add idl4k kernel firmware version 1.13.0.105

kernel/fs/9p/Kconfig

@@ -0,0 +1,19 @@
+config 9P_FS
+	tristate "Plan 9 Resource Sharing Support (9P2000) (Experimental)"
+	depends on INET && NET_9P && EXPERIMENTAL
+	help
+	  If you say Y here, you will get experimental support for
+	  Plan 9 resource sharing via the 9P2000 protocol.
+
+	  See <http://v9fs.sf.net> for more information.
+
+	  If unsure, say N.
+
+config 9P_FSCACHE
+	bool "Enable 9P client caching support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	depends on 9P_FS=m && FSCACHE || 9P_FS=y && FSCACHE=y
+	help
+	  Choose Y here to enable persistent, read-only local
+	  caching support for 9p clients using FS-Cache
+

kernel/fs/9p/Makefile

@@ -0,0 +1,13 @@
+obj-$(CONFIG_9P_FS) := 9p.o
+
+9p-objs := \
+	vfs_super.o \
+	vfs_inode.o \
+	vfs_addr.o \
+	vfs_file.o \
+	vfs_dir.o \
+	vfs_dentry.o \
+	v9fs.o \
+	fid.o
+
+9p-$(CONFIG_9P_FSCACHE) += cache.o

kernel/fs/9p/cache.c

@@ -0,0 +1,462 @@
+/*
+ * V9FS cache definitions.
+ *
+ *  Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/jiffies.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <net/9p/9p.h>
+
+#include "v9fs.h"
+#include "cache.h"
+
+#define CACHETAG_LEN  11
+
+struct kmem_cache *vcookie_cache;
+
+struct fscache_netfs v9fs_cache_netfs = {
+	.name 		= "9p",
+	.version 	= 0,
+};
+
+static void init_once(void *foo)
+{
+	struct v9fs_cookie *vcookie = (struct v9fs_cookie *) foo;
+	vcookie->fscache = NULL;
+	vcookie->qid = NULL;
+	inode_init_once(&vcookie->inode);
+}
+
+/**
+ * v9fs_init_vcookiecache - initialize a cache for vcookies to maintain
+ *			    vcookie to inode mapping
+ *
+ * Returns 0 on success.
+ */
+
+static int v9fs_init_vcookiecache(void)
+{
+	vcookie_cache = kmem_cache_create("vcookie_cache",
+					  sizeof(struct v9fs_cookie),
+					  0, (SLAB_RECLAIM_ACCOUNT|
+					      SLAB_MEM_SPREAD),
+					  init_once);
+	if (!vcookie_cache)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * v9fs_destroy_vcookiecache - destroy the cache of vcookies
+ *
+ */
+
+static void v9fs_destroy_vcookiecache(void)
+{
+	kmem_cache_destroy(vcookie_cache);
+}
+
+int __v9fs_cache_register(void)
+{
+	int ret;
+	ret = v9fs_init_vcookiecache();
+	if (ret < 0)
+		return ret;
+
+	return fscache_register_netfs(&v9fs_cache_netfs);
+}
+
+void __v9fs_cache_unregister(void)
+{
+	v9fs_destroy_vcookiecache();
+	fscache_unregister_netfs(&v9fs_cache_netfs);
+}
+
+/**
+ * v9fs_random_cachetag - Generate a random tag to be associated
+ *			  with a new cache session.
+ *
+ * The value of jiffies is used for a fairly randomly cache tag.
+ */
+
+static
+int v9fs_random_cachetag(struct v9fs_session_info *v9ses)
+{
+	v9ses->cachetag = kmalloc(CACHETAG_LEN, GFP_KERNEL);
+	if (!v9ses->cachetag)
+		return -ENOMEM;
+
+	return scnprintf(v9ses->cachetag, CACHETAG_LEN, "%lu", jiffies);
+}
+
+static uint16_t v9fs_cache_session_get_key(const void *cookie_netfs_data,
+					   void *buffer, uint16_t bufmax)
+{
+	struct v9fs_session_info *v9ses;
+	uint16_t klen = 0;
+
+	v9ses = (struct v9fs_session_info *)cookie_netfs_data;
+	P9_DPRINTK(P9_DEBUG_FSC, "session %p buf %p size %u", v9ses,
+		   buffer, bufmax);
+
+	if (v9ses->cachetag)
+		klen = strlen(v9ses->cachetag);
+
+	if (klen > bufmax)
+		return 0;
+
+	memcpy(buffer, v9ses->cachetag, klen);
+	P9_DPRINTK(P9_DEBUG_FSC, "cache session tag %s", v9ses->cachetag);
+	return klen;
+}
+
+const struct fscache_cookie_def v9fs_cache_session_index_def = {
+	.name 		= "9P.session",
+	.type 		= FSCACHE_COOKIE_TYPE_INDEX,
+	.get_key 	= v9fs_cache_session_get_key,
+};
+
+void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses)
+{
+	/* If no cache session tag was specified, we generate a random one. */
+	if (!v9ses->cachetag)
+		v9fs_random_cachetag(v9ses);
+
+	v9ses->fscache = fscache_acquire_cookie(v9fs_cache_netfs.primary_index,
+						&v9fs_cache_session_index_def,
+						v9ses);
+	P9_DPRINTK(P9_DEBUG_FSC, "session %p get cookie %p", v9ses,
+		   v9ses->fscache);
+}
+
+void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses)
+{
+	P9_DPRINTK(P9_DEBUG_FSC, "session %p put cookie %p", v9ses,
+		   v9ses->fscache);
+	fscache_relinquish_cookie(v9ses->fscache, 0);
+	v9ses->fscache = NULL;
+}
+
+
+static uint16_t v9fs_cache_inode_get_key(const void *cookie_netfs_data,
+					 void *buffer, uint16_t bufmax)
+{
+	const struct v9fs_cookie *vcookie = cookie_netfs_data;
+	memcpy(buffer, &vcookie->qid->path, sizeof(vcookie->qid->path));
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get key %llu", &vcookie->inode,
+		   vcookie->qid->path);
+	return sizeof(vcookie->qid->path);
+}
+
+static void v9fs_cache_inode_get_attr(const void *cookie_netfs_data,
+				      uint64_t *size)
+{
+	const struct v9fs_cookie *vcookie = cookie_netfs_data;
+	*size = i_size_read(&vcookie->inode);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get attr %llu", &vcookie->inode,
+		   *size);
+}
+
+static uint16_t v9fs_cache_inode_get_aux(const void *cookie_netfs_data,
+					 void *buffer, uint16_t buflen)
+{
+	const struct v9fs_cookie *vcookie = cookie_netfs_data;
+	memcpy(buffer, &vcookie->qid->version, sizeof(vcookie->qid->version));
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get aux %u", &vcookie->inode,
+		   vcookie->qid->version);
+	return sizeof(vcookie->qid->version);
+}
+
+static enum
+fscache_checkaux v9fs_cache_inode_check_aux(void *cookie_netfs_data,
+					    const void *buffer,
+					    uint16_t buflen)
+{
+	const struct v9fs_cookie *vcookie = cookie_netfs_data;
+
+	if (buflen != sizeof(vcookie->qid->version))
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	if (memcmp(buffer, &vcookie->qid->version,
+		   sizeof(vcookie->qid->version)))
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	return FSCACHE_CHECKAUX_OKAY;
+}
+
+static void v9fs_cache_inode_now_uncached(void *cookie_netfs_data)
+{
+	struct v9fs_cookie *vcookie = cookie_netfs_data;
+	struct pagevec pvec;
+	pgoff_t first;
+	int loop, nr_pages;
+
+	pagevec_init(&pvec, 0);
+	first = 0;
+
+	for (;;) {
+		nr_pages = pagevec_lookup(&pvec, vcookie->inode.i_mapping,
+					  first,
+					  PAGEVEC_SIZE - pagevec_count(&pvec));
+		if (!nr_pages)
+			break;
+
+		for (loop = 0; loop < nr_pages; loop++)
+			ClearPageFsCache(pvec.pages[loop]);
+
+		first = pvec.pages[nr_pages - 1]->index + 1;
+
+		pvec.nr = nr_pages;
+		pagevec_release(&pvec);
+		cond_resched();
+	}
+}
+
+const struct fscache_cookie_def v9fs_cache_inode_index_def = {
+	.name		= "9p.inode",
+	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
+	.get_key	= v9fs_cache_inode_get_key,
+	.get_attr	= v9fs_cache_inode_get_attr,
+	.get_aux	= v9fs_cache_inode_get_aux,
+	.check_aux	= v9fs_cache_inode_check_aux,
+	.now_uncached	= v9fs_cache_inode_now_uncached,
+};
+
+void v9fs_cache_inode_get_cookie(struct inode *inode)
+{
+	struct v9fs_cookie *vcookie;
+	struct v9fs_session_info *v9ses;
+
+	if (!S_ISREG(inode->i_mode))
+		return;
+
+	vcookie = v9fs_inode2cookie(inode);
+	if (vcookie->fscache)
+		return;
+
+	v9ses = v9fs_inode2v9ses(inode);
+	vcookie->fscache = fscache_acquire_cookie(v9ses->fscache,
+						  &v9fs_cache_inode_index_def,
+						  vcookie);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p get cookie %p", inode,
+		   vcookie->fscache);
+}
+
+void v9fs_cache_inode_put_cookie(struct inode *inode)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	if (!vcookie->fscache)
+		return;
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p put cookie %p", inode,
+		   vcookie->fscache);
+
+	fscache_relinquish_cookie(vcookie->fscache, 0);
+	vcookie->fscache = NULL;
+}
+
+void v9fs_cache_inode_flush_cookie(struct inode *inode)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	if (!vcookie->fscache)
+		return;
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p flush cookie %p", inode,
+		   vcookie->fscache);
+
+	fscache_relinquish_cookie(vcookie->fscache, 1);
+	vcookie->fscache = NULL;
+}
+
+void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+	struct p9_fid *fid;
+
+	if (!vcookie->fscache)
+		return;
+
+	spin_lock(&vcookie->lock);
+	fid = filp->private_data;
+	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
+		v9fs_cache_inode_flush_cookie(inode);
+	else
+		v9fs_cache_inode_get_cookie(inode);
+
+	spin_unlock(&vcookie->lock);
+}
+
+void v9fs_cache_inode_reset_cookie(struct inode *inode)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+	struct v9fs_session_info *v9ses;
+	struct fscache_cookie *old;
+
+	if (!vcookie->fscache)
+		return;
+
+	old = vcookie->fscache;
+
+	spin_lock(&vcookie->lock);
+	fscache_relinquish_cookie(vcookie->fscache, 1);
+
+	v9ses = v9fs_inode2v9ses(inode);
+	vcookie->fscache = fscache_acquire_cookie(v9ses->fscache,
+						  &v9fs_cache_inode_index_def,
+						  vcookie);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p",
+		   inode, old, vcookie->fscache);
+
+	spin_unlock(&vcookie->lock);
+}
+
+int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+	struct inode *inode = page->mapping->host;
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	BUG_ON(!vcookie->fscache);
+
+	return fscache_maybe_release_page(vcookie->fscache, page, gfp);
+}
+
+void __v9fs_fscache_invalidate_page(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	BUG_ON(!vcookie->fscache);
+
+	if (PageFsCache(page)) {
+		fscache_wait_on_page_write(vcookie->fscache, page);
+		BUG_ON(!PageLocked(page));
+		fscache_uncache_page(vcookie->fscache, page);
+	}
+}
+
+static void v9fs_vfs_readpage_complete(struct page *page, void *data,
+				       int error)
+{
+	if (!error)
+		SetPageUptodate(page);
+
+	unlock_page(page);
+}
+
+/**
+ * __v9fs_readpage_from_fscache - read a page from cache
+ *
+ * Returns 0 if the pages are in cache and a BIO is submitted,
+ * 1 if the pages are not in cache and -error otherwise.
+ */
+
+int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
+{
+	int ret;
+	const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
+	if (!vcookie->fscache)
+		return -ENOBUFS;
+
+	ret = fscache_read_or_alloc_page(vcookie->fscache,
+					 page,
+					 v9fs_vfs_readpage_complete,
+					 NULL,
+					 GFP_KERNEL);
+	switch (ret) {
+	case -ENOBUFS:
+	case -ENODATA:
+		P9_DPRINTK(P9_DEBUG_FSC, "page/inode not in cache %d", ret);
+		return 1;
+	case 0:
+		P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
+		return ret;
+	default:
+		P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
+		return ret;
+	}
+}
+
+/**
+ * __v9fs_readpages_from_fscache - read multiple pages from cache
+ *
+ * Returns 0 if the pages are in cache and a BIO is submitted,
+ * 1 if the pages are not in cache and -error otherwise.
+ */
+
+int __v9fs_readpages_from_fscache(struct inode *inode,
+				  struct address_space *mapping,
+				  struct list_head *pages,
+				  unsigned *nr_pages)
+{
+	int ret;
+	const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p pages %u", inode, *nr_pages);
+	if (!vcookie->fscache)
+		return -ENOBUFS;
+
+	ret = fscache_read_or_alloc_pages(vcookie->fscache,
+					  mapping, pages, nr_pages,
+					  v9fs_vfs_readpage_complete,
+					  NULL,
+					  mapping_gfp_mask(mapping));
+	switch (ret) {
+	case -ENOBUFS:
+	case -ENODATA:
+		P9_DPRINTK(P9_DEBUG_FSC, "pages/inodes not in cache %d", ret);
+		return 1;
+	case 0:
+		BUG_ON(!list_empty(pages));
+		BUG_ON(*nr_pages != 0);
+		P9_DPRINTK(P9_DEBUG_FSC, "BIO submitted");
+		return ret;
+	default:
+		P9_DPRINTK(P9_DEBUG_FSC, "ret %d", ret);
+		return ret;
+	}
+}
+
+/**
+ * __v9fs_readpage_to_fscache - write a page to the cache
+ *
+ */
+
+void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
+{
+	int ret;
+	const struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+
+	P9_DPRINTK(P9_DEBUG_FSC, "inode %p page %p", inode, page);
+	ret = fscache_write_page(vcookie->fscache, page, GFP_KERNEL);
+	P9_DPRINTK(P9_DEBUG_FSC, "ret =  %d", ret);
+	if (ret != 0)
+		v9fs_uncache_page(inode, page);
+}

kernel/fs/9p/cache.h

@@ -0,0 +1,176 @@
+/*
+ * V9FS cache definitions.
+ *
+ *  Copyright (C) 2009 by Abhishek Kulkarni <adkulkar@umail.iu.edu>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#ifndef _9P_CACHE_H
+#ifdef CONFIG_9P_FSCACHE
+#include <linux/fscache.h>
+#include <linux/spinlock.h>
+
+extern struct kmem_cache *vcookie_cache;
+
+struct v9fs_cookie {
+	spinlock_t lock;
+	struct inode inode;
+	struct fscache_cookie *fscache;
+	struct p9_qid *qid;
+};
+
+static inline struct v9fs_cookie *v9fs_inode2cookie(const struct inode *inode)
+{
+	return container_of(inode, struct v9fs_cookie, inode);
+}
+
+extern struct fscache_netfs v9fs_cache_netfs;
+extern const struct fscache_cookie_def v9fs_cache_session_index_def;
+extern const struct fscache_cookie_def v9fs_cache_inode_index_def;
+
+extern void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses);
+extern void v9fs_cache_session_put_cookie(struct v9fs_session_info *v9ses);
+
+extern void v9fs_cache_inode_get_cookie(struct inode *inode);
+extern void v9fs_cache_inode_put_cookie(struct inode *inode);
+extern void v9fs_cache_inode_flush_cookie(struct inode *inode);
+extern void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp);
+extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
+
+extern int __v9fs_cache_register(void);
+extern void __v9fs_cache_unregister(void);
+
+extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
+extern void __v9fs_fscache_invalidate_page(struct page *page);
+extern int __v9fs_readpage_from_fscache(struct inode *inode,
+					struct page *page);
+extern int __v9fs_readpages_from_fscache(struct inode *inode,
+					 struct address_space *mapping,
+					 struct list_head *pages,
+					 unsigned *nr_pages);
+extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
+
+
+/**
+ * v9fs_cache_register - Register v9fs file system with the cache
+ */
+static inline int v9fs_cache_register(void)
+{
+	return __v9fs_cache_register();
+}
+
+/**
+ * v9fs_cache_unregister - Unregister v9fs from the cache
+ */
+static inline void v9fs_cache_unregister(void)
+{
+	__v9fs_cache_unregister();
+}
+
+static inline int v9fs_fscache_release_page(struct page *page,
+					    gfp_t gfp)
+{
+	return __v9fs_fscache_release_page(page, gfp);
+}
+
+static inline void v9fs_fscache_invalidate_page(struct page *page)
+{
+	__v9fs_fscache_invalidate_page(page);
+}
+
+static inline int v9fs_readpage_from_fscache(struct inode *inode,
+					     struct page *page)
+{
+	return __v9fs_readpage_from_fscache(inode, page);
+}
+
+static inline int v9fs_readpages_from_fscache(struct inode *inode,
+					      struct address_space *mapping,
+					      struct list_head *pages,
+					      unsigned *nr_pages)
+{
+	return __v9fs_readpages_from_fscache(inode, mapping, pages,
+					     nr_pages);
+}
+
+static inline void v9fs_readpage_to_fscache(struct inode *inode,
+					    struct page *page)
+{
+	if (PageFsCache(page))
+		__v9fs_readpage_to_fscache(inode, page);
+}
+
+static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+	fscache_uncache_page(vcookie->fscache, page);
+	BUG_ON(PageFsCache(page));
+}
+
+static inline void v9fs_vcookie_set_qid(struct inode *inode,
+					struct p9_qid *qid)
+{
+	struct v9fs_cookie *vcookie = v9fs_inode2cookie(inode);
+	spin_lock(&vcookie->lock);
+	vcookie->qid = qid;
+	spin_unlock(&vcookie->lock);
+}
+
+#else /* CONFIG_9P_FSCACHE */
+
+static inline int v9fs_cache_register(void)
+{
+	return 1;
+}
+
+static inline void v9fs_cache_unregister(void) {}
+
+static inline int v9fs_fscache_release_page(struct page *page,
+					    gfp_t gfp) {
+	return 1;
+}
+
+static inline void v9fs_fscache_invalidate_page(struct page *page) {}
+
+static inline int v9fs_readpage_from_fscache(struct inode *inode,
+					     struct page *page)
+{
+	return -ENOBUFS;
+}
+
+static inline int v9fs_readpages_from_fscache(struct inode *inode,
+					      struct address_space *mapping,
+					      struct list_head *pages,
+					      unsigned *nr_pages)
+{
+	return -ENOBUFS;
+}
+
+static inline void v9fs_readpage_to_fscache(struct inode *inode,
+					    struct page *page)
+{}
+
+static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
+{}
+
+static inline void v9fs_vcookie_set_qid(struct inode *inode,
+					struct p9_qid *qid)
+{}
+
+#endif /* CONFIG_9P_FSCACHE */
+#endif /* _9P_CACHE_H */

kernel/fs/9p/fid.c

@@ -0,0 +1,209 @@
+/*
+ * V9FS FID Management
+ *
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ *  Copyright (C) 2005, 2006 by Eric Van Hensbergen <ericvh@gmail.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/idr.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+/**
+ * v9fs_fid_add - add a fid to a dentry
+ * @dentry: dentry that the fid is being added to
+ * @fid: fid to add
+ *
+ */
+
+int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
+{
+	struct v9fs_dentry *dent;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "fid %d dentry %s\n",
+					fid->fid, dentry->d_name.name);
+
+	dent = dentry->d_fsdata;
+	if (!dent) {
+		dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
+		if (!dent)
+			return -ENOMEM;
+
+		spin_lock_init(&dent->lock);
+		INIT_LIST_HEAD(&dent->fidlist);
+		dentry->d_fsdata = dent;
+	}
+
+	spin_lock(&dent->lock);
+	list_add(&fid->dlist, &dent->fidlist);
+	spin_unlock(&dent->lock);
+
+	return 0;
+}
+
+/**
+ * v9fs_fid_find - retrieve a fid that belongs to the specified uid
+ * @dentry: dentry to look for fid in
+ * @uid: return fid that belongs to the specified user
+ * @any: if non-zero, return any fid associated with the dentry
+ *
+ */
+
+static struct p9_fid *v9fs_fid_find(struct dentry *dentry, u32 uid, int any)
+{
+	struct v9fs_dentry *dent;
+	struct p9_fid *fid, *ret;
+
+	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
+		dentry->d_name.name, dentry, uid, any);
+	dent = (struct v9fs_dentry *) dentry->d_fsdata;
+	ret = NULL;
+	if (dent) {
+		spin_lock(&dent->lock);
+		list_for_each_entry(fid, &dent->fidlist, dlist) {
+			if (any || fid->uid == uid) {
+				ret = fid;
+				break;
+			}
+		}
+		spin_unlock(&dent->lock);
+	}
+
+	return ret;
+}
+
+/**
+ * v9fs_fid_lookup - lookup for a fid, try to walk if not found
+ * @dentry: dentry to look for fid in
+ *
+ * Look for a fid in the specified dentry for the current user.
+ * If no fid is found, try to create one walking from a fid from the parent
+ * dentry (if it has one), or the root dentry. If the user haven't accessed
+ * the fs yet, attach now and walk from the root.
+ */
+
+struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
+{
+	int i, n, l, clone, any, access;
+	u32 uid;
+	struct p9_fid *fid;
+	struct dentry *d, *ds;
+	struct v9fs_session_info *v9ses;
+	char **wnames, *uname;
+
+	v9ses = v9fs_inode2v9ses(dentry->d_inode);
+	access = v9ses->flags & V9FS_ACCESS_MASK;
+	switch (access) {
+	case V9FS_ACCESS_SINGLE:
+	case V9FS_ACCESS_USER:
+		uid = current_fsuid();
+		any = 0;
+		break;
+
+	case V9FS_ACCESS_ANY:
+		uid = v9ses->uid;
+		any = 1;
+		break;
+
+	default:
+		uid = ~0;
+		any = 0;
+		break;
+	}
+
+	fid = v9fs_fid_find(dentry, uid, any);
+	if (fid)
+		return fid;
+
+	ds = dentry->d_parent;
+	fid = v9fs_fid_find(ds, uid, any);
+	if (!fid) { /* walk from the root */
+		n = 0;
+		for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent)
+			n++;
+
+		fid = v9fs_fid_find(ds, uid, any);
+		if (!fid) { /* the user is not attached to the fs yet */
+			if (access == V9FS_ACCESS_SINGLE)
+				return ERR_PTR(-EPERM);
+
+			if (v9fs_extended(v9ses))
+				uname = NULL;
+			else
+				uname = v9ses->uname;
+
+			fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
+				v9ses->aname);
+
+			if (IS_ERR(fid))
+				return fid;
+
+			v9fs_fid_add(ds, fid);
+		}
+	} else /* walk from the parent */
+		n = 1;
+
+	if (ds == dentry)
+		return fid;
+
+	wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL);
+	if (!wnames)
+		return ERR_PTR(-ENOMEM);
+
+	for (d = dentry, i = (n-1); i >= 0; i--, d = d->d_parent)
+		wnames[i] = (char *) d->d_name.name;
+
+	clone = 1;
+	i = 0;
+	while (i < n) {
+		l = min(n - i, P9_MAXWELEM);
+		fid = p9_client_walk(fid, l, &wnames[i], clone);
+		if (IS_ERR(fid)) {
+			kfree(wnames);
+			return fid;
+		}
+
+		i += l;
+		clone = 0;
+	}
+
+	kfree(wnames);
+	v9fs_fid_add(dentry, fid);
+	return fid;
+}
+
+struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+{
+	struct p9_fid *fid, *ret;
+
+	fid = v9fs_fid_lookup(dentry);
+	if (IS_ERR(fid))
+		return fid;
+
+	ret = p9_client_walk(fid, 0, NULL, 1);
+	return ret;
+}

kernel/fs/9p/fid.h

@@ -0,0 +1,47 @@
+/*
+ * V9FS FID Management
+ *
+ *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/list.h>
+
+/**
+ * struct v9fs_dentry - 9p private data stored in dentry d_fsdata
+ * @lock: protects the fidlist
+ * @fidlist: list of FIDs currently associated with this dentry
+ *
+ * This structure defines the 9p private data associated with
+ * a particular dentry.  In particular, this private data is used
+ * to lookup which 9P FID handle should be used for a particular VFS
+ * operation.  FID handles are associated with dentries instead of
+ * inodes in order to more closely map functionality to the Plan 9
+ * expected behavior for FID reclaimation and tracking.
+ *
+ * See Also: Mapping FIDs to Linux VFS model in
+ * Design and Implementation of the Linux 9P File System documentation
+ */
+struct v9fs_dentry {
+	spinlock_t lock; /* protect fidlist */
+	struct list_head fidlist;
+};
+
+struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
+struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
+int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);

kernel/fs/9p/v9fs.c

@@ -0,0 +1,471 @@
+/*
+ *  linux/fs/9p/v9fs.c
+ *
+ *  This file contains functions assisting in mapping VFS to 9P2000
+ *
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/parser.h>
+#include <linux/idr.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+#include <net/9p/transport.h>
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "cache.h"
+
+static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
+static LIST_HEAD(v9fs_sessionlist);
+
+/*
+ * Option Parsing (code inspired by NFS code)
+ *  NOTE: each transport will parse its own options
+ */
+
+enum {
+	/* Options that take integer arguments */
+	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
+	/* String options */
+	Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
+	/* Options that take no arguments */
+	Opt_nodevmap,
+	/* Cache options */
+	Opt_cache_loose, Opt_fscache,
+	/* Access options */
+	Opt_access,
+	/* Error token */
+	Opt_err
+};
+
+static const match_table_t tokens = {
+	{Opt_debug, "debug=%x"},
+	{Opt_dfltuid, "dfltuid=%u"},
+	{Opt_dfltgid, "dfltgid=%u"},
+	{Opt_afid, "afid=%u"},
+	{Opt_uname, "uname=%s"},
+	{Opt_remotename, "aname=%s"},
+	{Opt_nodevmap, "nodevmap"},
+	{Opt_cache, "cache=%s"},
+	{Opt_cache_loose, "loose"},
+	{Opt_fscache, "fscache"},
+	{Opt_cachetag, "cachetag=%s"},
+	{Opt_access, "access=%s"},
+	{Opt_err, NULL}
+};
+
+/**
+ * v9fs_parse_options - parse mount options into session structure
+ * @v9ses: existing v9fs session information
+ *
+ * Return 0 upon success, -ERRNO upon failure.
+ */
+
+static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
+{
+	char *options;
+	substring_t args[MAX_OPT_ARGS];
+	char *p;
+	int option = 0;
+	char *s, *e;
+	int ret = 0;
+
+	/* setup defaults */
+	v9ses->afid = ~0;
+	v9ses->debug = 0;
+	v9ses->cache = 0;
+#ifdef CONFIG_9P_FSCACHE
+	v9ses->cachetag = NULL;
+#endif
+
+	if (!opts)
+		return 0;
+
+	options = kstrdup(opts, GFP_KERNEL);
+	if (!options)
+		goto fail_option_alloc;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		if (token < Opt_uname) {
+			int r = match_int(&args[0], &option);
+			if (r < 0) {
+				P9_DPRINTK(P9_DEBUG_ERROR,
+					"integer field, but no integer?\n");
+				ret = r;
+				continue;
+			}
+		}
+		switch (token) {
+		case Opt_debug:
+			v9ses->debug = option;
+#ifdef CONFIG_NET_9P_DEBUG
+			p9_debug_level = option;
+#endif
+			break;
+
+		case Opt_dfltuid:
+			v9ses->dfltuid = option;
+			break;
+		case Opt_dfltgid:
+			v9ses->dfltgid = option;
+			break;
+		case Opt_afid:
+			v9ses->afid = option;
+			break;
+		case Opt_uname:
+			match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
+			break;
+		case Opt_remotename:
+			match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
+			break;
+		case Opt_nodevmap:
+			v9ses->nodev = 1;
+			break;
+		case Opt_cache_loose:
+			v9ses->cache = CACHE_LOOSE;
+			break;
+		case Opt_fscache:
+			v9ses->cache = CACHE_FSCACHE;
+			break;
+		case Opt_cachetag:
+#ifdef CONFIG_9P_FSCACHE
+			v9ses->cachetag = match_strdup(&args[0]);
+#endif
+			break;
+		case Opt_cache:
+			s = match_strdup(&args[0]);
+			if (!s)
+				goto fail_option_alloc;
+
+			if (strcmp(s, "loose") == 0)
+				v9ses->cache = CACHE_LOOSE;
+			else if (strcmp(s, "fscache") == 0)
+				v9ses->cache = CACHE_FSCACHE;
+			else
+				v9ses->cache = CACHE_NONE;
+			kfree(s);
+			break;
+
+		case Opt_access:
+			s = match_strdup(&args[0]);
+			if (!s)
+				goto fail_option_alloc;
+
+			v9ses->flags &= ~V9FS_ACCESS_MASK;
+			if (strcmp(s, "user") == 0)
+				v9ses->flags |= V9FS_ACCESS_USER;
+			else if (strcmp(s, "any") == 0)
+				v9ses->flags |= V9FS_ACCESS_ANY;
+			else {
+				v9ses->flags |= V9FS_ACCESS_SINGLE;
+				v9ses->uid = simple_strtoul(s, &e, 10);
+				if (*e != '\0')
+					v9ses->uid = ~0;
+			}
+			kfree(s);
+			break;
+
+		default:
+			continue;
+		}
+	}
+	kfree(options);
+	return ret;
+
+fail_option_alloc:
+	P9_DPRINTK(P9_DEBUG_ERROR,
+		   "failed to allocate copy of option argument\n");
+	return -ENOMEM;
+}
+
+/**
+ * v9fs_session_init - initialize session
+ * @v9ses: session information structure
+ * @dev_name: device being mounted
+ * @data: options
+ *
+ */
+
+struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
+		  const char *dev_name, char *data)
+{
+	int retval = -EINVAL;
+	struct p9_fid *fid;
+	int rc;
+
+	v9ses->uname = __getname();
+	if (!v9ses->uname)
+		return ERR_PTR(-ENOMEM);
+
+	v9ses->aname = __getname();
+	if (!v9ses->aname) {
+		__putname(v9ses->uname);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	spin_lock(&v9fs_sessionlist_lock);
+	list_add(&v9ses->slist, &v9fs_sessionlist);
+	spin_unlock(&v9fs_sessionlist_lock);
+
+	v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
+	strcpy(v9ses->uname, V9FS_DEFUSER);
+	strcpy(v9ses->aname, V9FS_DEFANAME);
+	v9ses->uid = ~0;
+	v9ses->dfltuid = V9FS_DEFUID;
+	v9ses->dfltgid = V9FS_DEFGID;
+
+	rc = v9fs_parse_options(v9ses, data);
+	if (rc < 0) {
+		retval = rc;
+		goto error;
+	}
+
+	v9ses->clnt = p9_client_create(dev_name, data);
+	if (IS_ERR(v9ses->clnt)) {
+		retval = PTR_ERR(v9ses->clnt);
+		v9ses->clnt = NULL;
+		P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
+		goto error;
+	}
+
+	if (!v9ses->clnt->dotu)
+		v9ses->flags &= ~V9FS_EXTENDED;
+
+	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
+
+	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
+	if (!v9fs_extended(v9ses) &&
+		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
+
+		v9ses->flags &= ~V9FS_ACCESS_MASK;
+		v9ses->flags |= V9FS_ACCESS_ANY;
+		v9ses->uid = ~0;
+	}
+
+	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
+							v9ses->aname);
+	if (IS_ERR(fid)) {
+		retval = PTR_ERR(fid);
+		fid = NULL;
+		P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
+		goto error;
+	}
+
+	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
+		fid->uid = v9ses->uid;
+	else
+		fid->uid = ~0;
+
+#ifdef CONFIG_9P_FSCACHE
+	/* register the session for caching */
+	v9fs_cache_session_get_cookie(v9ses);
+#endif
+
+	return fid;
+
+error:
+	return ERR_PTR(retval);
+}
+
+/**
+ * v9fs_session_close - shutdown a session
+ * @v9ses: session information structure
+ *
+ */
+
+void v9fs_session_close(struct v9fs_session_info *v9ses)
+{
+	if (v9ses->clnt) {
+		p9_client_destroy(v9ses->clnt);
+		v9ses->clnt = NULL;
+	}
+
+#ifdef CONFIG_9P_FSCACHE
+	if (v9ses->fscache) {
+		v9fs_cache_session_put_cookie(v9ses);
+		kfree(v9ses->cachetag);
+	}
+#endif
+	__putname(v9ses->uname);
+	__putname(v9ses->aname);
+
+	spin_lock(&v9fs_sessionlist_lock);
+	list_del(&v9ses->slist);
+	spin_unlock(&v9fs_sessionlist_lock);
+}
+
+/**
+ * v9fs_session_cancel - terminate a session
+ * @v9ses: session to terminate
+ *
+ * mark transport as disconnected and cancel all pending requests.
+ */
+
+void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
+	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
+	p9_client_disconnect(v9ses->clnt);
+}
+
+extern int v9fs_error_init(void);
+
+static struct kobject *v9fs_kobj;
+
+#ifdef CONFIG_9P_FSCACHE
+/**
+ * caches_show - list caches associated with a session
+ *
+ * Returns the size of buffer written.
+ */
+
+static ssize_t caches_show(struct kobject *kobj,
+			   struct kobj_attribute *attr,
+			   char *buf)
+{
+	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
+	struct v9fs_session_info *v9ses;
+
+	spin_lock(&v9fs_sessionlist_lock);
+	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
+		if (v9ses->cachetag) {
+			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
+			if (n < 0) {
+				count = n;
+				break;
+			}
+
+			count += n;
+			limit -= n;
+		}
+	}
+
+	spin_unlock(&v9fs_sessionlist_lock);
+	return count;
+}
+
+static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
+#endif /* CONFIG_9P_FSCACHE */
+
+static struct attribute *v9fs_attrs[] = {
+#ifdef CONFIG_9P_FSCACHE
+	&v9fs_attr_cache.attr,
+#endif
+	NULL,
+};
+
+static struct attribute_group v9fs_attr_group = {
+	.attrs = v9fs_attrs,
+};
+
+/**
+ * v9fs_sysfs_init - Initialize the v9fs sysfs interface
+ *
+ */
+
+static int v9fs_sysfs_init(void)
+{
+	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
+	if (!v9fs_kobj)
+		return -ENOMEM;
+
+	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
+		kobject_put(v9fs_kobj);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
+ *
+ */
+
+static void v9fs_sysfs_cleanup(void)
+{
+	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
+	kobject_put(v9fs_kobj);
+}
+
+/**
+ * init_v9fs - Initialize module
+ *
+ */
+
+static int __init init_v9fs(void)
+{
+	int err;
+	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
+	/* TODO: Setup list of registered trasnport modules */
+	err = register_filesystem(&v9fs_fs_type);
+	if (err < 0) {
+		printk(KERN_ERR "Failed to register filesystem\n");
+		return err;
+	}
+
+	err = v9fs_cache_register();
+	if (err < 0) {
+		printk(KERN_ERR "Failed to register v9fs for caching\n");
+		goto out_fs_unreg;
+	}
+
+	err = v9fs_sysfs_init();
+	if (err < 0) {
+		printk(KERN_ERR "Failed to register with sysfs\n");
+		goto out_sysfs_cleanup;
+	}
+
+	return 0;
+
+out_sysfs_cleanup:
+	v9fs_sysfs_cleanup();
+
+out_fs_unreg:
+	unregister_filesystem(&v9fs_fs_type);
+
+	return err;
+}
+
+/**
+ * exit_v9fs - shutdown module
+ *
+ */
+
+static void __exit exit_v9fs(void)
+{
+	v9fs_sysfs_cleanup();
+	v9fs_cache_unregister();
+	unregister_filesystem(&v9fs_fs_type);
+}
+
+module_init(init_v9fs)
+module_exit(exit_v9fs)
+
+MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
+MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
+MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
+MODULE_LICENSE("GPL");

kernel/fs/9p/v9fs.h

@@ -0,0 +1,127 @@
+/*
+ * V9FS definitions.
+ *
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+/**
+ * enum p9_session_flags - option flags for each 9P session
+ * @V9FS_EXTENDED: whether or not to use 9P2000.u extensions
+ * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
+ * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
+ * @V9FS_ACCESS_ANY: use a single attach for all users
+ * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
+ *
+ * Session flags reflect options selected by users at mount time
+ */
+enum p9_session_flags {
+	V9FS_EXTENDED		= 0x01,
+	V9FS_ACCESS_SINGLE	= 0x02,
+	V9FS_ACCESS_USER	= 0x04,
+	V9FS_ACCESS_ANY		= 0x06,
+	V9FS_ACCESS_MASK	= 0x06,
+};
+
+/* possible values of ->cache */
+/**
+ * enum p9_cache_modes - user specified cache preferences
+ * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
+ * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
+ *
+ * eventually support loose, tight, time, session, default always none
+ */
+
+enum p9_cache_modes {
+	CACHE_NONE,
+	CACHE_LOOSE,
+	CACHE_FSCACHE,
+};
+
+/**
+ * struct v9fs_session_info - per-instance session information
+ * @flags: session options of type &p9_session_flags
+ * @nodev: set to 1 to disable device mapping
+ * @debug: debug level
+ * @afid: authentication handle
+ * @cache: cache mode of type &p9_cache_modes
+ * @cachetag: the tag of the cache associated with this session
+ * @fscache: session cookie associated with FS-Cache
+ * @options: copy of options string given by user
+ * @uname: string user name to mount hierarchy as
+ * @aname: mount specifier for remote hierarchy
+ * @maxdata: maximum data to be sent/recvd per protocol message
+ * @dfltuid: default numeric userid to mount hierarchy as
+ * @dfltgid: default numeric groupid to mount hierarchy as
+ * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
+ * @clnt: reference to 9P network client instantiated for this session
+ * @slist: reference to list of registered 9p sessions
+ *
+ * This structure holds state for each session instance established during
+ * a sys_mount() .
+ *
+ * Bugs: there seems to be a lot of state which could be condensed and/or
+ * removed.
+ */
+
+struct v9fs_session_info {
+	/* options */
+	unsigned char flags;
+	unsigned char nodev;
+	unsigned short debug;
+	unsigned int afid;
+	unsigned int cache;
+#ifdef CONFIG_9P_FSCACHE
+	char *cachetag;
+	struct fscache_cookie *fscache;
+#endif
+
+	char *uname;		/* user name to mount as */
+	char *aname;		/* name of remote hierarchy being mounted */
+	unsigned int maxdata;	/* max data for client interface */
+	unsigned int dfltuid;	/* default uid/muid for legacy support */
+	unsigned int dfltgid;	/* default gid for legacy support */
+	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
+	struct p9_client *clnt;	/* 9p client */
+	struct list_head slist; /* list of sessions registered with v9fs */
+};
+
+struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
+									char *);
+void v9fs_session_close(struct v9fs_session_info *v9ses);
+void v9fs_session_cancel(struct v9fs_session_info *v9ses);
+
+#define V9FS_MAGIC 0x01021997
+
+/* other default globals */
+#define V9FS_PORT	564
+#define V9FS_DEFUSER	"nobody"
+#define V9FS_DEFANAME	""
+#define V9FS_DEFUID	(-2)
+#define V9FS_DEFGID	(-2)
+
+static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
+{
+	return (inode->i_sb->s_fs_info);
+}
+
+static inline int v9fs_extended(struct v9fs_session_info *v9ses)
+{
+	return v9ses->flags & V9FS_EXTENDED;
+}

kernel/fs/9p/v9fs_vfs.h

@@ -0,0 +1,62 @@
+/*
+ * V9FS VFS extensions.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+/* plan9 semantics are that created files are implicitly opened.
+ * But linux semantics are that you call create, then open.
+ * the plan9 approach is superior as it provides an atomic
+ * open.
+ * we track the create fid here. When the file is opened, if fidopen is
+ * non-zero, we use the fid and can skip some steps.
+ * there may be a better way to do this, but I don't know it.
+ * one BAD way is to clunk the fid on create, then open it again:
+ * you lose the atomicity of file open
+ */
+
+/* special case:
+ * unlink calls remove, which is an implicit clunk. So we have to track
+ * that kind of thing so that we don't try to clunk a dead fid.
+ */
+
+extern struct file_system_type v9fs_fs_type;
+extern const struct address_space_operations v9fs_addr_operations;
+extern const struct file_operations v9fs_file_operations;
+extern const struct file_operations v9fs_dir_operations;
+extern const struct dentry_operations v9fs_dentry_operations;
+extern const struct dentry_operations v9fs_cached_dentry_operations;
+
+#ifdef CONFIG_9P_FSCACHE
+struct inode *v9fs_alloc_inode(struct super_block *sb);
+void v9fs_destroy_inode(struct inode *inode);
+#endif
+
+struct inode *v9fs_get_inode(struct super_block *sb, int mode);
+void v9fs_clear_inode(struct inode *inode);
+ino_t v9fs_qid2ino(struct p9_qid *qid);
+void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
+int v9fs_dir_release(struct inode *inode, struct file *filp);
+int v9fs_file_open(struct inode *inode, struct file *file);
+void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
+void v9fs_dentry_release(struct dentry *);
+int v9fs_uflags2omode(int uflags, int extended);
+
+ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);

kernel/fs/9p/vfs_addr.c

@@ -0,0 +1,163 @@
+/*
+ *  linux/fs/9p/vfs_addr.c
+ *
+ * This file contians vfs address (mmap) ops for 9P2000.
+ *
+ *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/pagemap.h>
+#include <linux/idr.h>
+#include <linux/sched.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "cache.h"
+
+/**
+ * v9fs_vfs_readpage - read an entire page in from 9P
+ *
+ * @filp: file being read
+ * @page: structure to page
+ *
+ */
+
+static int v9fs_vfs_readpage(struct file *filp, struct page *page)
+{
+	int retval;
+	loff_t offset;
+	char *buffer;
+	struct inode *inode;
+
+	inode = page->mapping->host;
+	P9_DPRINTK(P9_DEBUG_VFS, "\n");
+
+	BUG_ON(!PageLocked(page));
+
+	retval = v9fs_readpage_from_fscache(inode, page);
+	if (retval == 0)
+		return retval;
+
+	buffer = kmap(page);
+	offset = page_offset(page);
+
+	retval = v9fs_file_readn(filp, buffer, NULL, PAGE_CACHE_SIZE, offset);
+	if (retval < 0) {
+		v9fs_uncache_page(inode, page);
+		goto done;
+	}
+
+	memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval);
+	flush_dcache_page(page);
+	SetPageUptodate(page);
+
+	v9fs_readpage_to_fscache(inode, page);
+	retval = 0;
+
+done:
+	kunmap(page);
+	unlock_page(page);
+	return retval;
+}
+
+/**
+ * v9fs_vfs_readpages - read a set of pages from 9P
+ *
+ * @filp: file being read
+ * @mapping: the address space
+ * @pages: list of pages to read
+ * @nr_pages: count of pages to read
+ *
+ */
+
+static int v9fs_vfs_readpages(struct file *filp, struct address_space *mapping,
+			     struct list_head *pages, unsigned nr_pages)
+{
+	int ret = 0;
+	struct inode *inode;
+
+	inode = mapping->host;
+	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, filp);
+
+	ret = v9fs_readpages_from_fscache(inode, mapping, pages, &nr_pages);
+	if (ret == 0)
+		return ret;
+
+	ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp);
+	P9_DPRINTK(P9_DEBUG_VFS, "  = %d\n", ret);
+	return ret;
+}
+
+/**
+ * v9fs_release_page - release the private state associated with a page
+ *
+ * Returns 1 if the page can be released, false otherwise.
+ */
+
+static int v9fs_release_page(struct page *page, gfp_t gfp)
+{
+	if (PagePrivate(page))
+		return 0;
+
+	return v9fs_fscache_release_page(page, gfp);
+}
+
+/**
+ * v9fs_invalidate_page - Invalidate a page completely or partially
+ *
+ * @page: structure to page
+ * @offset: offset in the page
+ */
+
+static void v9fs_invalidate_page(struct page *page, unsigned long offset)
+{
+	if (offset == 0)
+		v9fs_fscache_invalidate_page(page);
+}
+
+/**
+ * v9fs_launder_page - Writeback a dirty page
+ * Since the writes go directly to the server, we simply return a 0
+ * here to indicate success.
+ *
+ * Returns 0 on success.
+ */
+
+static int v9fs_launder_page(struct page *page)
+{
+	return 0;
+}
+
+const struct address_space_operations v9fs_addr_operations = {
+      .readpage = v9fs_vfs_readpage,
+      .readpages = v9fs_vfs_readpages,
+      .releasepage = v9fs_release_page,
+      .invalidatepage = v9fs_invalidate_page,
+      .launder_page = v9fs_launder_page,
+};

kernel/fs/9p/vfs_dentry.c

@@ -0,0 +1,115 @@
+/*
+ *  linux/fs/9p/vfs_dentry.c
+ *
+ * This file contians vfs dentry ops for the 9P2000 protocol.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/namei.h>
+#include <linux/idr.h>
+#include <linux/sched.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+/**
+ * v9fs_dentry_delete - called when dentry refcount equals 0
+ * @dentry:  dentry in question
+ *
+ * By returning 1 here we should remove cacheing of unused
+ * dentry components.
+ *
+ */
+
+static int v9fs_dentry_delete(struct dentry *dentry)
+{
+	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
+									dentry);
+
+	return 1;
+}
+
+/**
+ * v9fs_cached_dentry_delete - called when dentry refcount equals 0
+ * @dentry:  dentry in question
+ *
+ * Only return 1 if our inode is invalid.  Only non-synthetic files
+ * (ones without mtime == 0) should be calling this function.
+ *
+ */
+
+static int v9fs_cached_dentry_delete(struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
+									dentry);
+
+	if(!inode)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * v9fs_dentry_release - called when dentry is going to be freed
+ * @dentry:  dentry that is being release
+ *
+ */
+
+void v9fs_dentry_release(struct dentry *dentry)
+{
+	struct v9fs_dentry *dent;
+	struct p9_fid *temp, *current_fid;
+
+	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
+									dentry);
+	dent = dentry->d_fsdata;
+	if (dent) {
+		list_for_each_entry_safe(current_fid, temp, &dent->fidlist,
+									dlist) {
+			p9_client_clunk(current_fid);
+		}
+
+		kfree(dent);
+		dentry->d_fsdata = NULL;
+	}
+}
+
+const struct dentry_operations v9fs_cached_dentry_operations = {
+	.d_delete = v9fs_cached_dentry_delete,
+	.d_release = v9fs_dentry_release,
+};
+
+const struct dentry_operations v9fs_dentry_operations = {
+	.d_delete = v9fs_dentry_delete,
+	.d_release = v9fs_dentry_release,
+};

kernel/fs/9p/vfs_dir.c

@@ -0,0 +1,193 @@
+/*
+ * linux/fs/9p/vfs_dir.c
+ *
+ * This file contains vfs directory ops for the 9P2000 protocol.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/sched.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+/**
+ * struct p9_rdir - readdir accounting
+ * @mutex: mutex protecting readdir
+ * @head: start offset of current dirread buffer
+ * @tail: end offset of current dirread buffer
+ * @buf: dirread buffer
+ *
+ * private structure for keeping track of readdir
+ * allocated on demand
+ */
+
+struct p9_rdir {
+	struct mutex mutex;
+	int head;
+	int tail;
+	uint8_t *buf;
+};
+
+/**
+ * dt_type - return file type
+ * @mistat: mistat structure
+ *
+ */
+
+static inline int dt_type(struct p9_wstat *mistat)
+{
+	unsigned long perm = mistat->mode;
+	int rettype = DT_REG;
+
+	if (perm & P9_DMDIR)
+		rettype = DT_DIR;
+	if (perm & P9_DMSYMLINK)
+		rettype = DT_LNK;
+
+	return rettype;
+}
+
+/**
+ * v9fs_dir_readdir - read a directory
+ * @filp: opened file structure
+ * @dirent: directory structure ???
+ * @filldir: function to populate directory structure ???
+ *
+ */
+
+static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	int over;
+	struct p9_wstat st;
+	int err = 0;
+	struct p9_fid *fid;
+	int buflen;
+	int reclen = 0;
+	struct p9_rdir *rdir;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
+	fid = filp->private_data;
+
+	buflen = fid->clnt->msize - P9_IOHDRSZ;
+
+	/* allocate rdir on demand */
+	if (!fid->rdir) {
+		rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
+
+		if (rdir == NULL) {
+			err = -ENOMEM;
+			goto exit;
+		}
+		spin_lock(&filp->f_dentry->d_lock);
+		if (!fid->rdir) {
+			rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
+			mutex_init(&rdir->mutex);
+			rdir->head = rdir->tail = 0;
+			fid->rdir = (void *) rdir;
+			rdir = NULL;
+		}
+		spin_unlock(&filp->f_dentry->d_lock);
+		kfree(rdir);
+	}
+	rdir = (struct p9_rdir *) fid->rdir;
+
+	err = mutex_lock_interruptible(&rdir->mutex);
+	while (err == 0) {
+		if (rdir->tail == rdir->head) {
+			err = v9fs_file_readn(filp, rdir->buf, NULL,
+							buflen, filp->f_pos);
+			if (err <= 0)
+				goto unlock_and_exit;
+
+			rdir->head = 0;
+			rdir->tail = err;
+		}
+
+		while (rdir->head < rdir->tail) {
+			err = p9stat_read(rdir->buf + rdir->head,
+						buflen - rdir->head, &st,
+						fid->clnt->dotu);
+			if (err) {
+				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
+				err = -EIO;
+				p9stat_free(&st);
+				goto unlock_and_exit;
+			}
+			reclen = st.size+2;
+
+			over = filldir(dirent, st.name, strlen(st.name),
+			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
+
+			p9stat_free(&st);
+
+			if (over) {
+				err = 0;
+				goto unlock_and_exit;
+			}
+			rdir->head += reclen;
+			filp->f_pos += reclen;
+		}
+	}
+
+unlock_and_exit:
+	mutex_unlock(&rdir->mutex);
+exit:
+	return err;
+}
+
+
+/**
+ * v9fs_dir_release - close a directory
+ * @inode: inode of the directory
+ * @filp: file pointer to a directory
+ *
+ */
+
+int v9fs_dir_release(struct inode *inode, struct file *filp)
+{
+	struct p9_fid *fid;
+
+	fid = filp->private_data;
+	P9_DPRINTK(P9_DEBUG_VFS,
+			"inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
+	filemap_write_and_wait(inode->i_mapping);
+	p9_client_clunk(fid);
+	return 0;
+}
+
+const struct file_operations v9fs_dir_operations = {
+	.read = generic_read_dir,
+	.llseek = generic_file_llseek,
+	.readdir = v9fs_dir_readdir,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+};

kernel/fs/9p/vfs_file.c

@@ -0,0 +1,279 @@
+/*
+ *  linux/fs/9p/vfs_file.c
+ *
+ * This file contians vfs file ops for 9P2000.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/list.h>
+#include <linux/pagemap.h>
+#include <asm/uaccess.h>
+#include <linux/idr.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+#include "cache.h"
+
+static const struct file_operations v9fs_cached_file_operations;
+
+/**
+ * v9fs_file_open - open a file (or directory)
+ * @inode: inode to be opened
+ * @file: file being opened
+ *
+ */
+
+int v9fs_file_open(struct inode *inode, struct file *file)
+{
+	int err;
+	struct v9fs_session_info *v9ses;
+	struct p9_fid *fid;
+	int omode;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
+	v9ses = v9fs_inode2v9ses(inode);
+	omode = v9fs_uflags2omode(file->f_flags, v9fs_extended(v9ses));
+	fid = file->private_data;
+	if (!fid) {
+		fid = v9fs_fid_clone(file->f_path.dentry);
+		if (IS_ERR(fid))
+			return PTR_ERR(fid);
+
+		err = p9_client_open(fid, omode);
+		if (err < 0) {
+			p9_client_clunk(fid);
+			return err;
+		}
+		if (omode & P9_OTRUNC) {
+			i_size_write(inode, 0);
+			inode->i_blocks = 0;
+		}
+		if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses)))
+			generic_file_llseek(file, 0, SEEK_END);
+	}
+
+	file->private_data = fid;
+	if ((fid->qid.version) && (v9ses->cache)) {
+		P9_DPRINTK(P9_DEBUG_VFS, "cached");
+		/* enable cached file options */
+		if(file->f_op == &v9fs_file_operations)
+			file->f_op = &v9fs_cached_file_operations;
+
+#ifdef CONFIG_9P_FSCACHE
+		v9fs_cache_inode_set_cookie(inode, file);
+#endif
+	}
+
+	return 0;
+}
+
+/**
+ * v9fs_file_lock - lock a file (or directory)
+ * @filp: file to be locked
+ * @cmd: lock command
+ * @fl: file lock structure
+ *
+ * Bugs: this looks like a local only lock, we should extend into 9P
+ *       by using open exclusive
+ */
+
+static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	int res = 0;
+	struct inode *inode = filp->f_path.dentry->d_inode;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
+
+	/* No mandatory locks */
+	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
+		return -ENOLCK;
+
+	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
+		filemap_write_and_wait(inode->i_mapping);
+		invalidate_mapping_pages(&inode->i_data, 0, -1);
+	}
+
+	return res;
+}
+
+/**
+ * v9fs_file_readn - read from a file
+ * @filp: file pointer to read
+ * @data: data buffer to read data into
+ * @udata: user data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
+ssize_t
+v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
+	       u64 offset)
+{
+	int n, total;
+	struct p9_fid *fid = filp->private_data;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
+					(long long unsigned) offset, count);
+
+	n = 0;
+	total = 0;
+	do {
+		n = p9_client_read(fid, data, udata, offset, count);
+		if (n <= 0)
+			break;
+
+		if (data)
+			data += n;
+		if (udata)
+			udata += n;
+
+		offset += n;
+		count -= n;
+		total += n;
+	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
+
+	if (n < 0)
+		total = n;
+
+	return total;
+}
+
+/**
+ * v9fs_file_read - read from a file
+ * @filp: file pointer to read
+ * @udata: user data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
+static ssize_t
+v9fs_file_read(struct file *filp, char __user *udata, size_t count,
+	       loff_t * offset)
+{
+	int ret;
+	struct p9_fid *fid;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
+	fid = filp->private_data;
+
+	if (count > (fid->clnt->msize - P9_IOHDRSZ))
+		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
+	else
+		ret = p9_client_read(fid, NULL, udata, *offset, count);
+
+	if (ret > 0)
+		*offset += ret;
+
+	return ret;
+}
+
+/**
+ * v9fs_file_write - write to a file
+ * @filp: file pointer to write
+ * @data: data buffer to write data from
+ * @count: size of buffer
+ * @offset: offset at which to write data
+ *
+ */
+
+static ssize_t
+v9fs_file_write(struct file *filp, const char __user * data,
+		size_t count, loff_t * offset)
+{
+	int n, rsize, total = 0;
+	struct p9_fid *fid;
+	struct p9_client *clnt;
+	struct inode *inode = filp->f_path.dentry->d_inode;
+	int origin = *offset;
+	unsigned long pg_start, pg_end;
+
+	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
+		(int)count, (int)*offset);
+
+	fid = filp->private_data;
+	clnt = fid->clnt;
+
+	rsize = fid->iounit;
+	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
+		rsize = clnt->msize - P9_IOHDRSZ;
+
+	do {
+		if (count < rsize)
+			rsize = count;
+
+		n = p9_client_write(fid, NULL, data+total, origin+total,
+									rsize);
+		if (n <= 0)
+			break;
+		count -= n;
+		total += n;
+	} while (count > 0);
+
+	if (total > 0) {
+		pg_start = origin >> PAGE_CACHE_SHIFT;
+		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
+		if (inode->i_mapping && inode->i_mapping->nrpages)
+			invalidate_inode_pages2_range(inode->i_mapping,
+						      pg_start, pg_end);
+		*offset += total;
+		i_size_write(inode, i_size_read(inode) + total);
+		inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
+	}
+
+	if (n < 0)
+		return n;
+
+	return total;
+}
+
+static const struct file_operations v9fs_cached_file_operations = {
+	.llseek = generic_file_llseek,
+	.read = do_sync_read,
+	.aio_read = generic_file_aio_read,
+	.write = v9fs_file_write,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+	.lock = v9fs_file_lock,
+	.mmap = generic_file_readonly_mmap,
+};
+
+const struct file_operations v9fs_file_operations = {
+	.llseek = generic_file_llseek,
+	.read = v9fs_file_read,
+	.write = v9fs_file_write,
+	.open = v9fs_file_open,
+	.release = v9fs_dir_release,
+	.lock = v9fs_file_lock,
+	.mmap = generic_file_readonly_mmap,
+};

kernel/fs/9p/vfs_super.c

@@ -0,0 +1,227 @@
+/*
+ *  linux/fs/9p/vfs_super.c
+ *
+ * This file contians superblock ops for 9P2000. It is intended that
+ * you mount this file system on directories.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/inet.h>
+#include <linux/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/idr.h>
+#include <linux/sched.h>
+#include <net/9p/9p.h>
+#include <net/9p/client.h>
+
+#include "v9fs.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+static const struct super_operations v9fs_super_ops;
+
+/**
+ * v9fs_set_super - set the superblock
+ * @s: super block
+ * @data: file system specific data
+ *
+ */
+
+static int v9fs_set_super(struct super_block *s, void *data)
+{
+	s->s_fs_info = data;
+	return set_anon_super(s, data);
+}
+
+/**
+ * v9fs_fill_super - populate superblock with info
+ * @sb: superblock
+ * @v9ses: session information
+ * @flags: flags propagated from v9fs_get_sb()
+ *
+ */
+
+static void
+v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
+		int flags, void *data)
+{
+	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
+	sb->s_blocksize = 1 << sb->s_blocksize_bits;
+	sb->s_magic = V9FS_MAGIC;
+	sb->s_op = &v9fs_super_ops;
+
+	sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
+	    MS_NOATIME;
+
+	save_mount_options(sb, data);
+}
+
+/**
+ * v9fs_get_sb - mount a superblock
+ * @fs_type: file system type
+ * @flags: mount flags
+ * @dev_name: device name that was mounted
+ * @data: mount options
+ * @mnt: mountpoint record to be instantiated
+ *
+ */
+
+static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
+		       const char *dev_name, void *data,
+		       struct vfsmount *mnt)
+{
+	struct super_block *sb = NULL;
+	struct inode *inode = NULL;
+	struct dentry *root = NULL;
+	struct v9fs_session_info *v9ses = NULL;
+	struct p9_wstat *st = NULL;
+	int mode = S_IRWXUGO | S_ISVTX;
+	struct p9_fid *fid;
+	int retval = 0;
+
+	P9_DPRINTK(P9_DEBUG_VFS, " \n");
+
+	v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
+	if (!v9ses)
+		return -ENOMEM;
+
+	fid = v9fs_session_init(v9ses, dev_name, data);
+	if (IS_ERR(fid)) {
+		retval = PTR_ERR(fid);
+		goto close_session;
+	}
+
+	st = p9_client_stat(fid);
+	if (IS_ERR(st)) {
+		retval = PTR_ERR(st);
+		goto clunk_fid;
+	}
+
+	sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
+	if (IS_ERR(sb)) {
+		retval = PTR_ERR(sb);
+		goto free_stat;
+	}
+	v9fs_fill_super(sb, v9ses, flags, data);
+
+	inode = v9fs_get_inode(sb, S_IFDIR | mode);
+	if (IS_ERR(inode)) {
+		retval = PTR_ERR(inode);
+		goto release_sb;
+	}
+
+	root = d_alloc_root(inode);
+	if (!root) {
+		iput(inode);
+		retval = -ENOMEM;
+		goto release_sb;
+	}
+
+	sb->s_root = root;
+	root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
+
+	v9fs_stat2inode(st, root->d_inode, sb);
+
+	v9fs_fid_add(root, fid);
+	p9stat_free(st);
+	kfree(st);
+
+P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
+	simple_set_mnt(mnt, sb);
+	return 0;
+
+free_stat:
+	p9stat_free(st);
+	kfree(st);
+
+clunk_fid:
+	p9_client_clunk(fid);
+
+close_session:
+	v9fs_session_close(v9ses);
+	kfree(v9ses);
+	return retval;
+
+release_sb:
+	p9stat_free(st);
+	kfree(st);
+	deactivate_locked_super(sb);
+	return retval;
+}
+
+/**
+ * v9fs_kill_super - Kill Superblock
+ * @s: superblock
+ *
+ */
+
+static void v9fs_kill_super(struct super_block *s)
+{
+	struct v9fs_session_info *v9ses = s->s_fs_info;
+
+	P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
+
+	if (s->s_root)
+		v9fs_dentry_release(s->s_root);	/* clunk root */
+
+	kill_anon_super(s);
+
+	v9fs_session_close(v9ses);
+	kfree(v9ses);
+	s->s_fs_info = NULL;
+	P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
+}
+
+static void
+v9fs_umount_begin(struct super_block *sb)
+{
+	struct v9fs_session_info *v9ses;
+
+	v9ses = sb->s_fs_info;
+	v9fs_session_cancel(v9ses);
+}
+
+static const struct super_operations v9fs_super_ops = {
+#ifdef CONFIG_9P_FSCACHE
+	.alloc_inode = v9fs_alloc_inode,
+	.destroy_inode = v9fs_destroy_inode,
+#endif
+	.statfs = simple_statfs,
+	.clear_inode = v9fs_clear_inode,
+	.show_options = generic_show_options,
+	.umount_begin = v9fs_umount_begin,
+};
+
+struct file_system_type v9fs_fs_type = {
+	.name = "9p",
+	.get_sb = v9fs_get_sb,
+	.kill_sb = v9fs_kill_super,
+	.owner = THIS_MODULE,
+};