pnfs/blocklayout: move all rpc_pipefs related code into a single file

Create a file to house all the rpc_pipefs boilerplate code instead of
sprinkling it over a few files.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

6 files changed, 378 insertions, 408 deletions

diff --git a/fs/nfs/blocklayout/Makefile b/fs/nfs/blocklayout/Makefile
index 3fa5ec7..e177026 100644
--- a/fs/nfs/blocklayout/Makefile
+++ b/fs/nfs/blocklayout/Makefile
@@ -2,5 +2,5 @@
 # Makefile for the pNFS block layout driver kernel module
 #
 obj-$(CONFIG_PNFS_BLOCK) += blocklayoutdriver.o
-blocklayoutdriver-objs := blocklayout.o blocklayoutdev.o blocklayoutdm.o \
-	extent_tree.o
+
+blocklayoutdriver-y += blocklayout.o extent_tree.o rpc_pipefs.o
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 76ec017..65a6b19b 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -863,132 +863,6 @@ static struct pnfs_layoutdriver_type blocklayout_type = {
 	.pg_write_ops			= &bl_pg_write_ops,
 };
 
-static const struct rpc_pipe_ops bl_upcall_ops = {
-	.upcall		= rpc_pipe_generic_upcall,
-	.downcall	= bl_pipe_downcall,
-	.destroy_msg	= bl_pipe_destroy_msg,
-};
-
-static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
-					    struct rpc_pipe *pipe)
-{
-	struct dentry *dir, *dentry;
-
-	dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
-	if (dir == NULL)
-		return ERR_PTR(-ENOENT);
-	dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
-	dput(dir);
-	return dentry;
-}
-
-static void nfs4blocklayout_unregister_sb(struct super_block *sb,
-					  struct rpc_pipe *pipe)
-{
-	if (pipe->dentry)
-		rpc_unlink(pipe->dentry);
-}
-
-static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
-			   void *ptr)
-{
-	struct super_block *sb = ptr;
-	struct net *net = sb->s_fs_info;
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct dentry *dentry;
-	int ret = 0;
-
-	if (!try_module_get(THIS_MODULE))
-		return 0;
-
-	if (nn->bl_device_pipe == NULL) {
-		module_put(THIS_MODULE);
-		return 0;
-	}
-
-	switch (event) {
-	case RPC_PIPEFS_MOUNT:
-		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
-		if (IS_ERR(dentry)) {
-			ret = PTR_ERR(dentry);
-			break;
-		}
-		nn->bl_device_pipe->dentry = dentry;
-		break;
-	case RPC_PIPEFS_UMOUNT:
-		if (nn->bl_device_pipe->dentry)
-			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
-		break;
-	default:
-		ret = -ENOTSUPP;
-		break;
-	}
-	module_put(THIS_MODULE);
-	return ret;
-}
-
-static struct notifier_block nfs4blocklayout_block = {
-	.notifier_call = rpc_pipefs_event,
-};
-
-static struct dentry *nfs4blocklayout_register_net(struct net *net,
-						   struct rpc_pipe *pipe)
-{
-	struct super_block *pipefs_sb;
-	struct dentry *dentry;
-
-	pipefs_sb = rpc_get_sb_net(net);
-	if (!pipefs_sb)
-		return NULL;
-	dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
-	rpc_put_sb_net(net);
-	return dentry;
-}
-
-static void nfs4blocklayout_unregister_net(struct net *net,
-					   struct rpc_pipe *pipe)
-{
-	struct super_block *pipefs_sb;
-
-	pipefs_sb = rpc_get_sb_net(net);
-	if (pipefs_sb) {
-		nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
-		rpc_put_sb_net(net);
-	}
-}
-
-static int nfs4blocklayout_net_init(struct net *net)
-{
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct dentry *dentry;
-
-	init_waitqueue_head(&nn->bl_wq);
-	nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
-	if (IS_ERR(nn->bl_device_pipe))
-		return PTR_ERR(nn->bl_device_pipe);
-	dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
-	if (IS_ERR(dentry)) {
-		rpc_destroy_pipe_data(nn->bl_device_pipe);
-		return PTR_ERR(dentry);
-	}
-	nn->bl_device_pipe->dentry = dentry;
-	return 0;
-}
-
-static void nfs4blocklayout_net_exit(struct net *net)
-{
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-
-	nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
-	rpc_destroy_pipe_data(nn->bl_device_pipe);
-	nn->bl_device_pipe = NULL;
-}
-
-static struct pernet_operations nfs4blocklayout_net_ops = {
-	.init = nfs4blocklayout_net_init,
-	.exit = nfs4blocklayout_net_exit,
-};
-
 static int __init nfs4blocklayout_init(void)
 {
 	int ret;
@@ -998,20 +872,14 @@ static int __init nfs4blocklayout_init(void)
 	ret = pnfs_register_layoutdriver(&blocklayout_type);
 	if (ret)
 		goto out;
-
-	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
-	if (ret)
-		goto out_remove;
-	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+	ret = bl_init_pipefs();
 	if (ret)
-		goto out_notifier;
-out:
-	return ret;
+		goto out_unregister;
+	return 0;
 
-out_notifier:
-	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
-out_remove:
+out_unregister:
 	pnfs_unregister_layoutdriver(&blocklayout_type);
+out:
 	return ret;
 }
 
@@ -1020,8 +888,7 @@ static void __exit nfs4blocklayout_exit(void)
 	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
 	       __func__);
 
-	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
-	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
+	bl_cleanup_pipefs();
 	pnfs_unregister_layoutdriver(&blocklayout_type);
 }
 
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index 00c11eb..c98d98a 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -110,17 +110,6 @@ struct bl_msg_hdr {
 #define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
 #define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
 
-/* blocklayoutdev.c */
-ssize_t bl_pipe_downcall(struct file *, const char __user *, size_t);
-void bl_pipe_destroy_msg(struct rpc_pipe_msg *);
-
-struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
-		struct pnfs_device *pdev, gfp_t gfp_mask);
-void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
-
-/* blocklayoutdm.c */
-void bl_dm_remove(struct net *net, dev_t dev);
-
 /* extent_tree.c */
 int ext_tree_insert(struct pnfs_block_layout *bl,
 		struct pnfs_block_extent *new);
@@ -133,4 +122,12 @@ bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
 int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
 void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
 
+/* rpc_pipefs.c */
+struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
+		struct pnfs_device *pdev, gfp_t gfp_mask);
+void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
+
+int __init bl_init_pipefs(void);
+void __exit bl_cleanup_pipefs(void);
+
 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c
deleted file mode 100644
index 2b54e29..0000000
--- a/fs/nfs/blocklayout/blocklayoutdev.c
+++ /dev/null
@@ -1,172 +0,0 @@
-/*
- *  linux/fs/nfs/blocklayout/blocklayoutdev.c
- *
- *  Device operations for the pnfs nfs4 file layout driver.
- *
- *  Copyright (c) 2006 The Regents of the University of Michigan.
- *  All rights reserved.
- *
- *  Andy Adamson <andros@citi.umich.edu>
- *  Fred Isaman <iisaman@umich.edu>
- *
- * permission is granted to use, copy, create derivative works and
- * redistribute this software and such derivative works for any purpose,
- * so long as the name of the university of michigan is not used in
- * any advertising or publicity pertaining to the use or distribution
- * of this software without specific, written prior authorization.  if
- * the above copyright notice or any other identification of the
- * university of michigan is included in any copy of any portion of
- * this software, then the disclaimer below must also be included.
- *
- * this software is provided as is, without representation from the
- * university of michigan as to its fitness for any purpose, and without
- * warranty by the university of michigan of any kind, either express
- * or implied, including without limitation the implied warranties of
- * merchantability and fitness for a particular purpose.  the regents
- * of the university of michigan shall not be liable for any damages,
- * including special, indirect, incidental, or consequential damages,
- * with respect to any claim arising out or in connection with the use
- * of the software, even if it has been or is hereafter advised of the
- * possibility of such damages.
- */
-#include <linux/module.h>
-#include <linux/buffer_head.h> /* __bread */
-
-#include <linux/genhd.h>
-#include <linux/blkdev.h>
-#include <linux/hash.h>
-
-#include "blocklayout.h"
-
-#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
-
-ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
-			 size_t mlen)
-{
-	struct nfs_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
-					 nfs_net_id);
-
-	if (mlen != sizeof (struct bl_dev_msg))
-		return -EINVAL;
-
-	if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)
-		return -EFAULT;
-
-	wake_up(&nn->bl_wq);
-
-	return mlen;
-}
-
-void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
-{
-	struct bl_pipe_msg *bl_pipe_msg = container_of(msg, struct bl_pipe_msg, msg);
-
-	if (msg->errno >= 0)
-		return;
-	wake_up(bl_pipe_msg->bl_wq);
-}
-
-/*
- * Decodes pnfs_block_deviceaddr4 which is XDR encoded in dev->dev_addr_buf.
- */
-struct nfs4_deviceid_node *
-bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *dev,
-		gfp_t gfp_mask)
-{
-	struct pnfs_block_dev *rv;
-	struct block_device *bd;
-	struct bl_pipe_msg bl_pipe_msg;
-	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
-	struct bl_msg_hdr bl_msg = {
-		.type = BL_DEVICE_MOUNT,
-		.totallen = dev->mincount,
-	};
-	uint8_t *dataptr;
-	DECLARE_WAITQUEUE(wq, current);
-	int offset, len, i, rc;
-	struct net *net = server->nfs_client->cl_net;
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-	struct bl_dev_msg *reply = &nn->bl_mount_reply;
-
-	dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
-	dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,
-		dev->mincount);
-
-	bl_pipe_msg.bl_wq = &nn->bl_wq;
-	memset(msg, 0, sizeof(*msg));
-	msg->data = kzalloc(sizeof(bl_msg) + dev->mincount, gfp_mask);
-	if (!msg->data)
-		goto out;
-
-	memcpy(msg->data, &bl_msg, sizeof(bl_msg));
-	dataptr = (uint8_t *) msg->data;
-	len = dev->mincount;
-	offset = sizeof(bl_msg);
-	for (i = 0; len > 0; i++) {
-		memcpy(&dataptr[offset], page_address(dev->pages[i]),
-				len < PAGE_CACHE_SIZE ? len : PAGE_CACHE_SIZE);
-		len -= PAGE_CACHE_SIZE;
-		offset += PAGE_CACHE_SIZE;
-	}
-	msg->len = sizeof(bl_msg) + dev->mincount;
-
-	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
-	add_wait_queue(&nn->bl_wq, &wq);
-	rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
-	if (rc < 0) {
-		remove_wait_queue(&nn->bl_wq, &wq);
-		goto out;
-	}
-
-	set_current_state(TASK_UNINTERRUPTIBLE);
-	schedule();
-	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(&nn->bl_wq, &wq);
-
-	if (reply->status != BL_DEVICE_REQUEST_PROC) {
-		printk(KERN_WARNING "%s failed to decode device: %d\n",
-			__func__, reply->status);
-		goto out;
-	}
-
-	bd = blkdev_get_by_dev(MKDEV(reply->major, reply->minor),
-			       FMODE_READ, NULL);
-	if (IS_ERR(bd)) {
-		printk(KERN_WARNING "%s failed to open device %d:%d (%ld)\n",
-			__func__, reply->major, reply->minor,
-			PTR_ERR(bd));
-		goto out;
-	}
-
-	rv = kzalloc(sizeof(*rv), gfp_mask);
-	if (!rv)
-		goto out;
-
-	nfs4_init_deviceid_node(&rv->d_node, server, &dev->dev_id);
-	rv->d_bdev = bd;
-
-	dprintk("%s Created device %s with bd_block_size %u\n",
-		__func__,
-		bd->bd_disk->disk_name,
-		bd->bd_block_size);
-
-	kfree(msg->data);
-	return &rv->d_node;
-
-out:
-	kfree(msg->data);
-	return NULL;
-}
-
-void
-bl_free_deviceid_node(struct nfs4_deviceid_node *d)
-{
-	struct pnfs_block_dev *dev =
-		container_of(d, struct pnfs_block_dev, d_node);
-	struct net *net = d->nfs_client->cl_net;
-
-	blkdev_put(dev->d_bdev, FMODE_READ);
-	bl_dm_remove(net, dev->d_bdev->bd_dev);
-
-	kfree(dev);
-}
diff --git a/fs/nfs/blocklayout/blocklayoutdm.c b/fs/nfs/blocklayout/blocklayoutdm.c
deleted file mode 100644
index abc2e9e..0000000
--- a/fs/nfs/blocklayout/blocklayoutdm.c
+++ /dev/null
@@ -1,84 +0,0 @@
-/*
- *  linux/fs/nfs/blocklayout/blocklayoutdm.c
- *
- *  Module for the NFSv4.1 pNFS block layout driver.
- *
- *  Copyright (c) 2007 The Regents of the University of Michigan.
- *  All rights reserved.
- *
- *  Fred Isaman <iisaman@umich.edu>
- *  Andy Adamson <andros@citi.umich.edu>
- *
- * permission is granted to use, copy, create derivative works and
- * redistribute this software and such derivative works for any purpose,
- * so long as the name of the university of michigan is not used in
- * any advertising or publicity pertaining to the use or distribution
- * of this software without specific, written prior authorization.  if
- * the above copyright notice or any other identification of the
- * university of michigan is included in any copy of any portion of
- * this software, then the disclaimer below must also be included.
- *
- * this software is provided as is, without representation from the
- * university of michigan as to its fitness for any purpose, and without
- * warranty by the university of michigan of any kind, either express
- * or implied, including without limitation the implied warranties of
- * merchantability and fitness for a particular purpose.  the regents
- * of the university of michigan shall not be liable for any damages,
- * including special, indirect, incidental, or consequential damages,
- * with respect to any claim arising out or in connection with the use
- * of the software, even if it has been or is hereafter advised of the
- * possibility of such damages.
- */
-
-#include <linux/genhd.h> /* gendisk - used in a dprintk*/
-#include <linux/sched.h>
-#include <linux/hash.h>
-
-#include "blocklayout.h"
-
-#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
-
-void bl_dm_remove(struct net *net, dev_t dev)
-{
-	struct bl_pipe_msg bl_pipe_msg;
-	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
-	struct bl_dev_msg bl_umount_request;
-	struct bl_msg_hdr bl_msg = {
-		.type = BL_DEVICE_UMOUNT,
-		.totallen = sizeof(bl_umount_request),
-	};
-	uint8_t *dataptr;
-	DECLARE_WAITQUEUE(wq, current);
-	struct nfs_net *nn = net_generic(net, nfs_net_id);
-
-	dprintk("Entering %s\n", __func__);
-
-	bl_pipe_msg.bl_wq = &nn->bl_wq;
-	memset(msg, 0, sizeof(*msg));
-	msg->len = sizeof(bl_msg) + bl_msg.totallen;
-	msg->data = kzalloc(msg->len, GFP_NOFS);
-	if (!msg->data)
-		goto out;
-
-	memset(&bl_umount_request, 0, sizeof(bl_umount_request));
-	bl_umount_request.major = MAJOR(dev);
-	bl_umount_request.minor = MINOR(dev);
-
-	memcpy(msg->data, &bl_msg, sizeof(bl_msg));
-	dataptr = (uint8_t *) msg->data;
-	memcpy(&dataptr[sizeof(bl_msg)], &bl_umount_request, sizeof(bl_umount_request));
-
-	add_wait_queue(&nn->bl_wq, &wq);
-	if (rpc_queue_upcall(nn->bl_device_pipe, msg) < 0) {
-		remove_wait_queue(&nn->bl_wq, &wq);
-		goto out;
-	}
-
-	set_current_state(TASK_UNINTERRUPTIBLE);
-	schedule();
-	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(&nn->bl_wq, &wq);
-
-out:
-	kfree(msg->data);
-}
diff --git a/fs/nfs/blocklayout/rpc_pipefs.c b/fs/nfs/blocklayout/rpc_pipefs.c
new file mode 100644
index 0000000..bfb0486
--- /dev/null
+++ b/fs/nfs/blocklayout/rpc_pipefs.c
@@ -0,0 +1,362 @@
+/*
+ *  Copyright (c) 2006,2007 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@citi.umich.edu>
+ *  Fred Isaman <iisaman@umich.edu>
+ *
+ * permission is granted to use, copy, create derivative works and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the university of michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization.  if
+ * the above copyright notice or any other identification of the
+ * university of michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * this software is provided as is, without representation from the
+ * university of michigan as to its fitness for any purpose, and without
+ * warranty by the university of michigan of any kind, either express
+ * or implied, including without limitation the implied warranties of
+ * merchantability and fitness for a particular purpose.  the regents
+ * of the university of michigan shall not be liable for any damages,
+ * including special, indirect, incidental, or consequential damages,
+ * with respect to any claim arising out or in connection with the use
+ * of the software, even if it has been or is hereafter advised of the
+ * possibility of such damages.
+ */
+
+#include <linux/module.h>
+#include <linux/genhd.h>
+#include <linux/blkdev.h>
+
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+static void bl_dm_remove(struct net *net, dev_t dev)
+{
+	struct bl_pipe_msg bl_pipe_msg;
+	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
+	struct bl_dev_msg bl_umount_request;
+	struct bl_msg_hdr bl_msg = {
+		.type = BL_DEVICE_UMOUNT,
+		.totallen = sizeof(bl_umount_request),
+	};
+	uint8_t *dataptr;
+	DECLARE_WAITQUEUE(wq, current);
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	dprintk("Entering %s\n", __func__);
+
+	bl_pipe_msg.bl_wq = &nn->bl_wq;
+	memset(msg, 0, sizeof(*msg));
+	msg->len = sizeof(bl_msg) + bl_msg.totallen;
+	msg->data = kzalloc(msg->len, GFP_NOFS);
+	if (!msg->data)
+		goto out;
+
+	memset(&bl_umount_request, 0, sizeof(bl_umount_request));
+	bl_umount_request.major = MAJOR(dev);
+	bl_umount_request.minor = MINOR(dev);
+
+	memcpy(msg->data, &bl_msg, sizeof(bl_msg));
+	dataptr = (uint8_t *) msg->data;
+	memcpy(&dataptr[sizeof(bl_msg)], &bl_umount_request, sizeof(bl_umount_request));
+
+	add_wait_queue(&nn->bl_wq, &wq);
+	if (rpc_queue_upcall(nn->bl_device_pipe, msg) < 0) {
+		remove_wait_queue(&nn->bl_wq, &wq);
+		goto out;
+	}
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule();
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&nn->bl_wq, &wq);
+
+out:
+	kfree(msg->data);
+}
+
+/*
+ * Decodes pnfs_block_deviceaddr4 which is XDR encoded in dev->dev_addr_buf.
+ */
+struct nfs4_deviceid_node *
+bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *dev,
+		gfp_t gfp_mask)
+{
+	struct pnfs_block_dev *rv;
+	struct block_device *bd;
+	struct bl_pipe_msg bl_pipe_msg;
+	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
+	struct bl_msg_hdr bl_msg = {
+		.type = BL_DEVICE_MOUNT,
+		.totallen = dev->mincount,
+	};
+	uint8_t *dataptr;
+	DECLARE_WAITQUEUE(wq, current);
+	int offset, len, i, rc;
+	struct net *net = server->nfs_client->cl_net;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct bl_dev_msg *reply = &nn->bl_mount_reply;
+
+	dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
+	dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,
+		dev->mincount);
+
+	bl_pipe_msg.bl_wq = &nn->bl_wq;
+	memset(msg, 0, sizeof(*msg));
+	msg->data = kzalloc(sizeof(bl_msg) + dev->mincount, gfp_mask);
+	if (!msg->data)
+		goto out;
+
+	memcpy(msg->data, &bl_msg, sizeof(bl_msg));
+	dataptr = (uint8_t *) msg->data;
+	len = dev->mincount;
+	offset = sizeof(bl_msg);
+	for (i = 0; len > 0; i++) {
+		memcpy(&dataptr[offset], page_address(dev->pages[i]),
+				len < PAGE_CACHE_SIZE ? len : PAGE_CACHE_SIZE);
+		len -= PAGE_CACHE_SIZE;
+		offset += PAGE_CACHE_SIZE;
+	}
+	msg->len = sizeof(bl_msg) + dev->mincount;
+
+	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
+	add_wait_queue(&nn->bl_wq, &wq);
+	rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
+	if (rc < 0) {
+		remove_wait_queue(&nn->bl_wq, &wq);
+		goto out;
+	}
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule();
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&nn->bl_wq, &wq);
+
+	if (reply->status != BL_DEVICE_REQUEST_PROC) {
+		printk(KERN_WARNING "%s failed to decode device: %d\n",
+			__func__, reply->status);
+		goto out;
+	}
+
+	bd = blkdev_get_by_dev(MKDEV(reply->major, reply->minor),
+			       FMODE_READ, NULL);
+	if (IS_ERR(bd)) {
+		printk(KERN_WARNING "%s failed to open device %d:%d (%ld)\n",
+			__func__, reply->major, reply->minor,
+			PTR_ERR(bd));
+		goto out;
+	}
+
+	rv = kzalloc(sizeof(*rv), gfp_mask);
+	if (!rv)
+		goto out;
+
+	nfs4_init_deviceid_node(&rv->d_node, server, &dev->dev_id);
+	rv->d_bdev = bd;
+
+	dprintk("%s Created device %s with bd_block_size %u\n",
+		__func__,
+		bd->bd_disk->disk_name,
+		bd->bd_block_size);
+
+	kfree(msg->data);
+	return &rv->d_node;
+
+out:
+	kfree(msg->data);
+	return NULL;
+}
+
+void
+bl_free_deviceid_node(struct nfs4_deviceid_node *d)
+{
+	struct pnfs_block_dev *dev =
+		container_of(d, struct pnfs_block_dev, d_node);
+	struct net *net = d->nfs_client->cl_net;
+
+	blkdev_put(dev->d_bdev, FMODE_READ);
+	bl_dm_remove(net, dev->d_bdev->bd_dev);
+
+	kfree(dev);
+}
+
+static ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
+			 size_t mlen)
+{
+	struct nfs_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,
+					 nfs_net_id);
+
+	if (mlen != sizeof (struct bl_dev_msg))
+		return -EINVAL;
+
+	if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)
+		return -EFAULT;
+
+	wake_up(&nn->bl_wq);
+
+	return mlen;
+}
+
+static void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct bl_pipe_msg *bl_pipe_msg =
+		container_of(msg, struct bl_pipe_msg, msg);
+
+	if (msg->errno >= 0)
+		return;
+	wake_up(bl_pipe_msg->bl_wq);
+}
+
+static const struct rpc_pipe_ops bl_upcall_ops = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= bl_pipe_downcall,
+	.destroy_msg	= bl_pipe_destroy_msg,
+};
+
+static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
+					    struct rpc_pipe *pipe)
+{
+	struct dentry *dir, *dentry;
+
+	dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
+	if (dir == NULL)
+		return ERR_PTR(-ENOENT);
+	dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
+	dput(dir);
+	return dentry;
+}
+
+static void nfs4blocklayout_unregister_sb(struct super_block *sb,
+					  struct rpc_pipe *pipe)
+{
+	if (pipe->dentry)
+		rpc_unlink(pipe->dentry);
+}
+
+static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
+			   void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *dentry;
+	int ret = 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	if (nn->bl_device_pipe == NULL) {
+		module_put(THIS_MODULE);
+		return 0;
+	}
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			break;
+		}
+		nn->bl_device_pipe->dentry = dentry;
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		if (nn->bl_device_pipe->dentry)
+			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfs4blocklayout_block = {
+	.notifier_call = rpc_pipefs_event,
+};
+
+static struct dentry *nfs4blocklayout_register_net(struct net *net,
+						   struct rpc_pipe *pipe)
+{
+	struct super_block *pipefs_sb;
+	struct dentry *dentry;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (!pipefs_sb)
+		return NULL;
+	dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
+	rpc_put_sb_net(net);
+	return dentry;
+}
+
+static void nfs4blocklayout_unregister_net(struct net *net,
+					   struct rpc_pipe *pipe)
+{
+	struct super_block *pipefs_sb;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (pipefs_sb) {
+		nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
+		rpc_put_sb_net(net);
+	}
+}
+
+static int nfs4blocklayout_net_init(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *dentry;
+
+	init_waitqueue_head(&nn->bl_wq);
+	nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
+	if (IS_ERR(nn->bl_device_pipe))
+		return PTR_ERR(nn->bl_device_pipe);
+	dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
+	if (IS_ERR(dentry)) {
+		rpc_destroy_pipe_data(nn->bl_device_pipe);
+		return PTR_ERR(dentry);
+	}
+	nn->bl_device_pipe->dentry = dentry;
+	return 0;
+}
+
+static void nfs4blocklayout_net_exit(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
+	rpc_destroy_pipe_data(nn->bl_device_pipe);
+	nn->bl_device_pipe = NULL;
+}
+
+static struct pernet_operations nfs4blocklayout_net_ops = {
+	.init = nfs4blocklayout_net_init,
+	.exit = nfs4blocklayout_net_exit,
+};
+
+int __init bl_init_pipefs(void)
+{
+	int ret;
+
+	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
+	if (ret)
+		goto out;
+	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+	if (ret)
+		goto out_unregister_notifier;
+	return 0;
+
+out_unregister_notifier:
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
+out:
+	return ret;
+}
+
+void __exit bl_cleanup_pipefs(void)
+{
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
+	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
+}