NFS: set layout driver
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: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
new file mode 100644
index 0000000..b483026
--- /dev/null
+++ b/fs/nfs/pnfs.c
@@ -0,0 +1,84 @@
+/*
+ * 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;
+}
+
+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;
+ if (!(server->nfs_client->cl_exchange_flags &
+ (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
+ printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__,
+ id, server->nfs_client->cl_exchange_flags);
+ 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;
+}