dir.c 55.8 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
 */

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#include <linux/module.h>
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#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 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 address_space_operations nfs_dir_aops = {
	.freepage = nfs_readdir_clear_array,
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};

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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 {
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			if (d_invalidate(dentry) != 0)
				goto out;
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			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);
}

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/* Perform conversion from xdr to cache array */
static
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int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
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				struct page **xdr_pages, struct page *page, unsigned int buflen)
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{
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	struct xdr_stream stream;
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	struct xdr_buf buf;
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	struct page *scratch;
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	struct nfs_cache_array *array;
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	unsigned int count = 0;
	int status;
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	scratch = alloc_page(GFP_KERNEL);
	if (scratch == NULL)
		return -ENOMEM;
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	xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
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	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
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	do {
		status = xdr_decode(desc, entry, &stream);
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		if (status != 0) {
			if (status == -EAGAIN)
				status = 0;
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			break;
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		}
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		count++;

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		if (desc->plus != 0)
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			nfs_prime_dcache(desc->file->f_path.dentry, entry);
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		status = nfs_readdir_add_to_array(entry, page);
		if (status != 0)
			break;
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	} while (!entry->eof);

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	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
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		array = nfs_readdir_get_array(page);
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		if (!IS_ERR(array)) {
			array->eof_index = array->size;
			status = 0;
			nfs_readdir_release_array(page);
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		} else
			status = PTR_ERR(array);
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	}
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	put_page(scratch);
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	return status;
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}

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
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int nfs_readdir_large_page(struct page **pages, unsigned int npages)
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{
	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;
	}
561
	return 0;
B
Bryan Schumaker 已提交
562 563 564

out_freepages:
	nfs_readdir_free_pagearray(pages, i);
565
	return -ENOMEM;
L
Linus Torvalds 已提交
566 567
}

B
Bryan Schumaker 已提交
568 569
static
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
570
{
B
Bryan Schumaker 已提交
571 572
	struct page *pages[NFS_MAX_READDIR_PAGES];
	void *pages_ptr = NULL;
B
Bryan Schumaker 已提交
573 574 575
	struct nfs_entry entry;
	struct file	*file = desc->file;
	struct nfs_cache_array *array;
576
	int status = -ENOMEM;
B
Bryan Schumaker 已提交
577
	unsigned int array_size = ARRAY_SIZE(pages);
B
Bryan Schumaker 已提交
578 579

	entry.prev_cookie = 0;
580
	entry.cookie = desc->last_cookie;
B
Bryan Schumaker 已提交
581 582 583
	entry.eof = 0;
	entry.fh = nfs_alloc_fhandle();
	entry.fattr = nfs_alloc_fattr();
584
	entry.server = NFS_SERVER(inode);
B
Bryan Schumaker 已提交
585 586
	if (entry.fh == NULL || entry.fattr == NULL)
		goto out;
587

B
Bryan Schumaker 已提交
588
	array = nfs_readdir_get_array(page);
589 590 591 592
	if (IS_ERR(array)) {
		status = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
593 594
	memset(array, 0, sizeof(struct nfs_cache_array));
	array->eof_index = -1;
595

596 597
	status = nfs_readdir_large_page(pages, array_size);
	if (status < 0)
B
Bryan Schumaker 已提交
598 599
		goto out_release_array;
	do {
600
		unsigned int pglen;
B
Bryan Schumaker 已提交
601
		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
602

B
Bryan Schumaker 已提交
603
		if (status < 0)
604
			break;
605
		pglen = status;
606
		status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
607 608 609 610 611 612
		if (status < 0) {
			if (status == -ENOSPC)
				status = 0;
			break;
		}
	} while (array->eof_index < 0);
B
Bryan Schumaker 已提交
613

B
Bryan Schumaker 已提交
614
	nfs_readdir_free_large_page(pages_ptr, pages, array_size);
B
Bryan Schumaker 已提交
615 616 617 618 619
out_release_array:
	nfs_readdir_release_array(page);
out:
	nfs_free_fattr(entry.fattr);
	nfs_free_fhandle(entry.fh);
620 621 622 623
	return status;
}

/*
B
Bryan Schumaker 已提交
624 625 626 627
 * 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
628
 */
B
Bryan Schumaker 已提交
629 630
static
int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
L
Linus Torvalds 已提交
631
{
632
	struct inode	*inode = desc->file->f_path.dentry->d_inode;
633
	int ret;
L
Linus Torvalds 已提交
634

635 636
	ret = nfs_readdir_xdr_to_array(desc, page, inode);
	if (ret < 0)
B
Bryan Schumaker 已提交
637 638
		goto error;
	SetPageUptodate(page);
L
Linus Torvalds 已提交
639

B
Bryan Schumaker 已提交
640 641 642
	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
643
	}
B
Bryan Schumaker 已提交
644 645 646 647
	unlock_page(page);
	return 0;
 error:
	unlock_page(page);
648
	return ret;
B
Bryan Schumaker 已提交
649
}
L
Linus Torvalds 已提交
650

B
Bryan Schumaker 已提交
651 652 653
static
void cache_page_release(nfs_readdir_descriptor_t *desc)
{
654 655
	if (!desc->page->mapping)
		nfs_readdir_clear_array(desc->page);
B
Bryan Schumaker 已提交
656 657 658 659 660 661 662
	page_cache_release(desc->page);
	desc->page = NULL;
}

static
struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
{
663
	return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
B
Bryan Schumaker 已提交
664
			desc->page_index, (filler_t *)nfs_readdir_filler, desc);
L
Linus Torvalds 已提交
665 666 667
}

/*
B
Bryan Schumaker 已提交
668
 * Returns 0 if desc->dir_cookie was found on page desc->page_index
L
Linus Torvalds 已提交
669
 */
B
Bryan Schumaker 已提交
670 671 672 673 674 675 676 677 678 679
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
680 681
	if (res != 0)
		cache_page_release(desc);
B
Bryan Schumaker 已提交
682 683 684 685
	return res;
}

/* Search for desc->dir_cookie from the beginning of the page cache */
L
Linus Torvalds 已提交
686 687 688
static inline
int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
{
689
	int res;
B
Bryan Schumaker 已提交
690

691
	if (desc->page_index == 0) {
692
		desc->current_index = 0;
693 694
		desc->last_cookie = 0;
	}
T
Trond Myklebust 已提交
695
	do {
B
Bryan Schumaker 已提交
696
		res = find_cache_page(desc);
T
Trond Myklebust 已提交
697
	} while (res == -EAGAIN);
L
Linus Torvalds 已提交
698 699 700 701 702 703 704 705 706 707 708
	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
709 710 711
	int i = 0;
	int res = 0;
	struct nfs_cache_array *array = NULL;
712 713
	struct nfs_open_dir_context *ctx = file->private_data;

B
Bryan Schumaker 已提交
714
	array = nfs_readdir_get_array(desc->page);
715 716 717 718
	if (IS_ERR(array)) {
		res = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
719 720

	for (i = desc->cache_entry_index; i < array->size; i++) {
721
		struct nfs_cache_array_entry *ent;
L
Linus Torvalds 已提交
722

723 724
		ent = &array->array[i];
		if (filldir(dirent, ent->string.name, ent->string.len,
725 726
		    file->f_pos, nfs_compat_user_ino64(ent->ino),
		    ent->d_type) < 0) {
727
			desc->eof = 1;
L
Linus Torvalds 已提交
728
			break;
729
		}
730
		file->f_pos++;
B
Bryan Schumaker 已提交
731 732 733 734
		if (i < (array->size-1))
			*desc->dir_cookie = array->array[i+1].cookie;
		else
			*desc->dir_cookie = array->last_cookie;
735 736
		if (ctx->duped != 0)
			ctx->duped = 1;
L
Linus Torvalds 已提交
737
	}
T
Trond Myklebust 已提交
738
	if (array->eof_index >= 0)
739
		desc->eof = 1;
B
Bryan Schumaker 已提交
740 741

	nfs_readdir_release_array(desc->page);
742
out:
B
Bryan Schumaker 已提交
743
	cache_page_release(desc);
C
Chuck Lever 已提交
744 745
	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
746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
	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
767
	struct inode *inode = desc->file->f_path.dentry->d_inode;
768
	struct nfs_open_dir_context *ctx = desc->file->private_data;
L
Linus Torvalds 已提交
769

C
Chuck Lever 已提交
770 771
	dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
			(unsigned long long)*desc->dir_cookie);
L
Linus Torvalds 已提交
772 773 774 775 776 777

	page = alloc_page(GFP_HIGHUSER);
	if (!page) {
		status = -ENOMEM;
		goto out;
	}
B
Bryan Schumaker 已提交
778

779
	desc->page_index = 0;
780
	desc->last_cookie = *desc->dir_cookie;
781
	desc->page = page;
782
	ctx->duped = 0;
783

784 785
	status = nfs_readdir_xdr_to_array(desc, page, inode);
	if (status < 0)
L
Linus Torvalds 已提交
786 787 788 789 790
		goto out_release;

	status = nfs_do_filldir(desc, dirent, filldir);

 out:
C
Chuck Lever 已提交
791
	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
792
			__func__, status);
L
Linus Torvalds 已提交
793 794
	return status;
 out_release:
B
Bryan Schumaker 已提交
795
	cache_page_release(desc);
L
Linus Torvalds 已提交
796 797 798
	goto out;
}

799 800 801
/* 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
802 803 804
 */
static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
805
	struct dentry	*dentry = filp->f_path.dentry;
L
Linus Torvalds 已提交
806 807 808
	struct inode	*inode = dentry->d_inode;
	nfs_readdir_descriptor_t my_desc,
			*desc = &my_desc;
809
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
T
Trond Myklebust 已提交
810
	int res;
L
Linus Torvalds 已提交
811

C
Chuck Lever 已提交
812
	dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
C
Chuck Lever 已提交
813 814
			dentry->d_parent->d_name.name, dentry->d_name.name,
			(long long)filp->f_pos);
C
Chuck Lever 已提交
815 816
	nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);

L
Linus Torvalds 已提交
817
	/*
818
	 * filp->f_pos points to the dirent entry number.
819
	 * *desc->dir_cookie has the cookie for the next entry. We have
820 821
	 * to either find the entry with the appropriate number or
	 * revalidate the cookie.
L
Linus Torvalds 已提交
822 823 824 825
	 */
	memset(desc, 0, sizeof(*desc));

	desc->file = filp;
826
	desc->dir_cookie = &dir_ctx->dir_cookie;
L
Linus Torvalds 已提交
827
	desc->decode = NFS_PROTO(inode)->decode_dirent;
828
	desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0;
L
Linus Torvalds 已提交
829

T
Trond Myklebust 已提交
830
	nfs_block_sillyrename(dentry);
831
	res = nfs_revalidate_mapping(inode, filp->f_mapping);
T
Trond Myklebust 已提交
832 833 834
	if (res < 0)
		goto out;

T
Trond Myklebust 已提交
835
	do {
L
Linus Torvalds 已提交
836
		res = readdir_search_pagecache(desc);
837

L
Linus Torvalds 已提交
838
		if (res == -EBADCOOKIE) {
839
			res = 0;
L
Linus Torvalds 已提交
840
			/* This means either end of directory */
B
Bryan Schumaker 已提交
841
			if (*desc->dir_cookie && desc->eof == 0) {
L
Linus Torvalds 已提交
842 843
				/* Or that the server has 'lost' a cookie */
				res = uncached_readdir(desc, dirent, filldir);
844
				if (res == 0)
L
Linus Torvalds 已提交
845 846 847 848 849
					continue;
			}
			break;
		}
		if (res == -ETOOSMALL && desc->plus) {
B
Benny Halevy 已提交
850
			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
L
Linus Torvalds 已提交
851
			nfs_zap_caches(inode);
852
			desc->page_index = 0;
L
Linus Torvalds 已提交
853
			desc->plus = 0;
B
Bryan Schumaker 已提交
854
			desc->eof = 0;
L
Linus Torvalds 已提交
855 856 857 858 859 860
			continue;
		}
		if (res < 0)
			break;

		res = nfs_do_filldir(desc, dirent, filldir);
861
		if (res < 0)
L
Linus Torvalds 已提交
862
			break;
T
Trond Myklebust 已提交
863
	} while (!desc->eof);
T
Trond Myklebust 已提交
864
out:
T
Trond Myklebust 已提交
865
	nfs_unblock_sillyrename(dentry);
C
Chuck Lever 已提交
866 867
	if (res > 0)
		res = 0;
868
	dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
C
Chuck Lever 已提交
869 870 871
			dentry->d_parent->d_name.name, dentry->d_name.name,
			res);
	return res;
L
Linus Torvalds 已提交
872 873
}

874
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
875
{
876 877
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
878
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
879

C
Chuck Lever 已提交
880
	dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
881 882
			dentry->d_parent->d_name.name,
			dentry->d_name.name,
883
			offset, whence);
884 885

	mutex_lock(&inode->i_mutex);
886
	switch (whence) {
887 888 889 890 891 892 893 894 895 896 897
		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;
898
		dir_ctx->dir_cookie = 0;
899
		dir_ctx->duped = 0;
900 901
	}
out:
902
	mutex_unlock(&inode->i_mutex);
903 904 905
	return offset;
}

L
Linus Torvalds 已提交
906 907 908 909
/*
 * All directory operations under NFS are synchronous, so fsync()
 * is a dummy operation.
 */
910 911
static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
			 int datasync)
L
Linus Torvalds 已提交
912
{
913
	struct dentry *dentry = filp->f_path.dentry;
914
	struct inode *inode = dentry->d_inode;
915

C
Chuck Lever 已提交
916
	dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
C
Chuck Lever 已提交
917 918 919
			dentry->d_parent->d_name.name, dentry->d_name.name,
			datasync);

920
	mutex_lock(&inode->i_mutex);
921
	nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
922
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
923 924 925
	return 0;
}

926 927 928 929 930 931 932 933 934 935 936 937
/**
 * 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)
{
938
	NFS_I(dir)->cache_change_attribute++;
939
}
B
Bryan Schumaker 已提交
940
EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
941

L
Linus Torvalds 已提交
942 943 944 945 946
/*
 * 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.
 */
947
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
948 949 950
{
	if (IS_ROOT(dentry))
		return 1;
951 952
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
		return 0;
953 954 955 956 957 958 959 960
	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
961 962
}

963 964 965 966
/*
 * Use intent information to check whether or not we're going to do
 * an O_EXCL create using this path component.
 */
967
static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
968 969 970
{
	if (NFS_PROTO(dir)->version == 2)
		return 0;
971
	return flags & LOOKUP_EXCL;
972 973
}

974 975 976 977 978 979 980 981
/*
 * 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.
 *
 */
982
static
983
int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
L
Linus Torvalds 已提交
984 985
{
	struct nfs_server *server = NFS_SERVER(inode);
986
	int ret;
L
Linus Torvalds 已提交
987

988
	if (IS_AUTOMOUNT(inode))
989
		return 0;
990
	/* VFS wants an on-the-wire revalidation */
991
	if (flags & LOOKUP_REVAL)
992 993
		goto out_force;
	/* This is an open(2) */
994 995
	if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
996
		goto out_force;
997 998
out:
	return (inode->i_nlink == 0) ? -ENOENT : 0;
L
Linus Torvalds 已提交
999
out_force:
1000 1001 1002 1003
	ret = __nfs_revalidate_inode(server, inode);
	if (ret != 0)
		return ret;
	goto out;
L
Linus Torvalds 已提交
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014
}

/*
 * 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,
1015
		       unsigned int flags)
L
Linus Torvalds 已提交
1016 1017
{
	/* Don't revalidate a negative dentry if we're creating a new file */
1018
	if (flags & LOOKUP_CREATE)
L
Linus Torvalds 已提交
1019
		return 0;
1020 1021
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
		return 1;
L
Linus Torvalds 已提交
1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
	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.
 */
1036
static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
L
Linus Torvalds 已提交
1037 1038 1039 1040
{
	struct inode *dir;
	struct inode *inode;
	struct dentry *parent;
1041 1042
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1043 1044
	int error;

1045
	if (flags & LOOKUP_RCU)
1046 1047
		return -ECHILD;

L
Linus Torvalds 已提交
1048 1049
	parent = dget_parent(dentry);
	dir = parent->d_inode;
C
Chuck Lever 已提交
1050
	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
L
Linus Torvalds 已提交
1051 1052 1053
	inode = dentry->d_inode;

	if (!inode) {
1054
		if (nfs_neg_need_reval(dir, dentry, flags))
L
Linus Torvalds 已提交
1055
			goto out_bad;
1056
		goto out_valid_noent;
L
Linus Torvalds 已提交
1057 1058 1059
	}

	if (is_bad_inode(inode)) {
C
Chuck Lever 已提交
1060
		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1061
				__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1062
				dentry->d_name.name);
L
Linus Torvalds 已提交
1063 1064 1065
		goto out_bad;
	}

1066
	if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
1067 1068
		goto out_set_verifier;

L
Linus Torvalds 已提交
1069
	/* Force a full look up iff the parent directory has changed */
1070 1071
	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
1072 1073 1074 1075 1076 1077 1078
			goto out_zap_parent;
		goto out_valid;
	}

	if (NFS_STALE(inode))
		goto out_bad;

1079 1080 1081 1082 1083 1084
	error = -ENOMEM;
	fhandle = nfs_alloc_fhandle();
	fattr = nfs_alloc_fattr();
	if (fhandle == NULL || fattr == NULL)
		goto out_error;

1085
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1086 1087
	if (error)
		goto out_bad;
1088
	if (nfs_compare_fh(NFS_FH(inode), fhandle))
L
Linus Torvalds 已提交
1089
		goto out_bad;
1090
	if ((error = nfs_refresh_inode(inode, fattr)) != 0)
L
Linus Torvalds 已提交
1091 1092
		goto out_bad;

1093 1094
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
1095
out_set_verifier:
1096
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1097
 out_valid:
1098 1099 1100
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);
 out_valid_noent:
L
Linus Torvalds 已提交
1101
	dput(parent);
C
Chuck Lever 已提交
1102
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1103
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1104
			dentry->d_name.name);
L
Linus Torvalds 已提交
1105 1106 1107 1108
	return 1;
out_zap_parent:
	nfs_zap_caches(dir);
 out_bad:
A
Al Viro 已提交
1109 1110
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
1111
	nfs_mark_for_revalidate(dir);
L
Linus Torvalds 已提交
1112 1113 1114 1115 1116 1117
	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;
1118 1119
		if (dentry->d_flags & DCACHE_DISCONNECTED)
			goto out_valid;
L
Linus Torvalds 已提交
1120 1121 1122 1123
		shrink_dcache_parent(dentry);
	}
	d_drop(dentry);
	dput(parent);
C
Chuck Lever 已提交
1124
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1125
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1126
			dentry->d_name.name);
L
Linus Torvalds 已提交
1127
	return 0;
1128 1129 1130 1131 1132 1133 1134 1135
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
1136 1137 1138 1139 1140
}

/*
 * This is called from dput() when d_count is going to 0.
 */
N
Nick Piggin 已提交
1141
static int nfs_dentry_delete(const struct dentry *dentry)
L
Linus Torvalds 已提交
1142 1143 1144 1145 1146
{
	dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		dentry->d_flags);

1147 1148 1149 1150
	/* 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
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
	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;

}

T
Trond Myklebust 已提交
1164
/* Ensure that we revalidate inode->i_nlink */
1165 1166 1167
static void nfs_drop_nlink(struct inode *inode)
{
	spin_lock(&inode->i_lock);
T
Trond Myklebust 已提交
1168 1169 1170 1171
	/* drop the inode if we're reasonably sure this is the last link */
	if (inode->i_nlink == 1)
		clear_nlink(inode);
	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
1172 1173 1174
	spin_unlock(&inode->i_lock);
}

L
Linus Torvalds 已提交
1175 1176 1177 1178 1179 1180
/*
 * 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)
{
1181 1182 1183 1184
	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
1185
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1186
		nfs_complete_unlink(dentry, inode);
T
Trond Myklebust 已提交
1187
		nfs_drop_nlink(inode);
L
Linus Torvalds 已提交
1188 1189 1190 1191
	}
	iput(inode);
}

1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
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
1203
const struct dentry_operations nfs_dentry_operations = {
L
Linus Torvalds 已提交
1204 1205 1206
	.d_revalidate	= nfs_lookup_revalidate,
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1207
	.d_automount	= nfs_d_automount,
1208
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1209
};
B
Bryan Schumaker 已提交
1210
EXPORT_SYMBOL_GPL(nfs_dentry_operations);
L
Linus Torvalds 已提交
1211

1212
struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
L
Linus Torvalds 已提交
1213 1214
{
	struct dentry *res;
T
Trond Myklebust 已提交
1215
	struct dentry *parent;
L
Linus Torvalds 已提交
1216
	struct inode *inode = NULL;
1217 1218
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1219 1220 1221 1222
	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
1223
	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
L
Linus Torvalds 已提交
1224 1225 1226 1227 1228

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

1229 1230 1231 1232
	/*
	 * If we're doing an exclusive create, optimize away the lookup
	 * but don't hash the dentry.
	 */
A
Al Viro 已提交
1233
	if (nfs_is_exclusive_create(dir, flags)) {
1234 1235
		d_instantiate(dentry, NULL);
		res = NULL;
1236
		goto out;
1237
	}
L
Linus Torvalds 已提交
1238

1239 1240 1241 1242 1243 1244
	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
1245 1246 1247
	parent = dentry->d_parent;
	/* Protect against concurrent sillydeletes */
	nfs_block_sillyrename(parent);
1248
	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1249 1250 1251 1252
	if (error == -ENOENT)
		goto no_entry;
	if (error < 0) {
		res = ERR_PTR(error);
T
Trond Myklebust 已提交
1253
		goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1254
	}
1255
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
N
Namhyung Kim 已提交
1256
	res = ERR_CAST(inode);
1257
	if (IS_ERR(res))
T
Trond Myklebust 已提交
1258
		goto out_unblock_sillyrename;
1259

1260 1261 1262
	/* Success: notify readdir to use READDIRPLUS */
	nfs_advise_use_readdirplus(dir);

L
Linus Torvalds 已提交
1263
no_entry:
1264
	res = d_materialise_unique(dentry, inode);
1265 1266
	if (res != NULL) {
		if (IS_ERR(res))
T
Trond Myklebust 已提交
1267
			goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1268
		dentry = res;
1269
	}
L
Linus Torvalds 已提交
1270
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
T
Trond Myklebust 已提交
1271 1272
out_unblock_sillyrename:
	nfs_unblock_sillyrename(parent);
L
Linus Torvalds 已提交
1273
out:
1274 1275
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1276 1277
	return res;
}
B
Bryan Schumaker 已提交
1278
EXPORT_SYMBOL_GPL(nfs_lookup);
L
Linus Torvalds 已提交
1279

B
Bryan Schumaker 已提交
1280
#if IS_ENABLED(CONFIG_NFS_V4)
1281
static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
L
Linus Torvalds 已提交
1282

A
Al Viro 已提交
1283
const struct dentry_operations nfs4_dentry_operations = {
1284
	.d_revalidate	= nfs4_lookup_revalidate,
L
Linus Torvalds 已提交
1285 1286
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1287
	.d_automount	= nfs_d_automount,
1288
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1289
};
B
Bryan Schumaker 已提交
1290
EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
L
Linus Torvalds 已提交
1291

1292 1293 1294 1295 1296 1297 1298 1299 1300 1301
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;
}

1302
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1303
{
1304
	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1305 1306 1307 1308 1309 1310 1311 1312
}

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
1313 1314
static int nfs_finish_open(struct nfs_open_context *ctx,
			   struct dentry *dentry,
A
Al Viro 已提交
1315
			   struct file *file, unsigned open_flags,
A
Al Viro 已提交
1316
			   int *opened)
1317
{
1318 1319 1320 1321 1322 1323
	int err;

	if (ctx->dentry != dentry) {
		dput(ctx->dentry);
		ctx->dentry = dget(dentry);
	}
1324 1325 1326

	/* If the open_intent is for execute, we have an extra check to make */
	if (ctx->mode & FMODE_EXEC) {
1327
		err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
A
Al Viro 已提交
1328
		if (err < 0)
1329 1330
			goto out;
	}
1331

A
Al Viro 已提交
1332 1333
	err = finish_open(file, dentry, do_open, opened);
	if (err)
A
Al Viro 已提交
1334
		goto out;
A
Al Viro 已提交
1335
	nfs_file_set_open_context(file, ctx);
1336

1337 1338
out:
	put_nfs_open_context(ctx);
A
Al Viro 已提交
1339
	return err;
1340 1341
}

1342 1343 1344
int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
		    struct file *file, unsigned open_flags,
		    umode_t mode, int *opened)
L
Linus Torvalds 已提交
1345
{
1346
	struct nfs_open_context *ctx;
1347 1348
	struct dentry *res;
	struct iattr attr = { .ia_valid = ATTR_OPEN };
1349
	struct inode *inode;
1350
	int err;
L
Linus Torvalds 已提交
1351

1352 1353 1354 1355
	/* Expect a negative dentry */
	BUG_ON(dentry->d_inode);

	dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
C
Chuck Lever 已提交
1356 1357
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);

1358 1359 1360 1361 1362 1363 1364 1365
	/* 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
1366
			return -ENOENT;
1367
		}
L
Linus Torvalds 已提交
1368
		goto no_open;
1369
	}
L
Linus Torvalds 已提交
1370

1371
	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
A
Al Viro 已提交
1372
		return -ENAMETOOLONG;
1373

1374
	if (open_flags & O_CREAT) {
1375
		attr.ia_valid |= ATTR_MODE;
1376 1377
		attr.ia_mode = mode & ~current_umask();
	}
1378 1379 1380
	if (open_flags & O_TRUNC) {
		attr.ia_valid |= ATTR_SIZE;
		attr.ia_size = 0;
1381 1382
	}

1383 1384 1385
	ctx = create_nfs_open_context(dentry, open_flags);
	err = PTR_ERR(ctx);
	if (IS_ERR(ctx))
A
Al Viro 已提交
1386
		goto out;
1387

1388
	nfs_block_sillyrename(dentry->d_parent);
1389
	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1390
	d_drop(dentry);
1391 1392
	if (IS_ERR(inode)) {
		nfs_unblock_sillyrename(dentry->d_parent);
1393
		put_nfs_open_context(ctx);
1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
		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))
1404
				goto no_open;
1405
			break;
L
Linus Torvalds 已提交
1406
			/* case -EINVAL: */
1407 1408
		default:
			break;
L
Linus Torvalds 已提交
1409
		}
A
Al Viro 已提交
1410
		goto out;
1411
	}
1412
	res = d_add_unique(dentry, inode);
1413
	if (res != NULL)
L
Linus Torvalds 已提交
1414
		dentry = res;
1415 1416

	nfs_unblock_sillyrename(dentry->d_parent);
1417
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1418

A
Al Viro 已提交
1419
	err = nfs_finish_open(ctx, dentry, file, open_flags, opened);
1420 1421

	dput(res);
A
Al Viro 已提交
1422 1423
out:
	return err;
1424

L
Linus Torvalds 已提交
1425
no_open:
A
Al Viro 已提交
1426
	res = nfs_lookup(dir, dentry, 0);
1427 1428
	err = PTR_ERR(res);
	if (IS_ERR(res))
A
Al Viro 已提交
1429
		goto out;
1430

A
Al Viro 已提交
1431
	return finish_no_open(file, res);
L
Linus Torvalds 已提交
1432
}
B
Bryan Schumaker 已提交
1433
EXPORT_SYMBOL_GPL(nfs_atomic_open);
L
Linus Torvalds 已提交
1434

1435
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
L
Linus Torvalds 已提交
1436 1437
{
	struct dentry *parent = NULL;
N
Nick Piggin 已提交
1438
	struct inode *inode;
L
Linus Torvalds 已提交
1439
	struct inode *dir;
1440
	int ret = 0;
L
Linus Torvalds 已提交
1441

1442
	if (flags & LOOKUP_RCU)
N
Nick Piggin 已提交
1443 1444
		return -ECHILD;

1445
	if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
1446 1447
		goto no_open;
	if (d_mountpoint(dentry))
T
Trond Myklebust 已提交
1448
		goto no_open;
1449

1450
	inode = dentry->d_inode;
L
Linus Torvalds 已提交
1451 1452
	parent = dget_parent(dentry);
	dir = parent->d_inode;
1453

L
Linus Torvalds 已提交
1454 1455 1456
	/* We can't create new files in nfs_open_revalidate(), so we
	 * optimize away revalidation of negative dentries.
	 */
1457
	if (inode == NULL) {
1458
		if (!nfs_neg_need_reval(dir, dentry, flags))
1459
			ret = 1;
L
Linus Torvalds 已提交
1460
		goto out;
1461 1462
	}

L
Linus Torvalds 已提交
1463 1464
	/* NFS only supports OPEN on regular files */
	if (!S_ISREG(inode->i_mode))
T
Trond Myklebust 已提交
1465
		goto no_open_dput;
L
Linus Torvalds 已提交
1466
	/* We cannot do exclusive creation on a positive dentry */
1467
	if (flags & LOOKUP_EXCL)
T
Trond Myklebust 已提交
1468
		goto no_open_dput;
L
Linus Torvalds 已提交
1469

1470 1471
	/* Let f_op->open() actually open (and revalidate) the file */
	ret = 1;
1472

L
Linus Torvalds 已提交
1473 1474 1475
out:
	dput(parent);
	return ret;
1476

T
Trond Myklebust 已提交
1477
no_open_dput:
L
Linus Torvalds 已提交
1478
	dput(parent);
T
Trond Myklebust 已提交
1479
no_open:
1480
	return nfs_lookup_revalidate(dentry, flags);
1481 1482
}

L
Linus Torvalds 已提交
1483 1484 1485 1486 1487 1488 1489 1490
#endif /* CONFIG_NFSV4 */

/*
 * Code common to create, mkdir, and mknod.
 */
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
				struct nfs_fattr *fattr)
{
1491 1492
	struct dentry *parent = dget_parent(dentry);
	struct inode *dir = parent->d_inode;
L
Linus Torvalds 已提交
1493 1494 1495
	struct inode *inode;
	int error = -EACCES;

1496 1497
	d_drop(dentry);

L
Linus Torvalds 已提交
1498 1499
	/* We may have been initialized further down */
	if (dentry->d_inode)
1500
		goto out;
L
Linus Torvalds 已提交
1501
	if (fhandle->size == 0) {
1502
		error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1503
		if (error)
1504
			goto out_error;
L
Linus Torvalds 已提交
1505
	}
1506
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1507 1508
	if (!(fattr->valid & NFS_ATTR_FATTR)) {
		struct nfs_server *server = NFS_SB(dentry->d_sb);
1509
		error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
L
Linus Torvalds 已提交
1510
		if (error < 0)
1511
			goto out_error;
L
Linus Torvalds 已提交
1512 1513
	}
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1514 1515
	error = PTR_ERR(inode);
	if (IS_ERR(inode))
1516 1517 1518 1519
		goto out_error;
	d_add(dentry, inode);
out:
	dput(parent);
L
Linus Torvalds 已提交
1520
	return 0;
1521 1522 1523 1524
out_error:
	nfs_mark_for_revalidate(dir);
	dput(parent);
	return error;
L
Linus Torvalds 已提交
1525
}
B
Bryan Schumaker 已提交
1526
EXPORT_SYMBOL_GPL(nfs_instantiate);
L
Linus Torvalds 已提交
1527 1528 1529 1530 1531 1532 1533

/*
 * 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.
 */
1534
int nfs_create(struct inode *dir, struct dentry *dentry,
A
Al Viro 已提交
1535
		umode_t mode, bool excl)
L
Linus Torvalds 已提交
1536 1537
{
	struct iattr attr;
A
Al Viro 已提交
1538
	int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
L
Linus Torvalds 已提交
1539 1540
	int error;

C
Chuck Lever 已提交
1541 1542
	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
1543 1544 1545 1546

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

1547
	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553 1554
	if (error != 0)
		goto out_err;
	return 0;
out_err:
	d_drop(dentry);
	return error;
}
B
Bryan Schumaker 已提交
1555
EXPORT_SYMBOL_GPL(nfs_create);
L
Linus Torvalds 已提交
1556 1557 1558 1559

/*
 * See comments for nfs_proc_create regarding failed operations.
 */
1560
int
A
Al Viro 已提交
1561
nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
L
Linus Torvalds 已提交
1562 1563 1564 1565
{
	struct iattr attr;
	int status;

C
Chuck Lever 已提交
1566 1567
	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
1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582

	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;
}
B
Bryan Schumaker 已提交
1583
EXPORT_SYMBOL_GPL(nfs_mknod);
L
Linus Torvalds 已提交
1584 1585 1586 1587

/*
 * See comments for nfs_proc_create regarding failed operations.
 */
1588
int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
1589 1590 1591 1592
{
	struct iattr attr;
	int error;

C
Chuck Lever 已提交
1593 1594
	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
1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606

	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;
}
B
Bryan Schumaker 已提交
1607
EXPORT_SYMBOL_GPL(nfs_mkdir);
L
Linus Torvalds 已提交
1608

1609 1610 1611 1612 1613 1614
static void nfs_dentry_handle_enoent(struct dentry *dentry)
{
	if (dentry->d_inode != NULL && !d_unhashed(dentry))
		d_delete(dentry);
}

1615
int nfs_rmdir(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
1616 1617 1618
{
	int error;

C
Chuck Lever 已提交
1619 1620
	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
1621 1622 1623 1624

	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
	/* Ensure the VFS deletes this inode */
	if (error == 0 && dentry->d_inode != NULL)
1625
		clear_nlink(dentry->d_inode);
1626 1627
	else if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1628 1629 1630

	return error;
}
B
Bryan Schumaker 已提交
1631
EXPORT_SYMBOL_GPL(nfs_rmdir);
L
Linus Torvalds 已提交
1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655

/*
 * 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) {
1656
		NFS_PROTO(inode)->return_delegation(inode);
L
Linus Torvalds 已提交
1657 1658
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
		if (error == 0)
1659
			nfs_drop_nlink(inode);
L
Linus Torvalds 已提交
1660 1661
	} else
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1662 1663
	if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1664 1665 1666 1667 1668 1669 1670 1671 1672
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.
 */
1673
int nfs_unlink(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
1674 1675 1676 1677 1678 1679 1680 1681
{
	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
1682
	if (dentry->d_count > 1) {
L
Linus Torvalds 已提交
1683
		spin_unlock(&dentry->d_lock);
T
Trond Myklebust 已提交
1684 1685
		/* Start asynchronous writeout of the inode */
		write_inode_now(dentry->d_inode, 0);
L
Linus Torvalds 已提交
1686 1687 1688 1689 1690 1691 1692 1693 1694
		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);
1695
	if (!error || error == -ENOENT) {
L
Linus Torvalds 已提交
1696 1697 1698 1699 1700
		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
	} else if (need_rehash)
		d_rehash(dentry);
	return error;
}
B
Bryan Schumaker 已提交
1701
EXPORT_SYMBOL_GPL(nfs_unlink);
L
Linus Torvalds 已提交
1702

1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
/*
 * 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.
 */
1718
int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
L
Linus Torvalds 已提交
1719
{
1720 1721 1722
	struct pagevec lru_pvec;
	struct page *page;
	char *kaddr;
L
Linus Torvalds 已提交
1723
	struct iattr attr;
1724
	unsigned int pathlen = strlen(symname);
L
Linus Torvalds 已提交
1725 1726 1727 1728 1729
	int error;

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

1730 1731
	if (pathlen > PAGE_SIZE)
		return -ENAMETOOLONG;
L
Linus Torvalds 已提交
1732

1733 1734
	attr.ia_mode = S_IFLNK | S_IRWXUGO;
	attr.ia_valid = ATTR_MODE;
L
Linus Torvalds 已提交
1735

1736
	page = alloc_page(GFP_HIGHUSER);
1737
	if (!page)
1738 1739
		return -ENOMEM;

1740
	kaddr = kmap_atomic(page);
1741 1742 1743
	memcpy(kaddr, symname, pathlen);
	if (pathlen < PAGE_SIZE)
		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1744
	kunmap_atomic(kaddr);
1745

1746
	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1747 1748 1749 1750
	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
1751
		d_drop(dentry);
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762
		__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)) {
1763
		pagevec_add(&lru_pvec, page);
1764
		pagevec_lru_add_file(&lru_pvec);
1765 1766 1767 1768 1769 1770
		SetPageUptodate(page);
		unlock_page(page);
	} else
		__free_page(page);

	return 0;
L
Linus Torvalds 已提交
1771
}
B
Bryan Schumaker 已提交
1772
EXPORT_SYMBOL_GPL(nfs_symlink);
L
Linus Torvalds 已提交
1773

1774
int
L
Linus Torvalds 已提交
1775 1776 1777 1778 1779 1780 1781 1782 1783
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);

1784
	NFS_PROTO(inode)->return_delegation(inode);
1785

1786
	d_drop(dentry);
L
Linus Torvalds 已提交
1787
	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1788
	if (error == 0) {
A
Al Viro 已提交
1789
		ihold(inode);
1790
		d_add(dentry, inode);
1791
	}
L
Linus Torvalds 已提交
1792 1793
	return error;
}
B
Bryan Schumaker 已提交
1794
EXPORT_SYMBOL_GPL(nfs_link);
L
Linus Torvalds 已提交
1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819

/*
 * 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.
 */
1820
int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
L
Linus Torvalds 已提交
1821 1822 1823 1824 1825 1826 1827 1828 1829 1830
		      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
1831
		 new_dentry->d_count);
L
Linus Torvalds 已提交
1832 1833

	/*
M
Miklos Szeredi 已提交
1834 1835 1836 1837
	 * 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
1838
	 */
1839 1840 1841 1842 1843 1844 1845 1846 1847
	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
1848

N
Nick Piggin 已提交
1849
		if (new_dentry->d_count > 2) {
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
			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);
1860
			if (err)
1861
				goto out;
1862 1863

			new_dentry = dentry;
O
OGAWA Hirofumi 已提交
1864
			rehash = NULL;
1865
			new_inode = NULL;
1866
		}
1867
	}
L
Linus Torvalds 已提交
1868

1869
	NFS_PROTO(old_inode)->return_delegation(old_inode);
1870
	if (new_inode != NULL)
1871
		NFS_PROTO(new_inode)->return_delegation(new_inode);
L
Linus Torvalds 已提交
1872 1873 1874

	error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
					   new_dir, &new_dentry->d_name);
1875
	nfs_mark_for_revalidate(old_inode);
L
Linus Torvalds 已提交
1876 1877 1878 1879
out:
	if (rehash)
		d_rehash(rehash);
	if (!error) {
1880 1881
		if (new_inode != NULL)
			nfs_drop_nlink(new_inode);
1882
		d_move(old_dentry, new_dentry);
1883 1884
		nfs_set_verifier(new_dentry,
					nfs_save_change_attribute(new_dir));
1885 1886
	} else if (error == -ENOENT)
		nfs_dentry_handle_enoent(old_dentry);
L
Linus Torvalds 已提交
1887 1888 1889 1890 1891 1892

	/* new dentry created? */
	if (dentry)
		dput(dentry);
	return error;
}
B
Bryan Schumaker 已提交
1893
EXPORT_SYMBOL_GPL(nfs_rename);
L
Linus Torvalds 已提交
1894

1895 1896 1897 1898
static DEFINE_SPINLOCK(nfs_access_lru_lock);
static LIST_HEAD(nfs_access_lru_list);
static atomic_long_t nfs_access_nr_entries;

1899 1900 1901 1902
static void nfs_access_free_entry(struct nfs_access_entry *entry)
{
	put_rpccred(entry->cred);
	kfree(entry);
1903 1904 1905
	smp_mb__before_atomic_dec();
	atomic_long_dec(&nfs_access_nr_entries);
	smp_mb__after_atomic_dec();
1906 1907
}

1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918
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);
	}
}

1919 1920
int nfs_access_cache_shrinker(struct shrinker *shrink,
			      struct shrink_control *sc)
1921 1922
{
	LIST_HEAD(head);
1923
	struct nfs_inode *nfsi, *next;
1924
	struct nfs_access_entry *cache;
1925 1926
	int nr_to_scan = sc->nr_to_scan;
	gfp_t gfp_mask = sc->gfp_mask;
1927

1928 1929
	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
		return (nr_to_scan == 0) ? 0 : -1;
1930

1931
	spin_lock(&nfs_access_lru_lock);
1932
	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
1933 1934 1935 1936
		struct inode *inode;

		if (nr_to_scan-- == 0)
			break;
1937
		inode = &nfsi->vfs_inode;
1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950
		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);
1951
			smp_mb__before_clear_bit();
1952
			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
1953
			smp_mb__after_clear_bit();
1954
		}
1955
		spin_unlock(&inode->i_lock);
1956 1957
	}
	spin_unlock(&nfs_access_lru_lock);
1958
	nfs_access_free_list(&head);
1959 1960 1961
	return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
}

1962
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
L
Linus Torvalds 已提交
1963
{
1964
	struct rb_root *root_node = &nfsi->access_cache;
1965
	struct rb_node *n;
1966 1967 1968 1969 1970 1971
	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);
1972
		list_move(&entry->lru, head);
1973 1974
	}
	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
L
Linus Torvalds 已提交
1975 1976
}

1977
void nfs_access_zap_cache(struct inode *inode)
L
Linus Torvalds 已提交
1978
{
1979 1980 1981 1982
	LIST_HEAD(head);

	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
		return;
1983
	/* Remove from global LRU init */
1984 1985
	spin_lock(&nfs_access_lru_lock);
	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
1986 1987
		list_del_init(&NFS_I(inode)->access_cache_inode_lru);

1988
	spin_lock(&inode->i_lock);
1989 1990 1991 1992
	__nfs_access_zap_cache(NFS_I(inode), &head);
	spin_unlock(&inode->i_lock);
	spin_unlock(&nfs_access_lru_lock);
	nfs_access_free_list(&head);
1993
}
B
Bryan Schumaker 已提交
1994
EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
L
Linus Torvalds 已提交
1995

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
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
2010
	}
2011 2012 2013
	return NULL;
}

2014
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2015 2016 2017 2018 2019
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_access_entry *cache;
	int err = -ENOENT;

2020
	spin_lock(&inode->i_lock);
2021 2022 2023 2024 2025
	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
		goto out_zap;
	cache = nfs_access_search_rbtree(inode, cred);
	if (cache == NULL)
		goto out;
2026
	if (!nfs_have_delegated_attributes(inode) &&
2027
	    !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2028 2029 2030 2031
		goto out_stale;
	res->jiffies = cache->jiffies;
	res->cred = cache->cred;
	res->mask = cache->mask;
2032
	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2033 2034 2035 2036 2037 2038
	err = 0;
out:
	spin_unlock(&inode->i_lock);
	return err;
out_stale:
	rb_erase(&cache->rb_node, &nfsi->access_cache);
2039
	list_del(&cache->lru);
2040 2041 2042 2043
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(cache);
	return -ENOENT;
out_zap:
2044 2045
	spin_unlock(&inode->i_lock);
	nfs_access_zap_cache(inode);
2046 2047 2048 2049 2050
	return -ENOENT;
}

static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
{
2051 2052
	struct nfs_inode *nfsi = NFS_I(inode);
	struct rb_root *root_node = &nfsi->access_cache;
2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
	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);
2071
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2072
	spin_unlock(&inode->i_lock);
2073 2074 2075
	return;
found:
	rb_replace_node(parent, &set->rb_node, root_node);
2076 2077
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
	list_del(&entry->lru);
2078 2079 2080 2081
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(entry);
}

2082
void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2083 2084 2085 2086 2087
{
	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
2088
	cache->jiffies = set->jiffies;
2089
	cache->cred = get_rpccred(set->cred);
L
Linus Torvalds 已提交
2090
	cache->mask = set->mask;
2091 2092

	nfs_access_add_rbtree(inode, cache);
2093 2094 2095 2096 2097 2098 2099

	/* 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 */
2100
	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2101
		spin_lock(&nfs_access_lru_lock);
2102 2103 2104
		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);
2105 2106
		spin_unlock(&nfs_access_lru_lock);
	}
L
Linus Torvalds 已提交
2107
}
2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
EXPORT_SYMBOL_GPL(nfs_access_add_cache);

void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
{
	entry->mask = 0;
	if (access_result & NFS4_ACCESS_READ)
		entry->mask |= MAY_READ;
	if (access_result &
	    (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE))
		entry->mask |= MAY_WRITE;
	if (access_result & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE))
		entry->mask |= MAY_EXEC;
}
EXPORT_SYMBOL_GPL(nfs_access_set_mask);
L
Linus Torvalds 已提交
2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136

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);
2137 2138 2139 2140 2141 2142
	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
2143
		return status;
2144
	}
L
Linus Torvalds 已提交
2145 2146
	nfs_access_add_cache(inode, &cache);
out:
2147
	if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2148 2149 2150 2151
		return 0;
	return -EACCES;
}

2152 2153 2154 2155
static int nfs_open_permission_mask(int openflags)
{
	int mask = 0;

2156
	if ((openflags & O_ACCMODE) != O_WRONLY)
2157
		mask |= MAY_READ;
2158
	if ((openflags & O_ACCMODE) != O_RDONLY)
2159
		mask |= MAY_WRITE;
2160
	if (openflags & __FMODE_EXEC)
2161 2162 2163 2164 2165 2166 2167 2168
		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));
}
B
Bryan Schumaker 已提交
2169
EXPORT_SYMBOL_GPL(nfs_may_open);
2170

2171
int nfs_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2172 2173 2174 2175
{
	struct rpc_cred *cred;
	int res = 0;

2176
	if (mask & MAY_NOT_BLOCK)
2177 2178
		return -ECHILD;

C
Chuck Lever 已提交
2179 2180
	nfs_inc_stats(inode, NFSIOS_VFSACCESS);

2181
	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2182 2183
		goto out;
	/* Is this sys_access() ? */
E
Eric Paris 已提交
2184
	if (mask & (MAY_ACCESS | MAY_CHDIR))
L
Linus Torvalds 已提交
2185 2186 2187 2188 2189 2190 2191 2192
		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)
2193 2194
					&& (mask & MAY_OPEN)
					&& !(mask & MAY_EXEC))
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209
				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;

2210
	cred = rpc_lookup_cred();
L
Linus Torvalds 已提交
2211 2212 2213 2214 2215 2216
	if (!IS_ERR(cred)) {
		res = nfs_do_access(inode, cred, mask);
		put_rpccred(cred);
	} else
		res = PTR_ERR(cred);
out:
2217 2218 2219
	if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
		res = -EACCES;

C
Chuck Lever 已提交
2220 2221
	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
2222 2223 2224 2225
	return res;
out_notsup:
	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (res == 0)
2226
		res = generic_permission(inode, mask);
C
Chuck Lever 已提交
2227
	goto out;
L
Linus Torvalds 已提交
2228
}
B
Bryan Schumaker 已提交
2229
EXPORT_SYMBOL_GPL(nfs_permission);
L
Linus Torvalds 已提交
2230 2231 2232 2233 2234 2235 2236

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