mirror of https://gitee.com/openkylin/linux.git
2518 lines
63 KiB
C
2518 lines
63 KiB
C
/*
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* linux/fs/nfs/dir.c
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*
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* Copyright (C) 1992 Rick Sladkey
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*
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* nfs directory handling functions
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*
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* 10 Apr 1996 Added silly rename for unlink --okir
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* 28 Sep 1996 Improved directory cache --okir
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* 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de
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* Re-implemented silly rename for unlink, newly implemented
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* silly rename for nfs_rename() following the suggestions
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* of Olaf Kirch (okir) found in this file.
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* Following Linus comments on my original hack, this version
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* depends only on the dcache stuff and doesn't touch the inode
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* layer (iput() and friends).
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* 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM
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*/
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/errno.h>
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#include <linux/stat.h>
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#include <linux/fcntl.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_mount.h>
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#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/swap.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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#include "nfstrace.h"
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/* #define NFS_DEBUG_VERBOSE 1 */
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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 *, struct dir_context *);
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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,
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.iterate = nfs_readdir,
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.open = nfs_opendir,
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.release = nfs_closedir,
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.fsync = nfs_fsync_dir,
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};
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const struct address_space_operations nfs_dir_aops = {
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.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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{
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struct nfs_inode *nfsi = NFS_I(dir);
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struct nfs_open_dir_context *ctx;
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ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
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if (ctx != NULL) {
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ctx->duped = 0;
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ctx->attr_gencount = nfsi->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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spin_lock(&dir->i_lock);
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list_add(&ctx->list, &nfsi->open_files);
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spin_unlock(&dir->i_lock);
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return ctx;
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}
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return ERR_PTR(-ENOMEM);
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}
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static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx)
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{
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spin_lock(&dir->i_lock);
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list_del(&ctx->list);
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spin_unlock(&dir->i_lock);
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put_rpccred(ctx->cred);
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kfree(ctx);
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}
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/*
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* Open file
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*/
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static int
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nfs_opendir(struct inode *inode, struct file *filp)
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{
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int res = 0;
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struct nfs_open_dir_context *ctx;
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struct rpc_cred *cred;
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dfprintk(FILE, "NFS: open dir(%pD2)\n", filp);
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nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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cred = rpc_lookup_cred();
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if (IS_ERR(cred))
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return PTR_ERR(cred);
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ctx = alloc_nfs_open_dir_context(inode, cred);
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if (IS_ERR(ctx)) {
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res = PTR_ERR(ctx);
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goto out;
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}
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filp->private_data = ctx;
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if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
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/* This is a mountpoint, so d_revalidate will never
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* have been called, so we need to refresh the
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* inode (for close-open consistency) ourselves.
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*/
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__nfs_revalidate_inode(NFS_SERVER(inode), inode);
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}
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out:
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put_rpccred(cred);
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return res;
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}
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static int
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nfs_closedir(struct inode *inode, struct file *filp)
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{
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put_nfs_open_dir_context(file_inode(filp), filp->private_data);
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return 0;
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}
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struct nfs_cache_array_entry {
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u64 cookie;
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u64 ino;
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struct qstr string;
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unsigned char d_type;
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};
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struct nfs_cache_array {
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int size;
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int eof_index;
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u64 last_cookie;
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struct nfs_cache_array_entry array[0];
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};
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typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
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typedef struct {
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struct file *file;
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struct page *page;
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struct dir_context *ctx;
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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;
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unsigned int plus:1;
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unsigned int eof:1;
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} nfs_readdir_descriptor_t;
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/*
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* The caller is responsible for calling nfs_readdir_release_array(page)
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*/
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static
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struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
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{
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void *ptr;
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if (page == NULL)
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return ERR_PTR(-EIO);
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ptr = kmap(page);
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if (ptr == NULL)
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return ERR_PTR(-ENOMEM);
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return ptr;
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}
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static
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void nfs_readdir_release_array(struct page *page)
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{
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kunmap(page);
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}
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/*
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* we are freeing strings created by nfs_add_to_readdir_array()
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*/
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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++)
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kfree(array->array[i].string.name);
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kunmap_atomic(array);
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}
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/*
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* the caller is responsible for freeing qstr.name
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* when called by nfs_readdir_add_to_array, the strings will be freed in
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* nfs_clear_readdir_array()
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*/
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static
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int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
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{
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string->len = len;
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string->name = kmemdup(name, len, GFP_KERNEL);
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if (string->name == NULL)
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return -ENOMEM;
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/*
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* Avoid a kmemleak false positive. The pointer to the name is stored
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* in a page cache page which kmemleak does not scan.
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*/
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kmemleak_not_leak(string->name);
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string->hash = full_name_hash(name, len);
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return 0;
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}
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static
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int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
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{
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struct nfs_cache_array *array = nfs_readdir_get_array(page);
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struct nfs_cache_array_entry *cache_entry;
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int ret;
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if (IS_ERR(array))
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return PTR_ERR(array);
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cache_entry = &array->array[array->size];
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/* 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;
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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);
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if (ret)
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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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}
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static
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int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
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{
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loff_t diff = desc->ctx->pos - desc->current_index;
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unsigned int index;
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if (diff < 0)
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goto out_eof;
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if (diff >= array->size) {
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if (array->eof_index >= 0)
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goto out_eof;
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return -EAGAIN;
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}
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index = (unsigned int)diff;
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*desc->dir_cookie = array->array[index].cookie;
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desc->cache_entry_index = index;
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return 0;
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out_eof:
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desc->eof = 1;
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return -EBADCOOKIE;
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}
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static bool
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nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
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{
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if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
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return false;
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smp_rmb();
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return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
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}
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static
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int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
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{
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int i;
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loff_t new_pos;
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int status = -EAGAIN;
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for (i = 0; i < array->size; i++) {
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if (array->array[i].cookie == *desc->dir_cookie) {
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struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
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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 ||
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!nfs_readdir_inode_mapping_valid(nfsi)) {
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ctx->duped = 0;
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ctx->attr_gencount = nfsi->attr_gencount;
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} else if (new_pos < desc->ctx->pos) {
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if (ctx->duped > 0
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&& ctx->dup_cookie == *desc->dir_cookie) {
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if (printk_ratelimit()) {
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pr_notice("NFS: directory %pD2 contains a readdir loop."
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"Please contact your server vendor. "
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"The file: %.*s has duplicate cookie %llu\n",
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desc->file, array->array[i].string.len,
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array->array[i].string.name, *desc->dir_cookie);
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}
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status = -ELOOP;
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goto out;
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}
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ctx->dup_cookie = *desc->dir_cookie;
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ctx->duped = -1;
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}
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desc->ctx->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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}
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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)
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desc->eof = 1;
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}
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out:
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return status;
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}
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static
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int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
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{
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struct nfs_cache_array *array;
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int status;
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array = nfs_readdir_get_array(desc->page);
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if (IS_ERR(array)) {
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status = PTR_ERR(array);
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goto out;
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}
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if (*desc->dir_cookie == 0)
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status = nfs_readdir_search_for_pos(array, desc);
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else
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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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}
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nfs_readdir_release_array(desc->page);
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out:
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return status;
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}
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/* Fill a page with xdr information before transferring to the cache page */
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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;
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struct rpc_cred *cred = ctx->cred;
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unsigned long timestamp, gencount;
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int error;
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again:
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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);
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if (error < 0) {
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/* We requested READDIRPLUS, but the server doesn't grok it */
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if (error == -ENOTSUPP && desc->plus) {
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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;
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goto again;
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}
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goto error;
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}
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desc->timestamp = timestamp;
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desc->gencount = gencount;
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error:
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return error;
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}
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|
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static int xdr_decode(nfs_readdir_descriptor_t *desc,
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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);
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if (error)
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return error;
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entry->fattr->time_start = desc->timestamp;
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entry->fattr->gencount = desc->gencount;
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return 0;
|
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}
|
|
|
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/* Match file and dirent using either filehandle or fileid
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* Note: caller is responsible for checking the fsid
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*/
|
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static
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int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
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{
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struct nfs_inode *nfsi;
|
|
|
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if (d_really_is_negative(dentry))
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return 0;
|
|
|
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nfsi = NFS_I(d_inode(dentry));
|
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if (entry->fattr->fileid == nfsi->fileid)
|
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return 1;
|
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if (nfs_compare_fh(entry->fh, &nfsi->fh) == 0)
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return 1;
|
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return 0;
|
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}
|
|
|
|
static
|
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bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx)
|
|
{
|
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if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
|
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return false;
|
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if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
|
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return true;
|
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if (ctx->pos == 0)
|
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return true;
|
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return false;
|
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}
|
|
|
|
/*
|
|
* This function is called by the lookup code to request the use of
|
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* readdirplus to accelerate any future lookups in the same
|
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* directory.
|
|
*/
|
|
static
|
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void nfs_advise_use_readdirplus(struct inode *dir)
|
|
{
|
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set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
|
|
}
|
|
|
|
/*
|
|
* This function is mainly for use by nfs_getattr().
|
|
*
|
|
* If this is an 'ls -l', we want to force use of readdirplus.
|
|
* Do this by checking if there is an active file descriptor
|
|
* and calling nfs_advise_use_readdirplus, then forcing a
|
|
* cache flush.
|
|
*/
|
|
void nfs_force_use_readdirplus(struct inode *dir)
|
|
{
|
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if (!list_empty(&NFS_I(dir)->open_files)) {
|
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nfs_advise_use_readdirplus(dir);
|
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nfs_zap_mapping(dir, dir->i_mapping);
|
|
}
|
|
}
|
|
|
|
static
|
|
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
|
|
{
|
|
struct qstr filename = QSTR_INIT(entry->name, entry->len);
|
|
struct dentry *dentry;
|
|
struct dentry *alias;
|
|
struct inode *dir = d_inode(parent);
|
|
struct inode *inode;
|
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int status;
|
|
|
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if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID))
|
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return;
|
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if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID))
|
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return;
|
|
if (filename.name[0] == '.') {
|
|
if (filename.len == 1)
|
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return;
|
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if (filename.len == 2 && filename.name[1] == '.')
|
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return;
|
|
}
|
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filename.hash = full_name_hash(filename.name, filename.len);
|
|
|
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dentry = d_lookup(parent, &filename);
|
|
if (dentry != NULL) {
|
|
/* Is there a mountpoint here? If so, just exit */
|
|
if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,
|
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&entry->fattr->fsid))
|
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goto out;
|
|
if (nfs_same_file(dentry, entry)) {
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
|
|
if (!status)
|
|
nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label);
|
|
goto out;
|
|
} else {
|
|
d_invalidate(dentry);
|
|
dput(dentry);
|
|
}
|
|
}
|
|
|
|
dentry = d_alloc(parent, &filename);
|
|
if (dentry == NULL)
|
|
return;
|
|
|
|
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
|
|
if (IS_ERR(inode))
|
|
goto out;
|
|
|
|
alias = d_splice_alias(inode, dentry);
|
|
if (IS_ERR(alias))
|
|
goto out;
|
|
else if (alias) {
|
|
nfs_set_verifier(alias, nfs_save_change_attribute(dir));
|
|
dput(alias);
|
|
} else
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
|
|
out:
|
|
dput(dentry);
|
|
}
|
|
|
|
/* Perform conversion from xdr to cache array */
|
|
static
|
|
int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
|
|
struct page **xdr_pages, struct page *page, unsigned int buflen)
|
|
{
|
|
struct xdr_stream stream;
|
|
struct xdr_buf buf;
|
|
struct page *scratch;
|
|
struct nfs_cache_array *array;
|
|
unsigned int count = 0;
|
|
int status;
|
|
|
|
scratch = alloc_page(GFP_KERNEL);
|
|
if (scratch == NULL)
|
|
return -ENOMEM;
|
|
|
|
if (buflen == 0)
|
|
goto out_nopages;
|
|
|
|
xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
|
|
xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
|
|
|
|
do {
|
|
status = xdr_decode(desc, entry, &stream);
|
|
if (status != 0) {
|
|
if (status == -EAGAIN)
|
|
status = 0;
|
|
break;
|
|
}
|
|
|
|
count++;
|
|
|
|
if (desc->plus != 0)
|
|
nfs_prime_dcache(desc->file->f_path.dentry, entry);
|
|
|
|
status = nfs_readdir_add_to_array(entry, page);
|
|
if (status != 0)
|
|
break;
|
|
} while (!entry->eof);
|
|
|
|
out_nopages:
|
|
if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
|
|
array = nfs_readdir_get_array(page);
|
|
if (!IS_ERR(array)) {
|
|
array->eof_index = array->size;
|
|
status = 0;
|
|
nfs_readdir_release_array(page);
|
|
} else
|
|
status = PTR_ERR(array);
|
|
}
|
|
|
|
put_page(scratch);
|
|
return status;
|
|
}
|
|
|
|
static
|
|
void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
|
|
{
|
|
unsigned int i;
|
|
for (i = 0; i < npages; i++)
|
|
put_page(pages[i]);
|
|
}
|
|
|
|
static
|
|
void nfs_readdir_free_large_page(void *ptr, struct page **pages,
|
|
unsigned int npages)
|
|
{
|
|
nfs_readdir_free_pagearray(pages, npages);
|
|
}
|
|
|
|
/*
|
|
* nfs_readdir_large_page will allocate pages that must be freed with a call
|
|
* to nfs_readdir_free_large_page
|
|
*/
|
|
static
|
|
int nfs_readdir_large_page(struct page **pages, unsigned int npages)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < npages; i++) {
|
|
struct page *page = alloc_page(GFP_KERNEL);
|
|
if (page == NULL)
|
|
goto out_freepages;
|
|
pages[i] = page;
|
|
}
|
|
return 0;
|
|
|
|
out_freepages:
|
|
nfs_readdir_free_pagearray(pages, i);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static
|
|
int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
|
|
{
|
|
struct page *pages[NFS_MAX_READDIR_PAGES];
|
|
void *pages_ptr = NULL;
|
|
struct nfs_entry entry;
|
|
struct file *file = desc->file;
|
|
struct nfs_cache_array *array;
|
|
int status = -ENOMEM;
|
|
unsigned int array_size = ARRAY_SIZE(pages);
|
|
|
|
entry.prev_cookie = 0;
|
|
entry.cookie = desc->last_cookie;
|
|
entry.eof = 0;
|
|
entry.fh = nfs_alloc_fhandle();
|
|
entry.fattr = nfs_alloc_fattr();
|
|
entry.server = NFS_SERVER(inode);
|
|
if (entry.fh == NULL || entry.fattr == NULL)
|
|
goto out;
|
|
|
|
entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
|
|
if (IS_ERR(entry.label)) {
|
|
status = PTR_ERR(entry.label);
|
|
goto out;
|
|
}
|
|
|
|
array = nfs_readdir_get_array(page);
|
|
if (IS_ERR(array)) {
|
|
status = PTR_ERR(array);
|
|
goto out_label_free;
|
|
}
|
|
memset(array, 0, sizeof(struct nfs_cache_array));
|
|
array->eof_index = -1;
|
|
|
|
status = nfs_readdir_large_page(pages, array_size);
|
|
if (status < 0)
|
|
goto out_release_array;
|
|
do {
|
|
unsigned int pglen;
|
|
status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
|
|
|
|
if (status < 0)
|
|
break;
|
|
pglen = status;
|
|
status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
|
|
if (status < 0) {
|
|
if (status == -ENOSPC)
|
|
status = 0;
|
|
break;
|
|
}
|
|
} while (array->eof_index < 0);
|
|
|
|
nfs_readdir_free_large_page(pages_ptr, pages, array_size);
|
|
out_release_array:
|
|
nfs_readdir_release_array(page);
|
|
out_label_free:
|
|
nfs4_label_free(entry.label);
|
|
out:
|
|
nfs_free_fattr(entry.fattr);
|
|
nfs_free_fhandle(entry.fh);
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* Now we cache directories properly, by converting xdr information
|
|
* to an array that can be used for lookups later. This results in
|
|
* fewer cache pages, since we can store more information on each page.
|
|
* We only need to convert from xdr once so future lookups are much simpler
|
|
*/
|
|
static
|
|
int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
|
|
{
|
|
struct inode *inode = file_inode(desc->file);
|
|
int ret;
|
|
|
|
ret = nfs_readdir_xdr_to_array(desc, page, inode);
|
|
if (ret < 0)
|
|
goto error;
|
|
SetPageUptodate(page);
|
|
|
|
if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
|
|
/* Should never happen */
|
|
nfs_zap_mapping(inode, inode->i_mapping);
|
|
}
|
|
unlock_page(page);
|
|
return 0;
|
|
error:
|
|
unlock_page(page);
|
|
return ret;
|
|
}
|
|
|
|
static
|
|
void cache_page_release(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
if (!desc->page->mapping)
|
|
nfs_readdir_clear_array(desc->page);
|
|
page_cache_release(desc->page);
|
|
desc->page = NULL;
|
|
}
|
|
|
|
static
|
|
struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
return read_cache_page(file_inode(desc->file)->i_mapping,
|
|
desc->page_index, (filler_t *)nfs_readdir_filler, desc);
|
|
}
|
|
|
|
/*
|
|
* Returns 0 if desc->dir_cookie was found on page desc->page_index
|
|
*/
|
|
static
|
|
int find_cache_page(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
int res;
|
|
|
|
desc->page = get_cache_page(desc);
|
|
if (IS_ERR(desc->page))
|
|
return PTR_ERR(desc->page);
|
|
|
|
res = nfs_readdir_search_array(desc);
|
|
if (res != 0)
|
|
cache_page_release(desc);
|
|
return res;
|
|
}
|
|
|
|
/* Search for desc->dir_cookie from the beginning of the page cache */
|
|
static inline
|
|
int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
int res;
|
|
|
|
if (desc->page_index == 0) {
|
|
desc->current_index = 0;
|
|
desc->last_cookie = 0;
|
|
}
|
|
do {
|
|
res = find_cache_page(desc);
|
|
} while (res == -EAGAIN);
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Once we've found the start of the dirent within a page: fill 'er up...
|
|
*/
|
|
static
|
|
int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
struct file *file = desc->file;
|
|
int i = 0;
|
|
int res = 0;
|
|
struct nfs_cache_array *array = NULL;
|
|
struct nfs_open_dir_context *ctx = file->private_data;
|
|
|
|
array = nfs_readdir_get_array(desc->page);
|
|
if (IS_ERR(array)) {
|
|
res = PTR_ERR(array);
|
|
goto out;
|
|
}
|
|
|
|
for (i = desc->cache_entry_index; i < array->size; i++) {
|
|
struct nfs_cache_array_entry *ent;
|
|
|
|
ent = &array->array[i];
|
|
if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
|
|
nfs_compat_user_ino64(ent->ino), ent->d_type)) {
|
|
desc->eof = 1;
|
|
break;
|
|
}
|
|
desc->ctx->pos++;
|
|
if (i < (array->size-1))
|
|
*desc->dir_cookie = array->array[i+1].cookie;
|
|
else
|
|
*desc->dir_cookie = array->last_cookie;
|
|
if (ctx->duped != 0)
|
|
ctx->duped = 1;
|
|
}
|
|
if (array->eof_index >= 0)
|
|
desc->eof = 1;
|
|
|
|
nfs_readdir_release_array(desc->page);
|
|
out:
|
|
cache_page_release(desc);
|
|
dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
|
|
(unsigned long long)*desc->dir_cookie, res);
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* If we cannot find a cookie in our cache, we suspect that this is
|
|
* because it points to a deleted file, so we ask the server to return
|
|
* whatever it thinks is the next entry. We then feed this to filldir.
|
|
* If all goes well, we should then be able to find our way round the
|
|
* cache on the next call to readdir_search_pagecache();
|
|
*
|
|
* NOTE: we cannot add the anonymous page to the pagecache because
|
|
* the data it contains might not be page aligned. Besides,
|
|
* we should already have a complete representation of the
|
|
* directory in the page cache by the time we get here.
|
|
*/
|
|
static inline
|
|
int uncached_readdir(nfs_readdir_descriptor_t *desc)
|
|
{
|
|
struct page *page = NULL;
|
|
int status;
|
|
struct inode *inode = file_inode(desc->file);
|
|
struct nfs_open_dir_context *ctx = desc->file->private_data;
|
|
|
|
dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
|
|
(unsigned long long)*desc->dir_cookie);
|
|
|
|
page = alloc_page(GFP_HIGHUSER);
|
|
if (!page) {
|
|
status = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
desc->page_index = 0;
|
|
desc->last_cookie = *desc->dir_cookie;
|
|
desc->page = page;
|
|
ctx->duped = 0;
|
|
|
|
status = nfs_readdir_xdr_to_array(desc, page, inode);
|
|
if (status < 0)
|
|
goto out_release;
|
|
|
|
status = nfs_do_filldir(desc);
|
|
|
|
out:
|
|
dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
|
|
__func__, status);
|
|
return status;
|
|
out_release:
|
|
cache_page_release(desc);
|
|
goto out;
|
|
}
|
|
|
|
static bool nfs_dir_mapping_need_revalidate(struct inode *dir)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(dir);
|
|
|
|
if (nfs_attribute_cache_expired(dir))
|
|
return true;
|
|
if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* The file offset position represents the dirent entry number. A
|
|
last cookie cache takes care of the common case of reading the
|
|
whole directory.
|
|
*/
|
|
static int nfs_readdir(struct file *file, struct dir_context *ctx)
|
|
{
|
|
struct dentry *dentry = file->f_path.dentry;
|
|
struct inode *inode = d_inode(dentry);
|
|
nfs_readdir_descriptor_t my_desc,
|
|
*desc = &my_desc;
|
|
struct nfs_open_dir_context *dir_ctx = file->private_data;
|
|
int res = 0;
|
|
|
|
dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
|
|
file, (long long)ctx->pos);
|
|
nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
|
|
|
|
/*
|
|
* ctx->pos points to the dirent entry number.
|
|
* *desc->dir_cookie has the cookie for the next entry. We have
|
|
* to either find the entry with the appropriate number or
|
|
* revalidate the cookie.
|
|
*/
|
|
memset(desc, 0, sizeof(*desc));
|
|
|
|
desc->file = file;
|
|
desc->ctx = ctx;
|
|
desc->dir_cookie = &dir_ctx->dir_cookie;
|
|
desc->decode = NFS_PROTO(inode)->decode_dirent;
|
|
desc->plus = nfs_use_readdirplus(inode, ctx) ? 1 : 0;
|
|
|
|
nfs_block_sillyrename(dentry);
|
|
if (ctx->pos == 0 || nfs_dir_mapping_need_revalidate(inode))
|
|
res = nfs_revalidate_mapping(inode, file->f_mapping);
|
|
if (res < 0)
|
|
goto out;
|
|
|
|
do {
|
|
res = readdir_search_pagecache(desc);
|
|
|
|
if (res == -EBADCOOKIE) {
|
|
res = 0;
|
|
/* This means either end of directory */
|
|
if (*desc->dir_cookie && desc->eof == 0) {
|
|
/* Or that the server has 'lost' a cookie */
|
|
res = uncached_readdir(desc);
|
|
if (res == 0)
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
if (res == -ETOOSMALL && desc->plus) {
|
|
clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
|
|
nfs_zap_caches(inode);
|
|
desc->page_index = 0;
|
|
desc->plus = 0;
|
|
desc->eof = 0;
|
|
continue;
|
|
}
|
|
if (res < 0)
|
|
break;
|
|
|
|
res = nfs_do_filldir(desc);
|
|
if (res < 0)
|
|
break;
|
|
} while (!desc->eof);
|
|
out:
|
|
nfs_unblock_sillyrename(dentry);
|
|
if (res > 0)
|
|
res = 0;
|
|
dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);
|
|
return res;
|
|
}
|
|
|
|
static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
struct nfs_open_dir_context *dir_ctx = filp->private_data;
|
|
|
|
dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
|
|
filp, offset, whence);
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
switch (whence) {
|
|
case 1:
|
|
offset += filp->f_pos;
|
|
case 0:
|
|
if (offset >= 0)
|
|
break;
|
|
default:
|
|
offset = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (offset != filp->f_pos) {
|
|
filp->f_pos = offset;
|
|
dir_ctx->dir_cookie = 0;
|
|
dir_ctx->duped = 0;
|
|
}
|
|
out:
|
|
mutex_unlock(&inode->i_mutex);
|
|
return offset;
|
|
}
|
|
|
|
/*
|
|
* All directory operations under NFS are synchronous, so fsync()
|
|
* is a dummy operation.
|
|
*/
|
|
static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
|
|
int datasync)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
|
|
dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync);
|
|
|
|
mutex_lock(&inode->i_mutex);
|
|
nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
|
|
mutex_unlock(&inode->i_mutex);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* nfs_force_lookup_revalidate - Mark the directory as having changed
|
|
* @dir - pointer to directory inode
|
|
*
|
|
* This forces the revalidation code in nfs_lookup_revalidate() to do a
|
|
* full lookup on all child dentries of 'dir' whenever a change occurs
|
|
* on the server that might have invalidated our dcache.
|
|
*
|
|
* The caller should be holding dir->i_lock
|
|
*/
|
|
void nfs_force_lookup_revalidate(struct inode *dir)
|
|
{
|
|
NFS_I(dir)->cache_change_attribute++;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
|
|
|
|
/*
|
|
* 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.
|
|
* If rcu_walk prevents us from performing a full check, return 0.
|
|
*/
|
|
static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
|
|
int rcu_walk)
|
|
{
|
|
int ret;
|
|
|
|
if (IS_ROOT(dentry))
|
|
return 1;
|
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
|
|
return 0;
|
|
if (!nfs_verify_change_attribute(dir, dentry->d_time))
|
|
return 0;
|
|
/* Revalidate nfsi->cache_change_attribute before we declare a match */
|
|
if (rcu_walk)
|
|
ret = nfs_revalidate_inode_rcu(NFS_SERVER(dir), dir);
|
|
else
|
|
ret = nfs_revalidate_inode(NFS_SERVER(dir), dir);
|
|
if (ret < 0)
|
|
return 0;
|
|
if (!nfs_verify_change_attribute(dir, dentry->d_time))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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, unsigned int flags)
|
|
{
|
|
if (NFS_PROTO(dir)->version == 2)
|
|
return 0;
|
|
return flags & LOOKUP_EXCL;
|
|
}
|
|
|
|
/*
|
|
* Inode and filehandle revalidation for lookups.
|
|
*
|
|
* We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
|
|
* or if the intent information indicates that we're about to open this
|
|
* particular file and the "nocto" mount flag is not set.
|
|
*
|
|
*/
|
|
static
|
|
int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
|
|
{
|
|
struct nfs_server *server = NFS_SERVER(inode);
|
|
int ret;
|
|
|
|
if (IS_AUTOMOUNT(inode))
|
|
return 0;
|
|
/* VFS wants an on-the-wire revalidation */
|
|
if (flags & LOOKUP_REVAL)
|
|
goto out_force;
|
|
/* This is an open(2) */
|
|
if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
|
|
(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
|
|
goto out_force;
|
|
out:
|
|
return (inode->i_nlink == 0) ? -ENOENT : 0;
|
|
out_force:
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
ret = __nfs_revalidate_inode(server, inode);
|
|
if (ret != 0)
|
|
return ret;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* If LOOKUP_RCU prevents us from performing a full check, return 1
|
|
* suggesting a reval is needed.
|
|
*/
|
|
static inline
|
|
int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
/* Don't revalidate a negative dentry if we're creating a new file */
|
|
if (flags & LOOKUP_CREATE)
|
|
return 0;
|
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
|
|
return 1;
|
|
return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU);
|
|
}
|
|
|
|
/*
|
|
* This is called every time the dcache has a lookup hit,
|
|
* and we should check whether we can really trust that
|
|
* lookup.
|
|
*
|
|
* NOTE! The hit can be a negative hit too, don't assume
|
|
* we have an inode!
|
|
*
|
|
* If the parent directory is seen to have changed, we throw out the
|
|
* cached dentry and do a new lookup.
|
|
*/
|
|
static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
struct inode *dir;
|
|
struct inode *inode;
|
|
struct dentry *parent;
|
|
struct nfs_fh *fhandle = NULL;
|
|
struct nfs_fattr *fattr = NULL;
|
|
struct nfs4_label *label = NULL;
|
|
int error;
|
|
|
|
if (flags & LOOKUP_RCU) {
|
|
parent = ACCESS_ONCE(dentry->d_parent);
|
|
dir = d_inode_rcu(parent);
|
|
if (!dir)
|
|
return -ECHILD;
|
|
} else {
|
|
parent = dget_parent(dentry);
|
|
dir = d_inode(parent);
|
|
}
|
|
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
|
|
inode = d_inode(dentry);
|
|
|
|
if (!inode) {
|
|
if (nfs_neg_need_reval(dir, dentry, flags)) {
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
goto out_bad;
|
|
}
|
|
goto out_valid_noent;
|
|
}
|
|
|
|
if (is_bad_inode(inode)) {
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
|
|
__func__, dentry);
|
|
goto out_bad;
|
|
}
|
|
|
|
if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
|
|
goto out_set_verifier;
|
|
|
|
/* Force a full look up iff the parent directory has changed */
|
|
if (!nfs_is_exclusive_create(dir, flags) &&
|
|
nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
|
|
|
|
if (nfs_lookup_verify_inode(inode, flags)) {
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
goto out_zap_parent;
|
|
}
|
|
goto out_valid;
|
|
}
|
|
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
|
|
if (NFS_STALE(inode))
|
|
goto out_bad;
|
|
|
|
error = -ENOMEM;
|
|
fhandle = nfs_alloc_fhandle();
|
|
fattr = nfs_alloc_fattr();
|
|
if (fhandle == NULL || fattr == NULL)
|
|
goto out_error;
|
|
|
|
label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
|
|
if (IS_ERR(label))
|
|
goto out_error;
|
|
|
|
trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
|
|
trace_nfs_lookup_revalidate_exit(dir, dentry, flags, error);
|
|
if (error)
|
|
goto out_bad;
|
|
if (nfs_compare_fh(NFS_FH(inode), fhandle))
|
|
goto out_bad;
|
|
if ((error = nfs_refresh_inode(inode, fattr)) != 0)
|
|
goto out_bad;
|
|
|
|
nfs_setsecurity(inode, fattr, label);
|
|
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
nfs4_label_free(label);
|
|
|
|
out_set_verifier:
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
out_valid:
|
|
/* Success: notify readdir to use READDIRPLUS */
|
|
nfs_advise_use_readdirplus(dir);
|
|
out_valid_noent:
|
|
if (flags & LOOKUP_RCU) {
|
|
if (parent != ACCESS_ONCE(dentry->d_parent))
|
|
return -ECHILD;
|
|
} else
|
|
dput(parent);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is valid\n",
|
|
__func__, dentry);
|
|
return 1;
|
|
out_zap_parent:
|
|
nfs_zap_caches(dir);
|
|
out_bad:
|
|
WARN_ON(flags & LOOKUP_RCU);
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
nfs4_label_free(label);
|
|
nfs_mark_for_revalidate(dir);
|
|
if (inode && S_ISDIR(inode->i_mode)) {
|
|
/* Purge readdir caches. */
|
|
nfs_zap_caches(inode);
|
|
/*
|
|
* We can't d_drop the root of a disconnected tree:
|
|
* its d_hash is on the s_anon list and d_drop() would hide
|
|
* it from shrink_dcache_for_unmount(), leading to busy
|
|
* inodes on unmount and further oopses.
|
|
*/
|
|
if (IS_ROOT(dentry))
|
|
goto out_valid;
|
|
}
|
|
dput(parent);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is invalid\n",
|
|
__func__, dentry);
|
|
return 0;
|
|
out_error:
|
|
WARN_ON(flags & LOOKUP_RCU);
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
nfs4_label_free(label);
|
|
dput(parent);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) lookup returned error %d\n",
|
|
__func__, dentry, error);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* A weaker form of d_revalidate for revalidating just the d_inode(dentry)
|
|
* when we don't really care about the dentry name. This is called when a
|
|
* pathwalk ends on a dentry that was not found via a normal lookup in the
|
|
* parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
|
|
*
|
|
* In this situation, we just want to verify that the inode itself is OK
|
|
* since the dentry might have changed on the server.
|
|
*/
|
|
static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
int error;
|
|
struct inode *inode = d_inode(dentry);
|
|
|
|
/*
|
|
* I believe we can only get a negative dentry here in the case of a
|
|
* procfs-style symlink. Just assume it's correct for now, but we may
|
|
* eventually need to do something more here.
|
|
*/
|
|
if (!inode) {
|
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n",
|
|
__func__, dentry);
|
|
return 1;
|
|
}
|
|
|
|
if (is_bad_inode(inode)) {
|
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
|
|
__func__, dentry);
|
|
return 0;
|
|
}
|
|
|
|
error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
|
|
dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
|
|
__func__, inode->i_ino, error ? "invalid" : "valid");
|
|
return !error;
|
|
}
|
|
|
|
/*
|
|
* This is called from dput() when d_count is going to 0.
|
|
*/
|
|
static int nfs_dentry_delete(const struct dentry *dentry)
|
|
{
|
|
dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n",
|
|
dentry, dentry->d_flags);
|
|
|
|
/* Unhash any dentry with a stale inode */
|
|
if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry)))
|
|
return 1;
|
|
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
|
|
/* Unhash it, so that ->d_iput() would be called */
|
|
return 1;
|
|
}
|
|
if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
|
|
/* Unhash it, so that ancestors of killed async unlink
|
|
* files will be cleaned up during umount */
|
|
return 1;
|
|
}
|
|
return 0;
|
|
|
|
}
|
|
|
|
/* Ensure that we revalidate inode->i_nlink */
|
|
static void nfs_drop_nlink(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
/* 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;
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
|
|
/*
|
|
* Called when the dentry loses inode.
|
|
* We use it to clean up silly-renamed files.
|
|
*/
|
|
static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
|
|
{
|
|
if (S_ISDIR(inode->i_mode))
|
|
/* drop any readdir cache as it could easily be old */
|
|
NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
|
|
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
|
|
nfs_complete_unlink(dentry, inode);
|
|
nfs_drop_nlink(inode);
|
|
}
|
|
iput(inode);
|
|
}
|
|
|
|
static void nfs_d_release(struct dentry *dentry)
|
|
{
|
|
/* free cached devname value, if it survived that far */
|
|
if (unlikely(dentry->d_fsdata)) {
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
|
|
WARN_ON(1);
|
|
else
|
|
kfree(dentry->d_fsdata);
|
|
}
|
|
}
|
|
|
|
const struct dentry_operations nfs_dentry_operations = {
|
|
.d_revalidate = nfs_lookup_revalidate,
|
|
.d_weak_revalidate = nfs_weak_revalidate,
|
|
.d_delete = nfs_dentry_delete,
|
|
.d_iput = nfs_dentry_iput,
|
|
.d_automount = nfs_d_automount,
|
|
.d_release = nfs_d_release,
|
|
};
|
|
EXPORT_SYMBOL_GPL(nfs_dentry_operations);
|
|
|
|
struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
|
|
{
|
|
struct dentry *res;
|
|
struct dentry *parent;
|
|
struct inode *inode = NULL;
|
|
struct nfs_fh *fhandle = NULL;
|
|
struct nfs_fattr *fattr = NULL;
|
|
struct nfs4_label *label = NULL;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
|
|
nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
|
|
|
|
res = ERR_PTR(-ENAMETOOLONG);
|
|
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
|
|
goto out;
|
|
|
|
/*
|
|
* If we're doing an exclusive create, optimize away the lookup
|
|
* but don't hash the dentry.
|
|
*/
|
|
if (nfs_is_exclusive_create(dir, flags)) {
|
|
d_instantiate(dentry, NULL);
|
|
res = NULL;
|
|
goto out;
|
|
}
|
|
|
|
res = ERR_PTR(-ENOMEM);
|
|
fhandle = nfs_alloc_fhandle();
|
|
fattr = nfs_alloc_fattr();
|
|
if (fhandle == NULL || fattr == NULL)
|
|
goto out;
|
|
|
|
label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT);
|
|
if (IS_ERR(label))
|
|
goto out;
|
|
|
|
parent = dentry->d_parent;
|
|
/* Protect against concurrent sillydeletes */
|
|
trace_nfs_lookup_enter(dir, dentry, flags);
|
|
nfs_block_sillyrename(parent);
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
|
|
if (error == -ENOENT)
|
|
goto no_entry;
|
|
if (error < 0) {
|
|
res = ERR_PTR(error);
|
|
goto out_unblock_sillyrename;
|
|
}
|
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
|
|
res = ERR_CAST(inode);
|
|
if (IS_ERR(res))
|
|
goto out_unblock_sillyrename;
|
|
|
|
/* Success: notify readdir to use READDIRPLUS */
|
|
nfs_advise_use_readdirplus(dir);
|
|
|
|
no_entry:
|
|
res = d_splice_alias(inode, dentry);
|
|
if (res != NULL) {
|
|
if (IS_ERR(res))
|
|
goto out_unblock_sillyrename;
|
|
dentry = res;
|
|
}
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
out_unblock_sillyrename:
|
|
nfs_unblock_sillyrename(parent);
|
|
trace_nfs_lookup_exit(dir, dentry, flags, error);
|
|
nfs4_label_free(label);
|
|
out:
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_lookup);
|
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4)
|
|
static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
|
|
|
|
const struct dentry_operations nfs4_dentry_operations = {
|
|
.d_revalidate = nfs4_lookup_revalidate,
|
|
.d_delete = nfs_dentry_delete,
|
|
.d_iput = nfs_dentry_iput,
|
|
.d_automount = nfs_d_automount,
|
|
.d_release = nfs_d_release,
|
|
};
|
|
EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
|
|
|
|
static fmode_t flags_to_mode(int flags)
|
|
{
|
|
fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
|
|
if ((flags & O_ACCMODE) != O_WRONLY)
|
|
res |= FMODE_READ;
|
|
if ((flags & O_ACCMODE) != O_RDONLY)
|
|
res |= FMODE_WRITE;
|
|
return res;
|
|
}
|
|
|
|
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
|
|
{
|
|
return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
|
|
}
|
|
|
|
static int do_open(struct inode *inode, struct file *filp)
|
|
{
|
|
nfs_fscache_open_file(inode, filp);
|
|
return 0;
|
|
}
|
|
|
|
static int nfs_finish_open(struct nfs_open_context *ctx,
|
|
struct dentry *dentry,
|
|
struct file *file, unsigned open_flags,
|
|
int *opened)
|
|
{
|
|
int err;
|
|
|
|
err = finish_open(file, dentry, do_open, opened);
|
|
if (err)
|
|
goto out;
|
|
nfs_file_set_open_context(file, ctx);
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
|
|
struct file *file, unsigned open_flags,
|
|
umode_t mode, int *opened)
|
|
{
|
|
struct nfs_open_context *ctx;
|
|
struct dentry *res;
|
|
struct iattr attr = { .ia_valid = ATTR_OPEN };
|
|
struct inode *inode;
|
|
unsigned int lookup_flags = 0;
|
|
int err;
|
|
|
|
/* Expect a negative dentry */
|
|
BUG_ON(d_inode(dentry));
|
|
|
|
dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry);
|
|
|
|
err = nfs_check_flags(open_flags);
|
|
if (err)
|
|
return err;
|
|
|
|
/* 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
|
|
*/
|
|
return -ENOENT;
|
|
}
|
|
lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY;
|
|
goto no_open;
|
|
}
|
|
|
|
if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
|
|
return -ENAMETOOLONG;
|
|
|
|
if (open_flags & O_CREAT) {
|
|
attr.ia_valid |= ATTR_MODE;
|
|
attr.ia_mode = mode & ~current_umask();
|
|
}
|
|
if (open_flags & O_TRUNC) {
|
|
attr.ia_valid |= ATTR_SIZE;
|
|
attr.ia_size = 0;
|
|
}
|
|
|
|
ctx = create_nfs_open_context(dentry, open_flags);
|
|
err = PTR_ERR(ctx);
|
|
if (IS_ERR(ctx))
|
|
goto out;
|
|
|
|
trace_nfs_atomic_open_enter(dir, ctx, open_flags);
|
|
nfs_block_sillyrename(dentry->d_parent);
|
|
inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, opened);
|
|
nfs_unblock_sillyrename(dentry->d_parent);
|
|
if (IS_ERR(inode)) {
|
|
err = PTR_ERR(inode);
|
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
|
|
put_nfs_open_context(ctx);
|
|
switch (err) {
|
|
case -ENOENT:
|
|
d_drop(dentry);
|
|
d_add(dentry, NULL);
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
break;
|
|
case -EISDIR:
|
|
case -ENOTDIR:
|
|
goto no_open;
|
|
case -ELOOP:
|
|
if (!(open_flags & O_NOFOLLOW))
|
|
goto no_open;
|
|
break;
|
|
/* case -EINVAL: */
|
|
default:
|
|
break;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
err = nfs_finish_open(ctx, ctx->dentry, file, open_flags, opened);
|
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
|
|
put_nfs_open_context(ctx);
|
|
out:
|
|
return err;
|
|
|
|
no_open:
|
|
res = nfs_lookup(dir, dentry, lookup_flags);
|
|
err = PTR_ERR(res);
|
|
if (IS_ERR(res))
|
|
goto out;
|
|
|
|
return finish_no_open(file, res);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_atomic_open);
|
|
|
|
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
struct inode *inode;
|
|
int ret = 0;
|
|
|
|
if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
|
|
goto no_open;
|
|
if (d_mountpoint(dentry))
|
|
goto no_open;
|
|
if (NFS_SB(dentry->d_sb)->caps & NFS_CAP_ATOMIC_OPEN_V1)
|
|
goto no_open;
|
|
|
|
inode = d_inode(dentry);
|
|
|
|
/* We can't create new files in nfs_open_revalidate(), so we
|
|
* optimize away revalidation of negative dentries.
|
|
*/
|
|
if (inode == NULL) {
|
|
struct dentry *parent;
|
|
struct inode *dir;
|
|
|
|
if (flags & LOOKUP_RCU) {
|
|
parent = ACCESS_ONCE(dentry->d_parent);
|
|
dir = d_inode_rcu(parent);
|
|
if (!dir)
|
|
return -ECHILD;
|
|
} else {
|
|
parent = dget_parent(dentry);
|
|
dir = d_inode(parent);
|
|
}
|
|
if (!nfs_neg_need_reval(dir, dentry, flags))
|
|
ret = 1;
|
|
else if (flags & LOOKUP_RCU)
|
|
ret = -ECHILD;
|
|
if (!(flags & LOOKUP_RCU))
|
|
dput(parent);
|
|
else if (parent != ACCESS_ONCE(dentry->d_parent))
|
|
return -ECHILD;
|
|
goto out;
|
|
}
|
|
|
|
/* NFS only supports OPEN on regular files */
|
|
if (!S_ISREG(inode->i_mode))
|
|
goto no_open;
|
|
/* We cannot do exclusive creation on a positive dentry */
|
|
if (flags & LOOKUP_EXCL)
|
|
goto no_open;
|
|
|
|
/* Let f_op->open() actually open (and revalidate) the file */
|
|
ret = 1;
|
|
|
|
out:
|
|
return ret;
|
|
|
|
no_open:
|
|
return nfs_lookup_revalidate(dentry, flags);
|
|
}
|
|
|
|
#endif /* CONFIG_NFSV4 */
|
|
|
|
/*
|
|
* Code common to create, mkdir, and mknod.
|
|
*/
|
|
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
|
|
struct nfs_fattr *fattr,
|
|
struct nfs4_label *label)
|
|
{
|
|
struct dentry *parent = dget_parent(dentry);
|
|
struct inode *dir = d_inode(parent);
|
|
struct inode *inode;
|
|
int error = -EACCES;
|
|
|
|
d_drop(dentry);
|
|
|
|
/* We may have been initialized further down */
|
|
if (d_really_is_positive(dentry))
|
|
goto out;
|
|
if (fhandle->size == 0) {
|
|
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, NULL);
|
|
if (error)
|
|
goto out_error;
|
|
}
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
if (!(fattr->valid & NFS_ATTR_FATTR)) {
|
|
struct nfs_server *server = NFS_SB(dentry->d_sb);
|
|
error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr, NULL);
|
|
if (error < 0)
|
|
goto out_error;
|
|
}
|
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
|
|
error = PTR_ERR(inode);
|
|
if (IS_ERR(inode))
|
|
goto out_error;
|
|
d_add(dentry, inode);
|
|
out:
|
|
dput(parent);
|
|
return 0;
|
|
out_error:
|
|
nfs_mark_for_revalidate(dir);
|
|
dput(parent);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_instantiate);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int nfs_create(struct inode *dir, struct dentry *dentry,
|
|
umode_t mode, bool excl)
|
|
{
|
|
struct iattr attr;
|
|
int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: create(%s/%lu), %pd\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry);
|
|
|
|
attr.ia_mode = mode;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
trace_nfs_create_enter(dir, dentry, open_flags);
|
|
error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
|
|
trace_nfs_create_exit(dir, dentry, open_flags, error);
|
|
if (error != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_create);
|
|
|
|
/*
|
|
* See comments for nfs_proc_create regarding failed operations.
|
|
*/
|
|
int
|
|
nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
|
|
{
|
|
struct iattr attr;
|
|
int status;
|
|
|
|
dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry);
|
|
|
|
if (!new_valid_dev(rdev))
|
|
return -EINVAL;
|
|
|
|
attr.ia_mode = mode;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
trace_nfs_mknod_enter(dir, dentry);
|
|
status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
|
|
trace_nfs_mknod_exit(dir, dentry, status);
|
|
if (status != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_mknod);
|
|
|
|
/*
|
|
* See comments for nfs_proc_create regarding failed operations.
|
|
*/
|
|
int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
|
|
{
|
|
struct iattr attr;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry);
|
|
|
|
attr.ia_valid = ATTR_MODE;
|
|
attr.ia_mode = mode | S_IFDIR;
|
|
|
|
trace_nfs_mkdir_enter(dir, dentry);
|
|
error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
|
|
trace_nfs_mkdir_exit(dir, dentry, error);
|
|
if (error != 0)
|
|
goto out_err;
|
|
return 0;
|
|
out_err:
|
|
d_drop(dentry);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_mkdir);
|
|
|
|
static void nfs_dentry_handle_enoent(struct dentry *dentry)
|
|
{
|
|
if (simple_positive(dentry))
|
|
d_delete(dentry);
|
|
}
|
|
|
|
int nfs_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n",
|
|
dir->i_sb->s_id, dir->i_ino, dentry);
|
|
|
|
trace_nfs_rmdir_enter(dir, dentry);
|
|
if (d_really_is_positive(dentry)) {
|
|
nfs_wait_on_sillyrename(dentry);
|
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
|
|
/* Ensure the VFS deletes this inode */
|
|
switch (error) {
|
|
case 0:
|
|
clear_nlink(d_inode(dentry));
|
|
break;
|
|
case -ENOENT:
|
|
nfs_dentry_handle_enoent(dentry);
|
|
}
|
|
} else
|
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
|
|
trace_nfs_rmdir_exit(dir, dentry, error);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_rmdir);
|
|
|
|
/*
|
|
* 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 = d_inode(dentry->d_parent);
|
|
struct inode *inode = d_inode(dentry);
|
|
int error = -EBUSY;
|
|
|
|
dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry);
|
|
|
|
/* If the dentry was sillyrenamed, we simply call d_delete() */
|
|
if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
|
|
error = 0;
|
|
goto out;
|
|
}
|
|
|
|
trace_nfs_remove_enter(dir, dentry);
|
|
if (inode != NULL) {
|
|
NFS_PROTO(inode)->return_delegation(inode);
|
|
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
|
|
if (error == 0)
|
|
nfs_drop_nlink(inode);
|
|
} else
|
|
error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
|
|
if (error == -ENOENT)
|
|
nfs_dentry_handle_enoent(dentry);
|
|
trace_nfs_remove_exit(dir, dentry, error);
|
|
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.
|
|
*/
|
|
int nfs_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
int error;
|
|
int need_rehash = 0;
|
|
|
|
dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id,
|
|
dir->i_ino, dentry);
|
|
|
|
trace_nfs_unlink_enter(dir, dentry);
|
|
spin_lock(&dentry->d_lock);
|
|
if (d_count(dentry) > 1) {
|
|
spin_unlock(&dentry->d_lock);
|
|
/* Start asynchronous writeout of the inode */
|
|
write_inode_now(d_inode(dentry), 0);
|
|
error = nfs_sillyrename(dir, dentry);
|
|
goto out;
|
|
}
|
|
if (!d_unhashed(dentry)) {
|
|
__d_drop(dentry);
|
|
need_rehash = 1;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
error = nfs_safe_remove(dentry);
|
|
if (!error || error == -ENOENT) {
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
} else if (need_rehash)
|
|
d_rehash(dentry);
|
|
out:
|
|
trace_nfs_unlink_exit(dir, dentry, error);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_unlink);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
|
|
{
|
|
struct page *page;
|
|
char *kaddr;
|
|
struct iattr attr;
|
|
unsigned int pathlen = strlen(symname);
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id,
|
|
dir->i_ino, dentry, symname);
|
|
|
|
if (pathlen > PAGE_SIZE)
|
|
return -ENAMETOOLONG;
|
|
|
|
attr.ia_mode = S_IFLNK | S_IRWXUGO;
|
|
attr.ia_valid = ATTR_MODE;
|
|
|
|
page = alloc_page(GFP_HIGHUSER);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
kaddr = kmap_atomic(page);
|
|
memcpy(kaddr, symname, pathlen);
|
|
if (pathlen < PAGE_SIZE)
|
|
memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
|
|
kunmap_atomic(kaddr);
|
|
|
|
trace_nfs_symlink_enter(dir, dentry);
|
|
error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
|
|
trace_nfs_symlink_exit(dir, dentry, error);
|
|
if (error != 0) {
|
|
dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n",
|
|
dir->i_sb->s_id, dir->i_ino,
|
|
dentry, symname, error);
|
|
d_drop(dentry);
|
|
__free_page(page);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* No big deal if we can't add this page to the page cache here.
|
|
* READLINK will get the missing page from the server if needed.
|
|
*/
|
|
if (!add_to_page_cache_lru(page, d_inode(dentry)->i_mapping, 0,
|
|
GFP_KERNEL)) {
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
/*
|
|
* add_to_page_cache_lru() grabs an extra page refcount.
|
|
* Drop it here to avoid leaking this page later.
|
|
*/
|
|
page_cache_release(page);
|
|
} else
|
|
__free_page(page);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_symlink);
|
|
|
|
int
|
|
nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct inode *inode = d_inode(old_dentry);
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n",
|
|
old_dentry, dentry);
|
|
|
|
trace_nfs_link_enter(inode, dir, dentry);
|
|
NFS_PROTO(inode)->return_delegation(inode);
|
|
|
|
d_drop(dentry);
|
|
error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
|
|
if (error == 0) {
|
|
ihold(inode);
|
|
d_add(dentry, inode);
|
|
}
|
|
trace_nfs_link_exit(inode, dir, dentry, error);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_link);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
|
|
struct inode *new_dir, struct dentry *new_dentry)
|
|
{
|
|
struct inode *old_inode = d_inode(old_dentry);
|
|
struct inode *new_inode = d_inode(new_dentry);
|
|
struct dentry *dentry = NULL, *rehash = NULL;
|
|
struct rpc_task *task;
|
|
int error = -EBUSY;
|
|
|
|
dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n",
|
|
old_dentry, new_dentry,
|
|
d_count(new_dentry));
|
|
|
|
trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry);
|
|
/*
|
|
* For non-directories, check whether the target is busy and if so,
|
|
* make a copy of the dentry and then do a silly-rename. If the
|
|
* silly-rename succeeds, the copied dentry is hashed and becomes
|
|
* the new target.
|
|
*/
|
|
if (new_inode && !S_ISDIR(new_inode->i_mode)) {
|
|
/*
|
|
* To prevent any new references to the target during the
|
|
* rename, we unhash the dentry in advance.
|
|
*/
|
|
if (!d_unhashed(new_dentry)) {
|
|
d_drop(new_dentry);
|
|
rehash = new_dentry;
|
|
}
|
|
|
|
if (d_count(new_dentry) > 2) {
|
|
int err;
|
|
|
|
/* copy the target dentry's name */
|
|
dentry = d_alloc(new_dentry->d_parent,
|
|
&new_dentry->d_name);
|
|
if (!dentry)
|
|
goto out;
|
|
|
|
/* silly-rename the existing target ... */
|
|
err = nfs_sillyrename(new_dir, new_dentry);
|
|
if (err)
|
|
goto out;
|
|
|
|
new_dentry = dentry;
|
|
rehash = NULL;
|
|
new_inode = NULL;
|
|
}
|
|
}
|
|
|
|
NFS_PROTO(old_inode)->return_delegation(old_inode);
|
|
if (new_inode != NULL)
|
|
NFS_PROTO(new_inode)->return_delegation(new_inode);
|
|
|
|
task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL);
|
|
if (IS_ERR(task)) {
|
|
error = PTR_ERR(task);
|
|
goto out;
|
|
}
|
|
|
|
error = rpc_wait_for_completion_task(task);
|
|
if (error == 0)
|
|
error = task->tk_status;
|
|
rpc_put_task(task);
|
|
nfs_mark_for_revalidate(old_inode);
|
|
out:
|
|
if (rehash)
|
|
d_rehash(rehash);
|
|
trace_nfs_rename_exit(old_dir, old_dentry,
|
|
new_dir, new_dentry, error);
|
|
if (!error) {
|
|
if (new_inode != NULL)
|
|
nfs_drop_nlink(new_inode);
|
|
d_move(old_dentry, new_dentry);
|
|
nfs_set_verifier(new_dentry,
|
|
nfs_save_change_attribute(new_dir));
|
|
} else if (error == -ENOENT)
|
|
nfs_dentry_handle_enoent(old_dentry);
|
|
|
|
/* new dentry created? */
|
|
if (dentry)
|
|
dput(dentry);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_rename);
|
|
|
|
static DEFINE_SPINLOCK(nfs_access_lru_lock);
|
|
static LIST_HEAD(nfs_access_lru_list);
|
|
static atomic_long_t nfs_access_nr_entries;
|
|
|
|
static unsigned long nfs_access_max_cachesize = ULONG_MAX;
|
|
module_param(nfs_access_max_cachesize, ulong, 0644);
|
|
MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
|
|
|
|
static void nfs_access_free_entry(struct nfs_access_entry *entry)
|
|
{
|
|
put_rpccred(entry->cred);
|
|
kfree_rcu(entry, rcu_head);
|
|
smp_mb__before_atomic();
|
|
atomic_long_dec(&nfs_access_nr_entries);
|
|
smp_mb__after_atomic();
|
|
}
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
static unsigned long
|
|
nfs_do_access_cache_scan(unsigned int nr_to_scan)
|
|
{
|
|
LIST_HEAD(head);
|
|
struct nfs_inode *nfsi, *next;
|
|
struct nfs_access_entry *cache;
|
|
long freed = 0;
|
|
|
|
spin_lock(&nfs_access_lru_lock);
|
|
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
|
|
struct inode *inode;
|
|
|
|
if (nr_to_scan-- == 0)
|
|
break;
|
|
inode = &nfsi->vfs_inode;
|
|
spin_lock(&inode->i_lock);
|
|
if (list_empty(&nfsi->access_cache_entry_lru))
|
|
goto remove_lru_entry;
|
|
cache = list_entry(nfsi->access_cache_entry_lru.next,
|
|
struct nfs_access_entry, lru);
|
|
list_move(&cache->lru, &head);
|
|
rb_erase(&cache->rb_node, &nfsi->access_cache);
|
|
freed++;
|
|
if (!list_empty(&nfsi->access_cache_entry_lru))
|
|
list_move_tail(&nfsi->access_cache_inode_lru,
|
|
&nfs_access_lru_list);
|
|
else {
|
|
remove_lru_entry:
|
|
list_del_init(&nfsi->access_cache_inode_lru);
|
|
smp_mb__before_atomic();
|
|
clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
|
|
smp_mb__after_atomic();
|
|
}
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
nfs_access_free_list(&head);
|
|
return freed;
|
|
}
|
|
|
|
unsigned long
|
|
nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
|
|
{
|
|
int nr_to_scan = sc->nr_to_scan;
|
|
gfp_t gfp_mask = sc->gfp_mask;
|
|
|
|
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
|
|
return SHRINK_STOP;
|
|
return nfs_do_access_cache_scan(nr_to_scan);
|
|
}
|
|
|
|
|
|
unsigned long
|
|
nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc)
|
|
{
|
|
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
|
|
}
|
|
|
|
static void
|
|
nfs_access_cache_enforce_limit(void)
|
|
{
|
|
long nr_entries = atomic_long_read(&nfs_access_nr_entries);
|
|
unsigned long diff;
|
|
unsigned int nr_to_scan;
|
|
|
|
if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize)
|
|
return;
|
|
nr_to_scan = 100;
|
|
diff = nr_entries - nfs_access_max_cachesize;
|
|
if (diff < nr_to_scan)
|
|
nr_to_scan = diff;
|
|
nfs_do_access_cache_scan(nr_to_scan);
|
|
}
|
|
|
|
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
|
|
{
|
|
struct rb_root *root_node = &nfsi->access_cache;
|
|
struct rb_node *n;
|
|
struct nfs_access_entry *entry;
|
|
|
|
/* Unhook entries from the cache */
|
|
while ((n = rb_first(root_node)) != NULL) {
|
|
entry = rb_entry(n, struct nfs_access_entry, rb_node);
|
|
rb_erase(n, root_node);
|
|
list_move(&entry->lru, head);
|
|
}
|
|
nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
|
|
}
|
|
|
|
void nfs_access_zap_cache(struct inode *inode)
|
|
{
|
|
LIST_HEAD(head);
|
|
|
|
if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
|
|
return;
|
|
/* Remove from global LRU init */
|
|
spin_lock(&nfs_access_lru_lock);
|
|
if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
|
|
list_del_init(&NFS_I(inode)->access_cache_inode_lru);
|
|
|
|
spin_lock(&inode->i_lock);
|
|
__nfs_access_zap_cache(NFS_I(inode), &head);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
nfs_access_free_list(&head);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
|
|
|
|
static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
|
|
{
|
|
struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
|
|
struct nfs_access_entry *entry;
|
|
|
|
while (n != NULL) {
|
|
entry = rb_entry(n, struct nfs_access_entry, rb_node);
|
|
|
|
if (cred < entry->cred)
|
|
n = n->rb_left;
|
|
else if (cred > entry->cred)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct nfs_access_entry *cache;
|
|
int err = -ENOENT;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
|
|
goto out_zap;
|
|
cache = nfs_access_search_rbtree(inode, cred);
|
|
if (cache == NULL)
|
|
goto out;
|
|
if (!nfs_have_delegated_attributes(inode) &&
|
|
!time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
|
|
goto out_stale;
|
|
res->jiffies = cache->jiffies;
|
|
res->cred = cache->cred;
|
|
res->mask = cache->mask;
|
|
list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
|
|
err = 0;
|
|
out:
|
|
spin_unlock(&inode->i_lock);
|
|
return err;
|
|
out_stale:
|
|
rb_erase(&cache->rb_node, &nfsi->access_cache);
|
|
list_del(&cache->lru);
|
|
spin_unlock(&inode->i_lock);
|
|
nfs_access_free_entry(cache);
|
|
return -ENOENT;
|
|
out_zap:
|
|
spin_unlock(&inode->i_lock);
|
|
nfs_access_zap_cache(inode);
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int nfs_access_get_cached_rcu(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
|
|
{
|
|
/* Only check the most recently returned cache entry,
|
|
* but do it without locking.
|
|
*/
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct nfs_access_entry *cache;
|
|
int err = -ECHILD;
|
|
struct list_head *lh;
|
|
|
|
rcu_read_lock();
|
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
|
|
goto out;
|
|
lh = rcu_dereference(nfsi->access_cache_entry_lru.prev);
|
|
cache = list_entry(lh, struct nfs_access_entry, lru);
|
|
if (lh == &nfsi->access_cache_entry_lru ||
|
|
cred != cache->cred)
|
|
cache = NULL;
|
|
if (cache == NULL)
|
|
goto out;
|
|
if (!nfs_have_delegated_attributes(inode) &&
|
|
!time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
|
|
goto out;
|
|
res->jiffies = cache->jiffies;
|
|
res->cred = cache->cred;
|
|
res->mask = cache->mask;
|
|
err = 0;
|
|
out:
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
|
|
static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct rb_root *root_node = &nfsi->access_cache;
|
|
struct rb_node **p = &root_node->rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct nfs_access_entry *entry;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
while (*p != NULL) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct nfs_access_entry, rb_node);
|
|
|
|
if (set->cred < entry->cred)
|
|
p = &parent->rb_left;
|
|
else if (set->cred > entry->cred)
|
|
p = &parent->rb_right;
|
|
else
|
|
goto found;
|
|
}
|
|
rb_link_node(&set->rb_node, parent, p);
|
|
rb_insert_color(&set->rb_node, root_node);
|
|
list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
|
|
spin_unlock(&inode->i_lock);
|
|
return;
|
|
found:
|
|
rb_replace_node(parent, &set->rb_node, root_node);
|
|
list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
|
|
list_del(&entry->lru);
|
|
spin_unlock(&inode->i_lock);
|
|
nfs_access_free_entry(entry);
|
|
}
|
|
|
|
void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
|
|
{
|
|
struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
|
|
if (cache == NULL)
|
|
return;
|
|
RB_CLEAR_NODE(&cache->rb_node);
|
|
cache->jiffies = set->jiffies;
|
|
cache->cred = get_rpccred(set->cred);
|
|
cache->mask = set->mask;
|
|
|
|
/* The above field assignments must be visible
|
|
* before this item appears on the lru. We cannot easily
|
|
* use rcu_assign_pointer, so just force the memory barrier.
|
|
*/
|
|
smp_wmb();
|
|
nfs_access_add_rbtree(inode, cache);
|
|
|
|
/* Update accounting */
|
|
smp_mb__before_atomic();
|
|
atomic_long_inc(&nfs_access_nr_entries);
|
|
smp_mb__after_atomic();
|
|
|
|
/* Add inode to global LRU list */
|
|
if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
|
|
spin_lock(&nfs_access_lru_lock);
|
|
if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
|
|
list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
|
|
&nfs_access_lru_list);
|
|
spin_unlock(&nfs_access_lru_lock);
|
|
}
|
|
nfs_access_cache_enforce_limit();
|
|
}
|
|
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);
|
|
|
|
static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
|
|
{
|
|
struct nfs_access_entry cache;
|
|
int status;
|
|
|
|
trace_nfs_access_enter(inode);
|
|
|
|
status = nfs_access_get_cached_rcu(inode, cred, &cache);
|
|
if (status != 0)
|
|
status = nfs_access_get_cached(inode, cred, &cache);
|
|
if (status == 0)
|
|
goto out_cached;
|
|
|
|
status = -ECHILD;
|
|
if (mask & MAY_NOT_BLOCK)
|
|
goto out;
|
|
|
|
/* Be clever: ask server to check for all possible rights */
|
|
cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
|
|
cache.cred = cred;
|
|
cache.jiffies = jiffies;
|
|
status = NFS_PROTO(inode)->access(inode, &cache);
|
|
if (status != 0) {
|
|
if (status == -ESTALE) {
|
|
nfs_zap_caches(inode);
|
|
if (!S_ISDIR(inode->i_mode))
|
|
set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
|
|
}
|
|
goto out;
|
|
}
|
|
nfs_access_add_cache(inode, &cache);
|
|
out_cached:
|
|
if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
|
|
status = -EACCES;
|
|
out:
|
|
trace_nfs_access_exit(inode, status);
|
|
return status;
|
|
}
|
|
|
|
static int nfs_open_permission_mask(int openflags)
|
|
{
|
|
int mask = 0;
|
|
|
|
if (openflags & __FMODE_EXEC) {
|
|
/* ONLY check exec rights */
|
|
mask = MAY_EXEC;
|
|
} else {
|
|
if ((openflags & O_ACCMODE) != O_WRONLY)
|
|
mask |= MAY_READ;
|
|
if ((openflags & O_ACCMODE) != O_RDONLY)
|
|
mask |= MAY_WRITE;
|
|
}
|
|
|
|
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));
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_may_open);
|
|
|
|
int nfs_permission(struct inode *inode, int mask)
|
|
{
|
|
struct rpc_cred *cred;
|
|
int res = 0;
|
|
|
|
nfs_inc_stats(inode, NFSIOS_VFSACCESS);
|
|
|
|
if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
|
|
goto out;
|
|
/* Is this sys_access() ? */
|
|
if (mask & (MAY_ACCESS | MAY_CHDIR))
|
|
goto force_lookup;
|
|
|
|
switch (inode->i_mode & S_IFMT) {
|
|
case S_IFLNK:
|
|
goto out;
|
|
case S_IFREG:
|
|
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;
|
|
|
|
/* Always try fast lookups first */
|
|
rcu_read_lock();
|
|
cred = rpc_lookup_cred_nonblock();
|
|
if (!IS_ERR(cred))
|
|
res = nfs_do_access(inode, cred, mask|MAY_NOT_BLOCK);
|
|
else
|
|
res = PTR_ERR(cred);
|
|
rcu_read_unlock();
|
|
if (res == -ECHILD && !(mask & MAY_NOT_BLOCK)) {
|
|
/* Fast lookup failed, try the slow way */
|
|
cred = rpc_lookup_cred();
|
|
if (!IS_ERR(cred)) {
|
|
res = nfs_do_access(inode, cred, mask);
|
|
put_rpccred(cred);
|
|
} else
|
|
res = PTR_ERR(cred);
|
|
}
|
|
out:
|
|
if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
|
|
res = -EACCES;
|
|
|
|
dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n",
|
|
inode->i_sb->s_id, inode->i_ino, mask, res);
|
|
return res;
|
|
out_notsup:
|
|
if (mask & MAY_NOT_BLOCK)
|
|
return -ECHILD;
|
|
|
|
res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
|
|
if (res == 0)
|
|
res = generic_permission(inode, mask);
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_permission);
|
|
|
|
/*
|
|
* Local variables:
|
|
* version-control: t
|
|
* kept-new-versions: 5
|
|
* End:
|
|
*/
|