init android origin source code

1 files changed, 2362 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/fs/nfs/dir.c b/ANDROID_3.4.5/fs/nfs/dir.c
new file mode 100644
index 00000000..8789210c
--- /dev/null
+++ b/ANDROID_3.4.5/fs/nfs/dir.c
@@ -0,0 +1,2362 @@
+/*
+ *  linux/fs/nfs/dir.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  nfs directory handling functions
+ *
+ * 10 Apr 1996	Added silly rename for unlink	--okir
+ * 28 Sep 1996	Improved directory cache --okir
+ * 23 Aug 1997  Claus Heine claus@momo.math.rwth-aachen.de 
+ *              Re-implemented silly rename for unlink, newly implemented
+ *              silly rename for nfs_rename() following the suggestions
+ *              of Olaf Kirch (okir) found in this file.
+ *              Following Linus comments on my original hack, this version
+ *              depends only on the dcache stuff and doesn't touch the inode
+ *              layer (iput() and friends).
+ *  6 Jun 1999	Cache readdir lookups in the page cache. -DaveM
+ */
+
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/sched.h>
+#include <linux/kmemleak.h>
+#include <linux/xattr.h>
+
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+
+/* #define NFS_DEBUG_VERBOSE 1 */
+
+static int nfs_opendir(struct inode *, struct file *);
+static int nfs_closedir(struct inode *, struct file *);
+static int nfs_readdir(struct file *, void *, filldir_t);
+static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
+static int nfs_create(struct inode *, struct dentry *, umode_t, struct nameidata *);
+static int nfs_mkdir(struct inode *, struct dentry *, umode_t);
+static int nfs_rmdir(struct inode *, struct dentry *);
+static int nfs_unlink(struct inode *, struct dentry *);
+static int nfs_symlink(struct inode *, struct dentry *, const char *);
+static int nfs_link(struct dentry *, struct inode *, struct dentry *);
+static int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+static int nfs_rename(struct inode *, struct dentry *,
+		      struct inode *, struct dentry *);
+static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
+static loff_t nfs_llseek_dir(struct file *, loff_t, int);
+static void nfs_readdir_clear_array(struct page*);
+
+const struct file_operations nfs_dir_operations = {
+	.llseek		= nfs_llseek_dir,
+	.read		= generic_read_dir,
+	.readdir	= nfs_readdir,
+	.open		= nfs_opendir,
+	.release	= nfs_closedir,
+	.fsync		= nfs_fsync_dir,
+};
+
+const struct inode_operations nfs_dir_inode_operations = {
+	.create		= nfs_create,
+	.lookup		= nfs_lookup,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
+
+const struct address_space_operations nfs_dir_aops = {
+	.freepage = nfs_readdir_clear_array,
+};
+
+#ifdef CONFIG_NFS_V3
+const struct inode_operations nfs3_dir_inode_operations = {
+	.create		= nfs_create,
+	.lookup		= nfs_lookup,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+	.listxattr	= nfs3_listxattr,
+	.getxattr	= nfs3_getxattr,
+	.setxattr	= nfs3_setxattr,
+	.removexattr	= nfs3_removexattr,
+};
+#endif  /* CONFIG_NFS_V3 */
+
+#ifdef CONFIG_NFS_V4
+
+static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
+static int nfs_open_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd);
+const struct inode_operations nfs4_dir_inode_operations = {
+	.create		= nfs_open_create,
+	.lookup		= nfs_atomic_lookup,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+	.getxattr	= generic_getxattr,
+	.setxattr	= generic_setxattr,
+	.listxattr	= generic_listxattr,
+	.removexattr	= generic_removexattr,
+};
+
+#endif /* CONFIG_NFS_V4 */
+
+static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
+{
+	struct nfs_open_dir_context *ctx;
+	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+	if (ctx != NULL) {
+		ctx->duped = 0;
+		ctx->attr_gencount = NFS_I(dir)->attr_gencount;
+		ctx->dir_cookie = 0;
+		ctx->dup_cookie = 0;
+		ctx->cred = get_rpccred(cred);
+		return ctx;
+	}
+	return  ERR_PTR(-ENOMEM);
+}
+
+static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
+{
+	put_rpccred(ctx->cred);
+	kfree(ctx);
+}
+
+/*
+ * Open file
+ */
+static int
+nfs_opendir(struct inode *inode, struct file *filp)
+{
+	int res = 0;
+	struct nfs_open_dir_context *ctx;
+	struct rpc_cred *cred;
+
+	dfprintk(FILE, "NFS: open dir(%s/%s)\n",
+			filp->f_path.dentry->d_parent->d_name.name,
+			filp->f_path.dentry->d_name.name);
+
+	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
+
+	cred = rpc_lookup_cred();
+	if (IS_ERR(cred))
+		return PTR_ERR(cred);
+	ctx = alloc_nfs_open_dir_context(inode, cred);
+	if (IS_ERR(ctx)) {
+		res = PTR_ERR(ctx);
+		goto out;
+	}
+	filp->private_data = ctx;
+	if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
+		/* This is a mountpoint, so d_revalidate will never
+		 * have been called, so we need to refresh the
+		 * inode (for close-open consistency) ourselves.
+		 */
+		__nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	}
+out:
+	put_rpccred(cred);
+	return res;
+}
+
+static int
+nfs_closedir(struct inode *inode, struct file *filp)
+{
+	put_nfs_open_dir_context(filp->private_data);
+	return 0;
+}
+
+struct nfs_cache_array_entry {
+	u64 cookie;
+	u64 ino;
+	struct qstr string;
+	unsigned char d_type;
+};
+
+struct nfs_cache_array {
+	int size;
+	int eof_index;
+	u64 last_cookie;
+	struct nfs_cache_array_entry array[0];
+};
+
+typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
+typedef struct {
+	struct file	*file;
+	struct page	*page;
+	unsigned long	page_index;
+	u64		*dir_cookie;
+	u64		last_cookie;
+	loff_t		current_index;
+	decode_dirent_t	decode;
+
+	unsigned long	timestamp;
+	unsigned long	gencount;
+	unsigned int	cache_entry_index;
+	unsigned int	plus:1;
+	unsigned int	eof:1;
+} nfs_readdir_descriptor_t;
+
+/*
+ * The caller is responsible for calling nfs_readdir_release_array(page)
+ */
+static
+struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
+{
+	void *ptr;
+	if (page == NULL)
+		return ERR_PTR(-EIO);
+	ptr = kmap(page);
+	if (ptr == NULL)
+		return ERR_PTR(-ENOMEM);
+	return ptr;
+}
+
+static
+void nfs_readdir_release_array(struct page *page)
+{
+	kunmap(page);
+}
+
+/*
+ * we are freeing strings created by nfs_add_to_readdir_array()
+ */
+static
+void nfs_readdir_clear_array(struct page *page)
+{
+	struct nfs_cache_array *array;
+	int i;
+
+	array = kmap_atomic(page);
+	for (i = 0; i < array->size; i++)
+		kfree(array->array[i].string.name);
+	kunmap_atomic(array);
+}
+
+/*
+ * the caller is responsible for freeing qstr.name
+ * when called by nfs_readdir_add_to_array, the strings will be freed in
+ * nfs_clear_readdir_array()
+ */
+static
+int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
+{
+	string->len = len;
+	string->name = kmemdup(name, len, GFP_KERNEL);
+	if (string->name == NULL)
+		return -ENOMEM;
+	/*
+	 * Avoid a kmemleak false positive. The pointer to the name is stored
+	 * in a page cache page which kmemleak does not scan.
+	 */
+	kmemleak_not_leak(string->name);
+	string->hash = full_name_hash(name, len);
+	return 0;
+}
+
+static
+int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+{
+	struct nfs_cache_array *array = nfs_readdir_get_array(page);
+	struct nfs_cache_array_entry *cache_entry;
+	int ret;
+
+	if (IS_ERR(array))
+		return PTR_ERR(array);
+
+	cache_entry = &array->array[array->size];
+
+	/* Check that this entry lies within the page bounds */
+	ret = -ENOSPC;
+	if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
+		goto out;
+
+	cache_entry->cookie = entry->prev_cookie;
+	cache_entry->ino = entry->ino;
+	cache_entry->d_type = entry->d_type;
+	ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
+	if (ret)
+		goto out;
+	array->last_cookie = entry->cookie;
+	array->size++;
+	if (entry->eof != 0)
+		array->eof_index = array->size;
+out:
+	nfs_readdir_release_array(page);
+	return ret;
+}
+
+static
+int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+	loff_t diff = desc->file->f_pos - desc->current_index;
+	unsigned int index;
+
+	if (diff < 0)
+		goto out_eof;
+	if (diff >= array->size) {
+		if (array->eof_index >= 0)
+			goto out_eof;
+		return -EAGAIN;
+	}
+
+	index = (unsigned int)diff;
+	*desc->dir_cookie = array->array[index].cookie;
+	desc->cache_entry_index = index;
+	return 0;
+out_eof:
+	desc->eof = 1;
+	return -EBADCOOKIE;
+}
+
+static
+int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+	int i;
+	loff_t new_pos;
+	int status = -EAGAIN;
+
+	for (i = 0; i < array->size; i++) {
+		if (array->array[i].cookie == *desc->dir_cookie) {
+			struct nfs_inode *nfsi = NFS_I(desc->file->f_path.dentry->d_inode);
+			struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+			new_pos = desc->current_index + i;
+			if (ctx->attr_gencount != nfsi->attr_gencount
+			    || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
+				ctx->duped = 0;
+				ctx->attr_gencount = nfsi->attr_gencount;
+			} else if (new_pos < desc->file->f_pos) {
+				if (ctx->duped > 0
+				    && ctx->dup_cookie == *desc->dir_cookie) {
+					if (printk_ratelimit()) {
+						pr_notice("NFS: directory %s/%s contains a readdir loop."
+								"Please contact your server vendor.  "
+								"The file: %s has duplicate cookie %llu\n",
+								desc->file->f_dentry->d_parent->d_name.name,
+								desc->file->f_dentry->d_name.name,
+								array->array[i].string.name,
+								*desc->dir_cookie);
+					}
+					status = -ELOOP;
+					goto out;
+				}
+				ctx->dup_cookie = *desc->dir_cookie;
+				ctx->duped = -1;
+			}
+			desc->file->f_pos = new_pos;
+			desc->cache_entry_index = i;
+			return 0;
+		}
+	}
+	if (array->eof_index >= 0) {
+		status = -EBADCOOKIE;
+		if (*desc->dir_cookie == array->last_cookie)
+			desc->eof = 1;
+	}
+out:
+	return status;
+}
+
+static
+int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
+{
+	struct nfs_cache_array *array;
+	int status;
+
+	array = nfs_readdir_get_array(desc->page);
+	if (IS_ERR(array)) {
+		status = PTR_ERR(array);
+		goto out;
+	}
+
+	if (*desc->dir_cookie == 0)
+		status = nfs_readdir_search_for_pos(array, desc);
+	else
+		status = nfs_readdir_search_for_cookie(array, desc);
+
+	if (status == -EAGAIN) {
+		desc->last_cookie = array->last_cookie;
+		desc->current_index += array->size;
+		desc->page_index++;
+	}
+	nfs_readdir_release_array(desc->page);
+out:
+	return status;
+}
+
+/* Fill a page with xdr information before transferring to the cache page */
+static
+int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
+			struct nfs_entry *entry, struct file *file, struct inode *inode)
+{
+	struct nfs_open_dir_context *ctx = file->private_data;
+	struct rpc_cred	*cred = ctx->cred;
+	unsigned long	timestamp, gencount;
+	int		error;
+
+ again:
+	timestamp = jiffies;
+	gencount = nfs_inc_attr_generation_counter();
+	error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
+					  NFS_SERVER(inode)->dtsize, desc->plus);
+	if (error < 0) {
+		/* We requested READDIRPLUS, but the server doesn't grok it */
+		if (error == -ENOTSUPP && desc->plus) {
+			NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
+			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+			desc->plus = 0;
+			goto again;
+		}
+		goto error;
+	}
+	desc->timestamp = timestamp;
+	desc->gencount = gencount;
+error:
+	return error;
+}
+
+static int xdr_decode(nfs_readdir_descriptor_t *desc,
+		      struct nfs_entry *entry, struct xdr_stream *xdr)
+{
+	int error;
+
+	error = desc->decode(xdr, entry, desc->plus);
+	if (error)
+		return error;
+	entry->fattr->time_start = desc->timestamp;
+	entry->fattr->gencount = desc->gencount;
+	return 0;
+}
+
+static
+int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
+{
+	if (dentry->d_inode == NULL)
+		goto different;
+	if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
+		goto different;
+	return 1;
+different:
+	return 0;
+}
+
+static
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
+{
+	struct qstr filename = {
+		.len = entry->len,
+		.name = entry->name,
+	};
+	struct dentry *dentry;
+	struct dentry *alias;
+	struct inode *dir = parent->d_inode;
+	struct inode *inode;
+
+	if (filename.name[0] == '.') {
+		if (filename.len == 1)
+			return;
+		if (filename.len == 2 && filename.name[1] == '.')
+			return;
+	}
+	filename.hash = full_name_hash(filename.name, filename.len);
+
+	dentry = d_lookup(parent, &filename);
+	if (dentry != NULL) {
+		if (nfs_same_file(dentry, entry)) {
+			nfs_refresh_inode(dentry->d_inode, entry->fattr);
+			goto out;
+		} else {
+			d_drop(dentry);
+			dput(dentry);
+		}
+	}
+
+	dentry = d_alloc(parent, &filename);
+	if (dentry == NULL)
+		return;
+
+	inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
+	if (IS_ERR(inode))
+		goto out;
+
+	alias = d_materialise_unique(dentry, inode);
+	if (IS_ERR(alias))
+		goto out;
+	else if (alias) {
+		nfs_set_verifier(alias, nfs_save_change_attribute(dir));
+		dput(alias);
+	} else
+		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+
+out:
+	dput(dentry);
+}
+
+/* Perform conversion from xdr to cache array */
+static
+int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
+				struct page **xdr_pages, struct page *page, unsigned int buflen)
+{
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	struct nfs_cache_array *array;
+	unsigned int count = 0;
+	int status;
+
+	scratch = alloc_page(GFP_KERNEL);
+	if (scratch == NULL)
+		return -ENOMEM;
+
+	xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	do {
+		status = xdr_decode(desc, entry, &stream);
+		if (status != 0) {
+			if (status == -EAGAIN)
+				status = 0;
+			break;
+		}
+
+		count++;
+
+		if (desc->plus != 0)
+			nfs_prime_dcache(desc->file->f_path.dentry, entry);
+
+		status = nfs_readdir_add_to_array(entry, page);
+		if (status != 0)
+			break;
+	} while (!entry->eof);
+
+	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
+		array = nfs_readdir_get_array(page);
+		if (!IS_ERR(array)) {
+			array->eof_index = array->size;
+			status = 0;
+			nfs_readdir_release_array(page);
+		} else
+			status = PTR_ERR(array);
+	}
+
+	put_page(scratch);
+	return status;
+}
+
+static
+void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
+{
+	unsigned int i;
+	for (i = 0; i < npages; i++)
+		put_page(pages[i]);
+}
+
+static
+void nfs_readdir_free_large_page(void *ptr, struct page **pages,
+		unsigned int npages)
+{
+	nfs_readdir_free_pagearray(pages, npages);
+}
+
+/*
+ * nfs_readdir_large_page will allocate pages that must be freed with a call
+ * to nfs_readdir_free_large_page
+ */
+static
+int nfs_readdir_large_page(struct page **pages, unsigned int npages)
+{
+	unsigned int i;
+
+	for (i = 0; i < npages; i++) {
+		struct page *page = alloc_page(GFP_KERNEL);
+		if (page == NULL)
+			goto out_freepages;
+		pages[i] = page;
+	}
+	return 0;
+
+out_freepages:
+	nfs_readdir_free_pagearray(pages, i);
+	return -ENOMEM;
+}
+
+static
+int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
+{
+	struct page *pages[NFS_MAX_READDIR_PAGES];
+	void *pages_ptr = NULL;
+	struct nfs_entry entry;
+	struct file	*file = desc->file;
+	struct nfs_cache_array *array;
+	int status = -ENOMEM;
+	unsigned int array_size = ARRAY_SIZE(pages);
+
+	entry.prev_cookie = 0;
+	entry.cookie = desc->last_cookie;
+	entry.eof = 0;
+	entry.fh = nfs_alloc_fhandle();
+	entry.fattr = nfs_alloc_fattr();
+	entry.server = NFS_SERVER(inode);
+	if (entry.fh == NULL || entry.fattr == NULL)
+		goto out;
+
+	array = nfs_readdir_get_array(page);
+	if (IS_ERR(array)) {
+		status = PTR_ERR(array);
+		goto out;
+	}
+	memset(array, 0, sizeof(struct nfs_cache_array));
+	array->eof_index = -1;
+
+	status = nfs_readdir_large_page(pages, array_size);
+	if (status < 0)
+		goto out_release_array;
+	do {
+		unsigned int pglen;
+		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
+
+		if (status < 0)
+			break;
+		pglen = status;
+		status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
+		if (status < 0) {
+			if (status == -ENOSPC)
+				status = 0;
+			break;
+		}
+	} while (array->eof_index < 0);
+
+	nfs_readdir_free_large_page(pages_ptr, pages, array_size);
+out_release_array:
+	nfs_readdir_release_array(page);
+out:
+	nfs_free_fattr(entry.fattr);
+	nfs_free_fhandle(entry.fh);
+	return status;
+}
+
+/*
+ * Now we cache directories properly, by converting xdr information
+ * to an array that can be used for lookups later.  This results in
+ * fewer cache pages, since we can store more information on each page.
+ * We only need to convert from xdr once so future lookups are much simpler
+ */
+static
+int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
+{
+	struct inode	*inode = desc->file->f_path.dentry->d_inode;
+	int ret;
+
+	ret = nfs_readdir_xdr_to_array(desc, page, inode);
+	if (ret < 0)
+		goto error;
+	SetPageUptodate(page);
+
+	if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
+		/* Should never happen */
+		nfs_zap_mapping(inode, inode->i_mapping);
+	}
+	unlock_page(page);
+	return 0;
+ error:
+	unlock_page(page);
+	return ret;
+}
+
+static
+void cache_page_release(nfs_readdir_descriptor_t *desc)
+{
+	if (!desc->page->mapping)
+		nfs_readdir_clear_array(desc->page);
+	page_cache_release(desc->page);
+	desc->page = NULL;
+}
+
+static
+struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
+{
+	return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
+			desc->page_index, (filler_t *)nfs_readdir_filler, desc);
+}
+
+/*
+ * Returns 0 if desc->dir_cookie was found on page desc->page_index
+ */
+static
+int find_cache_page(nfs_readdir_descriptor_t *desc)
+{
+	int res;
+
+	desc->page = get_cache_page(desc);
+	if (IS_ERR(desc->page))
+		return PTR_ERR(desc->page);
+
+	res = nfs_readdir_search_array(desc);
+	if (res != 0)
+		cache_page_release(desc);
+	return res;
+}
+
+/* Search for desc->dir_cookie from the beginning of the page cache */
+static inline
+int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
+{
+	int res;
+
+	if (desc->page_index == 0) {
+		desc->current_index = 0;
+		desc->last_cookie = 0;
+	}
+	do {
+		res = find_cache_page(desc);
+	} while (res == -EAGAIN);
+	return res;
+}
+
+/*
+ * Once we've found the start of the dirent within a page: fill 'er up...
+ */
+static 
+int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
+		   filldir_t filldir)
+{
+	struct file	*file = desc->file;
+	int i = 0;
+	int res = 0;
+	struct nfs_cache_array *array = NULL;
+	struct nfs_open_dir_context *ctx = file->private_data;
+
+	array = nfs_readdir_get_array(desc->page);
+	if (IS_ERR(array)) {
+		res = PTR_ERR(array);
+		goto out;
+	}
+
+	for (i = desc->cache_entry_index; i < array->size; i++) {
+		struct nfs_cache_array_entry *ent;
+
+		ent = &array->array[i];
+		if (filldir(dirent, ent->string.name, ent->string.len,
+		    file->f_pos, nfs_compat_user_ino64(ent->ino),
+		    ent->d_type) < 0) {
+			desc->eof = 1;
+			break;
+		}
+		file->f_pos++;
+		if (i < (array->size-1))
+			*desc->dir_cookie = array->array[i+1].cookie;
+		else
+			*desc->dir_cookie = array->last_cookie;
+		if (ctx->duped != 0)
+			ctx->duped = 1;
+	}
+	if (array->eof_index >= 0)
+		desc->eof = 1;
+
+	nfs_readdir_release_array(desc->page);
+out:
+	cache_page_release(desc);
+	dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
+			(unsigned long long)*desc->dir_cookie, res);
+	return res;
+}
+
+/*
+ * If we cannot find a cookie in our cache, we suspect that this is
+ * because it points to a deleted file, so we ask the server to return
+ * whatever it thinks is the next entry. We then feed this to filldir.
+ * If all goes well, we should then be able to find our way round the
+ * cache on the next call to readdir_search_pagecache();
+ *
+ * NOTE: we cannot add the anonymous page to the pagecache because
+ *	 the data it contains might not be page aligned. Besides,
+ *	 we should already have a complete representation of the
+ *	 directory in the page cache by the time we get here.
+ */
+static inline
+int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
+		     filldir_t filldir)
+{
+	struct page	*page = NULL;
+	int		status;
+	struct inode *inode = desc->file->f_path.dentry->d_inode;
+	struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+	dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
+			(unsigned long long)*desc->dir_cookie);
+
+	page = alloc_page(GFP_HIGHUSER);
+	if (!page) {
+		status = -ENOMEM;
+		goto out;
+	}
+
+	desc->page_index = 0;
+	desc->last_cookie = *desc->dir_cookie;
+	desc->page = page;
+	ctx->duped = 0;
+
+	status = nfs_readdir_xdr_to_array(desc, page, inode);
+	if (status < 0)
+		goto out_release;
+
+	status = nfs_do_filldir(desc, dirent, filldir);
+
+ out:
+	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
+			__func__, status);
+	return status;
+ out_release:
+	cache_page_release(desc);
+	goto out;
+}
+
+/* The file offset position represents the dirent entry number.  A
+   last cookie cache takes care of the common case of reading the
+   whole directory.
+ */
+static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct dentry	*dentry = filp->f_path.dentry;
+	struct inode	*inode = dentry->d_inode;
+	nfs_readdir_descriptor_t my_desc,
+			*desc = &my_desc;
+	struct nfs_open_dir_context *dir_ctx = filp->private_data;
+	int res;
+
+	dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
+			dentry->d_parent->d_name.name, dentry->d_name.name,
+			(long long)filp->f_pos);
+	nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
+
+	/*
+	 * filp->f_pos points to the dirent entry number.
+	 * *desc->dir_cookie has the cookie for the next entry. We have
+	 * to either find the entry with the appropriate number or
+	 * revalidate the cookie.
+	 */
+	memset(desc, 0, sizeof(*desc));
+
+	desc->file = filp;
+	desc->dir_cookie = &dir_ctx->dir_cookie;
+	desc->decode = NFS_PROTO(inode)->decode_dirent;
+	desc->plus = NFS_USE_READDIRPLUS(inode);
+
+	nfs_block_sillyrename(dentry);
+	res = nfs_revalidate_mapping(inode, filp->f_mapping);
+	if (res < 0)
+		goto out;
+
+	do {
+		res = readdir_search_pagecache(desc);
+
+		if (res == -EBADCOOKIE) {
+			res = 0;
+			/* This means either end of directory */
+			if (*desc->dir_cookie && desc->eof == 0) {
+				/* Or that the server has 'lost' a cookie */
+				res = uncached_readdir(desc, dirent, filldir);
+				if (res == 0)
+					continue;
+			}
+			break;
+		}
+		if (res == -ETOOSMALL && desc->plus) {
+			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+			nfs_zap_caches(inode);
+			desc->page_index = 0;
+			desc->plus = 0;
+			desc->eof = 0;
+			continue;
+		}
+		if (res < 0)
+			break;
+
+		res = nfs_do_filldir(desc, dirent, filldir);
+		if (res < 0)
+			break;
+	} while (!desc->eof);
+out:
+	nfs_unblock_sillyrename(dentry);
+	if (res > 0)
+		res = 0;
+	dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
+			dentry->d_parent->d_name.name, dentry->d_name.name,
+			res);
+	return res;
+}
+
+static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
+{
+	struct dentry *dentry = filp->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	struct nfs_open_dir_context *dir_ctx = filp->private_data;
+
+	dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
+			dentry->d_parent->d_name.name,
+			dentry->d_name.name,
+			offset, origin);
+
+	mutex_lock(&inode->i_mutex);
+	switch (origin) {
+		case 1:
+			offset += filp->f_pos;
+		case 0:
+			if (offset >= 0)
+				break;
+		default:
+			offset = -EINVAL;
+			goto out;
+	}
+	if (offset != filp->f_pos) {
+		filp->f_pos = offset;
+		dir_ctx->dir_cookie = 0;
+		dir_ctx->duped = 0;
+	}
+out:
+	mutex_unlock(&inode->i_mutex);
+	return offset;
+}
+
+/*
+ * All directory operations under NFS are synchronous, so fsync()
+ * is a dummy operation.
+ */
+static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
+			 int datasync)
+{
+	struct dentry *dentry = filp->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+
+	dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
+			dentry->d_parent->d_name.name, dentry->d_name.name,
+			datasync);
+
+	mutex_lock(&inode->i_mutex);
+	nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
+	mutex_unlock(&inode->i_mutex);
+	return 0;
+}
+
+/**
+ * nfs_force_lookup_revalidate - Mark the directory as having changed
+ * @dir - pointer to directory inode
+ *
+ * This forces the revalidation code in nfs_lookup_revalidate() to do a
+ * full lookup on all child dentries of 'dir' whenever a change occurs
+ * on the server that might have invalidated our dcache.
+ *
+ * The caller should be holding dir->i_lock
+ */
+void nfs_force_lookup_revalidate(struct inode *dir)
+{
+	NFS_I(dir)->cache_change_attribute++;
+}
+
+/*
+ * A check for whether or not the parent directory has changed.
+ * In the case it has, we assume that the dentries are untrustworthy
+ * and may need to be looked up again.
+ */
+static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
+{
+	if (IS_ROOT(dentry))
+		return 1;
+	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
+		return 0;
+	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+		return 0;
+	/* Revalidate nfsi->cache_change_attribute before we declare a match */
+	if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
+		return 0;
+	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+		return 0;
+	return 1;
+}
+
+/*
+ * Return the intent data that applies to this particular path component
+ *
+ * Note that the current set of intents only apply to the very last
+ * component of the path and none of them is set before that last
+ * component.
+ */
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+						unsigned int mask)
+{
+	return nd->flags & mask;
+}
+
+/*
+ * Use intent information to check whether or not we're going to do
+ * an O_EXCL create using this path component.
+ */
+static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
+{
+	if (NFS_PROTO(dir)->version == 2)
+		return 0;
+	return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL);
+}
+
+/*
+ * Inode and filehandle revalidation for lookups.
+ *
+ * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
+ * or if the intent information indicates that we're about to open this
+ * particular file and the "nocto" mount flag is not set.
+ *
+ */
+static inline
+int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+
+	if (IS_AUTOMOUNT(inode))
+		return 0;
+	if (nd != NULL) {
+		/* VFS wants an on-the-wire revalidation */
+		if (nd->flags & LOOKUP_REVAL)
+			goto out_force;
+		/* This is an open(2) */
+		if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
+				!(server->flags & NFS_MOUNT_NOCTO) &&
+				(S_ISREG(inode->i_mode) ||
+				 S_ISDIR(inode->i_mode)))
+			goto out_force;
+		return 0;
+	}
+	return nfs_revalidate_inode(server, inode);
+out_force:
+	return __nfs_revalidate_inode(server, inode);
+}
+
+/*
+ * We judge how long we want to trust negative
+ * dentries by looking at the parent inode mtime.
+ *
+ * If parent mtime has changed, we revalidate, else we wait for a
+ * period corresponding to the parent's attribute cache timeout value.
+ */
+static inline
+int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
+		       struct nameidata *nd)
+{
+	/* Don't revalidate a negative dentry if we're creating a new file */
+	if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
+		return 0;
+	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
+		return 1;
+	return !nfs_check_verifier(dir, dentry);
+}
+
+/*
+ * This is called every time the dcache has a lookup hit,
+ * and we should check whether we can really trust that
+ * lookup.
+ *
+ * NOTE! The hit can be a negative hit too, don't assume
+ * we have an inode!
+ *
+ * If the parent directory is seen to have changed, we throw out the
+ * cached dentry and do a new lookup.
+ */
+static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct inode *dir;
+	struct inode *inode;
+	struct dentry *parent;
+	struct nfs_fh *fhandle = NULL;
+	struct nfs_fattr *fattr = NULL;
+	int error;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	parent = dget_parent(dentry);
+	dir = parent->d_inode;
+	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
+	inode = dentry->d_inode;
+
+	if (!inode) {
+		if (nfs_neg_need_reval(dir, dentry, nd))
+			goto out_bad;
+		goto out_valid;
+	}
+
+	if (is_bad_inode(inode)) {
+		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
+				__func__, dentry->d_parent->d_name.name,
+				dentry->d_name.name);
+		goto out_bad;
+	}
+
+	if (nfs_have_delegation(inode, FMODE_READ))
+		goto out_set_verifier;
+
+	/* Force a full look up iff the parent directory has changed */
+	if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
+		if (nfs_lookup_verify_inode(inode, nd))
+			goto out_zap_parent;
+		goto out_valid;
+	}
+
+	if (NFS_STALE(inode))
+		goto out_bad;
+
+	error = -ENOMEM;
+	fhandle = nfs_alloc_fhandle();
+	fattr = nfs_alloc_fattr();
+	if (fhandle == NULL || fattr == NULL)
+		goto out_error;
+
+	error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+	if (error)
+		goto out_bad;
+	if (nfs_compare_fh(NFS_FH(inode), fhandle))
+		goto out_bad;
+	if ((error = nfs_refresh_inode(inode, fattr)) != 0)
+		goto out_bad;
+
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+out_set_verifier:
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ out_valid:
+	dput(parent);
+	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
+			__func__, dentry->d_parent->d_name.name,
+			dentry->d_name.name);
+	return 1;
+out_zap_parent:
+	nfs_zap_caches(dir);
+ out_bad:
+	nfs_mark_for_revalidate(dir);
+	if (inode && S_ISDIR(inode->i_mode)) {
+		/* Purge readdir caches. */
+		nfs_zap_caches(inode);
+		/* If we have submounts, don't unhash ! */
+		if (have_submounts(dentry))
+			goto out_valid;
+		if (dentry->d_flags & DCACHE_DISCONNECTED)
+			goto out_valid;
+		shrink_dcache_parent(dentry);
+	}
+	d_drop(dentry);
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+	dput(parent);
+	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
+			__func__, dentry->d_parent->d_name.name,
+			dentry->d_name.name);
+	return 0;
+out_error:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+	dput(parent);
+	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
+			__func__, dentry->d_parent->d_name.name,
+			dentry->d_name.name, error);
+	return error;
+}
+
+/*
+ * This is called from dput() when d_count is going to 0.
+ */
+static int nfs_dentry_delete(const struct dentry *dentry)
+{
+	dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
+		dentry->d_parent->d_name.name, dentry->d_name.name,
+		dentry->d_flags);
+
+	/* Unhash any dentry with a stale inode */
+	if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
+		return 1;
+
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		/* Unhash it, so that ->d_iput() would be called */
+		return 1;
+	}
+	if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
+		/* Unhash it, so that ancestors of killed async unlink
+		 * files will be cleaned up during umount */
+		return 1;
+	}
+	return 0;
+
+}
+
+static void nfs_drop_nlink(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	if (inode->i_nlink > 0)
+		drop_nlink(inode);
+	spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Called when the dentry loses inode.
+ * We use it to clean up silly-renamed files.
+ */
+static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+	if (S_ISDIR(inode->i_mode))
+		/* drop any readdir cache as it could easily be old */
+		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
+
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		drop_nlink(inode);
+		nfs_complete_unlink(dentry, inode);
+	}
+	iput(inode);
+}
+
+static void nfs_d_release(struct dentry *dentry)
+{
+	/* free cached devname value, if it survived that far */
+	if (unlikely(dentry->d_fsdata)) {
+		if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+			WARN_ON(1);
+		else
+			kfree(dentry->d_fsdata);
+	}
+}
+
+const struct dentry_operations nfs_dentry_operations = {
+	.d_revalidate	= nfs_lookup_revalidate,
+	.d_delete	= nfs_dentry_delete,
+	.d_iput		= nfs_dentry_iput,
+	.d_automount	= nfs_d_automount,
+	.d_release	= nfs_d_release,
+};
+
+static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
+{
+	struct dentry *res;
+	struct dentry *parent;
+	struct inode *inode = NULL;
+	struct nfs_fh *fhandle = NULL;
+	struct nfs_fattr *fattr = NULL;
+	int error;
+
+	dfprintk(VFS, "NFS: lookup(%s/%s)\n",
+		dentry->d_parent->d_name.name, dentry->d_name.name);
+	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
+
+	res = ERR_PTR(-ENAMETOOLONG);
+	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+		goto out;
+
+	/*
+	 * If we're doing an exclusive create, optimize away the lookup
+	 * but don't hash the dentry.
+	 */
+	if (nfs_is_exclusive_create(dir, nd)) {
+		d_instantiate(dentry, NULL);
+		res = NULL;
+		goto out;
+	}
+
+	res = ERR_PTR(-ENOMEM);
+	fhandle = nfs_alloc_fhandle();
+	fattr = nfs_alloc_fattr();
+	if (fhandle == NULL || fattr == NULL)
+		goto out;
+
+	parent = dentry->d_parent;
+	/* Protect against concurrent sillydeletes */
+	nfs_block_sillyrename(parent);
+	error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+	if (error == -ENOENT)
+		goto no_entry;
+	if (error < 0) {
+		res = ERR_PTR(error);
+		goto out_unblock_sillyrename;
+	}
+	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
+	res = ERR_CAST(inode);
+	if (IS_ERR(res))
+		goto out_unblock_sillyrename;
+
+no_entry:
+	res = d_materialise_unique(dentry, inode);
+	if (res != NULL) {
+		if (IS_ERR(res))
+			goto out_unblock_sillyrename;
+		dentry = res;
+	}
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+out_unblock_sillyrename:
+	nfs_unblock_sillyrename(parent);
+out:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+	return res;
+}
+
+#ifdef CONFIG_NFS_V4
+static int nfs_open_revalidate(struct dentry *, struct nameidata *);
+
+const struct dentry_operations nfs4_dentry_operations = {
+	.d_revalidate	= nfs_open_revalidate,
+	.d_delete	= nfs_dentry_delete,
+	.d_iput		= nfs_dentry_iput,
+	.d_automount	= nfs_d_automount,
+	.d_release	= nfs_d_release,
+};
+
+/*
+ * Use intent information to determine whether we need to substitute
+ * the NFSv4-style stateful OPEN for the LOOKUP call
+ */
+static int is_atomic_open(struct nameidata *nd)
+{
+	if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
+		return 0;
+	/* NFS does not (yet) have a stateful open for directories */
+	if (nd->flags & LOOKUP_DIRECTORY)
+		return 0;
+	/* Are we trying to write to a read only partition? */
+	if (__mnt_is_readonly(nd->path.mnt) &&
+	    (nd->intent.open.flags & (O_CREAT|O_TRUNC|O_ACCMODE)))
+		return 0;
+	return 1;
+}
+
+static fmode_t flags_to_mode(int flags)
+{
+	fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
+	if ((flags & O_ACCMODE) != O_WRONLY)
+		res |= FMODE_READ;
+	if ((flags & O_ACCMODE) != O_RDONLY)
+		res |= FMODE_WRITE;
+	return res;
+}
+
+static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
+{
+	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
+}
+
+static int do_open(struct inode *inode, struct file *filp)
+{
+	nfs_fscache_set_inode_cookie(inode, filp);
+	return 0;
+}
+
+static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
+{
+	struct file *filp;
+	int ret = 0;
+
+	/* If the open_intent is for execute, we have an extra check to make */
+	if (ctx->mode & FMODE_EXEC) {
+		ret = nfs_may_open(ctx->dentry->d_inode,
+				ctx->cred,
+				nd->intent.open.flags);
+		if (ret < 0)
+			goto out;
+	}
+	filp = lookup_instantiate_filp(nd, ctx->dentry, do_open);
+	if (IS_ERR(filp))
+		ret = PTR_ERR(filp);
+	else
+		nfs_file_set_open_context(filp, ctx);
+out:
+	put_nfs_open_context(ctx);
+	return ret;
+}
+
+static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+	struct nfs_open_context *ctx;
+	struct iattr attr;
+	struct dentry *res = NULL;
+	struct inode *inode;
+	int open_flags;
+	int err;
+
+	dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	/* Check that we are indeed trying to open this file */
+	if (!is_atomic_open(nd))
+		goto no_open;
+
+	if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
+		res = ERR_PTR(-ENAMETOOLONG);
+		goto out;
+	}
+
+	/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
+	 * the dentry. */
+	if (nd->flags & LOOKUP_EXCL) {
+		d_instantiate(dentry, NULL);
+		goto out;
+	}
+
+	open_flags = nd->intent.open.flags;
+	attr.ia_valid = ATTR_OPEN;
+
+	ctx = create_nfs_open_context(dentry, open_flags);
+	res = ERR_CAST(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	if (nd->flags & LOOKUP_CREATE) {
+		attr.ia_mode = nd->intent.open.create_mode;
+		attr.ia_valid |= ATTR_MODE;
+		attr.ia_mode &= ~current_umask();
+	} else
+		open_flags &= ~(O_EXCL | O_CREAT);
+
+	if (open_flags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+	}
+
+	/* Open the file on the server */
+	nfs_block_sillyrename(dentry->d_parent);
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
+	if (IS_ERR(inode)) {
+		nfs_unblock_sillyrename(dentry->d_parent);
+		put_nfs_open_context(ctx);
+		switch (PTR_ERR(inode)) {
+			/* Make a negative dentry */
+			case -ENOENT:
+				d_add(dentry, NULL);
+				res = NULL;
+				goto out;
+			/* This turned out not to be a regular file */
+			case -EISDIR:
+			case -ENOTDIR:
+				goto no_open;
+			case -ELOOP:
+				if (!(nd->intent.open.flags & O_NOFOLLOW))
+					goto no_open;
+			/* case -EINVAL: */
+			default:
+				res = ERR_CAST(inode);
+				goto out;
+		}
+	}
+	res = d_add_unique(dentry, inode);
+	nfs_unblock_sillyrename(dentry->d_parent);
+	if (res != NULL) {
+		dput(ctx->dentry);
+		ctx->dentry = dget(res);
+		dentry = res;
+	}
+	err = nfs_intent_set_file(nd, ctx);
+	if (err < 0) {
+		if (res != NULL)
+			dput(res);
+		return ERR_PTR(err);
+	}
+out:
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	return res;
+no_open:
+	return nfs_lookup(dir, dentry, nd);
+}
+
+static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct dentry *parent = NULL;
+	struct inode *inode;
+	struct inode *dir;
+	struct nfs_open_context *ctx;
+	struct iattr attr;
+	int openflags, ret = 0;
+
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = dentry->d_inode;
+	if (!is_atomic_open(nd) || d_mountpoint(dentry))
+		goto no_open;
+
+	parent = dget_parent(dentry);
+	dir = parent->d_inode;
+
+	/* We can't create new files in nfs_open_revalidate(), so we
+	 * optimize away revalidation of negative dentries.
+	 */
+	if (inode == NULL) {
+		if (!nfs_neg_need_reval(dir, dentry, nd))
+			ret = 1;
+		goto out;
+	}
+
+	/* NFS only supports OPEN on regular files */
+	if (!S_ISREG(inode->i_mode))
+		goto no_open_dput;
+	openflags = nd->intent.open.flags;
+	/* We cannot do exclusive creation on a positive dentry */
+	if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+		goto no_open_dput;
+	/* We can't create new files here */
+	openflags &= ~(O_CREAT|O_EXCL);
+
+	ctx = create_nfs_open_context(dentry, openflags);
+	ret = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	attr.ia_valid = ATTR_OPEN;
+	if (openflags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+		nfs_wb_all(inode);
+	}
+
+	/*
+	 * Note: we're not holding inode->i_mutex and so may be racing with
+	 * operations that change the directory. We therefore save the
+	 * change attribute *before* we do the RPC call.
+	 */
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr);
+	if (IS_ERR(inode)) {
+		ret = PTR_ERR(inode);
+		switch (ret) {
+		case -EPERM:
+		case -EACCES:
+		case -EDQUOT:
+		case -ENOSPC:
+		case -EROFS:
+			goto out_put_ctx;
+		default:
+			goto out_drop;
+		}
+	}
+	iput(inode);
+	if (inode != dentry->d_inode)
+		goto out_drop;
+
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	ret = nfs_intent_set_file(nd, ctx);
+	if (ret >= 0)
+		ret = 1;
+out:
+	dput(parent);
+	return ret;
+out_drop:
+	d_drop(dentry);
+	ret = 0;
+out_put_ctx:
+	put_nfs_open_context(ctx);
+	goto out;
+
+no_open_dput:
+	dput(parent);
+no_open:
+	return nfs_lookup_revalidate(dentry, nd);
+}
+
+static int nfs_open_create(struct inode *dir, struct dentry *dentry,
+		umode_t mode, struct nameidata *nd)
+{
+	struct nfs_open_context *ctx = NULL;
+	struct iattr attr;
+	int error;
+	int open_flags = O_CREAT|O_EXCL;
+
+	dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	attr.ia_mode = mode;
+	attr.ia_valid = ATTR_MODE;
+
+	if (nd)
+		open_flags = nd->intent.open.flags;
+
+	ctx = create_nfs_open_context(dentry, open_flags);
+	error = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out_err_drop;
+
+	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
+	if (error != 0)
+		goto out_put_ctx;
+	if (nd) {
+		error = nfs_intent_set_file(nd, ctx);
+		if (error < 0)
+			goto out_err;
+	} else {
+		put_nfs_open_context(ctx);
+	}
+	return 0;
+out_put_ctx:
+	put_nfs_open_context(ctx);
+out_err_drop:
+	d_drop(dentry);
+out_err:
+	return error;
+}
+
+#endif /* CONFIG_NFSV4 */
+
+/*
+ * Code common to create, mkdir, and mknod.
+ */
+int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
+				struct nfs_fattr *fattr)
+{
+	struct dentry *parent = dget_parent(dentry);
+	struct inode *dir = parent->d_inode;
+	struct inode *inode;
+	int error = -EACCES;
+
+	d_drop(dentry);
+
+	/* We may have been initialized further down */
+	if (dentry->d_inode)
+		goto out;
+	if (fhandle->size == 0) {
+		error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+		if (error)
+			goto out_error;
+	}
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	if (!(fattr->valid & NFS_ATTR_FATTR)) {
+		struct nfs_server *server = NFS_SB(dentry->d_sb);
+		error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
+		if (error < 0)
+			goto out_error;
+	}
+	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
+	error = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_error;
+	d_add(dentry, inode);
+out:
+	dput(parent);
+	return 0;
+out_error:
+	nfs_mark_for_revalidate(dir);
+	dput(parent);
+	return error;
+}
+
+/*
+ * Following a failed create operation, we drop the dentry rather
+ * than retain a negative dentry. This avoids a problem in the event
+ * that the operation succeeded on the server, but an error in the
+ * reply path made it appear to have failed.
+ */
+static int nfs_create(struct inode *dir, struct dentry *dentry,
+		umode_t mode, struct nameidata *nd)
+{
+	struct iattr attr;
+	int error;
+	int open_flags = O_CREAT|O_EXCL;
+
+	dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	attr.ia_mode = mode;
+	attr.ia_valid = ATTR_MODE;
+
+	if (nd)
+		open_flags = nd->intent.open.flags;
+
+	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL);
+	if (error != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return error;
+}
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+static int
+nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct iattr attr;
+	int status;
+
+	dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	if (!new_valid_dev(rdev))
+		return -EINVAL;
+
+	attr.ia_mode = mode;
+	attr.ia_valid = ATTR_MODE;
+
+	status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
+	if (status != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return status;
+}
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+static int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct iattr attr;
+	int error;
+
+	dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	attr.ia_valid = ATTR_MODE;
+	attr.ia_mode = mode | S_IFDIR;
+
+	error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
+	if (error != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return error;
+}
+
+static void nfs_dentry_handle_enoent(struct dentry *dentry)
+{
+	if (dentry->d_inode != NULL && !d_unhashed(dentry))
+		d_delete(dentry);
+}
+
+static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	int error;
+
+	dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
+			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+	/* Ensure the VFS deletes this inode */
+	if (error == 0 && dentry->d_inode != NULL)
+		clear_nlink(dentry->d_inode);
+	else if (error == -ENOENT)
+		nfs_dentry_handle_enoent(dentry);
+
+	return error;
+}
+
+/*
+ * Remove a file after making sure there are no pending writes,
+ * and after checking that the file has only one user. 
+ *
+ * We invalidate the attribute cache and free the inode prior to the operation
+ * to avoid possible races if the server reuses the inode.
+ */
+static int nfs_safe_remove(struct dentry *dentry)
+{
+	struct inode *dir = dentry->d_parent->d_inode;
+	struct inode *inode = dentry->d_inode;
+	int error = -EBUSY;
+		
+	dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
+		dentry->d_parent->d_name.name, dentry->d_name.name);
+
+	/* If the dentry was sillyrenamed, we simply call d_delete() */
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		error = 0;
+		goto out;
+	}
+
+	if (inode != NULL) {
+		nfs_inode_return_delegation(inode);
+		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
+		/* The VFS may want to delete this inode */
+		if (error == 0)
+			nfs_drop_nlink(inode);
+		nfs_mark_for_revalidate(inode);
+	} else
+		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
+	if (error == -ENOENT)
+		nfs_dentry_handle_enoent(dentry);
+out:
+	return error;
+}
+
+/*  We do silly rename. In case sillyrename() returns -EBUSY, the inode
+ *  belongs to an active ".nfs..." file and we return -EBUSY.
+ *
+ *  If sillyrename() returns 0, we do nothing, otherwise we unlink.
+ */
+static int nfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	int error;
+	int need_rehash = 0;
+
+	dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
+		dir->i_ino, dentry->d_name.name);
+
+	spin_lock(&dentry->d_lock);
+	if (dentry->d_count > 1) {
+		spin_unlock(&dentry->d_lock);
+		/* Start asynchronous writeout of the inode */
+		write_inode_now(dentry->d_inode, 0);
+		error = nfs_sillyrename(dir, dentry);
+		return error;
+	}
+	if (!d_unhashed(dentry)) {
+		__d_drop(dentry);
+		need_rehash = 1;
+	}
+	spin_unlock(&dentry->d_lock);
+	error = nfs_safe_remove(dentry);
+	if (!error || error == -ENOENT) {
+		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	} else if (need_rehash)
+		d_rehash(dentry);
+	return error;
+}
+
+/*
+ * To create a symbolic link, most file systems instantiate a new inode,
+ * add a page to it containing the path, then write it out to the disk
+ * using prepare_write/commit_write.
+ *
+ * Unfortunately the NFS client can't create the in-core inode first
+ * because it needs a file handle to create an in-core inode (see
+ * fs/nfs/inode.c:nfs_fhget).  We only have a file handle *after* the
+ * symlink request has completed on the server.
+ *
+ * So instead we allocate a raw page, copy the symname into it, then do
+ * the SYMLINK request with the page as the buffer.  If it succeeds, we
+ * now have a new file handle and can instantiate an in-core NFS inode
+ * and move the raw page into its mapping.
+ */
+static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+	struct pagevec lru_pvec;
+	struct page *page;
+	char *kaddr;
+	struct iattr attr;
+	unsigned int pathlen = strlen(symname);
+	int error;
+
+	dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
+		dir->i_ino, dentry->d_name.name, symname);
+
+	if (pathlen > PAGE_SIZE)
+		return -ENAMETOOLONG;
+
+	attr.ia_mode = S_IFLNK | S_IRWXUGO;
+	attr.ia_valid = ATTR_MODE;
+
+	page = alloc_page(GFP_HIGHUSER);
+	if (!page)
+		return -ENOMEM;
+
+	kaddr = kmap_atomic(page);
+	memcpy(kaddr, symname, pathlen);
+	if (pathlen < PAGE_SIZE)
+		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
+	kunmap_atomic(kaddr);
+
+	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
+	if (error != 0) {
+		dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
+			dir->i_sb->s_id, dir->i_ino,
+			dentry->d_name.name, symname, error);
+		d_drop(dentry);
+		__free_page(page);
+		return error;
+	}
+
+	/*
+	 * No big deal if we can't add this page to the page cache here.
+	 * READLINK will get the missing page from the server if needed.
+	 */
+	pagevec_init(&lru_pvec, 0);
+	if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
+							GFP_KERNEL)) {
+		pagevec_add(&lru_pvec, page);
+		pagevec_lru_add_file(&lru_pvec);
+		SetPageUptodate(page);
+		unlock_page(page);
+	} else
+		__free_page(page);
+
+	return 0;
+}
+
+static int 
+nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = old_dentry->d_inode;
+	int error;
+
+	dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
+		old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
+		dentry->d_parent->d_name.name, dentry->d_name.name);
+
+	nfs_inode_return_delegation(inode);
+
+	d_drop(dentry);
+	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
+	if (error == 0) {
+		ihold(inode);
+		d_add(dentry, inode);
+	}
+	return error;
+}
+
+/*
+ * RENAME
+ * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
+ * different file handle for the same inode after a rename (e.g. when
+ * moving to a different directory). A fail-safe method to do so would
+ * be to look up old_dir/old_name, create a link to new_dir/new_name and
+ * rename the old file using the sillyrename stuff. This way, the original
+ * file in old_dir will go away when the last process iput()s the inode.
+ *
+ * FIXED.
+ * 
+ * It actually works quite well. One needs to have the possibility for
+ * at least one ".nfs..." file in each directory the file ever gets
+ * moved or linked to which happens automagically with the new
+ * implementation that only depends on the dcache stuff instead of
+ * using the inode layer
+ *
+ * Unfortunately, things are a little more complicated than indicated
+ * above. For a cross-directory move, we want to make sure we can get
+ * rid of the old inode after the operation.  This means there must be
+ * no pending writes (if it's a file), and the use count must be 1.
+ * If these conditions are met, we can drop the dentries before doing
+ * the rename.
+ */
+static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+		      struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct inode *old_inode = old_dentry->d_inode;
+	struct inode *new_inode = new_dentry->d_inode;
+	struct dentry *dentry = NULL, *rehash = NULL;
+	int error = -EBUSY;
+
+	dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
+		 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
+		 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
+		 new_dentry->d_count);
+
+	/*
+	 * For non-directories, check whether the target is busy and if so,
+	 * make a copy of the dentry and then do a silly-rename. If the
+	 * silly-rename succeeds, the copied dentry is hashed and becomes
+	 * the new target.
+	 */
+	if (new_inode && !S_ISDIR(new_inode->i_mode)) {
+		/*
+		 * To prevent any new references to the target during the
+		 * rename, we unhash the dentry in advance.
+		 */
+		if (!d_unhashed(new_dentry)) {
+			d_drop(new_dentry);
+			rehash = new_dentry;
+		}
+
+		if (new_dentry->d_count > 2) {
+			int err;
+
+			/* copy the target dentry's name */
+			dentry = d_alloc(new_dentry->d_parent,
+					 &new_dentry->d_name);
+			if (!dentry)
+				goto out;
+
+			/* silly-rename the existing target ... */
+			err = nfs_sillyrename(new_dir, new_dentry);
+			if (err)
+				goto out;
+
+			new_dentry = dentry;
+			rehash = NULL;
+			new_inode = NULL;
+		}
+	}
+
+	nfs_inode_return_delegation(old_inode);
+	if (new_inode != NULL)
+		nfs_inode_return_delegation(new_inode);
+
+	error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
+					   new_dir, &new_dentry->d_name);
+	nfs_mark_for_revalidate(old_inode);
+out:
+	if (rehash)
+		d_rehash(rehash);
+	if (!error) {
+		if (new_inode != NULL)
+			nfs_drop_nlink(new_inode);
+		d_move(old_dentry, new_dentry);
+		nfs_set_verifier(new_dentry,
+					nfs_save_change_attribute(new_dir));
+	} else if (error == -ENOENT)
+		nfs_dentry_handle_enoent(old_dentry);
+
+	/* new dentry created? */
+	if (dentry)
+		dput(dentry);
+	return error;
+}
+
+static DEFINE_SPINLOCK(nfs_access_lru_lock);
+static LIST_HEAD(nfs_access_lru_list);
+static atomic_long_t nfs_access_nr_entries;
+
+static void nfs_access_free_entry(struct nfs_access_entry *entry)
+{
+	put_rpccred(entry->cred);
+	kfree(entry);
+	smp_mb__before_atomic_dec();
+	atomic_long_dec(&nfs_access_nr_entries);
+	smp_mb__after_atomic_dec();
+}
+
+static void nfs_access_free_list(struct list_head *head)
+{
+	struct nfs_access_entry *cache;
+
+	while (!list_empty(head)) {
+		cache = list_entry(head->next, struct nfs_access_entry, lru);
+		list_del(&cache->lru);
+		nfs_access_free_entry(cache);
+	}
+}
+
+int nfs_access_cache_shrinker(struct shrinker *shrink,
+			      struct shrink_control *sc)
+{
+	LIST_HEAD(head);
+	struct nfs_inode *nfsi, *next;
+	struct nfs_access_entry *cache;
+	int nr_to_scan = sc->nr_to_scan;
+	gfp_t gfp_mask = sc->gfp_mask;
+
+	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+		return (nr_to_scan == 0) ? 0 : -1;
+
+	spin_lock(&nfs_access_lru_lock);
+	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
+		struct inode *inode;
+
+		if (nr_to_scan-- == 0)
+			break;
+		inode = &nfsi->vfs_inode;
+		spin_lock(&inode->i_lock);
+		if (list_empty(&nfsi->access_cache_entry_lru))
+			goto remove_lru_entry;
+		cache = list_entry(nfsi->access_cache_entry_lru.next,
+				struct nfs_access_entry, lru);
+		list_move(&cache->lru, &head);
+		rb_erase(&cache->rb_node, &nfsi->access_cache);
+		if (!list_empty(&nfsi->access_cache_entry_lru))
+			list_move_tail(&nfsi->access_cache_inode_lru,
+					&nfs_access_lru_list);
+		else {
+remove_lru_entry:
+			list_del_init(&nfsi->access_cache_inode_lru);
+			smp_mb__before_clear_bit();
+			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
+			smp_mb__after_clear_bit();
+		}
+		spin_unlock(&inode->i_lock);
+	}
+	spin_unlock(&nfs_access_lru_lock);
+	nfs_access_free_list(&head);
+	return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
+}
+
+static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
+{
+	struct rb_root *root_node = &nfsi->access_cache;
+	struct rb_node *n;
+	struct nfs_access_entry *entry;
+
+	/* Unhook entries from the cache */
+	while ((n = rb_first(root_node)) != NULL) {
+		entry = rb_entry(n, struct nfs_access_entry, rb_node);
+		rb_erase(n, root_node);
+		list_move(&entry->lru, head);
+	}
+	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
+}
+
+void nfs_access_zap_cache(struct inode *inode)
+{
+	LIST_HEAD(head);
+
+	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
+		return;
+	/* Remove from global LRU init */
+	spin_lock(&nfs_access_lru_lock);
+	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+		list_del_init(&NFS_I(inode)->access_cache_inode_lru);
+
+	spin_lock(&inode->i_lock);
+	__nfs_access_zap_cache(NFS_I(inode), &head);
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&nfs_access_lru_lock);
+	nfs_access_free_list(&head);
+}
+
+static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
+{
+	struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
+	struct nfs_access_entry *entry;
+
+	while (n != NULL) {
+		entry = rb_entry(n, struct nfs_access_entry, rb_node);
+
+		if (cred < entry->cred)
+			n = n->rb_left;
+		else if (cred > entry->cred)
+			n = n->rb_right;
+		else
+			return entry;
+	}
+	return NULL;
+}
+
+static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_access_entry *cache;
+	int err = -ENOENT;
+
+	spin_lock(&inode->i_lock);
+	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+		goto out_zap;
+	cache = nfs_access_search_rbtree(inode, cred);
+	if (cache == NULL)
+		goto out;
+	if (!nfs_have_delegated_attributes(inode) &&
+	    !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
+		goto out_stale;
+	res->jiffies = cache->jiffies;
+	res->cred = cache->cred;
+	res->mask = cache->mask;
+	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
+	err = 0;
+out:
+	spin_unlock(&inode->i_lock);
+	return err;
+out_stale:
+	rb_erase(&cache->rb_node, &nfsi->access_cache);
+	list_del(&cache->lru);
+	spin_unlock(&inode->i_lock);
+	nfs_access_free_entry(cache);
+	return -ENOENT;
+out_zap:
+	spin_unlock(&inode->i_lock);
+	nfs_access_zap_cache(inode);
+	return -ENOENT;
+}
+
+static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct rb_root *root_node = &nfsi->access_cache;
+	struct rb_node **p = &root_node->rb_node;
+	struct rb_node *parent = NULL;
+	struct nfs_access_entry *entry;
+
+	spin_lock(&inode->i_lock);
+	while (*p != NULL) {
+		parent = *p;
+		entry = rb_entry(parent, struct nfs_access_entry, rb_node);
+
+		if (set->cred < entry->cred)
+			p = &parent->rb_left;
+		else if (set->cred > entry->cred)
+			p = &parent->rb_right;
+		else
+			goto found;
+	}
+	rb_link_node(&set->rb_node, parent, p);
+	rb_insert_color(&set->rb_node, root_node);
+	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+	spin_unlock(&inode->i_lock);
+	return;
+found:
+	rb_replace_node(parent, &set->rb_node, root_node);
+	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+	list_del(&entry->lru);
+	spin_unlock(&inode->i_lock);
+	nfs_access_free_entry(entry);
+}
+
+static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
+{
+	struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
+	if (cache == NULL)
+		return;
+	RB_CLEAR_NODE(&cache->rb_node);
+	cache->jiffies = set->jiffies;
+	cache->cred = get_rpccred(set->cred);
+	cache->mask = set->mask;
+
+	nfs_access_add_rbtree(inode, cache);
+
+	/* Update accounting */
+	smp_mb__before_atomic_inc();
+	atomic_long_inc(&nfs_access_nr_entries);
+	smp_mb__after_atomic_inc();
+
+	/* Add inode to global LRU list */
+	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
+		spin_lock(&nfs_access_lru_lock);
+		if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+			list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
+					&nfs_access_lru_list);
+		spin_unlock(&nfs_access_lru_lock);
+	}
+}
+
+static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
+{
+	struct nfs_access_entry cache;
+	int status;
+
+	status = nfs_access_get_cached(inode, cred, &cache);
+	if (status == 0)
+		goto out;
+
+	/* Be clever: ask server to check for all possible rights */
+	cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
+	cache.cred = cred;
+	cache.jiffies = jiffies;
+	status = NFS_PROTO(inode)->access(inode, &cache);
+	if (status != 0) {
+		if (status == -ESTALE) {
+			nfs_zap_caches(inode);
+			if (!S_ISDIR(inode->i_mode))
+				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
+		}
+		return status;
+	}
+	nfs_access_add_cache(inode, &cache);
+out:
+	if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
+		return 0;
+	return -EACCES;
+}
+
+static int nfs_open_permission_mask(int openflags)
+{
+	int mask = 0;
+
+	if ((openflags & O_ACCMODE) != O_WRONLY)
+		mask |= MAY_READ;
+	if ((openflags & O_ACCMODE) != O_RDONLY)
+		mask |= MAY_WRITE;
+	if (openflags & __FMODE_EXEC)
+		mask |= MAY_EXEC;
+	return mask;
+}
+
+int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
+{
+	return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
+}
+
+int nfs_permission(struct inode *inode, int mask)
+{
+	struct rpc_cred *cred;
+	int res = 0;
+
+	if (mask & MAY_NOT_BLOCK)
+		return -ECHILD;
+
+	nfs_inc_stats(inode, NFSIOS_VFSACCESS);
+
+	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
+		goto out;
+	/* Is this sys_access() ? */
+	if (mask & (MAY_ACCESS | MAY_CHDIR))
+		goto force_lookup;
+
+	switch (inode->i_mode & S_IFMT) {
+		case S_IFLNK:
+			goto out;
+		case S_IFREG:
+			/* NFSv4 has atomic_open... */
+			if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
+					&& (mask & MAY_OPEN)
+					&& !(mask & MAY_EXEC))
+				goto out;
+			break;
+		case S_IFDIR:
+			/*
+			 * Optimize away all write operations, since the server
+			 * will check permissions when we perform the op.
+			 */
+			if ((mask & MAY_WRITE) && !(mask & MAY_READ))
+				goto out;
+	}
+
+force_lookup:
+	if (!NFS_PROTO(inode)->access)
+		goto out_notsup;
+
+	cred = rpc_lookup_cred();
+	if (!IS_ERR(cred)) {
+		res = nfs_do_access(inode, cred, mask);
+		put_rpccred(cred);
+	} else
+		res = PTR_ERR(cred);
+out:
+	if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
+		res = -EACCES;
+
+	dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
+		inode->i_sb->s_id, inode->i_ino, mask, res);
+	return res;
+out_notsup:
+	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (res == 0)
+		res = generic_permission(inode, mask);
+	goto out;
+}
+
+/*
+ * Local variables:
+ *  version-control: t
+ *  kept-new-versions: 5
+ * End:
+ */