[PATCH 06/13] RFC: nfs: set layout driver

Fred Isaman
2010-09-09T18:10:38Z

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

Put in the infrastructure that uses information returned from the
server at mount to select a layout driver module.

In this patch, a stub is used that always returns "no driver found".

Signed-off-by: TBD - melding/reorganization of several patches
---
fs/nfs/Makefile | 1 +
fs/nfs/client.c | 4 ++
fs/nfs/pnfs.c | 78 +++++++++++++++++++++++++++++++++++++++++++++
fs/nfs/pnfs.h | 36 +++++++++++++++++++++
include/linux/nfs_fs.h | 1 +
include/linux/nfs_fs_sb.h | 1 +
6 files changed, 121 insertions(+), 0 deletions(-)
create mode 100644 fs/nfs/pnfs.c
create mode 100644 fs/nfs/pnfs.h

diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
index da7fda6..bb9e773 100644
--- a/fs/nfs/Makefile
+++ b/fs/nfs/Makefile
@@ -15,5 +15,6 @@ nfs-$(CONFIG_NFS_V4) += nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o \
delegation.o idmap.o \
callback.o callback_xdr.o callback_proc.o \
nfs4namespace.o
+nfs-$(CONFIG_NFS_V4_1) += pnfs.o
nfs-$(CONFIG_SYSCTL) += sysctl.o
nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 4e7df2a..eed1212 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -48,6 +48,7 @@
#include "iostat.h"
#include "internal.h"
#include "fscache.h"
+#include "pnfs.h"

#define NFSDBG_FACILITY NFSDBG_CLIENT

@@ -898,6 +899,8 @@ static void nfs_server_set_fsinfo(struct nfs_server *server, struct nfs_fsinfo *
if (server->wsize > NFS_MAX_FILE_IO_SIZE)
server->wsize = NFS_MAX_FILE_IO_SIZE;
server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ set_pnfs_layoutdriver(server, fsinfo->layouttype);
+
server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);

server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
@@ -1017,6 +1020,7 @@ void nfs_free_server(struct nfs_server *server)
{
dprintk("--> nfs_free_server()\n");

+ unset_pnfs_layoutdriver(server);
spin_lock(&nfs_client_lock);
list_del(&server->client_link);
list_del(&server->master_link);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
new file mode 100644
index 0000000..2e5dba1
--- /dev/null
+++ b/fs/nfs/pnfs.c
@@ -0,0 +1,78 @@
+/*
+ * pNFS functions to call and manage layout drivers.
+ *
+ * Copyright (c) 2002 [year of first publication]
+ * 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
+
+/* STUB that returns the equivalent of "no module found" */
+static struct pnfs_layoutdriver_type *
+find_pnfs_driver(u32 id) {
+ return NULL;
+}
+
+/* Unitialize a mountpoint in a layout driver */
+void
+unset_pnfs_layoutdriver(struct nfs_server *nfss)
+{
+ nfss->pnfs_curr_ld = NULL;
+}
+
+/*
+ * Try to set the server's pnfs module to the pnfs layout type specified by id.
+ * Currently only one pNFS layout driver per filesystem is supported.
+ *
+ * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
+ */
+void
+set_pnfs_layoutdriver(struct nfs_server *server, u32 id)
+{
+ struct pnfs_layoutdriver_type *ld_type = NULL;
+
+ if (id == 0)
+ goto out_no_driver;
+ ld_type = find_pnfs_driver(id);
+ if (!ld_type) {
+ request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
+ ld_type = find_pnfs_driver(id);
+ if (!ld_type) {
+ dprintk("%s: No pNFS module found for %u.\n",
+ __func__, id);
+ goto out_no_driver;
+ }
+ }
+ server->pnfs_curr_ld = ld_type;
+ dprintk("%s: pNFS module for %u set\n", __func__, id);
+ return;
+
+out_no_driver:
+ dprintk("%s: Using NFSv4 I/O\n", __func__);
+ server->pnfs_curr_ld = NULL;
+}
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
new file mode 100644
index 0000000..3281fbf
--- /dev/null
+++ b/fs/nfs/pnfs.h
@@ -0,0 +1,36 @@
+/*
+ * pNFS client data structures.
+ *
+ * Copyright (c) 2002 The Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Dean Hildebrand <dhildebz@umich.edu>
+ */
+
+#ifndef FS_NFS_PNFS_H
+#define FS_NFS_PNFS_H
+
+#ifdef CONFIG_NFS_V4_1
+
+#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
+
+/* Per-layout driver specific registration structure */
+struct pnfs_layoutdriver_type {
+};
+
+void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
+void unset_pnfs_layoutdriver(struct nfs_server *);
+
+#else /* CONFIG_NFS_V4_1 */
+
+static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
+{
+}
+
+static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
+{
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+#endif /* FS_NFS_PNFS_H */
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 508f8cf..042c2bd 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -613,6 +613,7 @@ extern void * nfs_root_data(void);
#define NFSDBG_CLIENT 0x0200
#define NFSDBG_MOUNT 0x0400
#define NFSDBG_FSCACHE 0x0800
+#define NFSDBG_PNFS 0x1000
#define NFSDBG_ALL 0xFFFF

#ifdef __KERNEL__
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index c82ee7c..29a821d 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -144,6 +144,7 @@ struct nfs_server {
u32 acl_bitmask; /* V4 bitmask representing the ACEs
that are supported on this
filesystem */
+ struct pnfs_layoutdriver_type *pnfs_curr_ld; /* Active layout driver */
#endif
void (*destroy)(struct nfs_server *);

--
1.7.2.1