dir.c 57.3 KB
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/*
 *  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>
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#include <linux/pagevec.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/sched.h>
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#include <linux/kmemleak.h>
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#include <linux/xattr.h>
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#include "delegation.h"
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#include "iostat.h"
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#include "internal.h"
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#include "fscache.h"
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/* #define NFS_DEBUG_VERBOSE 1 */

static int nfs_opendir(struct inode *, struct file *);
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static int nfs_closedir(struct inode *, struct file *);
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static int nfs_readdir(struct file *, void *, filldir_t);
static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
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static int nfs_create(struct inode *, struct dentry *, umode_t, struct nameidata *);
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static int nfs_mkdir(struct inode *, struct dentry *, umode_t);
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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 *);
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static int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
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static int nfs_rename(struct inode *, struct dentry *,
		      struct inode *, struct dentry *);
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static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
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static loff_t nfs_llseek_dir(struct file *, loff_t, int);
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static void nfs_readdir_clear_array(struct page*);
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const struct file_operations nfs_dir_operations = {
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	.llseek		= nfs_llseek_dir,
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	.read		= generic_read_dir,
	.readdir	= nfs_readdir,
	.open		= nfs_opendir,
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	.release	= nfs_closedir,
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	.fsync		= nfs_fsync_dir,
};

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const struct inode_operations nfs_dir_inode_operations = {
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	.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,
};

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const struct address_space_operations nfs_dir_aops = {
	.freepage = nfs_readdir_clear_array,
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};

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#ifdef CONFIG_NFS_V3
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const struct inode_operations nfs3_dir_inode_operations = {
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	.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 */

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#ifdef CONFIG_NFS_V4

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static int nfs_atomic_open(struct inode *, struct dentry *,
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			   struct file *, unsigned, umode_t,
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			   int *);
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const struct inode_operations nfs4_dir_inode_operations = {
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	.create		= nfs_create,
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	.lookup		= nfs_lookup,
	.atomic_open	= nfs_atomic_open,
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	.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,
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	.getxattr	= generic_getxattr,
	.setxattr	= generic_setxattr,
	.listxattr	= generic_listxattr,
	.removexattr	= generic_removexattr,
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};

#endif /* CONFIG_NFS_V4 */

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static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
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{
	struct nfs_open_dir_context *ctx;
	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
	if (ctx != NULL) {
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		ctx->duped = 0;
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		ctx->attr_gencount = NFS_I(dir)->attr_gencount;
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		ctx->dir_cookie = 0;
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		ctx->dup_cookie = 0;
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		ctx->cred = get_rpccred(cred);
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		return ctx;
	}
	return  ERR_PTR(-ENOMEM);
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}

static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
{
	put_rpccred(ctx->cred);
	kfree(ctx);
}

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/*
 * Open file
 */
static int
nfs_opendir(struct inode *inode, struct file *filp)
{
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	int res = 0;
	struct nfs_open_dir_context *ctx;
	struct rpc_cred *cred;
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	dfprintk(FILE, "NFS: open dir(%s/%s)\n",
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			filp->f_path.dentry->d_parent->d_name.name,
			filp->f_path.dentry->d_name.name);

	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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	cred = rpc_lookup_cred();
	if (IS_ERR(cred))
		return PTR_ERR(cred);
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	ctx = alloc_nfs_open_dir_context(inode, cred);
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	if (IS_ERR(ctx)) {
		res = PTR_ERR(ctx);
		goto out;
	}
	filp->private_data = ctx;
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	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);
	}
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out:
	put_rpccred(cred);
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	return res;
}

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static int
nfs_closedir(struct inode *inode, struct file *filp)
{
	put_nfs_open_dir_context(filp->private_data);
	return 0;
}

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struct nfs_cache_array_entry {
	u64 cookie;
	u64 ino;
	struct qstr string;
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	unsigned char d_type;
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};

struct nfs_cache_array {
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	int size;
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	int eof_index;
	u64 last_cookie;
	struct nfs_cache_array_entry array[0];
};

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typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
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typedef struct {
	struct file	*file;
	struct page	*page;
	unsigned long	page_index;
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	u64		*dir_cookie;
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	u64		last_cookie;
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	loff_t		current_index;
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	decode_dirent_t	decode;
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	unsigned long	timestamp;
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	unsigned long	gencount;
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	unsigned int	cache_entry_index;
	unsigned int	plus:1;
	unsigned int	eof:1;
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} nfs_readdir_descriptor_t;

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/*
 * The caller is responsible for calling nfs_readdir_release_array(page)
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 */
static
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struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
{
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	void *ptr;
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	if (page == NULL)
		return ERR_PTR(-EIO);
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	ptr = kmap(page);
	if (ptr == NULL)
		return ERR_PTR(-ENOMEM);
	return ptr;
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}

static
void nfs_readdir_release_array(struct page *page)
{
	kunmap(page);
}

/*
 * we are freeing strings created by nfs_add_to_readdir_array()
 */
static
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void nfs_readdir_clear_array(struct page *page)
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{
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	struct nfs_cache_array *array;
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	int i;
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	array = kmap_atomic(page);
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	for (i = 0; i < array->size; i++)
		kfree(array->array[i].string.name);
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	kunmap_atomic(array);
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}

/*
 * 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
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int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
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{
	string->len = len;
	string->name = kmemdup(name, len, GFP_KERNEL);
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	if (string->name == NULL)
		return -ENOMEM;
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	/*
	 * 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);
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	string->hash = full_name_hash(name, len);
	return 0;
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}

static
int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
{
	struct nfs_cache_array *array = nfs_readdir_get_array(page);
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	struct nfs_cache_array_entry *cache_entry;
	int ret;

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	if (IS_ERR(array))
		return PTR_ERR(array);
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	cache_entry = &array->array[array->size];

	/* Check that this entry lies within the page bounds */
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	ret = -ENOSPC;
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	if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
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		goto out;
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	cache_entry->cookie = entry->prev_cookie;
	cache_entry->ino = entry->ino;
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	cache_entry->d_type = entry->d_type;
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	ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
	if (ret)
		goto out;
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	array->last_cookie = entry->cookie;
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	array->size++;
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	if (entry->eof != 0)
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		array->eof_index = array->size;
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out:
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	nfs_readdir_release_array(page);
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	return ret;
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}

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) {
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		if (array->eof_index >= 0)
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			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;
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	loff_t new_pos;
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	int status = -EAGAIN;

	for (i = 0; i < array->size; i++) {
		if (array->array[i].cookie == *desc->dir_cookie) {
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			struct nfs_inode *nfsi = NFS_I(desc->file->f_path.dentry->d_inode);
			struct nfs_open_dir_context *ctx = desc->file->private_data;

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			new_pos = desc->current_index + i;
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			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.  "
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								"The file: %s has duplicate cookie %llu\n",
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								desc->file->f_dentry->d_parent->d_name.name,
								desc->file->f_dentry->d_name.name,
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								array->array[i].string.name,
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								*desc->dir_cookie);
					}
					status = -ELOOP;
					goto out;
				}
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				ctx->dup_cookie = *desc->dir_cookie;
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				ctx->duped = -1;
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			}
			desc->file->f_pos = new_pos;
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			desc->cache_entry_index = i;
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			return 0;
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		}
	}
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	if (array->eof_index >= 0) {
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		status = -EBADCOOKIE;
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		if (*desc->dir_cookie == array->last_cookie)
			desc->eof = 1;
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	}
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out:
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	return status;
}

static
int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
{
	struct nfs_cache_array *array;
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	int status;
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	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);

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	if (status == -EAGAIN) {
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		desc->last_cookie = array->last_cookie;
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		desc->current_index += array->size;
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		desc->page_index++;
	}
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	nfs_readdir_release_array(desc->page);
out:
	return status;
}

/* Fill a page with xdr information before transferring to the cache page */
static
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int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
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			struct nfs_entry *entry, struct file *file, struct inode *inode)
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{
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	struct nfs_open_dir_context *ctx = file->private_data;
	struct rpc_cred	*cred = ctx->cred;
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	unsigned long	timestamp, gencount;
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	int		error;

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	timestamp = jiffies;
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	gencount = nfs_inc_attr_generation_counter();
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	error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
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					  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;
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			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
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			desc->plus = 0;
			goto again;
		}
		goto error;
	}
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	desc->timestamp = timestamp;
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	desc->gencount = gencount;
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error:
	return error;
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}

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static int xdr_decode(nfs_readdir_descriptor_t *desc,
		      struct nfs_entry *entry, struct xdr_stream *xdr)
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{
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	int error;
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	error = desc->decode(xdr, entry, desc->plus);
	if (error)
		return error;
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	entry->fattr->time_start = desc->timestamp;
	entry->fattr->gencount = desc->gencount;
	return 0;
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}

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static
int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
{
	if (dentry->d_inode == NULL)
		goto different;
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	if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
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		goto different;
	return 1;
different:
	return 0;
}

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static
bool nfs_use_readdirplus(struct inode *dir, struct file *filp)
{
	if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
		return false;
	if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
		return true;
	if (filp->f_pos == 0)
		return true;
	return false;
}

/*
 * This function is called by the lookup code to request the use of
 * readdirplus to accelerate any future lookups in the same
 * directory.
 */
static
void nfs_advise_use_readdirplus(struct inode *dir)
{
	set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
}

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static
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
{
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	struct qstr filename = QSTR_INIT(entry->name, entry->len);
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	struct dentry *dentry;
	struct dentry *alias;
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	struct inode *dir = parent->d_inode;
	struct inode *inode;

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	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);
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	dentry = d_lookup(parent, &filename);
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	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);
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	if (dentry == NULL)
		return;

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	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);
}

B
Bryan Schumaker 已提交
551 552
/* Perform conversion from xdr to cache array */
static
553
int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
554
				struct page **xdr_pages, struct page *page, unsigned int buflen)
L
Linus Torvalds 已提交
555
{
556
	struct xdr_stream stream;
557
	struct xdr_buf buf;
558
	struct page *scratch;
B
Bryan Schumaker 已提交
559
	struct nfs_cache_array *array;
560 561
	unsigned int count = 0;
	int status;
562

563 564 565
	scratch = alloc_page(GFP_KERNEL);
	if (scratch == NULL)
		return -ENOMEM;
566

567
	xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
568
	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
B
Bryan Schumaker 已提交
569 570 571

	do {
		status = xdr_decode(desc, entry, &stream);
572 573 574
		if (status != 0) {
			if (status == -EAGAIN)
				status = 0;
B
Bryan Schumaker 已提交
575
			break;
576
		}
B
Bryan Schumaker 已提交
577

578 579
		count++;

T
Trond Myklebust 已提交
580
		if (desc->plus != 0)
B
Bryan Schumaker 已提交
581
			nfs_prime_dcache(desc->file->f_path.dentry, entry);
582 583 584 585

		status = nfs_readdir_add_to_array(entry, page);
		if (status != 0)
			break;
B
Bryan Schumaker 已提交
586 587
	} while (!entry->eof);

T
Trond Myklebust 已提交
588
	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
B
Bryan Schumaker 已提交
589
		array = nfs_readdir_get_array(page);
590 591 592 593
		if (!IS_ERR(array)) {
			array->eof_index = array->size;
			status = 0;
			nfs_readdir_release_array(page);
594 595
		} else
			status = PTR_ERR(array);
L
Linus Torvalds 已提交
596
	}
597 598

	put_page(scratch);
599
	return status;
B
Bryan Schumaker 已提交
600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621
}

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
622
int nfs_readdir_large_page(struct page **pages, unsigned int npages)
B
Bryan Schumaker 已提交
623 624 625 626 627 628 629 630 631
{
	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;
	}
632
	return 0;
B
Bryan Schumaker 已提交
633 634 635

out_freepages:
	nfs_readdir_free_pagearray(pages, i);
636
	return -ENOMEM;
L
Linus Torvalds 已提交
637 638
}

B
Bryan Schumaker 已提交
639 640
static
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
641
{
B
Bryan Schumaker 已提交
642 643
	struct page *pages[NFS_MAX_READDIR_PAGES];
	void *pages_ptr = NULL;
B
Bryan Schumaker 已提交
644 645 646
	struct nfs_entry entry;
	struct file	*file = desc->file;
	struct nfs_cache_array *array;
647
	int status = -ENOMEM;
B
Bryan Schumaker 已提交
648
	unsigned int array_size = ARRAY_SIZE(pages);
B
Bryan Schumaker 已提交
649 650

	entry.prev_cookie = 0;
651
	entry.cookie = desc->last_cookie;
B
Bryan Schumaker 已提交
652 653 654
	entry.eof = 0;
	entry.fh = nfs_alloc_fhandle();
	entry.fattr = nfs_alloc_fattr();
655
	entry.server = NFS_SERVER(inode);
B
Bryan Schumaker 已提交
656 657
	if (entry.fh == NULL || entry.fattr == NULL)
		goto out;
658

B
Bryan Schumaker 已提交
659
	array = nfs_readdir_get_array(page);
660 661 662 663
	if (IS_ERR(array)) {
		status = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
664 665
	memset(array, 0, sizeof(struct nfs_cache_array));
	array->eof_index = -1;
666

667 668
	status = nfs_readdir_large_page(pages, array_size);
	if (status < 0)
B
Bryan Schumaker 已提交
669 670
		goto out_release_array;
	do {
671
		unsigned int pglen;
B
Bryan Schumaker 已提交
672
		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
673

B
Bryan Schumaker 已提交
674
		if (status < 0)
675
			break;
676
		pglen = status;
677
		status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
678 679 680 681 682 683
		if (status < 0) {
			if (status == -ENOSPC)
				status = 0;
			break;
		}
	} while (array->eof_index < 0);
B
Bryan Schumaker 已提交
684

B
Bryan Schumaker 已提交
685
	nfs_readdir_free_large_page(pages_ptr, pages, array_size);
B
Bryan Schumaker 已提交
686 687 688 689 690
out_release_array:
	nfs_readdir_release_array(page);
out:
	nfs_free_fattr(entry.fattr);
	nfs_free_fhandle(entry.fh);
691 692 693 694
	return status;
}

/*
B
Bryan Schumaker 已提交
695 696 697 698
 * 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
L
Linus Torvalds 已提交
699
 */
B
Bryan Schumaker 已提交
700 701
static
int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
L
Linus Torvalds 已提交
702
{
703
	struct inode	*inode = desc->file->f_path.dentry->d_inode;
704
	int ret;
L
Linus Torvalds 已提交
705

706 707
	ret = nfs_readdir_xdr_to_array(desc, page, inode);
	if (ret < 0)
B
Bryan Schumaker 已提交
708 709
		goto error;
	SetPageUptodate(page);
L
Linus Torvalds 已提交
710

B
Bryan Schumaker 已提交
711 712 713
	if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
		/* Should never happen */
		nfs_zap_mapping(inode, inode->i_mapping);
L
Linus Torvalds 已提交
714
	}
B
Bryan Schumaker 已提交
715 716 717 718
	unlock_page(page);
	return 0;
 error:
	unlock_page(page);
719
	return ret;
B
Bryan Schumaker 已提交
720
}
L
Linus Torvalds 已提交
721

B
Bryan Schumaker 已提交
722 723 724
static
void cache_page_release(nfs_readdir_descriptor_t *desc)
{
725 726
	if (!desc->page->mapping)
		nfs_readdir_clear_array(desc->page);
B
Bryan Schumaker 已提交
727 728 729 730 731 732 733
	page_cache_release(desc->page);
	desc->page = NULL;
}

static
struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
{
734
	return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
B
Bryan Schumaker 已提交
735
			desc->page_index, (filler_t *)nfs_readdir_filler, desc);
L
Linus Torvalds 已提交
736 737 738
}

/*
B
Bryan Schumaker 已提交
739
 * Returns 0 if desc->dir_cookie was found on page desc->page_index
L
Linus Torvalds 已提交
740
 */
B
Bryan Schumaker 已提交
741 742 743 744 745 746 747 748 749 750
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);
T
Trond Myklebust 已提交
751 752
	if (res != 0)
		cache_page_release(desc);
B
Bryan Schumaker 已提交
753 754 755 756
	return res;
}

/* Search for desc->dir_cookie from the beginning of the page cache */
L
Linus Torvalds 已提交
757 758 759
static inline
int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
{
760
	int res;
B
Bryan Schumaker 已提交
761

762
	if (desc->page_index == 0) {
763
		desc->current_index = 0;
764 765
		desc->last_cookie = 0;
	}
T
Trond Myklebust 已提交
766
	do {
B
Bryan Schumaker 已提交
767
		res = find_cache_page(desc);
T
Trond Myklebust 已提交
768
	} while (res == -EAGAIN);
L
Linus Torvalds 已提交
769 770 771 772 773 774 775 776 777 778 779
	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;
B
Bryan Schumaker 已提交
780 781 782
	int i = 0;
	int res = 0;
	struct nfs_cache_array *array = NULL;
783 784
	struct nfs_open_dir_context *ctx = file->private_data;

B
Bryan Schumaker 已提交
785
	array = nfs_readdir_get_array(desc->page);
786 787 788 789
	if (IS_ERR(array)) {
		res = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
790 791

	for (i = desc->cache_entry_index; i < array->size; i++) {
792
		struct nfs_cache_array_entry *ent;
L
Linus Torvalds 已提交
793

794 795
		ent = &array->array[i];
		if (filldir(dirent, ent->string.name, ent->string.len,
796 797
		    file->f_pos, nfs_compat_user_ino64(ent->ino),
		    ent->d_type) < 0) {
798
			desc->eof = 1;
L
Linus Torvalds 已提交
799
			break;
800
		}
801
		file->f_pos++;
B
Bryan Schumaker 已提交
802 803 804 805
		if (i < (array->size-1))
			*desc->dir_cookie = array->array[i+1].cookie;
		else
			*desc->dir_cookie = array->last_cookie;
806 807
		if (ctx->duped != 0)
			ctx->duped = 1;
L
Linus Torvalds 已提交
808
	}
T
Trond Myklebust 已提交
809
	if (array->eof_index >= 0)
810
		desc->eof = 1;
B
Bryan Schumaker 已提交
811 812

	nfs_readdir_release_array(desc->page);
813
out:
B
Bryan Schumaker 已提交
814
	cache_page_release(desc);
C
Chuck Lever 已提交
815 816
	dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
			(unsigned long long)*desc->dir_cookie, res);
L
Linus Torvalds 已提交
817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
	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;
B
Bryan Schumaker 已提交
838
	struct inode *inode = desc->file->f_path.dentry->d_inode;
839
	struct nfs_open_dir_context *ctx = desc->file->private_data;
L
Linus Torvalds 已提交
840

C
Chuck Lever 已提交
841 842
	dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
			(unsigned long long)*desc->dir_cookie);
L
Linus Torvalds 已提交
843 844 845 846 847 848

	page = alloc_page(GFP_HIGHUSER);
	if (!page) {
		status = -ENOMEM;
		goto out;
	}
B
Bryan Schumaker 已提交
849

850
	desc->page_index = 0;
851
	desc->last_cookie = *desc->dir_cookie;
852
	desc->page = page;
853
	ctx->duped = 0;
854

855 856
	status = nfs_readdir_xdr_to_array(desc, page, inode);
	if (status < 0)
L
Linus Torvalds 已提交
857 858 859 860 861
		goto out_release;

	status = nfs_do_filldir(desc, dirent, filldir);

 out:
C
Chuck Lever 已提交
862
	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
863
			__func__, status);
L
Linus Torvalds 已提交
864 865
	return status;
 out_release:
B
Bryan Schumaker 已提交
866
	cache_page_release(desc);
L
Linus Torvalds 已提交
867 868 869
	goto out;
}

870 871 872
/* The file offset position represents the dirent entry number.  A
   last cookie cache takes care of the common case of reading the
   whole directory.
L
Linus Torvalds 已提交
873 874 875
 */
static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
876
	struct dentry	*dentry = filp->f_path.dentry;
L
Linus Torvalds 已提交
877 878 879
	struct inode	*inode = dentry->d_inode;
	nfs_readdir_descriptor_t my_desc,
			*desc = &my_desc;
880
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
T
Trond Myklebust 已提交
881
	int res;
L
Linus Torvalds 已提交
882

C
Chuck Lever 已提交
883
	dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
C
Chuck Lever 已提交
884 885
			dentry->d_parent->d_name.name, dentry->d_name.name,
			(long long)filp->f_pos);
C
Chuck Lever 已提交
886 887
	nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);

L
Linus Torvalds 已提交
888
	/*
889
	 * filp->f_pos points to the dirent entry number.
890
	 * *desc->dir_cookie has the cookie for the next entry. We have
891 892
	 * to either find the entry with the appropriate number or
	 * revalidate the cookie.
L
Linus Torvalds 已提交
893 894 895 896
	 */
	memset(desc, 0, sizeof(*desc));

	desc->file = filp;
897
	desc->dir_cookie = &dir_ctx->dir_cookie;
L
Linus Torvalds 已提交
898
	desc->decode = NFS_PROTO(inode)->decode_dirent;
899
	desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0;
L
Linus Torvalds 已提交
900

T
Trond Myklebust 已提交
901
	nfs_block_sillyrename(dentry);
902
	res = nfs_revalidate_mapping(inode, filp->f_mapping);
T
Trond Myklebust 已提交
903 904 905
	if (res < 0)
		goto out;

T
Trond Myklebust 已提交
906
	do {
L
Linus Torvalds 已提交
907
		res = readdir_search_pagecache(desc);
908

L
Linus Torvalds 已提交
909
		if (res == -EBADCOOKIE) {
910
			res = 0;
L
Linus Torvalds 已提交
911
			/* This means either end of directory */
B
Bryan Schumaker 已提交
912
			if (*desc->dir_cookie && desc->eof == 0) {
L
Linus Torvalds 已提交
913 914
				/* Or that the server has 'lost' a cookie */
				res = uncached_readdir(desc, dirent, filldir);
915
				if (res == 0)
L
Linus Torvalds 已提交
916 917 918 919 920
					continue;
			}
			break;
		}
		if (res == -ETOOSMALL && desc->plus) {
B
Benny Halevy 已提交
921
			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
L
Linus Torvalds 已提交
922
			nfs_zap_caches(inode);
923
			desc->page_index = 0;
L
Linus Torvalds 已提交
924
			desc->plus = 0;
B
Bryan Schumaker 已提交
925
			desc->eof = 0;
L
Linus Torvalds 已提交
926 927 928 929 930 931
			continue;
		}
		if (res < 0)
			break;

		res = nfs_do_filldir(desc, dirent, filldir);
932
		if (res < 0)
L
Linus Torvalds 已提交
933
			break;
T
Trond Myklebust 已提交
934
	} while (!desc->eof);
T
Trond Myklebust 已提交
935
out:
T
Trond Myklebust 已提交
936
	nfs_unblock_sillyrename(dentry);
C
Chuck Lever 已提交
937 938
	if (res > 0)
		res = 0;
939
	dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
C
Chuck Lever 已提交
940 941 942
			dentry->d_parent->d_name.name, dentry->d_name.name,
			res);
	return res;
L
Linus Torvalds 已提交
943 944
}

945
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
946
{
947 948
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
949
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
950

C
Chuck Lever 已提交
951
	dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
952 953 954 955 956
			dentry->d_parent->d_name.name,
			dentry->d_name.name,
			offset, origin);

	mutex_lock(&inode->i_mutex);
957 958 959 960 961 962 963 964 965 966 967 968
	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;
969
		dir_ctx->dir_cookie = 0;
970
		dir_ctx->duped = 0;
971 972
	}
out:
973
	mutex_unlock(&inode->i_mutex);
974 975 976
	return offset;
}

L
Linus Torvalds 已提交
977 978 979 980
/*
 * All directory operations under NFS are synchronous, so fsync()
 * is a dummy operation.
 */
981 982
static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
			 int datasync)
L
Linus Torvalds 已提交
983
{
984
	struct dentry *dentry = filp->f_path.dentry;
985
	struct inode *inode = dentry->d_inode;
986

C
Chuck Lever 已提交
987
	dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
C
Chuck Lever 已提交
988 989 990
			dentry->d_parent->d_name.name, dentry->d_name.name,
			datasync);

991
	mutex_lock(&inode->i_mutex);
992
	nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
993
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
994 995 996
	return 0;
}

997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
/**
 * 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)
{
1009
	NFS_I(dir)->cache_change_attribute++;
1010 1011
}

L
Linus Torvalds 已提交
1012 1013 1014 1015 1016
/*
 * 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.
 */
1017
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
1018 1019 1020
{
	if (IS_ROOT(dentry))
		return 1;
1021 1022
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
		return 0;
1023 1024 1025 1026 1027 1028 1029 1030
	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;
L
Linus Torvalds 已提交
1031 1032
}

1033 1034 1035 1036
/*
 * Return the intent data that applies to this particular path component
 *
 * Note that the current set of intents only apply to the very last
1037 1038
 * component of the path and none of them is set before that last
 * component.
1039
 */
1040
static inline unsigned int nfs_lookup_check_intent(unsigned int flags,
1041
						unsigned int mask)
1042
{
1043
	return flags & mask;
1044 1045
}

1046 1047 1048 1049 1050 1051 1052 1053
/*
 * 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;
1054
	return nd && nfs_lookup_check_intent(nd->flags, LOOKUP_EXCL);
1055 1056
}

1057 1058 1059 1060 1061 1062 1063 1064
/*
 * 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.
 *
 */
L
Linus Torvalds 已提交
1065 1066 1067 1068 1069
static inline
int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
{
	struct nfs_server *server = NFS_SERVER(inode);

1070
	if (IS_AUTOMOUNT(inode))
1071
		return 0;
1072 1073 1074 1075 1076 1077 1078 1079 1080 1081
	/* 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->flags, LOOKUP_OPEN) != 0 &&
			!(server->flags & NFS_MOUNT_NOCTO) &&
			(S_ISREG(inode->i_mode) ||
			 S_ISDIR(inode->i_mode)))
		goto out_force;
	return 0;
L
Linus Torvalds 已提交
1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097
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 */
1098
	if (nd != NULL && nfs_lookup_check_intent(nd->flags, LOOKUP_CREATE) != 0)
L
Linus Torvalds 已提交
1099
		return 0;
1100 1101
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
		return 1;
L
Linus Torvalds 已提交
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
	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.
 */
1116
static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
L
Linus Torvalds 已提交
1117 1118 1119 1120
{
	struct inode *dir;
	struct inode *inode;
	struct dentry *parent;
1121 1122
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1123 1124
	int error;

1125 1126 1127
	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

L
Linus Torvalds 已提交
1128 1129
	parent = dget_parent(dentry);
	dir = parent->d_inode;
C
Chuck Lever 已提交
1130
	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
L
Linus Torvalds 已提交
1131 1132 1133 1134 1135
	inode = dentry->d_inode;

	if (!inode) {
		if (nfs_neg_need_reval(dir, dentry, nd))
			goto out_bad;
1136
		goto out_valid_noent;
L
Linus Torvalds 已提交
1137 1138 1139
	}

	if (is_bad_inode(inode)) {
C
Chuck Lever 已提交
1140
		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1141
				__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1142
				dentry->d_name.name);
L
Linus Torvalds 已提交
1143 1144 1145
		goto out_bad;
	}

1146 1147 1148
	if (nfs_have_delegation(inode, FMODE_READ))
		goto out_set_verifier;

L
Linus Torvalds 已提交
1149
	/* Force a full look up iff the parent directory has changed */
1150
	if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
L
Linus Torvalds 已提交
1151 1152 1153 1154 1155 1156 1157 1158
		if (nfs_lookup_verify_inode(inode, nd))
			goto out_zap_parent;
		goto out_valid;
	}

	if (NFS_STALE(inode))
		goto out_bad;

1159 1160 1161 1162 1163 1164
	error = -ENOMEM;
	fhandle = nfs_alloc_fhandle();
	fattr = nfs_alloc_fattr();
	if (fhandle == NULL || fattr == NULL)
		goto out_error;

1165
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1166 1167
	if (error)
		goto out_bad;
1168
	if (nfs_compare_fh(NFS_FH(inode), fhandle))
L
Linus Torvalds 已提交
1169
		goto out_bad;
1170
	if ((error = nfs_refresh_inode(inode, fattr)) != 0)
L
Linus Torvalds 已提交
1171 1172
		goto out_bad;

1173 1174
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
1175
out_set_verifier:
1176
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1177
 out_valid:
1178 1179 1180
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);
 out_valid_noent:
L
Linus Torvalds 已提交
1181
	dput(parent);
C
Chuck Lever 已提交
1182
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1183
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1184
			dentry->d_name.name);
L
Linus Torvalds 已提交
1185 1186 1187 1188
	return 1;
out_zap_parent:
	nfs_zap_caches(dir);
 out_bad:
1189
	nfs_mark_for_revalidate(dir);
L
Linus Torvalds 已提交
1190 1191 1192 1193 1194 1195
	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;
1196 1197
		if (dentry->d_flags & DCACHE_DISCONNECTED)
			goto out_valid;
L
Linus Torvalds 已提交
1198 1199 1200
		shrink_dcache_parent(dentry);
	}
	d_drop(dentry);
1201 1202
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1203
	dput(parent);
C
Chuck Lever 已提交
1204
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1205
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1206
			dentry->d_name.name);
L
Linus Torvalds 已提交
1207
	return 0;
1208 1209 1210 1211 1212 1213 1214 1215
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;
L
Linus Torvalds 已提交
1216 1217 1218 1219 1220
}

/*
 * This is called from dput() when d_count is going to 0.
 */
N
Nick Piggin 已提交
1221
static int nfs_dentry_delete(const struct dentry *dentry)
L
Linus Torvalds 已提交
1222 1223 1224 1225 1226
{
	dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		dentry->d_flags);

1227 1228 1229 1230
	/* Unhash any dentry with a stale inode */
	if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
		return 1;

L
Linus Torvalds 已提交
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243
	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;

}

1244 1245 1246 1247 1248 1249 1250 1251
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);
}

L
Linus Torvalds 已提交
1252 1253 1254 1255 1256 1257
/*
 * 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)
{
1258 1259 1260 1261
	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;

L
Linus Torvalds 已提交
1262
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1263
		drop_nlink(inode);
1264
		nfs_complete_unlink(dentry, inode);
L
Linus Torvalds 已提交
1265 1266 1267 1268
	}
	iput(inode);
}

1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279
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);
	}
}

A
Al Viro 已提交
1280
const struct dentry_operations nfs_dentry_operations = {
L
Linus Torvalds 已提交
1281 1282 1283
	.d_revalidate	= nfs_lookup_revalidate,
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1284
	.d_automount	= nfs_d_automount,
1285
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1286 1287 1288 1289 1290
};

static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
	struct dentry *res;
T
Trond Myklebust 已提交
1291
	struct dentry *parent;
L
Linus Torvalds 已提交
1292
	struct inode *inode = NULL;
1293 1294
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1295 1296 1297 1298
	int error;

	dfprintk(VFS, "NFS: lookup(%s/%s)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
C
Chuck Lever 已提交
1299
	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
L
Linus Torvalds 已提交
1300 1301 1302 1303 1304

	res = ERR_PTR(-ENAMETOOLONG);
	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
		goto out;

1305 1306 1307 1308 1309 1310 1311
	/*
	 * 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;
1312
		goto out;
1313
	}
L
Linus Torvalds 已提交
1314

1315 1316 1317 1318 1319 1320
	res = ERR_PTR(-ENOMEM);
	fhandle = nfs_alloc_fhandle();
	fattr = nfs_alloc_fattr();
	if (fhandle == NULL || fattr == NULL)
		goto out;

T
Trond Myklebust 已提交
1321 1322 1323
	parent = dentry->d_parent;
	/* Protect against concurrent sillydeletes */
	nfs_block_sillyrename(parent);
1324
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1325 1326 1327 1328
	if (error == -ENOENT)
		goto no_entry;
	if (error < 0) {
		res = ERR_PTR(error);
T
Trond Myklebust 已提交
1329
		goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1330
	}
1331
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
N
Namhyung Kim 已提交
1332
	res = ERR_CAST(inode);
1333
	if (IS_ERR(res))
T
Trond Myklebust 已提交
1334
		goto out_unblock_sillyrename;
1335

1336 1337 1338
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);

L
Linus Torvalds 已提交
1339
no_entry:
1340
	res = d_materialise_unique(dentry, inode);
1341 1342
	if (res != NULL) {
		if (IS_ERR(res))
T
Trond Myklebust 已提交
1343
			goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1344
		dentry = res;
1345
	}
L
Linus Torvalds 已提交
1346
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
T
Trond Myklebust 已提交
1347 1348
out_unblock_sillyrename:
	nfs_unblock_sillyrename(parent);
L
Linus Torvalds 已提交
1349
out:
1350 1351
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1352 1353 1354 1355
	return res;
}

#ifdef CONFIG_NFS_V4
1356
static int nfs4_lookup_revalidate(struct dentry *, struct nameidata *);
L
Linus Torvalds 已提交
1357

A
Al Viro 已提交
1358
const struct dentry_operations nfs4_dentry_operations = {
1359
	.d_revalidate	= nfs4_lookup_revalidate,
L
Linus Torvalds 已提交
1360 1361
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1362
	.d_automount	= nfs_d_automount,
1363
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1364 1365
};

1366 1367 1368 1369 1370 1371 1372 1373 1374 1375
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;
}

1376
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1377
{
1378
	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1379 1380 1381 1382 1383 1384 1385 1386
}

static int do_open(struct inode *inode, struct file *filp)
{
	nfs_fscache_set_inode_cookie(inode, filp);
	return 0;
}

A
Al Viro 已提交
1387 1388
static int nfs_finish_open(struct nfs_open_context *ctx,
			   struct dentry *dentry,
A
Al Viro 已提交
1389
			   struct file *file, unsigned open_flags,
A
Al Viro 已提交
1390
			   int *opened)
1391
{
1392 1393 1394 1395 1396 1397
	int err;

	if (ctx->dentry != dentry) {
		dput(ctx->dentry);
		ctx->dentry = dget(dentry);
	}
1398 1399 1400

	/* If the open_intent is for execute, we have an extra check to make */
	if (ctx->mode & FMODE_EXEC) {
1401
		err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
A
Al Viro 已提交
1402
		if (err < 0)
1403 1404
			goto out;
	}
1405

A
Al Viro 已提交
1406 1407
	err = finish_open(file, dentry, do_open, opened);
	if (err)
A
Al Viro 已提交
1408
		goto out;
A
Al Viro 已提交
1409
	nfs_file_set_open_context(file, ctx);
1410

1411 1412
out:
	put_nfs_open_context(ctx);
A
Al Viro 已提交
1413
	return err;
1414 1415
}

A
Al Viro 已提交
1416
static int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
A
Al Viro 已提交
1417
			    struct file *file, unsigned open_flags,
A
Al Viro 已提交
1418
			    umode_t mode, int *opened)
L
Linus Torvalds 已提交
1419
{
1420
	struct nfs_open_context *ctx;
1421 1422
	struct dentry *res;
	struct iattr attr = { .ia_valid = ATTR_OPEN };
1423
	struct inode *inode;
1424
	int err;
L
Linus Torvalds 已提交
1425

1426 1427 1428 1429
	/* Expect a negative dentry */
	BUG_ON(dentry->d_inode);

	dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
C
Chuck Lever 已提交
1430 1431
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);

1432 1433 1434 1435 1436 1437 1438 1439
	/* NFS only supports OPEN on regular files */
	if ((open_flags & O_DIRECTORY)) {
		if (!d_unhashed(dentry)) {
			/*
			 * Hashed negative dentry with O_DIRECTORY: dentry was
			 * revalidated and is fine, no need to perform lookup
			 * again
			 */
A
Al Viro 已提交
1440
			return -ENOENT;
1441
		}
L
Linus Torvalds 已提交
1442
		goto no_open;
1443
	}
L
Linus Torvalds 已提交
1444

1445
	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
A
Al Viro 已提交
1446
		return -ENAMETOOLONG;
1447

1448
	if (open_flags & O_CREAT) {
1449
		attr.ia_valid |= ATTR_MODE;
1450 1451
		attr.ia_mode = mode & ~current_umask();
	}
1452 1453 1454
	if (open_flags & O_TRUNC) {
		attr.ia_valid |= ATTR_SIZE;
		attr.ia_size = 0;
1455 1456
	}

1457 1458 1459
	ctx = create_nfs_open_context(dentry, open_flags);
	err = PTR_ERR(ctx);
	if (IS_ERR(ctx))
A
Al Viro 已提交
1460
		goto out;
1461

1462
	nfs_block_sillyrename(dentry->d_parent);
1463
	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1464
	d_drop(dentry);
1465 1466
	if (IS_ERR(inode)) {
		nfs_unblock_sillyrename(dentry->d_parent);
1467
		put_nfs_open_context(ctx);
1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
		err = PTR_ERR(inode);
		switch (err) {
		case -ENOENT:
			d_add(dentry, NULL);
			break;
		case -EISDIR:
		case -ENOTDIR:
			goto no_open;
		case -ELOOP:
			if (!(open_flags & O_NOFOLLOW))
1478
				goto no_open;
1479
			break;
L
Linus Torvalds 已提交
1480
			/* case -EINVAL: */
1481 1482
		default:
			break;
L
Linus Torvalds 已提交
1483
		}
A
Al Viro 已提交
1484
		goto out;
1485
	}
1486
	res = d_add_unique(dentry, inode);
1487
	if (res != NULL)
L
Linus Torvalds 已提交
1488
		dentry = res;
1489 1490

	nfs_unblock_sillyrename(dentry->d_parent);
1491
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1492

A
Al Viro 已提交
1493
	err = nfs_finish_open(ctx, dentry, file, open_flags, opened);
1494 1495

	dput(res);
A
Al Viro 已提交
1496 1497
out:
	return err;
1498

L
Linus Torvalds 已提交
1499
no_open:
1500 1501 1502
	res = nfs_lookup(dir, dentry, NULL);
	err = PTR_ERR(res);
	if (IS_ERR(res))
A
Al Viro 已提交
1503
		goto out;
1504

A
Al Viro 已提交
1505
	return finish_no_open(file, res);
L
Linus Torvalds 已提交
1506 1507
}

1508
static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
L
Linus Torvalds 已提交
1509 1510
{
	struct dentry *parent = NULL;
N
Nick Piggin 已提交
1511
	struct inode *inode;
L
Linus Torvalds 已提交
1512
	struct inode *dir;
1513
	int ret = 0;
L
Linus Torvalds 已提交
1514

N
Nick Piggin 已提交
1515 1516 1517
	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

1518 1519 1520
	if (!(nd->flags & LOOKUP_OPEN) || (nd->flags & LOOKUP_DIRECTORY))
		goto no_open;
	if (d_mountpoint(dentry))
T
Trond Myklebust 已提交
1521
		goto no_open;
1522

1523
	inode = dentry->d_inode;
L
Linus Torvalds 已提交
1524 1525
	parent = dget_parent(dentry);
	dir = parent->d_inode;
1526

L
Linus Torvalds 已提交
1527 1528 1529
	/* We can't create new files in nfs_open_revalidate(), so we
	 * optimize away revalidation of negative dentries.
	 */
1530 1531 1532
	if (inode == NULL) {
		if (!nfs_neg_need_reval(dir, dentry, nd))
			ret = 1;
L
Linus Torvalds 已提交
1533
		goto out;
1534 1535
	}

L
Linus Torvalds 已提交
1536 1537
	/* NFS only supports OPEN on regular files */
	if (!S_ISREG(inode->i_mode))
T
Trond Myklebust 已提交
1538
		goto no_open_dput;
L
Linus Torvalds 已提交
1539
	/* We cannot do exclusive creation on a positive dentry */
1540
	if (nd && nd->flags & LOOKUP_EXCL)
T
Trond Myklebust 已提交
1541
		goto no_open_dput;
L
Linus Torvalds 已提交
1542

1543 1544
	/* Let f_op->open() actually open (and revalidate) the file */
	ret = 1;
1545

L
Linus Torvalds 已提交
1546 1547 1548
out:
	dput(parent);
	return ret;
1549

T
Trond Myklebust 已提交
1550
no_open_dput:
L
Linus Torvalds 已提交
1551
	dput(parent);
T
Trond Myklebust 已提交
1552
no_open:
L
Linus Torvalds 已提交
1553 1554
	return nfs_lookup_revalidate(dentry, nd);
}
1555

L
Linus Torvalds 已提交
1556 1557 1558 1559 1560 1561 1562 1563
#endif /* CONFIG_NFSV4 */

/*
 * Code common to create, mkdir, and mknod.
 */
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
				struct nfs_fattr *fattr)
{
1564 1565
	struct dentry *parent = dget_parent(dentry);
	struct inode *dir = parent->d_inode;
L
Linus Torvalds 已提交
1566 1567 1568
	struct inode *inode;
	int error = -EACCES;

1569 1570
	d_drop(dentry);

L
Linus Torvalds 已提交
1571 1572
	/* We may have been initialized further down */
	if (dentry->d_inode)
1573
		goto out;
L
Linus Torvalds 已提交
1574
	if (fhandle->size == 0) {
1575
		error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1576
		if (error)
1577
			goto out_error;
L
Linus Torvalds 已提交
1578
	}
1579
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1580 1581
	if (!(fattr->valid & NFS_ATTR_FATTR)) {
		struct nfs_server *server = NFS_SB(dentry->d_sb);
1582
		error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
L
Linus Torvalds 已提交
1583
		if (error < 0)
1584
			goto out_error;
L
Linus Torvalds 已提交
1585 1586
	}
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1587 1588
	error = PTR_ERR(inode);
	if (IS_ERR(inode))
1589 1590 1591 1592
		goto out_error;
	d_add(dentry, inode);
out:
	dput(parent);
L
Linus Torvalds 已提交
1593
	return 0;
1594 1595 1596 1597
out_error:
	nfs_mark_for_revalidate(dir);
	dput(parent);
	return error;
L
Linus Torvalds 已提交
1598 1599 1600 1601 1602 1603 1604 1605
}

/*
 * 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.
 */
A
Al Viro 已提交
1606 1607
static int nfs_create(struct inode *dir, struct dentry *dentry,
		umode_t mode, struct nameidata *nd)
L
Linus Torvalds 已提交
1608 1609 1610
{
	struct iattr attr;
	int error;
1611
	int open_flags = O_CREAT|O_EXCL;
L
Linus Torvalds 已提交
1612

C
Chuck Lever 已提交
1613 1614
	dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
L
Linus Torvalds 已提交
1615 1616 1617 1618

	attr.ia_mode = mode;
	attr.ia_valid = ATTR_MODE;

1619 1620
	if (nd && !(nd->flags & LOOKUP_EXCL))
		open_flags = O_CREAT;
1621

1622
	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
L
Linus Torvalds 已提交
1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634
	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
A
Al Viro 已提交
1635
nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
L
Linus Torvalds 已提交
1636 1637 1638 1639
{
	struct iattr attr;
	int status;

C
Chuck Lever 已提交
1640 1641
	dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
L
Linus Torvalds 已提交
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660

	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.
 */
1661
static int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
1662 1663 1664 1665
{
	struct iattr attr;
	int error;

C
Chuck Lever 已提交
1666 1667
	dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
L
Linus Torvalds 已提交
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680

	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;
}

1681 1682 1683 1684 1685 1686
static void nfs_dentry_handle_enoent(struct dentry *dentry)
{
	if (dentry->d_inode != NULL && !d_unhashed(dentry))
		d_delete(dentry);
}

L
Linus Torvalds 已提交
1687 1688 1689 1690
static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int error;

C
Chuck Lever 已提交
1691 1692
	dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
L
Linus Torvalds 已提交
1693 1694 1695 1696

	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
	/* Ensure the VFS deletes this inode */
	if (error == 0 && dentry->d_inode != NULL)
1697
		clear_nlink(dentry->d_inode);
1698 1699
	else if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726

	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) {
1727
		nfs_inode_return_delegation(inode);
L
Linus Torvalds 已提交
1728 1729 1730
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
		/* The VFS may want to delete this inode */
		if (error == 0)
1731
			nfs_drop_nlink(inode);
1732
		nfs_mark_for_revalidate(inode);
L
Linus Torvalds 已提交
1733 1734
	} else
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1735 1736
	if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
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);
N
Nick Piggin 已提交
1755
	if (dentry->d_count > 1) {
L
Linus Torvalds 已提交
1756
		spin_unlock(&dentry->d_lock);
T
Trond Myklebust 已提交
1757 1758
		/* Start asynchronous writeout of the inode */
		write_inode_now(dentry->d_inode, 0);
L
Linus Torvalds 已提交
1759 1760 1761 1762 1763 1764 1765 1766 1767
		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);
1768
	if (!error || error == -ENOENT) {
L
Linus Torvalds 已提交
1769 1770 1771 1772 1773 1774
		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
	} else if (need_rehash)
		d_rehash(dentry);
	return error;
}

1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790
/*
 * 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)
L
Linus Torvalds 已提交
1791
{
1792 1793 1794
	struct pagevec lru_pvec;
	struct page *page;
	char *kaddr;
L
Linus Torvalds 已提交
1795
	struct iattr attr;
1796
	unsigned int pathlen = strlen(symname);
L
Linus Torvalds 已提交
1797 1798 1799 1800 1801
	int error;

	dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
		dir->i_ino, dentry->d_name.name, symname);

1802 1803
	if (pathlen > PAGE_SIZE)
		return -ENAMETOOLONG;
L
Linus Torvalds 已提交
1804

1805 1806
	attr.ia_mode = S_IFLNK | S_IRWXUGO;
	attr.ia_valid = ATTR_MODE;
L
Linus Torvalds 已提交
1807

1808
	page = alloc_page(GFP_HIGHUSER);
1809
	if (!page)
1810 1811
		return -ENOMEM;

1812
	kaddr = kmap_atomic(page);
1813 1814 1815
	memcpy(kaddr, symname, pathlen);
	if (pathlen < PAGE_SIZE)
		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1816
	kunmap_atomic(kaddr);
1817

1818
	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1819 1820 1821 1822
	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);
L
Linus Torvalds 已提交
1823
		d_drop(dentry);
1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
		__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)) {
1835
		pagevec_add(&lru_pvec, page);
1836
		pagevec_lru_add_file(&lru_pvec);
1837 1838 1839 1840 1841 1842
		SetPageUptodate(page);
		unlock_page(page);
	} else
		__free_page(page);

	return 0;
L
Linus Torvalds 已提交
1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854
}

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);

1855 1856
	nfs_inode_return_delegation(inode);

1857
	d_drop(dentry);
L
Linus Torvalds 已提交
1858
	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1859
	if (error == 0) {
A
Al Viro 已提交
1860
		ihold(inode);
1861
		d_add(dentry, inode);
1862
	}
L
Linus Torvalds 已提交
1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
	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,
N
Nick Piggin 已提交
1901
		 new_dentry->d_count);
L
Linus Torvalds 已提交
1902 1903

	/*
M
Miklos Szeredi 已提交
1904 1905 1906 1907
	 * 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.
L
Linus Torvalds 已提交
1908
	 */
1909 1910 1911 1912 1913 1914 1915 1916 1917
	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;
		}
L
Linus Torvalds 已提交
1918

N
Nick Piggin 已提交
1919
		if (new_dentry->d_count > 2) {
1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
			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);
1930
			if (err)
1931
				goto out;
1932 1933

			new_dentry = dentry;
O
OGAWA Hirofumi 已提交
1934
			rehash = NULL;
1935
			new_inode = NULL;
1936
		}
1937
	}
L
Linus Torvalds 已提交
1938

1939
	nfs_inode_return_delegation(old_inode);
1940
	if (new_inode != NULL)
1941
		nfs_inode_return_delegation(new_inode);
L
Linus Torvalds 已提交
1942 1943 1944

	error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
					   new_dir, &new_dentry->d_name);
1945
	nfs_mark_for_revalidate(old_inode);
L
Linus Torvalds 已提交
1946 1947 1948 1949
out:
	if (rehash)
		d_rehash(rehash);
	if (!error) {
1950 1951
		if (new_inode != NULL)
			nfs_drop_nlink(new_inode);
1952
		d_move(old_dentry, new_dentry);
1953 1954
		nfs_set_verifier(new_dentry,
					nfs_save_change_attribute(new_dir));
1955 1956
	} else if (error == -ENOENT)
		nfs_dentry_handle_enoent(old_dentry);
L
Linus Torvalds 已提交
1957 1958 1959 1960 1961 1962 1963

	/* new dentry created? */
	if (dentry)
		dput(dentry);
	return error;
}

1964 1965 1966 1967
static DEFINE_SPINLOCK(nfs_access_lru_lock);
static LIST_HEAD(nfs_access_lru_list);
static atomic_long_t nfs_access_nr_entries;

1968 1969 1970 1971
static void nfs_access_free_entry(struct nfs_access_entry *entry)
{
	put_rpccred(entry->cred);
	kfree(entry);
1972 1973 1974
	smp_mb__before_atomic_dec();
	atomic_long_dec(&nfs_access_nr_entries);
	smp_mb__after_atomic_dec();
1975 1976
}

1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
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);
	}
}

1988 1989
int nfs_access_cache_shrinker(struct shrinker *shrink,
			      struct shrink_control *sc)
1990 1991
{
	LIST_HEAD(head);
1992
	struct nfs_inode *nfsi, *next;
1993
	struct nfs_access_entry *cache;
1994 1995
	int nr_to_scan = sc->nr_to_scan;
	gfp_t gfp_mask = sc->gfp_mask;
1996

1997 1998
	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
		return (nr_to_scan == 0) ? 0 : -1;
1999

2000
	spin_lock(&nfs_access_lru_lock);
2001
	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
2002 2003 2004 2005
		struct inode *inode;

		if (nr_to_scan-- == 0)
			break;
2006
		inode = &nfsi->vfs_inode;
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
		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);
2020
			smp_mb__before_clear_bit();
2021
			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2022
			smp_mb__after_clear_bit();
2023
		}
2024
		spin_unlock(&inode->i_lock);
2025 2026
	}
	spin_unlock(&nfs_access_lru_lock);
2027
	nfs_access_free_list(&head);
2028 2029 2030
	return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
}

2031
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
L
Linus Torvalds 已提交
2032
{
2033
	struct rb_root *root_node = &nfsi->access_cache;
2034
	struct rb_node *n;
2035 2036 2037 2038 2039 2040
	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);
2041
		list_move(&entry->lru, head);
2042 2043
	}
	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
L
Linus Torvalds 已提交
2044 2045
}

2046
void nfs_access_zap_cache(struct inode *inode)
L
Linus Torvalds 已提交
2047
{
2048 2049 2050 2051
	LIST_HEAD(head);

	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
		return;
2052
	/* Remove from global LRU init */
2053 2054
	spin_lock(&nfs_access_lru_lock);
	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2055 2056
		list_del_init(&NFS_I(inode)->access_cache_inode_lru);

2057
	spin_lock(&inode->i_lock);
2058 2059 2060 2061
	__nfs_access_zap_cache(NFS_I(inode), &head);
	spin_unlock(&inode->i_lock);
	spin_unlock(&nfs_access_lru_lock);
	nfs_access_free_list(&head);
2062
}
L
Linus Torvalds 已提交
2063

2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077
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;
L
Linus Torvalds 已提交
2078
	}
2079 2080 2081
	return NULL;
}

2082
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2083 2084 2085 2086 2087
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_access_entry *cache;
	int err = -ENOENT;

2088
	spin_lock(&inode->i_lock);
2089 2090 2091 2092 2093
	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
		goto out_zap;
	cache = nfs_access_search_rbtree(inode, cred);
	if (cache == NULL)
		goto out;
2094
	if (!nfs_have_delegated_attributes(inode) &&
2095
	    !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2096 2097 2098 2099
		goto out_stale;
	res->jiffies = cache->jiffies;
	res->cred = cache->cred;
	res->mask = cache->mask;
2100
	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2101 2102 2103 2104 2105 2106
	err = 0;
out:
	spin_unlock(&inode->i_lock);
	return err;
out_stale:
	rb_erase(&cache->rb_node, &nfsi->access_cache);
2107
	list_del(&cache->lru);
2108 2109 2110 2111
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(cache);
	return -ENOENT;
out_zap:
2112 2113
	spin_unlock(&inode->i_lock);
	nfs_access_zap_cache(inode);
2114 2115 2116 2117 2118
	return -ENOENT;
}

static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
{
2119 2120
	struct nfs_inode *nfsi = NFS_I(inode);
	struct rb_root *root_node = &nfsi->access_cache;
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138
	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);
2139
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2140
	spin_unlock(&inode->i_lock);
2141 2142 2143
	return;
found:
	rb_replace_node(parent, &set->rb_node, root_node);
2144 2145
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
	list_del(&entry->lru);
2146 2147 2148 2149
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(entry);
}

2150
static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2151 2152 2153 2154 2155
{
	struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
	if (cache == NULL)
		return;
	RB_CLEAR_NODE(&cache->rb_node);
L
Linus Torvalds 已提交
2156
	cache->jiffies = set->jiffies;
2157
	cache->cred = get_rpccred(set->cred);
L
Linus Torvalds 已提交
2158
	cache->mask = set->mask;
2159 2160

	nfs_access_add_rbtree(inode, cache);
2161 2162 2163 2164 2165 2166 2167

	/* 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 */
2168
	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2169
		spin_lock(&nfs_access_lru_lock);
2170 2171 2172
		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);
2173 2174
		spin_unlock(&nfs_access_lru_lock);
	}
L
Linus Torvalds 已提交
2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190
}

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);
2191 2192 2193 2194 2195 2196
	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);
		}
L
Linus Torvalds 已提交
2197
		return status;
2198
	}
L
Linus Torvalds 已提交
2199 2200
	nfs_access_add_cache(inode, &cache);
out:
2201
	if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2202 2203 2204 2205
		return 0;
	return -EACCES;
}

2206 2207 2208 2209
static int nfs_open_permission_mask(int openflags)
{
	int mask = 0;

2210
	if ((openflags & O_ACCMODE) != O_WRONLY)
2211
		mask |= MAY_READ;
2212
	if ((openflags & O_ACCMODE) != O_RDONLY)
2213
		mask |= MAY_WRITE;
2214
	if (openflags & __FMODE_EXEC)
2215 2216 2217 2218 2219 2220 2221 2222 2223
		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));
}

2224
int nfs_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2225 2226 2227 2228
{
	struct rpc_cred *cred;
	int res = 0;

2229
	if (mask & MAY_NOT_BLOCK)
2230 2231
		return -ECHILD;

C
Chuck Lever 已提交
2232 2233
	nfs_inc_stats(inode, NFSIOS_VFSACCESS);

2234
	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2235 2236
		goto out;
	/* Is this sys_access() ? */
E
Eric Paris 已提交
2237
	if (mask & (MAY_ACCESS | MAY_CHDIR))
L
Linus Torvalds 已提交
2238 2239 2240 2241 2242 2243 2244 2245
		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)
2246 2247
					&& (mask & MAY_OPEN)
					&& !(mask & MAY_EXEC))
L
Linus Torvalds 已提交
2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262
				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;

2263
	cred = rpc_lookup_cred();
L
Linus Torvalds 已提交
2264 2265 2266 2267 2268 2269
	if (!IS_ERR(cred)) {
		res = nfs_do_access(inode, cred, mask);
		put_rpccred(cred);
	} else
		res = PTR_ERR(cred);
out:
2270 2271 2272
	if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
		res = -EACCES;

C
Chuck Lever 已提交
2273 2274
	dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
		inode->i_sb->s_id, inode->i_ino, mask, res);
L
Linus Torvalds 已提交
2275 2276 2277 2278
	return res;
out_notsup:
	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (res == 0)
2279
		res = generic_permission(inode, mask);
C
Chuck Lever 已提交
2280
	goto out;
L
Linus Torvalds 已提交
2281 2282 2283 2284 2285 2286 2287 2288
}

/*
 * Local variables:
 *  version-control: t
 *  kept-new-versions: 5
 * End:
 */