[PATCH 08/13] RFC: pnfs: filelayout: introduce minimal file layout driver

[Fred Isaman <iisaman@netapp.com>]

From: The pNFS Team <linux-nfs@vger.kernel.org>

This driver just registers itself and supplies trivial mount/umount functions.

Signed-off-by: TBD - melding/reorganization of several patches
---
 fs/nfs/Kconfig          |    5 +++
 fs/nfs/Makefile         |    3 ++
 fs/nfs/nfs4filelayout.c |   89 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/nfs_fs.h  |    1 +
 4 files changed, 98 insertions(+), 0 deletions(-)
 create mode 100644 fs/nfs/nfs4filelayout.c

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 5f1b936..980f2dc 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -82,6 +82,11 @@ config NFS_V4_1
 
 	  If unsure, say N.
 
+config PNFS_FILE_LAYOUT
+	tristate
+	depends on NFS_FS && NFS_V4_1
+	default m
+
 config ROOT_NFS
 	bool "Root file system on NFS"
 	depends on NFS_FS=y && IP_PNP
diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index bb9e773..08a8889 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -18,3 +18,6 @@ nfs-$(CONFIG_NFS_V4)	+= nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o \
 nfs-$(CONFIG_NFS_V4_1)	+= pnfs.o
 nfs-$(CONFIG_SYSCTL) += sysctl.o
 nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
+
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
+nfs_layout_nfsv41_files-y := nfs4filelayout.o
diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
new file mode 100644
index 0000000..c685196
--- /dev/null
+++ b/fs/nfs/nfs4filelayout.c
@@ -0,0 +1,89 @@
+/*
+ *  Module for the pnfs nfs4 file layout driver.
+ *  Defines all I/O and Policy interface operations, plus code
+ *  to register itself with the pNFS client.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@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 or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  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 of 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/nfs_fs.h>
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
+MODULE_DESCRIPTION("The NFSv4 file layout driver");
+
+int
+filelayout_initialize_mountpoint(struct nfs_client *clp)
+{
+	return 0;
+}
+
+int
+filelayout_uninitialize_mountpoint(struct nfs_client *clp)
+{
+	dprintk("--> %s\n", __func__);
+
+	return 0;
+}
+
+struct layoutdriver_io_operations filelayout_io_operations = {
+	.initialize_mountpoint   = filelayout_initialize_mountpoint,
+	.uninitialize_mountpoint = filelayout_uninitialize_mountpoint,
+};
+
+
+struct pnfs_layoutdriver_type filelayout_type = {
+	.id = LAYOUT_NFSV4_1_FILES,
+	.name = "LAYOUT_NFSV4_1_FILES",
+	.ld_io_ops = &filelayout_io_operations,
+};
+
+static int __init nfs4filelayout_init(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
+	       __func__);
+
+	/*
+	 * Need to register file_operations struct with global list to indicate
+	 * that NFS4 file layout is a possible pNFS I/O module
+	 */
+	return pnfs_register_layoutdriver(&filelayout_type);
+}
+
+static void __exit nfs4filelayout_exit(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
+	       __func__);
+
+	/* Unregister NFS4 file layout driver with pNFS client*/
+	pnfs_unregister_layoutdriver(&filelayout_type);
+}
+
+module_init(nfs4filelayout_init);
+module_exit(nfs4filelayout_exit);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 042c2bd..a0f49a3 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -614,6 +614,7 @@ extern void * nfs_root_data(void);
 #define NFSDBG_MOUNT		0x0400
 #define NFSDBG_FSCACHE		0x0800
 #define NFSDBG_PNFS		0x1000
+#define NFSDBG_PNFS_LD		0x2000
 #define NFSDBG_ALL		0xFFFF
 
 #ifdef __KERNEL__
-- 
1.7.2.1