NFS using CacheFS

1/1

@@ -30,6 +30,7 @@
 #include <linux/nfs_xdr.h>
 #include <linux/rwsem.h>
 #include <linux/workqueue.h>
+#include <linux/cachefs.h>
 
 /*
  * Enable debugging support for nfs client.

@@ -189,6 +190,10 @@ struct nfs_inode {
 	struct rw_semaphore	rwsem;
 #endif /* CONFIG_NFS_V4*/
 
+#ifdef CONFIG_NFS_CACHEFS
+	struct cachefs_cookie	*cachefs;
+#endif
+
 	struct inode		vfs_inode;
 };
 

@@ -3,6 +3,7 @@
 
 #include <linux/list.h>
 #include <linux/backing-dev.h>
+#include <linux/cachefs.h>
 
 /*
  * NFS client parameters stored in the superblock.

@@ -46,6 +47,10 @@ struct nfs_server {
 						   that are supported on this
 						   filesystem */
 #endif
+
+#ifdef CONFIG_NFS_CACHEFS
+	struct cachefs_cookie	*cachefs;	/* cache cookie */
+#endif
 };
 
 /* Server capabilities */

@@ -60,6 +60,7 @@ struct nfs_mount_data {
 #define NFS_MOUNT_BROKEN_SUID	0x0400	/* 4 */
 #define NFS_MOUNT_STRICTLOCK	0x1000	/* reserved for NFSv4 */
 #define NFS_MOUNT_SECFLAVOUR	0x2000	/* 5 */
+#define NFS_MOUNT_CACHEFS		NFS_MOUNT_POSIX
 #define NFS_MOUNT_FLAGMASK	0xFFFF
 
 #endif

@@ -12,4 +12,5 @@ nfs-$(CONFIG_NFS_V4)	+= nfs4proc.o nfs4x
 			   delegation.o idmap.o \
 			   callback.o callback_xdr.o callback_proc.o
 nfs-$(CONFIG_NFS_DIRECTIO) += direct.o
+nfs-$(CONFIG_NFS_CACHEFS) += nfs-cachefs.o
 nfs-objs		:= $(nfs-y)

@@ -0,0 +1,27 @@
+/* nfs-cachefs.h: NFS CacheFS interface definitions
+ *
+ * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _NFS_CACHEFS_H
+#define _NFS_CACHEFS_H
+
+#include <linux/cachefs.h>
+
+#ifdef CONFIG_NFS_CACHEFS
+#ifndef CONFIG_CACHEFS
+#error "CONFIG_NFS_CACHEFS is defined but not CONFIG_CACHEFS"
+#endif
+
+extern struct cachefs_netfs nfs_cache_netfs;
+extern struct cachefs_index_def nfs_cache_server_index_def;
+extern struct cachefs_index_def nfs_cache_fh_index_def;
+
+#endif
+#endif /* _NFS_CACHEFS_H */

@@ -273,6 +273,38 @@ static int wb_priority(struct writeback_
 }
 
 /*
+ * store an updated page in cachefs
+ */
+#ifdef CONFIG_NFS_CACHEFS
+static void
+nfs_writepage_to_cachefs_complete(void *cookie_data, struct page *page, void *data, int error)
+{
+	/* really need to synchronise the end of writeback, probably using a page flag */
+}
+static inline void
+nfs_writepage_to_cachefs(struct inode *inode, struct page *page)
+{
+	int ret;
+
+	dprintk("NFS: writepage_to_cachefs (0x%p/0x%p/0x%p)\n", 
+		NFS_I(inode)->cachefs, page, inode);
+
+	ret = cachefs_write_page(NFS_I(inode)->cachefs, page,
+		nfs_writepage_to_cachefs_complete, NULL, GFP_KERNEL);
+	if (ret != 0 ) {
+		dprintk("NFS:    cachefs_write_page error %d\n", ret);
+		cachefs_uncache_page(NFS_I(inode)->cachefs, page);
+	}
+}
+#else
+static inline void
+nfs_writepage_to_cachefs(struct inode *inode, struct page *page)
+{
+	BUG();
+}
+#endif
+
+/*
  * Write an mmapped page to the server.
  */
 int nfs_writepage(struct page *page, struct writeback_control *wbc)

@@ -317,6 +349,10 @@ do_it:
 		err = -EBADF;
 		goto out;
 	}
+
+	if (NFS_SERVER(inode)->flags & NFS_MOUNT_CACHEFS)
+		nfs_writepage_to_cachefs(inode, page);
+
 	lock_kernel();
 	if (!IS_SYNC(inode) && inode_referenced) {
 		err = nfs_writepage_async(ctx, inode, page, 0, offset);

@@ -1322,6 +1358,7 @@ nfs_commit_done(struct rpc_task *task)
 			(long long)NFS_FILEID(req->wb_context->dentry->d_inode),
 			req->wb_bytes,
 			(long long)req_offset(req));
+
 		if (task->tk_status < 0) {
 			req->wb_context->error = task->tk_status;
 			nfs_inode_remove_request(req);

@@ -1482,6 +1482,13 @@ config NFS_V4
 
 	  If unsure, say N.
 
+config NFS_CACHEFS
+	bool "Provide NFS client caching support through CacheFS"
+	depends on NFS_FS && CACHEFS && EXPERIMENTAL
+	help
+		Say Y here if you want NFS data to be cached locally on disc through
+		the CacheFS filesystem.
+
 config NFS_DIRECTIO
 	bool "Allow direct I/O on NFS files (EXPERIMENTAL)"
 	depends on NFS_FS && EXPERIMENTAL

| 3) There is no user level support. I realize this is extremely cheesy
|     but I noticed that the NFS posix mount  option (in the 2.6 kernel)
|     was no longer being used, so I high jacked it.  Which means
|     to make NFS to used CacheFS you need to use the posix option:
|
|     mount -o posix server:/export/home /mnt/server/home
Martin Waitz

NFS using CacheFS

Steve Dickson

Trond Myklebust

David Howells

Clemens Schwaighofer

David Howells

Steve Dickson

Clemens Schwaighofer

Martin Waitz

David Howells

Trond Myklebust

bruce

David Howells