dir.c 58.7 KB
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/*
 *  linux/fs/nfs/dir.c
 *
 *  Copyright (C) 1992  Rick Sladkey
 *
 *  nfs directory handling functions
 *
 * 10 Apr 1996	Added silly rename for unlink	--okir
 * 28 Sep 1996	Improved directory cache --okir
 * 23 Aug 1997  Claus Heine claus@momo.math.rwth-aachen.de 
 *              Re-implemented silly rename for unlink, newly implemented
 *              silly rename for nfs_rename() following the suggestions
 *              of Olaf Kirch (okir) found in this file.
 *              Following Linus comments on my original hack, this version
 *              depends only on the dcache stuff and doesn't touch the inode
 *              layer (iput() and friends).
 *  6 Jun 1999	Cache readdir lookups in the page cache. -DaveM
 */

#include <linux/time.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/pagemap.h>
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#include <linux/pagevec.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/sched.h>
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#include <linux/kmemleak.h>
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#include <linux/xattr.h>
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#include "delegation.h"
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#include "iostat.h"
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#include "internal.h"
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#include "fscache.h"
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/* #define NFS_DEBUG_VERBOSE 1 */

static int nfs_opendir(struct inode *, struct file *);
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static int nfs_closedir(struct inode *, struct file *);
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static int nfs_readdir(struct file *, void *, filldir_t);
static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
static int nfs_mkdir(struct inode *, struct dentry *, int);
static int nfs_rmdir(struct inode *, struct dentry *);
static int nfs_unlink(struct inode *, struct dentry *);
static int nfs_symlink(struct inode *, struct dentry *, const char *);
static int nfs_link(struct dentry *, struct inode *, struct dentry *);
static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
static int nfs_rename(struct inode *, struct dentry *,
		      struct inode *, struct dentry *);
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static int nfs_fsync_dir(struct file *, 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

static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
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static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd);
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const struct inode_operations nfs4_dir_inode_operations = {
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	.create		= nfs_open_create,
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	.lookup		= nfs_atomic_lookup,
	.link		= nfs_link,
	.unlink		= nfs_unlink,
	.symlink	= nfs_symlink,
	.mkdir		= nfs_mkdir,
	.rmdir		= nfs_rmdir,
	.mknod		= nfs_mknod,
	.rename		= nfs_rename,
	.permission	= nfs_permission,
	.getattr	= nfs_getattr,
	.setattr	= nfs_setattr,
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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 rpc_cred *cred)
{
	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->dir_cookie = 0;
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		ctx->dup_cookie = 0;
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		ctx->cred = get_rpccred(cred);
	} else
		ctx = ERR_PTR(-ENOMEM);
	return ctx;
}

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);
	ctx = alloc_nfs_open_dir_context(cred);
	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 {
	unsigned int size;
	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, KM_USER0);
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	for (i = 0; i < array->size; i++)
		kfree(array->array[i].string.name);
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	kunmap_atomic(array, KM_USER0);
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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;
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	struct nfs_open_dir_context *ctx = desc->file->private_data;
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	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;
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	ctx->duped = 0;
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	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;
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	struct nfs_open_dir_context *ctx = desc->file->private_data;
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	for (i = 0; i < array->size; i++) {
		if (array->array[i].cookie == *desc->dir_cookie) {
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			new_pos = desc->current_index + i;
			if (new_pos < desc->file->f_pos) {
				ctx->dup_cookie = *desc->dir_cookie;
				ctx->duped = 1;
			}
			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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	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;
}

static
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
{
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	struct qstr filename = {
		.len = entry->len,
		.name = entry->name,
	};
	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);
}

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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);
548 549 550 551
		if (!IS_ERR(array)) {
			array->eof_index = array->size;
			status = 0;
			nfs_readdir_release_array(page);
552 553
		} else
			status = PTR_ERR(array);
L
Linus Torvalds 已提交
554
	}
555 556

	put_page(scratch);
557
	return status;
B
Bryan Schumaker 已提交
558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579
}

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
580
int nfs_readdir_large_page(struct page **pages, unsigned int npages)
B
Bryan Schumaker 已提交
581 582 583 584 585 586 587 588 589
{
	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;
	}
590
	return 0;
B
Bryan Schumaker 已提交
591 592 593

out_freepages:
	nfs_readdir_free_pagearray(pages, i);
594
	return -ENOMEM;
L
Linus Torvalds 已提交
595 596
}

B
Bryan Schumaker 已提交
597 598
static
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
599
{
B
Bryan Schumaker 已提交
600 601
	struct page *pages[NFS_MAX_READDIR_PAGES];
	void *pages_ptr = NULL;
B
Bryan Schumaker 已提交
602 603 604
	struct nfs_entry entry;
	struct file	*file = desc->file;
	struct nfs_cache_array *array;
605
	int status = -ENOMEM;
B
Bryan Schumaker 已提交
606
	unsigned int array_size = ARRAY_SIZE(pages);
B
Bryan Schumaker 已提交
607 608

	entry.prev_cookie = 0;
609
	entry.cookie = desc->last_cookie;
B
Bryan Schumaker 已提交
610 611 612
	entry.eof = 0;
	entry.fh = nfs_alloc_fhandle();
	entry.fattr = nfs_alloc_fattr();
613
	entry.server = NFS_SERVER(inode);
B
Bryan Schumaker 已提交
614 615
	if (entry.fh == NULL || entry.fattr == NULL)
		goto out;
616

B
Bryan Schumaker 已提交
617
	array = nfs_readdir_get_array(page);
618 619 620 621
	if (IS_ERR(array)) {
		status = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
622 623
	memset(array, 0, sizeof(struct nfs_cache_array));
	array->eof_index = -1;
624

625 626
	status = nfs_readdir_large_page(pages, array_size);
	if (status < 0)
B
Bryan Schumaker 已提交
627 628
		goto out_release_array;
	do {
629
		unsigned int pglen;
B
Bryan Schumaker 已提交
630
		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
631

B
Bryan Schumaker 已提交
632
		if (status < 0)
633
			break;
634
		pglen = status;
635
		status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
636 637 638 639 640 641
		if (status < 0) {
			if (status == -ENOSPC)
				status = 0;
			break;
		}
	} while (array->eof_index < 0);
B
Bryan Schumaker 已提交
642

B
Bryan Schumaker 已提交
643
	nfs_readdir_free_large_page(pages_ptr, pages, array_size);
B
Bryan Schumaker 已提交
644 645 646 647 648
out_release_array:
	nfs_readdir_release_array(page);
out:
	nfs_free_fattr(entry.fattr);
	nfs_free_fhandle(entry.fh);
649 650 651 652
	return status;
}

/*
B
Bryan Schumaker 已提交
653 654 655 656
 * 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
657
 */
B
Bryan Schumaker 已提交
658 659
static
int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
L
Linus Torvalds 已提交
660
{
661
	struct inode	*inode = desc->file->f_path.dentry->d_inode;
662
	int ret;
L
Linus Torvalds 已提交
663

664 665
	ret = nfs_readdir_xdr_to_array(desc, page, inode);
	if (ret < 0)
B
Bryan Schumaker 已提交
666 667
		goto error;
	SetPageUptodate(page);
L
Linus Torvalds 已提交
668

B
Bryan Schumaker 已提交
669 670 671
	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
672
	}
B
Bryan Schumaker 已提交
673 674 675 676
	unlock_page(page);
	return 0;
 error:
	unlock_page(page);
677
	return ret;
B
Bryan Schumaker 已提交
678
}
L
Linus Torvalds 已提交
679

B
Bryan Schumaker 已提交
680 681 682
static
void cache_page_release(nfs_readdir_descriptor_t *desc)
{
683 684
	if (!desc->page->mapping)
		nfs_readdir_clear_array(desc->page);
B
Bryan Schumaker 已提交
685 686 687 688 689 690 691
	page_cache_release(desc->page);
	desc->page = NULL;
}

static
struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
{
692
	return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
B
Bryan Schumaker 已提交
693
			desc->page_index, (filler_t *)nfs_readdir_filler, desc);
L
Linus Torvalds 已提交
694 695 696
}

/*
B
Bryan Schumaker 已提交
697
 * Returns 0 if desc->dir_cookie was found on page desc->page_index
L
Linus Torvalds 已提交
698
 */
B
Bryan Schumaker 已提交
699 700 701 702 703 704 705 706 707 708
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
709 710
	if (res != 0)
		cache_page_release(desc);
B
Bryan Schumaker 已提交
711 712 713 714
	return res;
}

/* Search for desc->dir_cookie from the beginning of the page cache */
L
Linus Torvalds 已提交
715 716 717
static inline
int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
{
718
	int res;
B
Bryan Schumaker 已提交
719

720
	if (desc->page_index == 0) {
721
		desc->current_index = 0;
722 723
		desc->last_cookie = 0;
	}
T
Trond Myklebust 已提交
724
	do {
B
Bryan Schumaker 已提交
725
		res = find_cache_page(desc);
T
Trond Myklebust 已提交
726
	} while (res == -EAGAIN);
L
Linus Torvalds 已提交
727 728 729 730 731 732 733 734 735 736 737
	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
738 739 740
	int i = 0;
	int res = 0;
	struct nfs_cache_array *array = NULL;
741 742 743 744 745 746 747 748 749 750 751 752 753 754
	struct nfs_open_dir_context *ctx = file->private_data;

	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.  "
				"Offending cookie: %llu\n",
				file->f_dentry->d_parent->d_name.name,
				file->f_dentry->d_name.name,
				*desc->dir_cookie);
		}
		res = -ELOOP;
		goto out;
	}
B
Bryan Schumaker 已提交
755 756

	array = nfs_readdir_get_array(desc->page);
757 758 759 760
	if (IS_ERR(array)) {
		res = PTR_ERR(array);
		goto out;
	}
B
Bryan Schumaker 已提交
761 762

	for (i = desc->cache_entry_index; i < array->size; i++) {
763
		struct nfs_cache_array_entry *ent;
L
Linus Torvalds 已提交
764

765 766
		ent = &array->array[i];
		if (filldir(dirent, ent->string.name, ent->string.len,
767 768
		    file->f_pos, nfs_compat_user_ino64(ent->ino),
		    ent->d_type) < 0) {
769
			desc->eof = 1;
L
Linus Torvalds 已提交
770
			break;
771
		}
772
		file->f_pos++;
B
Bryan Schumaker 已提交
773 774 775 776
		if (i < (array->size-1))
			*desc->dir_cookie = array->array[i+1].cookie;
		else
			*desc->dir_cookie = array->last_cookie;
L
Linus Torvalds 已提交
777
	}
T
Trond Myklebust 已提交
778
	if (array->eof_index >= 0)
779
		desc->eof = 1;
B
Bryan Schumaker 已提交
780 781

	nfs_readdir_release_array(desc->page);
782
out:
B
Bryan Schumaker 已提交
783
	cache_page_release(desc);
C
Chuck Lever 已提交
784 785
	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
786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806
	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
807
	struct inode *inode = desc->file->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
808

C
Chuck Lever 已提交
809 810
	dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
			(unsigned long long)*desc->dir_cookie);
L
Linus Torvalds 已提交
811 812 813 814 815 816

	page = alloc_page(GFP_HIGHUSER);
	if (!page) {
		status = -ENOMEM;
		goto out;
	}
B
Bryan Schumaker 已提交
817

818
	desc->page_index = 0;
819
	desc->last_cookie = *desc->dir_cookie;
820 821
	desc->page = page;

822 823
	status = nfs_readdir_xdr_to_array(desc, page, inode);
	if (status < 0)
L
Linus Torvalds 已提交
824 825 826 827 828
		goto out_release;

	status = nfs_do_filldir(desc, dirent, filldir);

 out:
C
Chuck Lever 已提交
829
	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
830
			__func__, status);
L
Linus Torvalds 已提交
831 832
	return status;
 out_release:
B
Bryan Schumaker 已提交
833
	cache_page_release(desc);
L
Linus Torvalds 已提交
834 835 836
	goto out;
}

837 838 839
/* 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
840 841 842
 */
static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
843
	struct dentry	*dentry = filp->f_path.dentry;
L
Linus Torvalds 已提交
844 845 846
	struct inode	*inode = dentry->d_inode;
	nfs_readdir_descriptor_t my_desc,
			*desc = &my_desc;
847
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
T
Trond Myklebust 已提交
848
	int res;
L
Linus Torvalds 已提交
849

C
Chuck Lever 已提交
850
	dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
C
Chuck Lever 已提交
851 852
			dentry->d_parent->d_name.name, dentry->d_name.name,
			(long long)filp->f_pos);
C
Chuck Lever 已提交
853 854
	nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);

L
Linus Torvalds 已提交
855
	/*
856
	 * filp->f_pos points to the dirent entry number.
857
	 * *desc->dir_cookie has the cookie for the next entry. We have
858 859
	 * to either find the entry with the appropriate number or
	 * revalidate the cookie.
L
Linus Torvalds 已提交
860 861 862 863
	 */
	memset(desc, 0, sizeof(*desc));

	desc->file = filp;
864
	desc->dir_cookie = &dir_ctx->dir_cookie;
L
Linus Torvalds 已提交
865 866 867
	desc->decode = NFS_PROTO(inode)->decode_dirent;
	desc->plus = NFS_USE_READDIRPLUS(inode);

T
Trond Myklebust 已提交
868
	nfs_block_sillyrename(dentry);
869
	res = nfs_revalidate_mapping(inode, filp->f_mapping);
T
Trond Myklebust 已提交
870 871 872
	if (res < 0)
		goto out;

T
Trond Myklebust 已提交
873
	do {
L
Linus Torvalds 已提交
874
		res = readdir_search_pagecache(desc);
875

L
Linus Torvalds 已提交
876
		if (res == -EBADCOOKIE) {
877
			res = 0;
L
Linus Torvalds 已提交
878
			/* This means either end of directory */
B
Bryan Schumaker 已提交
879
			if (*desc->dir_cookie && desc->eof == 0) {
L
Linus Torvalds 已提交
880 881
				/* Or that the server has 'lost' a cookie */
				res = uncached_readdir(desc, dirent, filldir);
882
				if (res == 0)
L
Linus Torvalds 已提交
883 884 885 886 887
					continue;
			}
			break;
		}
		if (res == -ETOOSMALL && desc->plus) {
B
Benny Halevy 已提交
888
			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
L
Linus Torvalds 已提交
889
			nfs_zap_caches(inode);
890
			desc->page_index = 0;
L
Linus Torvalds 已提交
891
			desc->plus = 0;
B
Bryan Schumaker 已提交
892
			desc->eof = 0;
L
Linus Torvalds 已提交
893 894 895 896 897 898
			continue;
		}
		if (res < 0)
			break;

		res = nfs_do_filldir(desc, dirent, filldir);
899
		if (res < 0)
L
Linus Torvalds 已提交
900
			break;
T
Trond Myklebust 已提交
901
	} while (!desc->eof);
T
Trond Myklebust 已提交
902
out:
T
Trond Myklebust 已提交
903
	nfs_unblock_sillyrename(dentry);
C
Chuck Lever 已提交
904 905
	if (res > 0)
		res = 0;
906
	dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
C
Chuck Lever 已提交
907 908 909
			dentry->d_parent->d_name.name, dentry->d_name.name,
			res);
	return res;
L
Linus Torvalds 已提交
910 911
}

912
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
913
{
914 915
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *inode = dentry->d_inode;
916
	struct nfs_open_dir_context *dir_ctx = filp->private_data;
917

C
Chuck Lever 已提交
918
	dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
919 920 921 922 923
			dentry->d_parent->d_name.name,
			dentry->d_name.name,
			offset, origin);

	mutex_lock(&inode->i_mutex);
924 925 926 927 928 929 930 931 932 933 934 935
	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;
936
		dir_ctx->dir_cookie = 0;
937
		dir_ctx->duped = 0;
938 939
	}
out:
940
	mutex_unlock(&inode->i_mutex);
941 942 943
	return offset;
}

L
Linus Torvalds 已提交
944 945 946 947
/*
 * All directory operations under NFS are synchronous, so fsync()
 * is a dummy operation.
 */
948
static int nfs_fsync_dir(struct file *filp, int datasync)
L
Linus Torvalds 已提交
949
{
950 951
	struct dentry *dentry = filp->f_path.dentry;

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

956
	nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
L
Linus Torvalds 已提交
957 958 959
	return 0;
}

960 961 962 963 964 965 966 967 968 969 970 971
/**
 * 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)
{
972
	NFS_I(dir)->cache_change_attribute++;
973 974
}

L
Linus Torvalds 已提交
975 976 977 978 979
/*
 * 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.
 */
980
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
981 982 983
{
	if (IS_ROOT(dentry))
		return 1;
984 985
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
		return 0;
986 987 988 989 990 991 992 993
	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
994 995
}

996 997 998 999 1000 1001 1002
/*
 * Return the intent data that applies to this particular path component
 *
 * Note that the current set of intents only apply to the very last
 * component of the path.
 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
 */
1003 1004
static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
						unsigned int mask)
1005 1006 1007 1008 1009 1010
{
	if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
		return 0;
	return nd->flags & mask;
}

1011 1012 1013 1014 1015 1016 1017 1018
/*
 * Use intent information to check whether or not we're going to do
 * an O_EXCL create using this path component.
 */
static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
{
	if (NFS_PROTO(dir)->version == 2)
		return 0;
1019
	return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL);
1020 1021
}

1022 1023 1024 1025 1026 1027 1028 1029
/*
 * 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
1030 1031 1032 1033 1034
static inline
int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
{
	struct nfs_server *server = NFS_SERVER(inode);

1035
	if (IS_AUTOMOUNT(inode))
1036
		return 0;
L
Linus Torvalds 已提交
1037 1038
	if (nd != NULL) {
		/* VFS wants an on-the-wire revalidation */
1039
		if (nd->flags & LOOKUP_REVAL)
L
Linus Torvalds 已提交
1040 1041
			goto out_force;
		/* This is an open(2) */
1042
		if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
1043 1044 1045
				!(server->flags & NFS_MOUNT_NOCTO) &&
				(S_ISREG(inode->i_mode) ||
				 S_ISDIR(inode->i_mode)))
L
Linus Torvalds 已提交
1046
			goto out_force;
1047
		return 0;
L
Linus Torvalds 已提交
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	}
	return nfs_revalidate_inode(server, inode);
out_force:
	return __nfs_revalidate_inode(server, inode);
}

/*
 * We judge how long we want to trust negative
 * dentries by looking at the parent inode mtime.
 *
 * If parent mtime has changed, we revalidate, else we wait for a
 * period corresponding to the parent's attribute cache timeout value.
 */
static inline
int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
		       struct nameidata *nd)
{
	/* Don't revalidate a negative dentry if we're creating a new file */
1066
	if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
L
Linus Torvalds 已提交
1067
		return 0;
1068 1069
	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
		return 1;
L
Linus Torvalds 已提交
1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083
	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.
 */
1084
static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
L
Linus Torvalds 已提交
1085 1086 1087 1088
{
	struct inode *dir;
	struct inode *inode;
	struct dentry *parent;
1089 1090
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1091 1092
	int error;

1093 1094 1095
	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

L
Linus Torvalds 已提交
1096 1097
	parent = dget_parent(dentry);
	dir = parent->d_inode;
C
Chuck Lever 已提交
1098
	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
L
Linus Torvalds 已提交
1099 1100 1101 1102 1103 1104 1105 1106 1107
	inode = dentry->d_inode;

	if (!inode) {
		if (nfs_neg_need_reval(dir, dentry, nd))
			goto out_bad;
		goto out_valid;
	}

	if (is_bad_inode(inode)) {
C
Chuck Lever 已提交
1108
		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1109
				__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1110
				dentry->d_name.name);
L
Linus Torvalds 已提交
1111 1112 1113
		goto out_bad;
	}

1114 1115 1116
	if (nfs_have_delegation(inode, FMODE_READ))
		goto out_set_verifier;

L
Linus Torvalds 已提交
1117
	/* Force a full look up iff the parent directory has changed */
1118
	if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
L
Linus Torvalds 已提交
1119 1120 1121 1122 1123 1124 1125 1126
		if (nfs_lookup_verify_inode(inode, nd))
			goto out_zap_parent;
		goto out_valid;
	}

	if (NFS_STALE(inode))
		goto out_bad;

1127 1128 1129 1130 1131 1132
	error = -ENOMEM;
	fhandle = nfs_alloc_fhandle();
	fattr = nfs_alloc_fattr();
	if (fhandle == NULL || fattr == NULL)
		goto out_error;

1133
	error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1134 1135
	if (error)
		goto out_bad;
1136
	if (nfs_compare_fh(NFS_FH(inode), fhandle))
L
Linus Torvalds 已提交
1137
		goto out_bad;
1138
	if ((error = nfs_refresh_inode(inode, fattr)) != 0)
L
Linus Torvalds 已提交
1139 1140
		goto out_bad;

1141 1142
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
1143
out_set_verifier:
1144
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1145 1146
 out_valid:
	dput(parent);
C
Chuck Lever 已提交
1147
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1148
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1149
			dentry->d_name.name);
L
Linus Torvalds 已提交
1150 1151 1152 1153
	return 1;
out_zap_parent:
	nfs_zap_caches(dir);
 out_bad:
1154
	nfs_mark_for_revalidate(dir);
L
Linus Torvalds 已提交
1155 1156 1157 1158 1159 1160
	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;
1161 1162
		if (dentry->d_flags & DCACHE_DISCONNECTED)
			goto out_valid;
L
Linus Torvalds 已提交
1163 1164 1165
		shrink_dcache_parent(dentry);
	}
	d_drop(dentry);
1166 1167
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1168
	dput(parent);
C
Chuck Lever 已提交
1169
	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1170
			__func__, dentry->d_parent->d_name.name,
C
Chuck Lever 已提交
1171
			dentry->d_name.name);
L
Linus Torvalds 已提交
1172
	return 0;
1173 1174 1175 1176 1177 1178 1179 1180
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
1181 1182 1183 1184 1185
}

/*
 * This is called from dput() when d_count is going to 0.
 */
N
Nick Piggin 已提交
1186
static int nfs_dentry_delete(const struct dentry *dentry)
L
Linus Torvalds 已提交
1187 1188 1189 1190 1191
{
	dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
		dentry->d_parent->d_name.name, dentry->d_name.name,
		dentry->d_flags);

1192 1193 1194 1195
	/* 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
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208
	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;

}

1209 1210 1211 1212 1213 1214 1215 1216
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
1217 1218 1219 1220 1221 1222
/*
 * 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)
{
1223 1224 1225 1226
	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
1227
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1228
		drop_nlink(inode);
1229
		nfs_complete_unlink(dentry, inode);
L
Linus Torvalds 已提交
1230 1231 1232 1233
	}
	iput(inode);
}

1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244
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
1245
const struct dentry_operations nfs_dentry_operations = {
L
Linus Torvalds 已提交
1246 1247 1248
	.d_revalidate	= nfs_lookup_revalidate,
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1249
	.d_automount	= nfs_d_automount,
1250
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1251 1252 1253 1254 1255
};

static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
	struct dentry *res;
T
Trond Myklebust 已提交
1256
	struct dentry *parent;
L
Linus Torvalds 已提交
1257
	struct inode *inode = NULL;
1258 1259
	struct nfs_fh *fhandle = NULL;
	struct nfs_fattr *fattr = NULL;
L
Linus Torvalds 已提交
1260 1261 1262 1263
	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
1264
	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
L
Linus Torvalds 已提交
1265 1266 1267 1268 1269

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

1270 1271 1272 1273 1274 1275 1276
	/*
	 * If we're doing an exclusive create, optimize away the lookup
	 * but don't hash the dentry.
	 */
	if (nfs_is_exclusive_create(dir, nd)) {
		d_instantiate(dentry, NULL);
		res = NULL;
1277
		goto out;
1278
	}
L
Linus Torvalds 已提交
1279

1280 1281 1282 1283 1284 1285
	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
1286 1287 1288
	parent = dentry->d_parent;
	/* Protect against concurrent sillydeletes */
	nfs_block_sillyrename(parent);
1289
	error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1290 1291 1292 1293
	if (error == -ENOENT)
		goto no_entry;
	if (error < 0) {
		res = ERR_PTR(error);
T
Trond Myklebust 已提交
1294
		goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1295
	}
1296
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
N
Namhyung Kim 已提交
1297
	res = ERR_CAST(inode);
1298
	if (IS_ERR(res))
T
Trond Myklebust 已提交
1299
		goto out_unblock_sillyrename;
1300

L
Linus Torvalds 已提交
1301
no_entry:
1302
	res = d_materialise_unique(dentry, inode);
1303 1304
	if (res != NULL) {
		if (IS_ERR(res))
T
Trond Myklebust 已提交
1305
			goto out_unblock_sillyrename;
L
Linus Torvalds 已提交
1306
		dentry = res;
1307
	}
L
Linus Torvalds 已提交
1308
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
T
Trond Myklebust 已提交
1309 1310
out_unblock_sillyrename:
	nfs_unblock_sillyrename(parent);
L
Linus Torvalds 已提交
1311
out:
1312 1313
	nfs_free_fattr(fattr);
	nfs_free_fhandle(fhandle);
L
Linus Torvalds 已提交
1314 1315 1316 1317 1318 1319
	return res;
}

#ifdef CONFIG_NFS_V4
static int nfs_open_revalidate(struct dentry *, struct nameidata *);

A
Al Viro 已提交
1320
const struct dentry_operations nfs4_dentry_operations = {
L
Linus Torvalds 已提交
1321 1322 1323
	.d_revalidate	= nfs_open_revalidate,
	.d_delete	= nfs_dentry_delete,
	.d_iput		= nfs_dentry_iput,
1324
	.d_automount	= nfs_d_automount,
1325
	.d_release	= nfs_d_release,
L
Linus Torvalds 已提交
1326 1327
};

1328 1329 1330 1331
/*
 * Use intent information to determine whether we need to substitute
 * the NFSv4-style stateful OPEN for the LOOKUP call
 */
T
Trond Myklebust 已提交
1332
static int is_atomic_open(struct nameidata *nd)
L
Linus Torvalds 已提交
1333
{
1334
	if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
L
Linus Torvalds 已提交
1335 1336 1337 1338 1339
		return 0;
	/* NFS does not (yet) have a stateful open for directories */
	if (nd->flags & LOOKUP_DIRECTORY)
		return 0;
	/* Are we trying to write to a read only partition? */
1340 1341
	if (__mnt_is_readonly(nd->path.mnt) &&
	    (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
L
Linus Torvalds 已提交
1342 1343 1344 1345
		return 0;
	return 1;
}

1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
static struct nfs_open_context *nameidata_to_nfs_open_context(struct dentry *dentry, struct nameidata *nd)
{
	struct path path = {
		.mnt = nd->path.mnt,
		.dentry = dentry,
	};
	struct nfs_open_context *ctx;
	struct rpc_cred *cred;
	fmode_t fmode = nd->intent.open.flags & (FMODE_READ | FMODE_WRITE | FMODE_EXEC);

	cred = rpc_lookup_cred();
	if (IS_ERR(cred))
		return ERR_CAST(cred);
	ctx = alloc_nfs_open_context(&path, cred, fmode);
	put_rpccred(cred);
	if (ctx == NULL)
		return ERR_PTR(-ENOMEM);
	return ctx;
}

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

static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
{
	struct file *filp;
	int ret = 0;

	/* If the open_intent is for execute, we have an extra check to make */
	if (ctx->mode & FMODE_EXEC) {
		ret = nfs_may_open(ctx->path.dentry->d_inode,
				ctx->cred,
				nd->intent.open.flags);
		if (ret < 0)
			goto out;
	}
	filp = lookup_instantiate_filp(nd, ctx->path.dentry, do_open);
	if (IS_ERR(filp))
		ret = PTR_ERR(filp);
	else
		nfs_file_set_open_context(filp, ctx);
out:
	put_nfs_open_context(ctx);
	return ret;
}

L
Linus Torvalds 已提交
1395 1396
static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
1397 1398
	struct nfs_open_context *ctx;
	struct iattr attr;
L
Linus Torvalds 已提交
1399
	struct dentry *res = NULL;
1400
	struct inode *inode;
1401
	int open_flags;
1402
	int err;
L
Linus Torvalds 已提交
1403

C
Chuck Lever 已提交
1404 1405 1406
	dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
			dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);

L
Linus Torvalds 已提交
1407
	/* Check that we are indeed trying to open this file */
T
Trond Myklebust 已提交
1408
	if (!is_atomic_open(nd))
L
Linus Torvalds 已提交
1409 1410 1411 1412 1413 1414 1415
		goto no_open;

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

1416 1417
	/* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
	 * the dentry. */
1418
	if (nd->flags & LOOKUP_EXCL) {
1419
		d_instantiate(dentry, NULL);
1420 1421
		goto out;
	}
L
Linus Torvalds 已提交
1422

1423 1424 1425 1426 1427 1428 1429 1430 1431
	ctx = nameidata_to_nfs_open_context(dentry, nd);
	res = ERR_CAST(ctx);
	if (IS_ERR(ctx))
		goto out;

	open_flags = nd->intent.open.flags;
	if (nd->flags & LOOKUP_CREATE) {
		attr.ia_mode = nd->intent.open.create_mode;
		attr.ia_valid = ATTR_MODE;
A
Aneesh Kumar K.V 已提交
1432
		attr.ia_mode &= ~current_umask();
1433
	} else {
1434
		open_flags &= ~(O_EXCL | O_CREAT);
1435 1436 1437
		attr.ia_valid = 0;
	}

L
Linus Torvalds 已提交
1438
	/* Open the file on the server */
1439
	nfs_block_sillyrename(dentry->d_parent);
1440
	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1441 1442
	if (IS_ERR(inode)) {
		nfs_unblock_sillyrename(dentry->d_parent);
1443
		put_nfs_open_context(ctx);
1444
		switch (PTR_ERR(inode)) {
L
Linus Torvalds 已提交
1445 1446
			/* Make a negative dentry */
			case -ENOENT:
1447
				d_add(dentry, NULL);
1448 1449
				res = NULL;
				goto out;
L
Linus Torvalds 已提交
1450
			/* This turned out not to be a regular file */
1451 1452
			case -ENOTDIR:
				goto no_open;
L
Linus Torvalds 已提交
1453 1454 1455
			case -ELOOP:
				if (!(nd->intent.open.flags & O_NOFOLLOW))
					goto no_open;
1456
			/* case -EISDIR: */
L
Linus Torvalds 已提交
1457 1458
			/* case -EINVAL: */
			default:
1459
				res = ERR_CAST(inode);
L
Linus Torvalds 已提交
1460 1461
				goto out;
		}
1462
	}
1463
	res = d_add_unique(dentry, inode);
1464
	nfs_unblock_sillyrename(dentry->d_parent);
1465 1466 1467
	if (res != NULL) {
		dput(ctx->path.dentry);
		ctx->path.dentry = dget(res);
L
Linus Torvalds 已提交
1468
		dentry = res;
1469
	}
1470 1471 1472 1473 1474 1475
	err = nfs_intent_set_file(nd, ctx);
	if (err < 0) {
		if (res != NULL)
			dput(res);
		return ERR_PTR(err);
	}
L
Linus Torvalds 已提交
1476
out:
1477
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1478 1479 1480 1481 1482 1483 1484 1485
	return res;
no_open:
	return nfs_lookup(dir, dentry, nd);
}

static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
{
	struct dentry *parent = NULL;
N
Nick Piggin 已提交
1486
	struct inode *inode;
L
Linus Torvalds 已提交
1487
	struct inode *dir;
1488
	struct nfs_open_context *ctx;
L
Linus Torvalds 已提交
1489 1490
	int openflags, ret = 0;

N
Nick Piggin 已提交
1491 1492 1493 1494
	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

	inode = dentry->d_inode;
1495
	if (!is_atomic_open(nd) || d_mountpoint(dentry))
T
Trond Myklebust 已提交
1496
		goto no_open;
1497

L
Linus Torvalds 已提交
1498 1499
	parent = dget_parent(dentry);
	dir = parent->d_inode;
1500

L
Linus Torvalds 已提交
1501 1502 1503
	/* We can't create new files in nfs_open_revalidate(), so we
	 * optimize away revalidation of negative dentries.
	 */
1504 1505 1506
	if (inode == NULL) {
		if (!nfs_neg_need_reval(dir, dentry, nd))
			ret = 1;
L
Linus Torvalds 已提交
1507
		goto out;
1508 1509
	}

L
Linus Torvalds 已提交
1510 1511
	/* NFS only supports OPEN on regular files */
	if (!S_ISREG(inode->i_mode))
T
Trond Myklebust 已提交
1512
		goto no_open_dput;
L
Linus Torvalds 已提交
1513 1514 1515
	openflags = nd->intent.open.flags;
	/* We cannot do exclusive creation on a positive dentry */
	if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
T
Trond Myklebust 已提交
1516
		goto no_open_dput;
L
Linus Torvalds 已提交
1517
	/* We can't create new files, or truncate existing ones here */
1518
	openflags &= ~(O_CREAT|O_EXCL|O_TRUNC);
L
Linus Torvalds 已提交
1519

1520 1521 1522 1523
	ctx = nameidata_to_nfs_open_context(dentry, nd);
	ret = PTR_ERR(ctx);
	if (IS_ERR(ctx))
		goto out;
L
Linus Torvalds 已提交
1524
	/*
1525
	 * Note: we're not holding inode->i_mutex and so may be racing with
L
Linus Torvalds 已提交
1526 1527 1528
	 * operations that change the directory. We therefore save the
	 * change attribute *before* we do the RPC call.
	 */
1529
	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, NULL);
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543
	if (IS_ERR(inode)) {
		ret = PTR_ERR(inode);
		switch (ret) {
		case -EPERM:
		case -EACCES:
		case -EDQUOT:
		case -ENOSPC:
		case -EROFS:
			goto out_put_ctx;
		default:
			goto out_drop;
		}
	}
	iput(inode);
1544
	if (inode != dentry->d_inode)
1545
		goto out_drop;
1546 1547 1548 1549 1550

	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
	ret = nfs_intent_set_file(nd, ctx);
	if (ret >= 0)
		ret = 1;
L
Linus Torvalds 已提交
1551 1552 1553
out:
	dput(parent);
	return ret;
1554 1555 1556 1557 1558 1559 1560
out_drop:
	d_drop(dentry);
	ret = 0;
out_put_ctx:
	put_nfs_open_context(ctx);
	goto out;

T
Trond Myklebust 已提交
1561
no_open_dput:
L
Linus Torvalds 已提交
1562
	dput(parent);
T
Trond Myklebust 已提交
1563
no_open:
L
Linus Torvalds 已提交
1564 1565
	return nfs_lookup_revalidate(dentry, nd);
}
1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586

static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
	struct nfs_open_context *ctx = NULL;
	struct iattr attr;
	int error;
	int open_flags = 0;

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

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

	if ((nd->flags & LOOKUP_CREATE) != 0) {
		open_flags = nd->intent.open.flags;

		ctx = nameidata_to_nfs_open_context(dentry, nd);
		error = PTR_ERR(ctx);
		if (IS_ERR(ctx))
1587
			goto out_err_drop;
1588 1589 1590 1591 1592
	}

	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
	if (error != 0)
		goto out_put_ctx;
1593 1594 1595 1596 1597
	if (ctx != NULL) {
		error = nfs_intent_set_file(nd, ctx);
		if (error < 0)
			goto out_err;
	}
1598 1599 1600 1601
	return 0;
out_put_ctx:
	if (ctx != NULL)
		put_nfs_open_context(ctx);
1602
out_err_drop:
1603
	d_drop(dentry);
1604
out_err:
1605 1606 1607
	return error;
}

L
Linus Torvalds 已提交
1608 1609 1610 1611 1612 1613 1614 1615
#endif /* CONFIG_NFSV4 */

/*
 * Code common to create, mkdir, and mknod.
 */
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
				struct nfs_fattr *fattr)
{
1616 1617
	struct dentry *parent = dget_parent(dentry);
	struct inode *dir = parent->d_inode;
L
Linus Torvalds 已提交
1618 1619 1620
	struct inode *inode;
	int error = -EACCES;

1621 1622
	d_drop(dentry);

L
Linus Torvalds 已提交
1623 1624
	/* We may have been initialized further down */
	if (dentry->d_inode)
1625
		goto out;
L
Linus Torvalds 已提交
1626
	if (fhandle->size == 0) {
1627
		error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
L
Linus Torvalds 已提交
1628
		if (error)
1629
			goto out_error;
L
Linus Torvalds 已提交
1630
	}
1631
	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
L
Linus Torvalds 已提交
1632 1633
	if (!(fattr->valid & NFS_ATTR_FATTR)) {
		struct nfs_server *server = NFS_SB(dentry->d_sb);
1634
		error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
L
Linus Torvalds 已提交
1635
		if (error < 0)
1636
			goto out_error;
L
Linus Torvalds 已提交
1637 1638
	}
	inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1639 1640
	error = PTR_ERR(inode);
	if (IS_ERR(inode))
1641 1642 1643 1644
		goto out_error;
	d_add(dentry, inode);
out:
	dput(parent);
L
Linus Torvalds 已提交
1645
	return 0;
1646 1647 1648 1649
out_error:
	nfs_mark_for_revalidate(dir);
	dput(parent);
	return error;
L
Linus Torvalds 已提交
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662
}

/*
 * Following a failed create operation, we drop the dentry rather
 * than retain a negative dentry. This avoids a problem in the event
 * that the operation succeeded on the server, but an error in the
 * reply path made it appear to have failed.
 */
static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
	struct iattr attr;
	int error;
1663
	int open_flags = 0;
L
Linus Torvalds 已提交
1664

C
Chuck Lever 已提交
1665 1666
	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
1667 1668 1669 1670

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

1671 1672 1673 1674
	if ((nd->flags & LOOKUP_CREATE) != 0)
		open_flags = nd->intent.open.flags;

	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL);
L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691
	if (error != 0)
		goto out_err;
	return 0;
out_err:
	d_drop(dentry);
	return error;
}

/*
 * See comments for nfs_proc_create regarding failed operations.
 */
static int
nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
{
	struct iattr attr;
	int status;

C
Chuck Lever 已提交
1692 1693
	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
1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717

	if (!new_valid_dev(rdev))
		return -EINVAL;

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

	status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
	if (status != 0)
		goto out_err;
	return 0;
out_err:
	d_drop(dentry);
	return status;
}

/*
 * See comments for nfs_proc_create regarding failed operations.
 */
static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct iattr attr;
	int error;

C
Chuck Lever 已提交
1718 1719
	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
1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732

	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;
}

1733 1734 1735 1736 1737 1738
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
1739 1740 1741 1742
static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int error;

C
Chuck Lever 已提交
1743 1744
	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
1745 1746 1747 1748

	error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
	/* Ensure the VFS deletes this inode */
	if (error == 0 && dentry->d_inode != NULL)
1749
		clear_nlink(dentry->d_inode);
1750 1751
	else if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778

	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) {
1779
		nfs_inode_return_delegation(inode);
L
Linus Torvalds 已提交
1780 1781 1782
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
		/* The VFS may want to delete this inode */
		if (error == 0)
1783
			nfs_drop_nlink(inode);
1784
		nfs_mark_for_revalidate(inode);
L
Linus Torvalds 已提交
1785 1786
	} else
		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1787 1788
	if (error == -ENOENT)
		nfs_dentry_handle_enoent(dentry);
L
Linus Torvalds 已提交
1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806
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
1807
	if (dentry->d_count > 1) {
L
Linus Torvalds 已提交
1808
		spin_unlock(&dentry->d_lock);
T
Trond Myklebust 已提交
1809 1810
		/* Start asynchronous writeout of the inode */
		write_inode_now(dentry->d_inode, 0);
L
Linus Torvalds 已提交
1811 1812 1813 1814 1815 1816 1817 1818 1819
		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);
1820
	if (!error || error == -ENOENT) {
L
Linus Torvalds 已提交
1821 1822 1823 1824 1825 1826
		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
	} else if (need_rehash)
		d_rehash(dentry);
	return error;
}

1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842
/*
 * 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
1843
{
1844 1845 1846
	struct pagevec lru_pvec;
	struct page *page;
	char *kaddr;
L
Linus Torvalds 已提交
1847
	struct iattr attr;
1848
	unsigned int pathlen = strlen(symname);
L
Linus Torvalds 已提交
1849 1850 1851 1852 1853
	int error;

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

1854 1855
	if (pathlen > PAGE_SIZE)
		return -ENAMETOOLONG;
L
Linus Torvalds 已提交
1856

1857 1858
	attr.ia_mode = S_IFLNK | S_IRWXUGO;
	attr.ia_valid = ATTR_MODE;
L
Linus Torvalds 已提交
1859

1860
	page = alloc_page(GFP_HIGHUSER);
1861
	if (!page)
1862 1863 1864 1865 1866 1867 1868 1869
		return -ENOMEM;

	kaddr = kmap_atomic(page, KM_USER0);
	memcpy(kaddr, symname, pathlen);
	if (pathlen < PAGE_SIZE)
		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
	kunmap_atomic(kaddr, KM_USER0);

1870
	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1871 1872 1873 1874
	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
1875
		d_drop(dentry);
1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886
		__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)) {
1887
		pagevec_add(&lru_pvec, page);
1888
		pagevec_lru_add_file(&lru_pvec);
1889 1890 1891 1892 1893 1894
		SetPageUptodate(page);
		unlock_page(page);
	} else
		__free_page(page);

	return 0;
L
Linus Torvalds 已提交
1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
}

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);

1907 1908
	nfs_inode_return_delegation(inode);

1909
	d_drop(dentry);
L
Linus Torvalds 已提交
1910
	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1911
	if (error == 0) {
A
Al Viro 已提交
1912
		ihold(inode);
1913
		d_add(dentry, inode);
1914
	}
L
Linus Torvalds 已提交
1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952
	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
1953
		 new_dentry->d_count);
L
Linus Torvalds 已提交
1954 1955

	/*
M
Miklos Szeredi 已提交
1956 1957 1958 1959
	 * 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
1960
	 */
1961 1962 1963 1964 1965 1966 1967 1968 1969
	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
1970

N
Nick Piggin 已提交
1971
		if (new_dentry->d_count > 2) {
1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
			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);
1982
			if (err)
1983
				goto out;
1984 1985

			new_dentry = dentry;
O
OGAWA Hirofumi 已提交
1986
			rehash = NULL;
1987
			new_inode = NULL;
1988
		}
1989
	}
L
Linus Torvalds 已提交
1990

1991
	nfs_inode_return_delegation(old_inode);
1992
	if (new_inode != NULL)
1993
		nfs_inode_return_delegation(new_inode);
L
Linus Torvalds 已提交
1994 1995 1996

	error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
					   new_dir, &new_dentry->d_name);
1997
	nfs_mark_for_revalidate(old_inode);
L
Linus Torvalds 已提交
1998 1999 2000 2001
out:
	if (rehash)
		d_rehash(rehash);
	if (!error) {
2002 2003
		if (new_inode != NULL)
			nfs_drop_nlink(new_inode);
2004
		d_move(old_dentry, new_dentry);
2005 2006
		nfs_set_verifier(new_dentry,
					nfs_save_change_attribute(new_dir));
2007 2008
	} else if (error == -ENOENT)
		nfs_dentry_handle_enoent(old_dentry);
L
Linus Torvalds 已提交
2009 2010 2011 2012 2013 2014 2015

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

2016 2017 2018 2019
static DEFINE_SPINLOCK(nfs_access_lru_lock);
static LIST_HEAD(nfs_access_lru_list);
static atomic_long_t nfs_access_nr_entries;

2020 2021 2022 2023
static void nfs_access_free_entry(struct nfs_access_entry *entry)
{
	put_rpccred(entry->cred);
	kfree(entry);
2024 2025 2026
	smp_mb__before_atomic_dec();
	atomic_long_dec(&nfs_access_nr_entries);
	smp_mb__after_atomic_dec();
2027 2028
}

2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039
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);
	}
}

2040 2041
int nfs_access_cache_shrinker(struct shrinker *shrink,
			      struct shrink_control *sc)
2042 2043
{
	LIST_HEAD(head);
2044
	struct nfs_inode *nfsi, *next;
2045
	struct nfs_access_entry *cache;
2046 2047
	int nr_to_scan = sc->nr_to_scan;
	gfp_t gfp_mask = sc->gfp_mask;
2048

2049 2050
	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
		return (nr_to_scan == 0) ? 0 : -1;
2051

2052
	spin_lock(&nfs_access_lru_lock);
2053
	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
2054 2055 2056 2057
		struct inode *inode;

		if (nr_to_scan-- == 0)
			break;
2058
		inode = &nfsi->vfs_inode;
2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071
		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);
2072
			smp_mb__before_clear_bit();
2073
			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2074
			smp_mb__after_clear_bit();
2075
		}
2076
		spin_unlock(&inode->i_lock);
2077 2078
	}
	spin_unlock(&nfs_access_lru_lock);
2079
	nfs_access_free_list(&head);
2080 2081 2082
	return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
}

2083
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
L
Linus Torvalds 已提交
2084
{
2085
	struct rb_root *root_node = &nfsi->access_cache;
2086
	struct rb_node *n;
2087 2088 2089 2090 2091 2092
	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);
2093
		list_move(&entry->lru, head);
2094 2095
	}
	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
L
Linus Torvalds 已提交
2096 2097
}

2098
void nfs_access_zap_cache(struct inode *inode)
L
Linus Torvalds 已提交
2099
{
2100 2101 2102 2103
	LIST_HEAD(head);

	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
		return;
2104
	/* Remove from global LRU init */
2105 2106
	spin_lock(&nfs_access_lru_lock);
	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2107 2108
		list_del_init(&NFS_I(inode)->access_cache_inode_lru);

2109
	spin_lock(&inode->i_lock);
2110 2111 2112 2113
	__nfs_access_zap_cache(NFS_I(inode), &head);
	spin_unlock(&inode->i_lock);
	spin_unlock(&nfs_access_lru_lock);
	nfs_access_free_list(&head);
2114
}
L
Linus Torvalds 已提交
2115

2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
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
2130
	}
2131 2132 2133
	return NULL;
}

2134
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2135 2136 2137 2138 2139
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_access_entry *cache;
	int err = -ENOENT;

2140
	spin_lock(&inode->i_lock);
2141 2142 2143 2144 2145
	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
		goto out_zap;
	cache = nfs_access_search_rbtree(inode, cred);
	if (cache == NULL)
		goto out;
2146
	if (!nfs_have_delegated_attributes(inode) &&
2147
	    !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2148 2149 2150 2151
		goto out_stale;
	res->jiffies = cache->jiffies;
	res->cred = cache->cred;
	res->mask = cache->mask;
2152
	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2153 2154 2155 2156 2157 2158
	err = 0;
out:
	spin_unlock(&inode->i_lock);
	return err;
out_stale:
	rb_erase(&cache->rb_node, &nfsi->access_cache);
2159
	list_del(&cache->lru);
2160 2161 2162 2163
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(cache);
	return -ENOENT;
out_zap:
2164 2165
	spin_unlock(&inode->i_lock);
	nfs_access_zap_cache(inode);
2166 2167 2168 2169 2170
	return -ENOENT;
}

static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
{
2171 2172
	struct nfs_inode *nfsi = NFS_I(inode);
	struct rb_root *root_node = &nfsi->access_cache;
2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190
	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);
2191
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2192
	spin_unlock(&inode->i_lock);
2193 2194 2195
	return;
found:
	rb_replace_node(parent, &set->rb_node, root_node);
2196 2197
	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
	list_del(&entry->lru);
2198 2199 2200 2201
	spin_unlock(&inode->i_lock);
	nfs_access_free_entry(entry);
}

2202
static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2203 2204 2205 2206 2207
{
	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
2208
	cache->jiffies = set->jiffies;
2209
	cache->cred = get_rpccred(set->cred);
L
Linus Torvalds 已提交
2210
	cache->mask = set->mask;
2211 2212

	nfs_access_add_rbtree(inode, cache);
2213 2214 2215 2216 2217 2218 2219

	/* 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 */
2220
	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2221
		spin_lock(&nfs_access_lru_lock);
2222 2223 2224
		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);
2225 2226
		spin_unlock(&nfs_access_lru_lock);
	}
L
Linus Torvalds 已提交
2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
}

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);
2243 2244 2245 2246 2247 2248
	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
2249
		return status;
2250
	}
L
Linus Torvalds 已提交
2251 2252
	nfs_access_add_cache(inode, &cache);
out:
2253
	if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2254 2255 2256 2257
		return 0;
	return -EACCES;
}

2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275
static int nfs_open_permission_mask(int openflags)
{
	int mask = 0;

	if (openflags & FMODE_READ)
		mask |= MAY_READ;
	if (openflags & FMODE_WRITE)
		mask |= MAY_WRITE;
	if (openflags & FMODE_EXEC)
		mask |= MAY_EXEC;
	return mask;
}

int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
{
	return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
}

2276
int nfs_permission(struct inode *inode, int mask, unsigned int flags)
L
Linus Torvalds 已提交
2277 2278 2279 2280
{
	struct rpc_cred *cred;
	int res = 0;

2281 2282 2283
	if (flags & IPERM_FLAG_RCU)
		return -ECHILD;

C
Chuck Lever 已提交
2284 2285
	nfs_inc_stats(inode, NFSIOS_VFSACCESS);

2286
	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
L
Linus Torvalds 已提交
2287 2288
		goto out;
	/* Is this sys_access() ? */
E
Eric Paris 已提交
2289
	if (mask & (MAY_ACCESS | MAY_CHDIR))
L
Linus Torvalds 已提交
2290 2291 2292 2293 2294 2295 2296 2297
		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)
2298 2299
					&& (mask & MAY_OPEN)
					&& !(mask & MAY_EXEC))
L
Linus Torvalds 已提交
2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314
				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;

2315
	cred = rpc_lookup_cred();
L
Linus Torvalds 已提交
2316 2317 2318 2319 2320 2321
	if (!IS_ERR(cred)) {
		res = nfs_do_access(inode, cred, mask);
		put_rpccred(cred);
	} else
		res = PTR_ERR(cred);
out:
2322 2323 2324
	if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
		res = -EACCES;

C
Chuck Lever 已提交
2325 2326
	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
2327 2328 2329 2330
	return res;
out_notsup:
	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (res == 0)
2331
		res = generic_permission(inode, mask, flags);
C
Chuck Lever 已提交
2332
	goto out;
L
Linus Torvalds 已提交
2333 2334 2335 2336 2337 2338 2339 2340
}

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