dir.c 56.8 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);
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static struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
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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
/*
 * Use intent information to check whether or not we're going to do
 * an O_EXCL create using this path component.
 */
1037
static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
1038 1039 1040
{
	if (NFS_PROTO(dir)->version == 2)
		return 0;
1041
	return flags & LOOKUP_EXCL;
1042 1043
}

1044 1045 1046 1047 1048 1049 1050 1051
/*
 * 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
1052
static inline
1053
int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
L
Linus Torvalds 已提交
1054 1055 1056
{
	struct nfs_server *server = NFS_SERVER(inode);

1057
	if (IS_AUTOMOUNT(inode))
1058
		return 0;
1059
	/* VFS wants an on-the-wire revalidation */
1060
	if (flags & LOOKUP_REVAL)
1061 1062
		goto out_force;
	/* This is an open(2) */
1063 1064
	if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
1065 1066
		goto out_force;
	return 0;
L
Linus Torvalds 已提交
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
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,
1080
		       unsigned int flags)
L
Linus Torvalds 已提交
1081 1082
{
	/* Don't revalidate a negative dentry if we're creating a new file */
1083
	if (flags & LOOKUP_CREATE)
L
Linus Torvalds 已提交
1084
		return 0;
1085 1086
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
		return 1;
L
Linus Torvalds 已提交
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100
	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.
 */
1101
static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
L
Linus Torvalds 已提交
1102 1103 1104 1105
{
	struct inode *dir;
	struct inode *inode;
	struct dentry *parent;
1106 1107
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1108 1109
	int error;

1110
	if (flags & LOOKUP_RCU)
1111 1112
		return -ECHILD;

L
Linus Torvalds 已提交
1113 1114
	parent = dget_parent(dentry);
	dir = parent->d_inode;
C
Chuck Lever 已提交
1115
	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
L
Linus Torvalds 已提交
1116 1117 1118
	inode = dentry->d_inode;

	if (!inode) {
1119
		if (nfs_neg_need_reval(dir, dentry, flags))
L
Linus Torvalds 已提交
1120
			goto out_bad;
1121
		goto out_valid_noent;
L
Linus Torvalds 已提交
1122 1123 1124
	}

	if (is_bad_inode(inode)) {
C
Chuck Lever 已提交
1125
		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1126
				__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1127
				dentry->d_name.name);
L
Linus Torvalds 已提交
1128 1129 1130
		goto out_bad;
	}

1131 1132 1133
	if (nfs_have_delegation(inode, FMODE_READ))
		goto out_set_verifier;

L
Linus Torvalds 已提交
1134
	/* Force a full look up iff the parent directory has changed */
1135 1136
	if (!nfs_is_exclusive_create(dir, flags) && nfs_check_verifier(dir, dentry)) {
		if (nfs_lookup_verify_inode(inode, flags))
L
Linus Torvalds 已提交
1137 1138 1139 1140 1141 1142 1143
			goto out_zap_parent;
		goto out_valid;
	}

	if (NFS_STALE(inode))
		goto out_bad;

1144 1145 1146 1147 1148 1149
	error = -ENOMEM;
	fhandle = nfs_alloc_fhandle();
	fattr = nfs_alloc_fattr();
	if (fhandle == NULL || fattr == NULL)
		goto out_error;

1150
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1151 1152
	if (error)
		goto out_bad;
1153
	if (nfs_compare_fh(NFS_FH(inode), fhandle))
L
Linus Torvalds 已提交
1154
		goto out_bad;
1155
	if ((error = nfs_refresh_inode(inode, fattr)) != 0)
L
Linus Torvalds 已提交
1156 1157
		goto out_bad;

1158 1159
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
1160
out_set_verifier:
1161
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1162
 out_valid:
1163 1164 1165
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);
 out_valid_noent:
L
Linus Torvalds 已提交
1166
	dput(parent);
C
Chuck Lever 已提交
1167
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1168
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1169
			dentry->d_name.name);
L
Linus Torvalds 已提交
1170 1171 1172 1173
	return 1;
out_zap_parent:
	nfs_zap_caches(dir);
 out_bad:
1174
	nfs_mark_for_revalidate(dir);
L
Linus Torvalds 已提交
1175 1176 1177 1178 1179 1180
	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;
1181 1182
		if (dentry->d_flags & DCACHE_DISCONNECTED)
			goto out_valid;
L
Linus Torvalds 已提交
1183 1184 1185
		shrink_dcache_parent(dentry);
	}
	d_drop(dentry);
1186 1187
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1188
	dput(parent);
C
Chuck Lever 已提交
1189
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1190
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1191
			dentry->d_name.name);
L
Linus Torvalds 已提交
1192
	return 0;
1193 1194 1195 1196 1197 1198 1199 1200
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
1201 1202 1203 1204 1205
}

/*
 * This is called from dput() when d_count is going to 0.
 */
N
Nick Piggin 已提交
1206
static int nfs_dentry_delete(const struct dentry *dentry)
L
Linus Torvalds 已提交
1207 1208 1209 1210 1211
{
	dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		dentry->d_flags);

1212 1213 1214 1215
	/* 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
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
	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;

}

1229 1230 1231 1232 1233 1234 1235 1236
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
1237 1238 1239 1240 1241 1242
/*
 * 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)
{
1243 1244 1245 1246
	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
1247
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1248
		drop_nlink(inode);
1249
		nfs_complete_unlink(dentry, inode);
L
Linus Torvalds 已提交
1250 1251 1252 1253
	}
	iput(inode);
}

1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264
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
1265
const struct dentry_operations nfs_dentry_operations = {
L
Linus Torvalds 已提交
1266 1267 1268
	.d_revalidate	= nfs_lookup_revalidate,
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1269
	.d_automount	= nfs_d_automount,
1270
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1271 1272
};

A
Al Viro 已提交
1273
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
L
Linus Torvalds 已提交
1274 1275
{
	struct dentry *res;
T
Trond Myklebust 已提交
1276
	struct dentry *parent;
L
Linus Torvalds 已提交
1277
	struct inode *inode = NULL;
1278 1279
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1280 1281 1282 1283
	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
1284
	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
L
Linus Torvalds 已提交
1285 1286 1287 1288 1289

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

1290 1291 1292 1293
	/*
	 * If we're doing an exclusive create, optimize away the lookup
	 * but don't hash the dentry.
	 */
A
Al Viro 已提交
1294
	if (nfs_is_exclusive_create(dir, flags)) {
1295 1296
		d_instantiate(dentry, NULL);
		res = NULL;
1297
		goto out;
1298
	}
L
Linus Torvalds 已提交
1299

1300 1301 1302 1303 1304 1305
	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
1306 1307 1308
	parent = dentry->d_parent;
	/* Protect against concurrent sillydeletes */
	nfs_block_sillyrename(parent);
1309
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1310 1311 1312 1313
	if (error == -ENOENT)
		goto no_entry;
	if (error < 0) {
		res = ERR_PTR(error);
T
Trond Myklebust 已提交
1314
		goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1315
	}
1316
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
N
Namhyung Kim 已提交
1317
	res = ERR_CAST(inode);
1318
	if (IS_ERR(res))
T
Trond Myklebust 已提交
1319
		goto out_unblock_sillyrename;
1320

1321 1322 1323
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);

L
Linus Torvalds 已提交
1324
no_entry:
1325
	res = d_materialise_unique(dentry, inode);
1326 1327
	if (res != NULL) {
		if (IS_ERR(res))
T
Trond Myklebust 已提交
1328
			goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1329
		dentry = res;
1330
	}
L
Linus Torvalds 已提交
1331
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
T
Trond Myklebust 已提交
1332 1333
out_unblock_sillyrename:
	nfs_unblock_sillyrename(parent);
L
Linus Torvalds 已提交
1334
out:
1335 1336
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1337 1338 1339 1340
	return res;
}

#ifdef CONFIG_NFS_V4
1341
static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
L
Linus Torvalds 已提交
1342

A
Al Viro 已提交
1343
const struct dentry_operations nfs4_dentry_operations = {
1344
	.d_revalidate	= nfs4_lookup_revalidate,
L
Linus Torvalds 已提交
1345 1346
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1347
	.d_automount	= nfs_d_automount,
1348
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1349 1350
};

1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
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;
}

1361
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1362
{
1363
	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1364 1365 1366 1367 1368 1369 1370 1371
}

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
1372 1373
static int nfs_finish_open(struct nfs_open_context *ctx,
			   struct dentry *dentry,
A
Al Viro 已提交
1374
			   struct file *file, unsigned open_flags,
A
Al Viro 已提交
1375
			   int *opened)
1376
{
1377 1378 1379 1380 1381 1382
	int err;

	if (ctx->dentry != dentry) {
		dput(ctx->dentry);
		ctx->dentry = dget(dentry);
	}
1383 1384 1385

	/* If the open_intent is for execute, we have an extra check to make */
	if (ctx->mode & FMODE_EXEC) {
1386
		err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
A
Al Viro 已提交
1387
		if (err < 0)
1388 1389
			goto out;
	}
1390

A
Al Viro 已提交
1391 1392
	err = finish_open(file, dentry, do_open, opened);
	if (err)
A
Al Viro 已提交
1393
		goto out;
A
Al Viro 已提交
1394
	nfs_file_set_open_context(file, ctx);
1395

1396 1397
out:
	put_nfs_open_context(ctx);
A
Al Viro 已提交
1398
	return err;
1399 1400
}

A
Al Viro 已提交
1401
static int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
A
Al Viro 已提交
1402
			    struct file *file, unsigned open_flags,
A
Al Viro 已提交
1403
			    umode_t mode, int *opened)
L
Linus Torvalds 已提交
1404
{
1405
	struct nfs_open_context *ctx;
1406 1407
	struct dentry *res;
	struct iattr attr = { .ia_valid = ATTR_OPEN };
1408
	struct inode *inode;
1409
	int err;
L
Linus Torvalds 已提交
1410

1411 1412 1413 1414
	/* Expect a negative dentry */
	BUG_ON(dentry->d_inode);

	dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
C
Chuck Lever 已提交
1415 1416
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);

1417 1418 1419 1420 1421 1422 1423 1424
	/* 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
1425
			return -ENOENT;
1426
		}
L
Linus Torvalds 已提交
1427
		goto no_open;
1428
	}
L
Linus Torvalds 已提交
1429

1430
	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
A
Al Viro 已提交
1431
		return -ENAMETOOLONG;
1432

1433
	if (open_flags & O_CREAT) {
1434
		attr.ia_valid |= ATTR_MODE;
1435 1436
		attr.ia_mode = mode & ~current_umask();
	}
1437 1438 1439
	if (open_flags & O_TRUNC) {
		attr.ia_valid |= ATTR_SIZE;
		attr.ia_size = 0;
1440 1441
	}

1442 1443 1444
	ctx = create_nfs_open_context(dentry, open_flags);
	err = PTR_ERR(ctx);
	if (IS_ERR(ctx))
A
Al Viro 已提交
1445
		goto out;
1446

1447
	nfs_block_sillyrename(dentry->d_parent);
1448
	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1449
	d_drop(dentry);
1450 1451
	if (IS_ERR(inode)) {
		nfs_unblock_sillyrename(dentry->d_parent);
1452
		put_nfs_open_context(ctx);
1453 1454 1455 1456 1457 1458 1459 1460 1461 1462
		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))
1463
				goto no_open;
1464
			break;
L
Linus Torvalds 已提交
1465
			/* case -EINVAL: */
1466 1467
		default:
			break;
L
Linus Torvalds 已提交
1468
		}
A
Al Viro 已提交
1469
		goto out;
1470
	}
1471
	res = d_add_unique(dentry, inode);
1472
	if (res != NULL)
L
Linus Torvalds 已提交
1473
		dentry = res;
1474 1475

	nfs_unblock_sillyrename(dentry->d_parent);
1476
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1477

A
Al Viro 已提交
1478
	err = nfs_finish_open(ctx, dentry, file, open_flags, opened);
1479 1480

	dput(res);
A
Al Viro 已提交
1481 1482
out:
	return err;
1483

L
Linus Torvalds 已提交
1484
no_open:
A
Al Viro 已提交
1485
	res = nfs_lookup(dir, dentry, 0);
1486 1487
	err = PTR_ERR(res);
	if (IS_ERR(res))
A
Al Viro 已提交
1488
		goto out;
1489

A
Al Viro 已提交
1490
	return finish_no_open(file, res);
L
Linus Torvalds 已提交
1491 1492
}

1493
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
L
Linus Torvalds 已提交
1494 1495
{
	struct dentry *parent = NULL;
N
Nick Piggin 已提交
1496
	struct inode *inode;
L
Linus Torvalds 已提交
1497
	struct inode *dir;
1498
	int ret = 0;
L
Linus Torvalds 已提交
1499

1500
	if (flags & LOOKUP_RCU)
N
Nick Piggin 已提交
1501 1502
		return -ECHILD;

1503
	if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
1504 1505
		goto no_open;
	if (d_mountpoint(dentry))
T
Trond Myklebust 已提交
1506
		goto no_open;
1507

1508
	inode = dentry->d_inode;
L
Linus Torvalds 已提交
1509 1510
	parent = dget_parent(dentry);
	dir = parent->d_inode;
1511

L
Linus Torvalds 已提交
1512 1513 1514
	/* We can't create new files in nfs_open_revalidate(), so we
	 * optimize away revalidation of negative dentries.
	 */
1515
	if (inode == NULL) {
1516
		if (!nfs_neg_need_reval(dir, dentry, flags))
1517
			ret = 1;
L
Linus Torvalds 已提交
1518
		goto out;
1519 1520
	}

L
Linus Torvalds 已提交
1521 1522
	/* NFS only supports OPEN on regular files */
	if (!S_ISREG(inode->i_mode))
T
Trond Myklebust 已提交
1523
		goto no_open_dput;
L
Linus Torvalds 已提交
1524
	/* We cannot do exclusive creation on a positive dentry */
1525
	if (flags & LOOKUP_EXCL)
T
Trond Myklebust 已提交
1526
		goto no_open_dput;
L
Linus Torvalds 已提交
1527

1528 1529
	/* Let f_op->open() actually open (and revalidate) the file */
	ret = 1;
1530

L
Linus Torvalds 已提交
1531 1532 1533
out:
	dput(parent);
	return ret;
1534

T
Trond Myklebust 已提交
1535
no_open_dput:
L
Linus Torvalds 已提交
1536
	dput(parent);
T
Trond Myklebust 已提交
1537
no_open:
1538
	return nfs_lookup_revalidate(dentry, flags);
L
Linus Torvalds 已提交
1539
}
1540

L
Linus Torvalds 已提交
1541 1542 1543 1544 1545 1546 1547 1548
#endif /* CONFIG_NFSV4 */

/*
 * Code common to create, mkdir, and mknod.
 */
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
				struct nfs_fattr *fattr)
{
1549 1550
	struct dentry *parent = dget_parent(dentry);
	struct inode *dir = parent->d_inode;
L
Linus Torvalds 已提交
1551 1552 1553
	struct inode *inode;
	int error = -EACCES;

1554 1555
	d_drop(dentry);

L
Linus Torvalds 已提交
1556 1557
	/* We may have been initialized further down */
	if (dentry->d_inode)
1558
		goto out;
L
Linus Torvalds 已提交
1559
	if (fhandle->size == 0) {
1560
		error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1561
		if (error)
1562
			goto out_error;
L
Linus Torvalds 已提交
1563
	}
1564
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1565 1566
	if (!(fattr->valid & NFS_ATTR_FATTR)) {
		struct nfs_server *server = NFS_SB(dentry->d_sb);
1567
		error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
L
Linus Torvalds 已提交
1568
		if (error < 0)
1569
			goto out_error;
L
Linus Torvalds 已提交
1570 1571
	}
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1572 1573
	error = PTR_ERR(inode);
	if (IS_ERR(inode))
1574 1575 1576 1577
		goto out_error;
	d_add(dentry, inode);
out:
	dput(parent);
L
Linus Torvalds 已提交
1578
	return 0;
1579 1580 1581 1582
out_error:
	nfs_mark_for_revalidate(dir);
	dput(parent);
	return error;
L
Linus Torvalds 已提交
1583 1584 1585 1586 1587 1588 1589 1590
}

/*
 * 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
1591 1592
static int nfs_create(struct inode *dir, struct dentry *dentry,
		umode_t mode, struct nameidata *nd)
L
Linus Torvalds 已提交
1593 1594 1595
{
	struct iattr attr;
	int error;
1596
	int open_flags = O_CREAT|O_EXCL;
L
Linus Torvalds 已提交
1597

C
Chuck Lever 已提交
1598 1599
	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
1600 1601 1602 1603

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

1604 1605
	if (nd && !(nd->flags & LOOKUP_EXCL))
		open_flags = O_CREAT;
1606

1607
	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
L
Linus Torvalds 已提交
1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619
	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
1620
nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
L
Linus Torvalds 已提交
1621 1622 1623 1624
{
	struct iattr attr;
	int status;

C
Chuck Lever 已提交
1625 1626
	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
1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645

	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.
 */
1646
static int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
1647 1648 1649 1650
{
	struct iattr attr;
	int error;

C
Chuck Lever 已提交
1651 1652
	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
1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665

	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;
}

1666 1667 1668 1669 1670 1671
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
1672 1673 1674 1675
static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int error;

C
Chuck Lever 已提交
1676 1677
	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
1678 1679 1680 1681

	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
	/* Ensure the VFS deletes this inode */
	if (error == 0 && dentry->d_inode != NULL)
1682
		clear_nlink(dentry->d_inode);
1683 1684
	else if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711

	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) {
1712
		nfs_inode_return_delegation(inode);
L
Linus Torvalds 已提交
1713 1714 1715
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
		/* The VFS may want to delete this inode */
		if (error == 0)
1716
			nfs_drop_nlink(inode);
1717
		nfs_mark_for_revalidate(inode);
L
Linus Torvalds 已提交
1718 1719
	} else
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1720 1721
	if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
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
1740
	if (dentry->d_count > 1) {
L
Linus Torvalds 已提交
1741
		spin_unlock(&dentry->d_lock);
T
Trond Myklebust 已提交
1742 1743
		/* Start asynchronous writeout of the inode */
		write_inode_now(dentry->d_inode, 0);
L
Linus Torvalds 已提交
1744 1745 1746 1747 1748 1749 1750 1751 1752
		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);
1753
	if (!error || error == -ENOENT) {
L
Linus Torvalds 已提交
1754 1755 1756 1757 1758 1759
		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
	} else if (need_rehash)
		d_rehash(dentry);
	return error;
}

1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775
/*
 * 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
1776
{
1777 1778 1779
	struct pagevec lru_pvec;
	struct page *page;
	char *kaddr;
L
Linus Torvalds 已提交
1780
	struct iattr attr;
1781
	unsigned int pathlen = strlen(symname);
L
Linus Torvalds 已提交
1782 1783 1784 1785 1786
	int error;

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

1787 1788
	if (pathlen > PAGE_SIZE)
		return -ENAMETOOLONG;
L
Linus Torvalds 已提交
1789

1790 1791
	attr.ia_mode = S_IFLNK | S_IRWXUGO;
	attr.ia_valid = ATTR_MODE;
L
Linus Torvalds 已提交
1792

1793
	page = alloc_page(GFP_HIGHUSER);
1794
	if (!page)
1795 1796
		return -ENOMEM;

1797
	kaddr = kmap_atomic(page);
1798 1799 1800
	memcpy(kaddr, symname, pathlen);
	if (pathlen < PAGE_SIZE)
		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1801
	kunmap_atomic(kaddr);
1802

1803
	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1804 1805 1806 1807
	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
1808
		d_drop(dentry);
1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
		__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)) {
1820
		pagevec_add(&lru_pvec, page);
1821
		pagevec_lru_add_file(&lru_pvec);
1822 1823 1824 1825 1826 1827
		SetPageUptodate(page);
		unlock_page(page);
	} else
		__free_page(page);

	return 0;
L
Linus Torvalds 已提交
1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839
}

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);

1840 1841
	nfs_inode_return_delegation(inode);

1842
	d_drop(dentry);
L
Linus Torvalds 已提交
1843
	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1844
	if (error == 0) {
A
Al Viro 已提交
1845
		ihold(inode);
1846
		d_add(dentry, inode);
1847
	}
L
Linus Torvalds 已提交
1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
	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
1886
		 new_dentry->d_count);
L
Linus Torvalds 已提交
1887 1888

	/*
M
Miklos Szeredi 已提交
1889 1890 1891 1892
	 * 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
1893
	 */
1894 1895 1896 1897 1898 1899 1900 1901 1902
	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
1903

N
Nick Piggin 已提交
1904
		if (new_dentry->d_count > 2) {
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914
			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);
1915
			if (err)
1916
				goto out;
1917 1918

			new_dentry = dentry;
O
OGAWA Hirofumi 已提交
1919
			rehash = NULL;
1920
			new_inode = NULL;
1921
		}
1922
	}
L
Linus Torvalds 已提交
1923

1924
	nfs_inode_return_delegation(old_inode);
1925
	if (new_inode != NULL)
1926
		nfs_inode_return_delegation(new_inode);
L
Linus Torvalds 已提交
1927 1928 1929

	error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
					   new_dir, &new_dentry->d_name);
1930
	nfs_mark_for_revalidate(old_inode);
L
Linus Torvalds 已提交
1931 1932 1933 1934
out:
	if (rehash)
		d_rehash(rehash);
	if (!error) {
1935 1936
		if (new_inode != NULL)
			nfs_drop_nlink(new_inode);
1937
		d_move(old_dentry, new_dentry);
1938 1939
		nfs_set_verifier(new_dentry,
					nfs_save_change_attribute(new_dir));
1940 1941
	} else if (error == -ENOENT)
		nfs_dentry_handle_enoent(old_dentry);
L
Linus Torvalds 已提交
1942 1943 1944 1945 1946 1947 1948

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

1949 1950 1951 1952
static DEFINE_SPINLOCK(nfs_access_lru_lock);
static LIST_HEAD(nfs_access_lru_list);
static atomic_long_t nfs_access_nr_entries;

1953 1954 1955 1956
static void nfs_access_free_entry(struct nfs_access_entry *entry)
{
	put_rpccred(entry->cred);
	kfree(entry);
1957 1958 1959
	smp_mb__before_atomic_dec();
	atomic_long_dec(&nfs_access_nr_entries);
	smp_mb__after_atomic_dec();
1960 1961
}

1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
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);
	}
}

1973 1974
int nfs_access_cache_shrinker(struct shrinker *shrink,
			      struct shrink_control *sc)
1975 1976
{
	LIST_HEAD(head);
1977
	struct nfs_inode *nfsi, *next;
1978
	struct nfs_access_entry *cache;
1979 1980
	int nr_to_scan = sc->nr_to_scan;
	gfp_t gfp_mask = sc->gfp_mask;
1981

1982 1983
	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
		return (nr_to_scan == 0) ? 0 : -1;
1984

1985
	spin_lock(&nfs_access_lru_lock);
1986
	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
1987 1988 1989 1990
		struct inode *inode;

		if (nr_to_scan-- == 0)
			break;
1991
		inode = &nfsi->vfs_inode;
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
		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);
2005
			smp_mb__before_clear_bit();
2006
			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2007
			smp_mb__after_clear_bit();
2008
		}
2009
		spin_unlock(&inode->i_lock);
2010 2011
	}
	spin_unlock(&nfs_access_lru_lock);
2012
	nfs_access_free_list(&head);
2013 2014 2015
	return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
}

2016
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
L
Linus Torvalds 已提交
2017
{
2018
	struct rb_root *root_node = &nfsi->access_cache;
2019
	struct rb_node *n;
2020 2021 2022 2023 2024 2025
	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);
2026
		list_move(&entry->lru, head);
2027 2028
	}
	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
L
Linus Torvalds 已提交
2029 2030
}

2031
void nfs_access_zap_cache(struct inode *inode)
L
Linus Torvalds 已提交
2032
{
2033 2034 2035 2036
	LIST_HEAD(head);

	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
		return;
2037
	/* Remove from global LRU init */
2038 2039
	spin_lock(&nfs_access_lru_lock);
	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2040 2041
		list_del_init(&NFS_I(inode)->access_cache_inode_lru);

2042
	spin_lock(&inode->i_lock);
2043 2044 2045 2046
	__nfs_access_zap_cache(NFS_I(inode), &head);
	spin_unlock(&inode->i_lock);
	spin_unlock(&nfs_access_lru_lock);
	nfs_access_free_list(&head);
2047
}
L
Linus Torvalds 已提交
2048

2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062
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
2063
	}
2064 2065 2066
	return NULL;
}

2067
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2068 2069 2070 2071 2072
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_access_entry *cache;
	int err = -ENOENT;

2073
	spin_lock(&inode->i_lock);
2074 2075 2076 2077 2078
	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
		goto out_zap;
	cache = nfs_access_search_rbtree(inode, cred);
	if (cache == NULL)
		goto out;
2079
	if (!nfs_have_delegated_attributes(inode) &&
2080
	    !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2081 2082 2083 2084
		goto out_stale;
	res->jiffies = cache->jiffies;
	res->cred = cache->cred;
	res->mask = cache->mask;
2085
	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2086 2087 2088 2089 2090 2091
	err = 0;
out:
	spin_unlock(&inode->i_lock);
	return err;
out_stale:
	rb_erase(&cache->rb_node, &nfsi->access_cache);
2092
	list_del(&cache->lru);
2093 2094 2095 2096
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(cache);
	return -ENOENT;
out_zap:
2097 2098
	spin_unlock(&inode->i_lock);
	nfs_access_zap_cache(inode);
2099 2100 2101 2102 2103
	return -ENOENT;
}

static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
{
2104 2105
	struct nfs_inode *nfsi = NFS_I(inode);
	struct rb_root *root_node = &nfsi->access_cache;
2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
	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);
2124
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2125
	spin_unlock(&inode->i_lock);
2126 2127 2128
	return;
found:
	rb_replace_node(parent, &set->rb_node, root_node);
2129 2130
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
	list_del(&entry->lru);
2131 2132 2133 2134
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(entry);
}

2135
static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2136 2137 2138 2139 2140
{
	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
2141
	cache->jiffies = set->jiffies;
2142
	cache->cred = get_rpccred(set->cred);
L
Linus Torvalds 已提交
2143
	cache->mask = set->mask;
2144 2145

	nfs_access_add_rbtree(inode, cache);
2146 2147 2148 2149 2150 2151 2152

	/* 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 */
2153
	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2154
		spin_lock(&nfs_access_lru_lock);
2155 2156 2157
		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);
2158 2159
		spin_unlock(&nfs_access_lru_lock);
	}
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175
}

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);
2176 2177 2178 2179 2180 2181
	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
2182
		return status;
2183
	}
L
Linus Torvalds 已提交
2184 2185
	nfs_access_add_cache(inode, &cache);
out:
2186
	if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2187 2188 2189 2190
		return 0;
	return -EACCES;
}

2191 2192 2193 2194
static int nfs_open_permission_mask(int openflags)
{
	int mask = 0;

2195
	if ((openflags & O_ACCMODE) != O_WRONLY)
2196
		mask |= MAY_READ;
2197
	if ((openflags & O_ACCMODE) != O_RDONLY)
2198
		mask |= MAY_WRITE;
2199
	if (openflags & __FMODE_EXEC)
2200 2201 2202 2203 2204 2205 2206 2207 2208
		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));
}

2209
int nfs_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2210 2211 2212 2213
{
	struct rpc_cred *cred;
	int res = 0;

2214
	if (mask & MAY_NOT_BLOCK)
2215 2216
		return -ECHILD;

C
Chuck Lever 已提交
2217 2218
	nfs_inc_stats(inode, NFSIOS_VFSACCESS);

2219
	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2220 2221
		goto out;
	/* Is this sys_access() ? */
E
Eric Paris 已提交
2222
	if (mask & (MAY_ACCESS | MAY_CHDIR))
L
Linus Torvalds 已提交
2223 2224 2225 2226 2227 2228 2229 2230
		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)
2231 2232
					&& (mask & MAY_OPEN)
					&& !(mask & MAY_EXEC))
L
Linus Torvalds 已提交
2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247
				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;

2248
	cred = rpc_lookup_cred();
L
Linus Torvalds 已提交
2249 2250 2251 2252 2253 2254
	if (!IS_ERR(cred)) {
		res = nfs_do_access(inode, cred, mask);
		put_rpccred(cred);
	} else
		res = PTR_ERR(cred);
out:
2255 2256 2257
	if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
		res = -EACCES;

C
Chuck Lever 已提交
2258 2259
	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
2260 2261 2262 2263
	return res;
out_notsup:
	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (res == 0)
2264
		res = generic_permission(inode, mask);
C
Chuck Lever 已提交
2265
	goto out;
L
Linus Torvalds 已提交
2266 2267 2268 2269 2270 2271 2272 2273
}

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