gss_auth->pipe[0]->dentry);
 err_unlink_pipe_1:
-	rpc_unlink(gss_auth->dentry[1]);
+	rpc_unlink(gss_auth->pipe[1]->dentry);
+err_destroy_pipe_0:
+	rpc_destroy_pipe_data(gss_auth->pipe[0]);
+err_destroy_pipe_1:
+	rpc_destroy_pipe_data(gss_auth->pipe[1]);
 err_put_mech:
 	gss_mech_put(gss_auth->mech);
 err_free:
···
 static void
 gss_free(struct gss_auth *gss_auth)
 {
-	rpc_unlink(gss_auth->dentry[1]);
-	rpc_unlink(gss_auth->dentry[0]);
+	rpc_unlink(gss_auth->pipe[0]->dentry);
+	rpc_unlink(gss_auth->pipe[1]->dentry);
+	rpc_destroy_pipe_data(gss_auth->pipe[0]);
+	rpc_destroy_pipe_data(gss_auth->pipe[1]);
 	gss_mech_put(gss_auth->mech);
 
 	kfree(gss_auth);

net/sunrpc/rpc_pipe.c

···
 rpc_i_callback(struct rcu_head *head)
 {
 	struct inode *inode = container_of(head, struct inode, i_rcu);
-	kfree(RPC_I(inode)->pipe);
 	kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 }
 
···
 			    rpc_timeout_upcall_queue);
 	pipe->ops = NULL;
 	spin_lock_init(&pipe->lock);
-
+	pipe->dentry = NULL;
 }
 
-static int __rpc_mkpipe(struct inode *dir, struct dentry *dentry,
-			umode_t mode,
-			const struct file_operations *i_fop,
-			void *private,
-			const struct rpc_pipe_ops *ops,
-			int flags)
+void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
+{
+	kfree(pipe);
+}
+EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
+
+struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 {
 	struct rpc_pipe *pipe;
-	struct rpc_inode *rpci;
-	int err;
 
 	pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 	if (!pipe)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	init_pipe(pipe);
+	pipe->ops = ops;
+	pipe->flags = flags;
+	return pipe;
+}
+EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
+
+static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
+			       umode_t mode,
+			       const struct file_operations *i_fop,
+			       void *private,
+			       struct rpc_pipe *pipe)
+{
+	struct rpc_inode *rpci;
+	int err;
+
 	err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
-	if (err) {
-		kfree(pipe);
+	if (err)
 		return err;
-	}
 	rpci = RPC_I(dentry->d_inode);
 	rpci->private = private;
 	rpci->pipe = pipe;
-	rpci->pipe->flags = flags;
-	rpci->pipe->ops = ops;
 	fsnotify_create(dir, dentry);
 	return 0;
 }
···
  * The @private argument passed here will be available to all these methods
  * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
  */
-struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
-			  void *private, const struct rpc_pipe_ops *ops,
-			  int flags)
+struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
+				 void *private, struct rpc_pipe *pipe)
 {
 	struct dentry *dentry;
 	struct inode *dir = parent->d_inode;
···
 	struct qstr q;
 	int err;
 
-	if (ops->upcall == NULL)
+	if (pipe->ops->upcall == NULL)
 		umode &= ~S_IRUGO;
-	if (ops->downcall == NULL)
+	if (pipe->ops->downcall == NULL)
 		umode &= ~S_IWUGO;
 
 	q.name = name;
···
 	dentry = __rpc_lookup_create_exclusive(parent, &q);
 	if (IS_ERR(dentry))
 		goto out;
-	err = __rpc_mkpipe(dir, dentry, umode, &rpc_pipe_fops,
-			   private, ops, flags);
+	err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
+				  private, pipe);
 	if (err)
 		goto out_err;
 out:
···
 			err);
 	goto out;
 }
-EXPORT_SYMBOL_GPL(rpc_mkpipe);
+EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 
 /**
  * rpc_unlink - remove a pipe