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![Kinglong Mee](/assets/img/avatar_default.png)
When a directory contains 17 files (except . and ..), nfs client sends a redundant readdir request after get eof. A simple reproduce, At NFS server, create a directory with 17 files under exported directory. # mkdir test # cd test # for i in {0..16} ; do touch $i; done At NFS client, no matter mounting through nfsv3 or nfsv4, does ls (or ll) at the created test directory. A tshark output likes following (for nfsv4), # tshark -i eth0 tcp port 2049 -Tfields -e ip.src -e ip.dst -e nfs -e nfs.cookie4 srcip dstip SEQUENCE, PUTFH, READDIR 0 dstip srcip SEQUENCE PUTFH READDIR 909539109313539306,2108391201987888856,2305312124304486544,2566335452463141496,2978225129081509984,4263037479923412583,4304697173036510679,4666703455469210097,4759208201298769007,4776701232145978803,5338408478512081262,5949498658935544804,5971526429894832903,6294060338267709855,6528840566229532529,8600463293536422524,9223372036854775807 srcip dstip srcip dstip SEQUENCE, PUTFH, READDIR 9223372036854775807 dstip srcip SEQUENCE PUTFH READDIR The READDIR with cookie 9223372036854775807(0x7FFFFFFFFFFFFFFF) is redundant. Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
3324 lines
86 KiB
C
3324 lines
86 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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/compat.h>
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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 <linux/hash.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 folio *);
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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_shared = 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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.free_folio = nfs_readdir_clear_array,
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};
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#define NFS_INIT_DTSIZE PAGE_SIZE
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static struct nfs_open_dir_context *
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alloc_nfs_open_dir_context(struct inode *dir)
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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 = kzalloc(sizeof(*ctx), GFP_KERNEL_ACCOUNT);
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if (ctx != NULL) {
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ctx->attr_gencount = nfsi->attr_gencount;
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ctx->dtsize = NFS_INIT_DTSIZE;
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spin_lock(&dir->i_lock);
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if (list_empty(&nfsi->open_files) &&
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(nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
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nfs_set_cache_invalid(dir,
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NFS_INO_INVALID_DATA |
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NFS_INO_REVAL_FORCED);
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list_add_tail_rcu(&ctx->list, &nfsi->open_files);
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memcpy(ctx->verf, nfsi->cookieverf, sizeof(ctx->verf));
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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_rcu(&ctx->list);
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spin_unlock(&dir->i_lock);
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kfree_rcu(ctx, rcu_head);
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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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dfprintk(FILE, "NFS: open dir(%pD2)\n", filp);
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nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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ctx = alloc_nfs_open_dir_context(inode);
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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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out:
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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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const char *name;
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unsigned int name_len;
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unsigned char d_type;
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};
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struct nfs_cache_array {
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u64 change_attr;
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u64 last_cookie;
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unsigned int size;
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unsigned char folio_full : 1,
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folio_is_eof : 1,
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cookies_are_ordered : 1;
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struct nfs_cache_array_entry array[];
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};
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struct nfs_readdir_descriptor {
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struct file *file;
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struct folio *folio;
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struct dir_context *ctx;
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pgoff_t folio_index;
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pgoff_t folio_index_max;
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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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__be32 verf[NFS_DIR_VERIFIER_SIZE];
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unsigned long dir_verifier;
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unsigned long timestamp;
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unsigned long gencount;
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unsigned long attr_gencount;
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unsigned int cache_entry_index;
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unsigned int buffer_fills;
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unsigned int dtsize;
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bool clear_cache;
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bool plus;
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bool eob;
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bool eof;
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};
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static void nfs_set_dtsize(struct nfs_readdir_descriptor *desc, unsigned int sz)
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{
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struct nfs_server *server = NFS_SERVER(file_inode(desc->file));
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unsigned int maxsize = server->dtsize;
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if (sz > maxsize)
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sz = maxsize;
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if (sz < NFS_MIN_FILE_IO_SIZE)
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sz = NFS_MIN_FILE_IO_SIZE;
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desc->dtsize = sz;
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}
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static void nfs_shrink_dtsize(struct nfs_readdir_descriptor *desc)
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{
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nfs_set_dtsize(desc, desc->dtsize >> 1);
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}
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static void nfs_grow_dtsize(struct nfs_readdir_descriptor *desc)
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{
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nfs_set_dtsize(desc, desc->dtsize << 1);
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}
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static void nfs_readdir_folio_init_array(struct folio *folio, u64 last_cookie,
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u64 change_attr)
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{
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struct nfs_cache_array *array;
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array = kmap_local_folio(folio, 0);
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array->change_attr = change_attr;
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array->last_cookie = last_cookie;
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array->size = 0;
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array->folio_full = 0;
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array->folio_is_eof = 0;
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array->cookies_are_ordered = 1;
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kunmap_local(array);
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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 void nfs_readdir_clear_array(struct folio *folio)
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{
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struct nfs_cache_array *array;
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unsigned int i;
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array = kmap_local_folio(folio, 0);
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for (i = 0; i < array->size; i++)
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kfree(array->array[i].name);
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array->size = 0;
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kunmap_local(array);
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}
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static void nfs_readdir_folio_reinit_array(struct folio *folio, u64 last_cookie,
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u64 change_attr)
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{
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nfs_readdir_clear_array(folio);
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nfs_readdir_folio_init_array(folio, last_cookie, change_attr);
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}
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static struct folio *
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nfs_readdir_folio_array_alloc(u64 last_cookie, gfp_t gfp_flags)
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{
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struct folio *folio = folio_alloc(gfp_flags, 0);
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if (folio)
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nfs_readdir_folio_init_array(folio, last_cookie, 0);
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return folio;
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}
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static void nfs_readdir_folio_array_free(struct folio *folio)
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{
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if (folio) {
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nfs_readdir_clear_array(folio);
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folio_put(folio);
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}
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}
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static u64 nfs_readdir_array_index_cookie(struct nfs_cache_array *array)
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{
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return array->size == 0 ? array->last_cookie : array->array[0].cookie;
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}
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static void nfs_readdir_array_set_eof(struct nfs_cache_array *array)
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{
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array->folio_is_eof = 1;
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array->folio_full = 1;
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}
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static bool nfs_readdir_array_is_full(struct nfs_cache_array *array)
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{
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return array->folio_full;
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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 const char *nfs_readdir_copy_name(const char *name, unsigned int len)
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{
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const char *ret = kmemdup_nul(name, len, GFP_KERNEL);
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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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if (ret != NULL)
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kmemleak_not_leak(ret);
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return ret;
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}
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static size_t nfs_readdir_array_maxentries(void)
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{
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return (PAGE_SIZE - sizeof(struct nfs_cache_array)) /
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sizeof(struct nfs_cache_array_entry);
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}
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/*
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* Check that the next array entry lies entirely within the page bounds
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*/
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static int nfs_readdir_array_can_expand(struct nfs_cache_array *array)
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{
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if (array->folio_full)
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return -ENOSPC;
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if (array->size == nfs_readdir_array_maxentries()) {
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array->folio_full = 1;
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return -ENOSPC;
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}
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return 0;
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}
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static int nfs_readdir_folio_array_append(struct folio *folio,
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const struct nfs_entry *entry,
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u64 *cookie)
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{
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struct nfs_cache_array *array;
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struct nfs_cache_array_entry *cache_entry;
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const char *name;
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int ret = -ENOMEM;
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name = nfs_readdir_copy_name(entry->name, entry->len);
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array = kmap_local_folio(folio, 0);
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if (!name)
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goto out;
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ret = nfs_readdir_array_can_expand(array);
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if (ret) {
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kfree(name);
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goto out;
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}
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cache_entry = &array->array[array->size];
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cache_entry->cookie = array->last_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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cache_entry->name_len = entry->len;
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cache_entry->name = name;
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array->last_cookie = entry->cookie;
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if (array->last_cookie <= cache_entry->cookie)
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array->cookies_are_ordered = 0;
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array->size++;
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if (entry->eof != 0)
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nfs_readdir_array_set_eof(array);
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out:
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*cookie = array->last_cookie;
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kunmap_local(array);
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return ret;
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}
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#define NFS_READDIR_COOKIE_MASK (U32_MAX >> 14)
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/*
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* Hash algorithm allowing content addressible access to sequences
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* of directory cookies. Content is addressed by the value of the
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* cookie index of the first readdir entry in a page.
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*
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* We select only the first 18 bits to avoid issues with excessive
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* memory use for the page cache XArray. 18 bits should allow the caching
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* of 262144 pages of sequences of readdir entries. Since each page holds
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* 127 readdir entries for a typical 64-bit system, that works out to a
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* cache of ~ 33 million entries per directory.
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*/
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static pgoff_t nfs_readdir_folio_cookie_hash(u64 cookie)
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{
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if (cookie == 0)
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return 0;
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return hash_64(cookie, 18);
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}
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static bool nfs_readdir_folio_validate(struct folio *folio, u64 last_cookie,
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u64 change_attr)
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{
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struct nfs_cache_array *array = kmap_local_folio(folio, 0);
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int ret = true;
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if (array->change_attr != change_attr)
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ret = false;
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if (nfs_readdir_array_index_cookie(array) != last_cookie)
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ret = false;
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kunmap_local(array);
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return ret;
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}
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static void nfs_readdir_folio_unlock_and_put(struct folio *folio)
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{
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folio_unlock(folio);
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folio_put(folio);
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}
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static void nfs_readdir_folio_init_and_validate(struct folio *folio, u64 cookie,
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u64 change_attr)
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{
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if (folio_test_uptodate(folio)) {
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if (nfs_readdir_folio_validate(folio, cookie, change_attr))
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return;
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nfs_readdir_clear_array(folio);
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}
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nfs_readdir_folio_init_array(folio, cookie, change_attr);
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folio_mark_uptodate(folio);
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}
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static struct folio *nfs_readdir_folio_get_locked(struct address_space *mapping,
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u64 cookie, u64 change_attr)
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{
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pgoff_t index = nfs_readdir_folio_cookie_hash(cookie);
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struct folio *folio;
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folio = filemap_grab_folio(mapping, index);
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if (IS_ERR(folio))
|
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return NULL;
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nfs_readdir_folio_init_and_validate(folio, cookie, change_attr);
|
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return folio;
|
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}
|
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|
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static u64 nfs_readdir_folio_last_cookie(struct folio *folio)
|
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{
|
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struct nfs_cache_array *array;
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u64 ret;
|
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array = kmap_local_folio(folio, 0);
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ret = array->last_cookie;
|
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kunmap_local(array);
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return ret;
|
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}
|
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|
|
static bool nfs_readdir_folio_needs_filling(struct folio *folio)
|
|
{
|
|
struct nfs_cache_array *array;
|
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bool ret;
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|
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array = kmap_local_folio(folio, 0);
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ret = !nfs_readdir_array_is_full(array);
|
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kunmap_local(array);
|
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return ret;
|
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}
|
|
|
|
static void nfs_readdir_folio_set_eof(struct folio *folio)
|
|
{
|
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struct nfs_cache_array *array;
|
|
|
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array = kmap_local_folio(folio, 0);
|
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nfs_readdir_array_set_eof(array);
|
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kunmap_local(array);
|
|
}
|
|
|
|
static struct folio *nfs_readdir_folio_get_next(struct address_space *mapping,
|
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u64 cookie, u64 change_attr)
|
|
{
|
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pgoff_t index = nfs_readdir_folio_cookie_hash(cookie);
|
|
struct folio *folio;
|
|
|
|
folio = __filemap_get_folio(mapping, index,
|
|
FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
|
|
mapping_gfp_mask(mapping));
|
|
if (IS_ERR(folio))
|
|
return NULL;
|
|
nfs_readdir_folio_init_and_validate(folio, cookie, change_attr);
|
|
if (nfs_readdir_folio_last_cookie(folio) != cookie)
|
|
nfs_readdir_folio_reinit_array(folio, cookie, change_attr);
|
|
return folio;
|
|
}
|
|
|
|
static inline
|
|
int is_32bit_api(void)
|
|
{
|
|
#ifdef CONFIG_COMPAT
|
|
return in_compat_syscall();
|
|
#else
|
|
return (BITS_PER_LONG == 32);
|
|
#endif
|
|
}
|
|
|
|
static
|
|
bool nfs_readdir_use_cookie(const struct file *filp)
|
|
{
|
|
if ((filp->f_mode & FMODE_32BITHASH) ||
|
|
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static void nfs_readdir_seek_next_array(struct nfs_cache_array *array,
|
|
struct nfs_readdir_descriptor *desc)
|
|
{
|
|
if (array->folio_full) {
|
|
desc->last_cookie = array->last_cookie;
|
|
desc->current_index += array->size;
|
|
desc->cache_entry_index = 0;
|
|
desc->folio_index++;
|
|
} else
|
|
desc->last_cookie = nfs_readdir_array_index_cookie(array);
|
|
}
|
|
|
|
static void nfs_readdir_rewind_search(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
desc->current_index = 0;
|
|
desc->last_cookie = 0;
|
|
desc->folio_index = 0;
|
|
}
|
|
|
|
static int nfs_readdir_search_for_pos(struct nfs_cache_array *array,
|
|
struct nfs_readdir_descriptor *desc)
|
|
{
|
|
loff_t diff = desc->ctx->pos - desc->current_index;
|
|
unsigned int index;
|
|
|
|
if (diff < 0)
|
|
goto out_eof;
|
|
if (diff >= array->size) {
|
|
if (array->folio_is_eof)
|
|
goto out_eof;
|
|
nfs_readdir_seek_next_array(array, desc);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
index = (unsigned int)diff;
|
|
desc->dir_cookie = array->array[index].cookie;
|
|
desc->cache_entry_index = index;
|
|
return 0;
|
|
out_eof:
|
|
desc->eof = true;
|
|
return -EBADCOOKIE;
|
|
}
|
|
|
|
static bool nfs_readdir_array_cookie_in_range(struct nfs_cache_array *array,
|
|
u64 cookie)
|
|
{
|
|
if (!array->cookies_are_ordered)
|
|
return true;
|
|
/* Optimisation for monotonically increasing cookies */
|
|
if (cookie >= array->last_cookie)
|
|
return false;
|
|
if (array->size && cookie < array->array[0].cookie)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array,
|
|
struct nfs_readdir_descriptor *desc)
|
|
{
|
|
unsigned int i;
|
|
int status = -EAGAIN;
|
|
|
|
if (!nfs_readdir_array_cookie_in_range(array, desc->dir_cookie))
|
|
goto check_eof;
|
|
|
|
for (i = 0; i < array->size; i++) {
|
|
if (array->array[i].cookie == desc->dir_cookie) {
|
|
if (nfs_readdir_use_cookie(desc->file))
|
|
desc->ctx->pos = desc->dir_cookie;
|
|
else
|
|
desc->ctx->pos = desc->current_index + i;
|
|
desc->cache_entry_index = i;
|
|
return 0;
|
|
}
|
|
}
|
|
check_eof:
|
|
if (array->folio_is_eof) {
|
|
status = -EBADCOOKIE;
|
|
if (desc->dir_cookie == array->last_cookie)
|
|
desc->eof = true;
|
|
} else
|
|
nfs_readdir_seek_next_array(array, desc);
|
|
return status;
|
|
}
|
|
|
|
static int nfs_readdir_search_array(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
struct nfs_cache_array *array;
|
|
int status;
|
|
|
|
array = kmap_local_folio(desc->folio, 0);
|
|
|
|
if (desc->dir_cookie == 0)
|
|
status = nfs_readdir_search_for_pos(array, desc);
|
|
else
|
|
status = nfs_readdir_search_for_cookie(array, desc);
|
|
|
|
kunmap_local(array);
|
|
return status;
|
|
}
|
|
|
|
/* Fill a page with xdr information before transferring to the cache page */
|
|
static int nfs_readdir_xdr_filler(struct nfs_readdir_descriptor *desc,
|
|
__be32 *verf, u64 cookie,
|
|
struct page **pages, size_t bufsize,
|
|
__be32 *verf_res)
|
|
{
|
|
struct inode *inode = file_inode(desc->file);
|
|
struct nfs_readdir_arg arg = {
|
|
.dentry = file_dentry(desc->file),
|
|
.cred = desc->file->f_cred,
|
|
.verf = verf,
|
|
.cookie = cookie,
|
|
.pages = pages,
|
|
.page_len = bufsize,
|
|
.plus = desc->plus,
|
|
};
|
|
struct nfs_readdir_res res = {
|
|
.verf = verf_res,
|
|
};
|
|
unsigned long timestamp, gencount;
|
|
int error;
|
|
|
|
again:
|
|
timestamp = jiffies;
|
|
gencount = nfs_inc_attr_generation_counter();
|
|
desc->dir_verifier = nfs_save_change_attribute(inode);
|
|
error = NFS_PROTO(inode)->readdir(&arg, &res);
|
|
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;
|
|
desc->plus = arg.plus = false;
|
|
goto again;
|
|
}
|
|
goto error;
|
|
}
|
|
desc->timestamp = timestamp;
|
|
desc->gencount = gencount;
|
|
error:
|
|
return error;
|
|
}
|
|
|
|
static int xdr_decode(struct nfs_readdir_descriptor *desc,
|
|
struct nfs_entry *entry, struct xdr_stream *xdr)
|
|
{
|
|
struct inode *inode = file_inode(desc->file);
|
|
int error;
|
|
|
|
error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus);
|
|
if (error)
|
|
return error;
|
|
entry->fattr->time_start = desc->timestamp;
|
|
entry->fattr->gencount = desc->gencount;
|
|
return 0;
|
|
}
|
|
|
|
/* Match file and dirent using either filehandle or fileid
|
|
* Note: caller is responsible for checking the fsid
|
|
*/
|
|
static
|
|
int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
|
|
{
|
|
struct inode *inode;
|
|
struct nfs_inode *nfsi;
|
|
|
|
if (d_really_is_negative(dentry))
|
|
return 0;
|
|
|
|
inode = d_inode(dentry);
|
|
if (is_bad_inode(inode) || NFS_STALE(inode))
|
|
return 0;
|
|
|
|
nfsi = NFS_I(inode);
|
|
if (entry->fattr->fileid != nfsi->fileid)
|
|
return 0;
|
|
if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
#define NFS_READDIR_CACHE_USAGE_THRESHOLD (8UL)
|
|
|
|
static bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx,
|
|
unsigned int cache_hits,
|
|
unsigned int cache_misses)
|
|
{
|
|
if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
|
|
return false;
|
|
if (ctx->pos == 0 ||
|
|
cache_hits + cache_misses > NFS_READDIR_CACHE_USAGE_THRESHOLD)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* This function is called by the getattr code to request the
|
|
* use of readdirplus to accelerate any future lookups in the same
|
|
* directory.
|
|
*/
|
|
void nfs_readdir_record_entry_cache_hit(struct inode *dir)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(dir);
|
|
struct nfs_open_dir_context *ctx;
|
|
|
|
if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
|
|
S_ISDIR(dir->i_mode)) {
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu (ctx, &nfsi->open_files, list)
|
|
atomic_inc(&ctx->cache_hits);
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function is mainly for use by nfs_getattr().
|
|
*
|
|
* If this is an 'ls -l', we want to force use of readdirplus.
|
|
*/
|
|
void nfs_readdir_record_entry_cache_miss(struct inode *dir)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(dir);
|
|
struct nfs_open_dir_context *ctx;
|
|
|
|
if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
|
|
S_ISDIR(dir->i_mode)) {
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu (ctx, &nfsi->open_files, list)
|
|
atomic_inc(&ctx->cache_misses);
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
|
|
static void nfs_lookup_advise_force_readdirplus(struct inode *dir,
|
|
unsigned int flags)
|
|
{
|
|
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
|
|
return;
|
|
if (flags & (LOOKUP_EXCL | LOOKUP_PARENT | LOOKUP_REVAL))
|
|
return;
|
|
nfs_readdir_record_entry_cache_miss(dir);
|
|
}
|
|
|
|
static
|
|
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry,
|
|
unsigned long dir_verifier)
|
|
{
|
|
struct qstr filename = QSTR_INIT(entry->name, entry->len);
|
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
|
|
struct dentry *dentry;
|
|
struct dentry *alias;
|
|
struct inode *inode;
|
|
int status;
|
|
|
|
if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID))
|
|
return;
|
|
if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID))
|
|
return;
|
|
if (filename.len == 0)
|
|
return;
|
|
/* Validate that the name doesn't contain any illegal '\0' */
|
|
if (strnlen(filename.name, filename.len) != filename.len)
|
|
return;
|
|
/* ...or '/' */
|
|
if (strnchr(filename.name, filename.len, '/'))
|
|
return;
|
|
if (filename.name[0] == '.') {
|
|
if (filename.len == 1)
|
|
return;
|
|
if (filename.len == 2 && filename.name[1] == '.')
|
|
return;
|
|
}
|
|
filename.hash = full_name_hash(parent, filename.name, filename.len);
|
|
|
|
dentry = d_lookup(parent, &filename);
|
|
again:
|
|
if (!dentry) {
|
|
dentry = d_alloc_parallel(parent, &filename, &wq);
|
|
if (IS_ERR(dentry))
|
|
return;
|
|
}
|
|
if (!d_in_lookup(dentry)) {
|
|
/* Is there a mountpoint here? If so, just exit */
|
|
if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,
|
|
&entry->fattr->fsid))
|
|
goto out;
|
|
if (nfs_same_file(dentry, entry)) {
|
|
if (!entry->fh->size)
|
|
goto out;
|
|
nfs_set_verifier(dentry, dir_verifier);
|
|
status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
|
|
if (!status)
|
|
nfs_setsecurity(d_inode(dentry), entry->fattr);
|
|
trace_nfs_readdir_lookup_revalidate(d_inode(parent),
|
|
dentry, 0, status);
|
|
goto out;
|
|
} else {
|
|
trace_nfs_readdir_lookup_revalidate_failed(
|
|
d_inode(parent), dentry, 0);
|
|
d_invalidate(dentry);
|
|
dput(dentry);
|
|
dentry = NULL;
|
|
goto again;
|
|
}
|
|
}
|
|
if (!entry->fh->size) {
|
|
d_lookup_done(dentry);
|
|
goto out;
|
|
}
|
|
|
|
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
|
|
alias = d_splice_alias(inode, dentry);
|
|
d_lookup_done(dentry);
|
|
if (alias) {
|
|
if (IS_ERR(alias))
|
|
goto out;
|
|
dput(dentry);
|
|
dentry = alias;
|
|
}
|
|
nfs_set_verifier(dentry, dir_verifier);
|
|
trace_nfs_readdir_lookup(d_inode(parent), dentry, 0);
|
|
out:
|
|
dput(dentry);
|
|
}
|
|
|
|
static int nfs_readdir_entry_decode(struct nfs_readdir_descriptor *desc,
|
|
struct nfs_entry *entry,
|
|
struct xdr_stream *stream)
|
|
{
|
|
int ret;
|
|
|
|
if (entry->fattr->label)
|
|
entry->fattr->label->len = NFS4_MAXLABELLEN;
|
|
ret = xdr_decode(desc, entry, stream);
|
|
if (ret || !desc->plus)
|
|
return ret;
|
|
nfs_prime_dcache(file_dentry(desc->file), entry, desc->dir_verifier);
|
|
return 0;
|
|
}
|
|
|
|
/* Perform conversion from xdr to cache array */
|
|
static int nfs_readdir_folio_filler(struct nfs_readdir_descriptor *desc,
|
|
struct nfs_entry *entry,
|
|
struct page **xdr_pages, unsigned int buflen,
|
|
struct folio **arrays, size_t narrays,
|
|
u64 change_attr)
|
|
{
|
|
struct address_space *mapping = desc->file->f_mapping;
|
|
struct folio *new, *folio = *arrays;
|
|
struct xdr_stream stream;
|
|
struct page *scratch;
|
|
struct xdr_buf buf;
|
|
u64 cookie;
|
|
int status;
|
|
|
|
scratch = alloc_page(GFP_KERNEL);
|
|
if (scratch == NULL)
|
|
return -ENOMEM;
|
|
|
|
xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
|
|
xdr_set_scratch_page(&stream, scratch);
|
|
|
|
do {
|
|
status = nfs_readdir_entry_decode(desc, entry, &stream);
|
|
if (status != 0)
|
|
break;
|
|
|
|
status = nfs_readdir_folio_array_append(folio, entry, &cookie);
|
|
if (status != -ENOSPC)
|
|
continue;
|
|
|
|
if (folio->mapping != mapping) {
|
|
if (!--narrays)
|
|
break;
|
|
new = nfs_readdir_folio_array_alloc(cookie, GFP_KERNEL);
|
|
if (!new)
|
|
break;
|
|
arrays++;
|
|
*arrays = folio = new;
|
|
} else {
|
|
new = nfs_readdir_folio_get_next(mapping, cookie,
|
|
change_attr);
|
|
if (!new)
|
|
break;
|
|
if (folio != *arrays)
|
|
nfs_readdir_folio_unlock_and_put(folio);
|
|
folio = new;
|
|
}
|
|
desc->folio_index_max++;
|
|
status = nfs_readdir_folio_array_append(folio, entry, &cookie);
|
|
} while (!status && !entry->eof);
|
|
|
|
switch (status) {
|
|
case -EBADCOOKIE:
|
|
if (!entry->eof)
|
|
break;
|
|
nfs_readdir_folio_set_eof(folio);
|
|
fallthrough;
|
|
case -EAGAIN:
|
|
status = 0;
|
|
break;
|
|
case -ENOSPC:
|
|
status = 0;
|
|
if (!desc->plus)
|
|
break;
|
|
while (!nfs_readdir_entry_decode(desc, entry, &stream))
|
|
;
|
|
}
|
|
|
|
if (folio != *arrays)
|
|
nfs_readdir_folio_unlock_and_put(folio);
|
|
|
|
put_page(scratch);
|
|
return status;
|
|
}
|
|
|
|
static void nfs_readdir_free_pages(struct page **pages, size_t npages)
|
|
{
|
|
while (npages--)
|
|
put_page(pages[npages]);
|
|
kfree(pages);
|
|
}
|
|
|
|
/*
|
|
* nfs_readdir_alloc_pages() will allocate pages that must be freed with a call
|
|
* to nfs_readdir_free_pages()
|
|
*/
|
|
static struct page **nfs_readdir_alloc_pages(size_t npages)
|
|
{
|
|
struct page **pages;
|
|
size_t i;
|
|
|
|
pages = kmalloc_array(npages, sizeof(*pages), GFP_KERNEL);
|
|
if (!pages)
|
|
return NULL;
|
|
for (i = 0; i < npages; i++) {
|
|
struct page *page = alloc_page(GFP_KERNEL);
|
|
if (page == NULL)
|
|
goto out_freepages;
|
|
pages[i] = page;
|
|
}
|
|
return pages;
|
|
|
|
out_freepages:
|
|
nfs_readdir_free_pages(pages, i);
|
|
return NULL;
|
|
}
|
|
|
|
static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc,
|
|
__be32 *verf_arg, __be32 *verf_res,
|
|
struct folio **arrays, size_t narrays)
|
|
{
|
|
u64 change_attr;
|
|
struct page **pages;
|
|
struct folio *folio = *arrays;
|
|
struct nfs_entry *entry;
|
|
size_t array_size;
|
|
struct inode *inode = file_inode(desc->file);
|
|
unsigned int dtsize = desc->dtsize;
|
|
unsigned int pglen;
|
|
int status = -ENOMEM;
|
|
|
|
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry)
|
|
return -ENOMEM;
|
|
entry->cookie = nfs_readdir_folio_last_cookie(folio);
|
|
entry->fh = nfs_alloc_fhandle();
|
|
entry->fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
|
|
entry->server = NFS_SERVER(inode);
|
|
if (entry->fh == NULL || entry->fattr == NULL)
|
|
goto out;
|
|
|
|
array_size = (dtsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
pages = nfs_readdir_alloc_pages(array_size);
|
|
if (!pages)
|
|
goto out;
|
|
|
|
change_attr = inode_peek_iversion_raw(inode);
|
|
status = nfs_readdir_xdr_filler(desc, verf_arg, entry->cookie, pages,
|
|
dtsize, verf_res);
|
|
if (status < 0)
|
|
goto free_pages;
|
|
|
|
pglen = status;
|
|
if (pglen != 0)
|
|
status = nfs_readdir_folio_filler(desc, entry, pages, pglen,
|
|
arrays, narrays, change_attr);
|
|
else
|
|
nfs_readdir_folio_set_eof(folio);
|
|
desc->buffer_fills++;
|
|
|
|
free_pages:
|
|
nfs_readdir_free_pages(pages, array_size);
|
|
out:
|
|
nfs_free_fattr(entry->fattr);
|
|
nfs_free_fhandle(entry->fh);
|
|
kfree(entry);
|
|
return status;
|
|
}
|
|
|
|
static void nfs_readdir_folio_put(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
folio_put(desc->folio);
|
|
desc->folio = NULL;
|
|
}
|
|
|
|
static void
|
|
nfs_readdir_folio_unlock_and_put_cached(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
folio_unlock(desc->folio);
|
|
nfs_readdir_folio_put(desc);
|
|
}
|
|
|
|
static struct folio *
|
|
nfs_readdir_folio_get_cached(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
struct address_space *mapping = desc->file->f_mapping;
|
|
u64 change_attr = inode_peek_iversion_raw(mapping->host);
|
|
u64 cookie = desc->last_cookie;
|
|
struct folio *folio;
|
|
|
|
folio = nfs_readdir_folio_get_locked(mapping, cookie, change_attr);
|
|
if (!folio)
|
|
return NULL;
|
|
if (desc->clear_cache && !nfs_readdir_folio_needs_filling(folio))
|
|
nfs_readdir_folio_reinit_array(folio, cookie, change_attr);
|
|
return folio;
|
|
}
|
|
|
|
/*
|
|
* Returns 0 if desc->dir_cookie was found on page desc->page_index
|
|
* and locks the page to prevent removal from the page cache.
|
|
*/
|
|
static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
struct inode *inode = file_inode(desc->file);
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
__be32 verf[NFS_DIR_VERIFIER_SIZE];
|
|
int res;
|
|
|
|
desc->folio = nfs_readdir_folio_get_cached(desc);
|
|
if (!desc->folio)
|
|
return -ENOMEM;
|
|
if (nfs_readdir_folio_needs_filling(desc->folio)) {
|
|
/* Grow the dtsize if we had to go back for more pages */
|
|
if (desc->folio_index == desc->folio_index_max)
|
|
nfs_grow_dtsize(desc);
|
|
desc->folio_index_max = desc->folio_index;
|
|
trace_nfs_readdir_cache_fill(desc->file, nfsi->cookieverf,
|
|
desc->last_cookie,
|
|
desc->folio->index, desc->dtsize);
|
|
res = nfs_readdir_xdr_to_array(desc, nfsi->cookieverf, verf,
|
|
&desc->folio, 1);
|
|
if (res < 0) {
|
|
nfs_readdir_folio_unlock_and_put_cached(desc);
|
|
trace_nfs_readdir_cache_fill_done(inode, res);
|
|
if (res == -EBADCOOKIE || res == -ENOTSYNC) {
|
|
invalidate_inode_pages2(desc->file->f_mapping);
|
|
nfs_readdir_rewind_search(desc);
|
|
trace_nfs_readdir_invalidate_cache_range(
|
|
inode, 0, MAX_LFS_FILESIZE);
|
|
return -EAGAIN;
|
|
}
|
|
return res;
|
|
}
|
|
/*
|
|
* Set the cookie verifier if the page cache was empty
|
|
*/
|
|
if (desc->last_cookie == 0 &&
|
|
memcmp(nfsi->cookieverf, verf, sizeof(nfsi->cookieverf))) {
|
|
memcpy(nfsi->cookieverf, verf,
|
|
sizeof(nfsi->cookieverf));
|
|
invalidate_inode_pages2_range(desc->file->f_mapping, 1,
|
|
-1);
|
|
trace_nfs_readdir_invalidate_cache_range(
|
|
inode, 1, MAX_LFS_FILESIZE);
|
|
}
|
|
desc->clear_cache = false;
|
|
}
|
|
res = nfs_readdir_search_array(desc);
|
|
if (res == 0)
|
|
return 0;
|
|
nfs_readdir_folio_unlock_and_put_cached(desc);
|
|
return res;
|
|
}
|
|
|
|
/* Search for desc->dir_cookie from the beginning of the page cache */
|
|
static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
int res;
|
|
|
|
do {
|
|
res = find_and_lock_cache_page(desc);
|
|
} while (res == -EAGAIN);
|
|
return res;
|
|
}
|
|
|
|
#define NFS_READDIR_CACHE_MISS_THRESHOLD (16UL)
|
|
|
|
/*
|
|
* Once we've found the start of the dirent within a page: fill 'er up...
|
|
*/
|
|
static void nfs_do_filldir(struct nfs_readdir_descriptor *desc,
|
|
const __be32 *verf)
|
|
{
|
|
struct file *file = desc->file;
|
|
struct nfs_cache_array *array;
|
|
unsigned int i;
|
|
bool first_emit = !desc->dir_cookie;
|
|
|
|
array = kmap_local_folio(desc->folio, 0);
|
|
for (i = desc->cache_entry_index; i < array->size; i++) {
|
|
struct nfs_cache_array_entry *ent;
|
|
|
|
/*
|
|
* nfs_readdir_handle_cache_misses return force clear at
|
|
* (cache_misses > NFS_READDIR_CACHE_MISS_THRESHOLD) for
|
|
* readdir heuristic, NFS_READDIR_CACHE_MISS_THRESHOLD + 1
|
|
* entries need be emitted here.
|
|
*/
|
|
if (first_emit && i > NFS_READDIR_CACHE_MISS_THRESHOLD + 2) {
|
|
desc->eob = true;
|
|
break;
|
|
}
|
|
|
|
ent = &array->array[i];
|
|
if (!dir_emit(desc->ctx, ent->name, ent->name_len,
|
|
nfs_compat_user_ino64(ent->ino), ent->d_type)) {
|
|
desc->eob = true;
|
|
break;
|
|
}
|
|
memcpy(desc->verf, verf, sizeof(desc->verf));
|
|
if (i == array->size - 1) {
|
|
desc->dir_cookie = array->last_cookie;
|
|
nfs_readdir_seek_next_array(array, desc);
|
|
} else {
|
|
desc->dir_cookie = array->array[i + 1].cookie;
|
|
desc->last_cookie = array->array[0].cookie;
|
|
}
|
|
if (nfs_readdir_use_cookie(file))
|
|
desc->ctx->pos = desc->dir_cookie;
|
|
else
|
|
desc->ctx->pos++;
|
|
}
|
|
if (array->folio_is_eof)
|
|
desc->eof = !desc->eob;
|
|
|
|
kunmap_local(array);
|
|
dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %llu\n",
|
|
(unsigned long long)desc->dir_cookie);
|
|
}
|
|
|
|
/*
|
|
* 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 int uncached_readdir(struct nfs_readdir_descriptor *desc)
|
|
{
|
|
struct folio **arrays;
|
|
size_t i, sz = 512;
|
|
__be32 verf[NFS_DIR_VERIFIER_SIZE];
|
|
int status = -ENOMEM;
|
|
|
|
dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %llu\n",
|
|
(unsigned long long)desc->dir_cookie);
|
|
|
|
arrays = kcalloc(sz, sizeof(*arrays), GFP_KERNEL);
|
|
if (!arrays)
|
|
goto out;
|
|
arrays[0] = nfs_readdir_folio_array_alloc(desc->dir_cookie, GFP_KERNEL);
|
|
if (!arrays[0])
|
|
goto out;
|
|
|
|
desc->folio_index = 0;
|
|
desc->cache_entry_index = 0;
|
|
desc->last_cookie = desc->dir_cookie;
|
|
desc->folio_index_max = 0;
|
|
|
|
trace_nfs_readdir_uncached(desc->file, desc->verf, desc->last_cookie,
|
|
-1, desc->dtsize);
|
|
|
|
status = nfs_readdir_xdr_to_array(desc, desc->verf, verf, arrays, sz);
|
|
if (status < 0) {
|
|
trace_nfs_readdir_uncached_done(file_inode(desc->file), status);
|
|
goto out_free;
|
|
}
|
|
|
|
for (i = 0; !desc->eob && i < sz && arrays[i]; i++) {
|
|
desc->folio = arrays[i];
|
|
nfs_do_filldir(desc, verf);
|
|
}
|
|
desc->folio = NULL;
|
|
|
|
/*
|
|
* Grow the dtsize if we have to go back for more pages,
|
|
* or shrink it if we're reading too many.
|
|
*/
|
|
if (!desc->eof) {
|
|
if (!desc->eob)
|
|
nfs_grow_dtsize(desc);
|
|
else if (desc->buffer_fills == 1 &&
|
|
i < (desc->folio_index_max >> 1))
|
|
nfs_shrink_dtsize(desc);
|
|
}
|
|
out_free:
|
|
for (i = 0; i < sz && arrays[i]; i++)
|
|
nfs_readdir_folio_array_free(arrays[i]);
|
|
out:
|
|
if (!nfs_readdir_use_cookie(desc->file))
|
|
nfs_readdir_rewind_search(desc);
|
|
desc->folio_index_max = -1;
|
|
kfree(arrays);
|
|
dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
|
|
static bool nfs_readdir_handle_cache_misses(struct inode *inode,
|
|
struct nfs_readdir_descriptor *desc,
|
|
unsigned int cache_misses,
|
|
bool force_clear)
|
|
{
|
|
if (desc->ctx->pos == 0 || !desc->plus)
|
|
return false;
|
|
if (cache_misses <= NFS_READDIR_CACHE_MISS_THRESHOLD && !force_clear)
|
|
return false;
|
|
trace_nfs_readdir_force_readdirplus(inode);
|
|
return true;
|
|
}
|
|
|
|
/* 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_dentry(file);
|
|
struct inode *inode = d_inode(dentry);
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
struct nfs_open_dir_context *dir_ctx = file->private_data;
|
|
struct nfs_readdir_descriptor *desc;
|
|
unsigned int cache_hits, cache_misses;
|
|
bool force_clear;
|
|
int res;
|
|
|
|
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.
|
|
*/
|
|
nfs_revalidate_mapping(inode, file->f_mapping);
|
|
|
|
res = -ENOMEM;
|
|
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
|
|
if (!desc)
|
|
goto out;
|
|
desc->file = file;
|
|
desc->ctx = ctx;
|
|
desc->folio_index_max = -1;
|
|
|
|
spin_lock(&file->f_lock);
|
|
desc->dir_cookie = dir_ctx->dir_cookie;
|
|
desc->folio_index = dir_ctx->page_index;
|
|
desc->last_cookie = dir_ctx->last_cookie;
|
|
desc->attr_gencount = dir_ctx->attr_gencount;
|
|
desc->eof = dir_ctx->eof;
|
|
nfs_set_dtsize(desc, dir_ctx->dtsize);
|
|
memcpy(desc->verf, dir_ctx->verf, sizeof(desc->verf));
|
|
cache_hits = atomic_xchg(&dir_ctx->cache_hits, 0);
|
|
cache_misses = atomic_xchg(&dir_ctx->cache_misses, 0);
|
|
force_clear = dir_ctx->force_clear;
|
|
spin_unlock(&file->f_lock);
|
|
|
|
if (desc->eof) {
|
|
res = 0;
|
|
goto out_free;
|
|
}
|
|
|
|
desc->plus = nfs_use_readdirplus(inode, ctx, cache_hits, cache_misses);
|
|
force_clear = nfs_readdir_handle_cache_misses(inode, desc, cache_misses,
|
|
force_clear);
|
|
desc->clear_cache = force_clear;
|
|
|
|
do {
|
|
res = readdir_search_pagecache(desc);
|
|
|
|
if (res == -EBADCOOKIE) {
|
|
res = 0;
|
|
/* This means either end of directory */
|
|
if (desc->dir_cookie && !desc->eof) {
|
|
/* Or that the server has 'lost' a cookie */
|
|
res = uncached_readdir(desc);
|
|
if (res == 0)
|
|
continue;
|
|
if (res == -EBADCOOKIE || res == -ENOTSYNC)
|
|
res = 0;
|
|
}
|
|
break;
|
|
}
|
|
if (res == -ETOOSMALL && desc->plus) {
|
|
nfs_zap_caches(inode);
|
|
desc->plus = false;
|
|
desc->eof = false;
|
|
continue;
|
|
}
|
|
if (res < 0)
|
|
break;
|
|
|
|
nfs_do_filldir(desc, nfsi->cookieverf);
|
|
nfs_readdir_folio_unlock_and_put_cached(desc);
|
|
if (desc->folio_index == desc->folio_index_max)
|
|
desc->clear_cache = force_clear;
|
|
} while (!desc->eob && !desc->eof);
|
|
|
|
spin_lock(&file->f_lock);
|
|
dir_ctx->dir_cookie = desc->dir_cookie;
|
|
dir_ctx->last_cookie = desc->last_cookie;
|
|
dir_ctx->attr_gencount = desc->attr_gencount;
|
|
dir_ctx->page_index = desc->folio_index;
|
|
dir_ctx->force_clear = force_clear;
|
|
dir_ctx->eof = desc->eof;
|
|
dir_ctx->dtsize = desc->dtsize;
|
|
memcpy(dir_ctx->verf, desc->verf, sizeof(dir_ctx->verf));
|
|
spin_unlock(&file->f_lock);
|
|
out_free:
|
|
kfree(desc);
|
|
|
|
out:
|
|
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 nfs_open_dir_context *dir_ctx = filp->private_data;
|
|
|
|
dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
|
|
filp, offset, whence);
|
|
|
|
switch (whence) {
|
|
default:
|
|
return -EINVAL;
|
|
case SEEK_SET:
|
|
if (offset < 0)
|
|
return -EINVAL;
|
|
spin_lock(&filp->f_lock);
|
|
break;
|
|
case SEEK_CUR:
|
|
if (offset == 0)
|
|
return filp->f_pos;
|
|
spin_lock(&filp->f_lock);
|
|
offset += filp->f_pos;
|
|
if (offset < 0) {
|
|
spin_unlock(&filp->f_lock);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (offset != filp->f_pos) {
|
|
filp->f_pos = offset;
|
|
dir_ctx->page_index = 0;
|
|
if (!nfs_readdir_use_cookie(filp)) {
|
|
dir_ctx->dir_cookie = 0;
|
|
dir_ctx->last_cookie = 0;
|
|
} else {
|
|
dir_ctx->dir_cookie = offset;
|
|
dir_ctx->last_cookie = offset;
|
|
}
|
|
dir_ctx->eof = false;
|
|
}
|
|
spin_unlock(&filp->f_lock);
|
|
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)
|
|
{
|
|
dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync);
|
|
|
|
nfs_inc_stats(file_inode(filp), NFSIOS_VFSFSYNC);
|
|
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.
|
|
*
|
|
* Note that we reserve bit '0' as a tag to let us know when a dentry
|
|
* was revalidated while holding a delegation on its inode.
|
|
*
|
|
* The caller should be holding dir->i_lock
|
|
*/
|
|
void nfs_force_lookup_revalidate(struct inode *dir)
|
|
{
|
|
NFS_I(dir)->cache_change_attribute += 2;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
|
|
|
|
/**
|
|
* nfs_verify_change_attribute - Detects NFS remote directory changes
|
|
* @dir: pointer to parent directory inode
|
|
* @verf: previously saved change attribute
|
|
*
|
|
* Return "false" if the verifiers doesn't match the change attribute.
|
|
* This would usually indicate that the directory contents have changed on
|
|
* the server, and that any dentries need revalidating.
|
|
*/
|
|
static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf)
|
|
{
|
|
return (verf & ~1UL) == nfs_save_change_attribute(dir);
|
|
}
|
|
|
|
static void nfs_set_verifier_delegated(unsigned long *verf)
|
|
{
|
|
*verf |= 1UL;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4)
|
|
static void nfs_unset_verifier_delegated(unsigned long *verf)
|
|
{
|
|
*verf &= ~1UL;
|
|
}
|
|
#endif /* IS_ENABLED(CONFIG_NFS_V4) */
|
|
|
|
static bool nfs_test_verifier_delegated(unsigned long verf)
|
|
{
|
|
return verf & 1;
|
|
}
|
|
|
|
static bool nfs_verifier_is_delegated(struct dentry *dentry)
|
|
{
|
|
return nfs_test_verifier_delegated(dentry->d_time);
|
|
}
|
|
|
|
static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct inode *dir = d_inode(dentry->d_parent);
|
|
|
|
if (!nfs_verify_change_attribute(dir, verf))
|
|
return;
|
|
if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
|
|
nfs_set_verifier_delegated(&verf);
|
|
dentry->d_time = verf;
|
|
}
|
|
|
|
/**
|
|
* nfs_set_verifier - save a parent directory verifier in the dentry
|
|
* @dentry: pointer to dentry
|
|
* @verf: verifier to save
|
|
*
|
|
* Saves the parent directory verifier in @dentry. If the inode has
|
|
* a delegation, we also tag the dentry as having been revalidated
|
|
* while holding a delegation so that we know we don't have to
|
|
* look it up again after a directory change.
|
|
*/
|
|
void nfs_set_verifier(struct dentry *dentry, unsigned long verf)
|
|
{
|
|
|
|
spin_lock(&dentry->d_lock);
|
|
nfs_set_verifier_locked(dentry, verf);
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_set_verifier);
|
|
|
|
#if IS_ENABLED(CONFIG_NFS_V4)
|
|
/**
|
|
* nfs_clear_verifier_delegated - clear the dir verifier delegation tag
|
|
* @inode: pointer to inode
|
|
*
|
|
* Iterates through the dentries in the inode alias list and clears
|
|
* the tag used to indicate that the dentry has been revalidated
|
|
* while holding a delegation.
|
|
* This function is intended for use when the delegation is being
|
|
* returned or revoked.
|
|
*/
|
|
void nfs_clear_verifier_delegated(struct inode *inode)
|
|
{
|
|
struct dentry *alias;
|
|
|
|
if (!inode)
|
|
return;
|
|
spin_lock(&inode->i_lock);
|
|
hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
|
|
spin_lock(&alias->d_lock);
|
|
nfs_unset_verifier_delegated(&alias->d_time);
|
|
spin_unlock(&alias->d_lock);
|
|
}
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);
|
|
#endif /* IS_ENABLED(CONFIG_NFS_V4) */
|
|
|
|
static int nfs_dentry_verify_change(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE) &&
|
|
d_really_is_negative(dentry))
|
|
return dentry->d_time == inode_peek_iversion_raw(dir);
|
|
return nfs_verify_change_attribute(dir, dentry->d_time);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
if (IS_ROOT(dentry))
|
|
return 1;
|
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
|
|
return 0;
|
|
if (!nfs_dentry_verify_change(dir, dentry))
|
|
return 0;
|
|
/* Revalidate nfsi->cache_change_attribute before we declare a match */
|
|
if (nfs_mapping_need_revalidate_inode(dir)) {
|
|
if (rcu_walk)
|
|
return 0;
|
|
if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
|
|
return 0;
|
|
}
|
|
if (!nfs_dentry_verify_change(dir, dentry))
|
|
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;
|
|
|
|
if (flags & LOOKUP_OPEN) {
|
|
switch (inode->i_mode & S_IFMT) {
|
|
case S_IFREG:
|
|
/* A NFSv4 OPEN will revalidate later */
|
|
if (server->caps & NFS_CAP_ATOMIC_OPEN)
|
|
goto out;
|
|
fallthrough;
|
|
case S_IFDIR:
|
|
if (server->flags & NFS_MOUNT_NOCTO)
|
|
break;
|
|
/* NFS close-to-open cache consistency validation */
|
|
goto out_force;
|
|
}
|
|
}
|
|
|
|
/* VFS wants an on-the-wire revalidation */
|
|
if (flags & LOOKUP_REVAL)
|
|
goto out_force;
|
|
out:
|
|
if (inode->i_nlink > 0 ||
|
|
(inode->i_nlink == 0 &&
|
|
test_bit(NFS_INO_PRESERVE_UNLINKED, &NFS_I(inode)->flags)))
|
|
return 0;
|
|
else
|
|
return -ESTALE;
|
|
out_force:
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
ret = __nfs_revalidate_inode(server, inode);
|
|
if (ret != 0)
|
|
return ret;
|
|
goto out;
|
|
}
|
|
|
|
static void nfs_mark_dir_for_revalidate(struct inode *inode)
|
|
{
|
|
spin_lock(&inode->i_lock);
|
|
nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
|
|
spin_unlock(&inode->i_lock);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* Note that when creating a new file, or looking up a rename target,
|
|
* then it shouldn't be necessary to revalidate a negative dentry.
|
|
*/
|
|
static inline
|
|
int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
|
|
return 0;
|
|
if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
|
|
return 1;
|
|
/* Case insensitive server? Revalidate negative dentries */
|
|
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
|
|
return 1;
|
|
return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU);
|
|
}
|
|
|
|
static int
|
|
nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry,
|
|
struct inode *inode, int error)
|
|
{
|
|
switch (error) {
|
|
case 1:
|
|
break;
|
|
case 0:
|
|
/*
|
|
* 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 (inode && IS_ROOT(dentry))
|
|
error = 1;
|
|
break;
|
|
}
|
|
trace_nfs_lookup_revalidate_exit(dir, dentry, 0, error);
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
int ret = 1;
|
|
if (nfs_neg_need_reval(dir, dentry, flags)) {
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
ret = 0;
|
|
}
|
|
return nfs_lookup_revalidate_done(dir, dentry, NULL, ret);
|
|
}
|
|
|
|
static int
|
|
nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry,
|
|
struct inode *inode)
|
|
{
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
|
|
}
|
|
|
|
static int nfs_lookup_revalidate_dentry(struct inode *dir,
|
|
struct dentry *dentry,
|
|
struct inode *inode, unsigned int flags)
|
|
{
|
|
struct nfs_fh *fhandle;
|
|
struct nfs_fattr *fattr;
|
|
unsigned long dir_verifier;
|
|
int ret;
|
|
|
|
trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
|
|
|
|
ret = -ENOMEM;
|
|
fhandle = nfs_alloc_fhandle();
|
|
fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
|
|
if (fhandle == NULL || fattr == NULL)
|
|
goto out;
|
|
|
|
dir_verifier = nfs_save_change_attribute(dir);
|
|
ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr);
|
|
if (ret < 0) {
|
|
switch (ret) {
|
|
case -ESTALE:
|
|
case -ENOENT:
|
|
ret = 0;
|
|
break;
|
|
case -ETIMEDOUT:
|
|
if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)
|
|
ret = 1;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
/* Request help from readdirplus */
|
|
nfs_lookup_advise_force_readdirplus(dir, flags);
|
|
|
|
ret = 0;
|
|
if (nfs_compare_fh(NFS_FH(inode), fhandle))
|
|
goto out;
|
|
if (nfs_refresh_inode(inode, fattr) < 0)
|
|
goto out;
|
|
|
|
nfs_setsecurity(inode, fattr);
|
|
nfs_set_verifier(dentry, dir_verifier);
|
|
|
|
ret = 1;
|
|
out:
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
|
|
/*
|
|
* If the lookup failed despite the dentry change attribute being
|
|
* a match, then we should revalidate the directory cache.
|
|
*/
|
|
if (!ret && nfs_dentry_verify_change(dir, dentry))
|
|
nfs_mark_dir_for_revalidate(dir);
|
|
return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
|
|
}
|
|
|
|
/*
|
|
* 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_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct inode *inode;
|
|
int error;
|
|
|
|
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
|
|
inode = d_inode(dentry);
|
|
|
|
if (!inode)
|
|
return nfs_lookup_revalidate_negative(dir, dentry, flags);
|
|
|
|
if (is_bad_inode(inode)) {
|
|
dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
|
|
__func__, dentry);
|
|
goto out_bad;
|
|
}
|
|
|
|
if ((flags & LOOKUP_RENAME_TARGET) && d_count(dentry) < 2 &&
|
|
nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
|
|
goto out_bad;
|
|
|
|
if (nfs_verifier_is_delegated(dentry))
|
|
return nfs_lookup_revalidate_delegated(dir, dentry, inode);
|
|
|
|
/* Force a full look up iff the parent directory has changed */
|
|
if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) &&
|
|
nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
|
|
error = nfs_lookup_verify_inode(inode, flags);
|
|
if (error) {
|
|
if (error == -ESTALE)
|
|
nfs_mark_dir_for_revalidate(dir);
|
|
goto out_bad;
|
|
}
|
|
goto out_valid;
|
|
}
|
|
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
|
|
if (NFS_STALE(inode))
|
|
goto out_bad;
|
|
|
|
return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags);
|
|
out_valid:
|
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
|
|
out_bad:
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
return nfs_lookup_revalidate_done(dir, dentry, inode, 0);
|
|
}
|
|
|
|
static int
|
|
__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags,
|
|
int (*reval)(struct inode *, struct dentry *, unsigned int))
|
|
{
|
|
struct dentry *parent;
|
|
struct inode *dir;
|
|
int ret;
|
|
|
|
if (flags & LOOKUP_RCU) {
|
|
if (dentry->d_fsdata == NFS_FSDATA_BLOCKED)
|
|
return -ECHILD;
|
|
parent = READ_ONCE(dentry->d_parent);
|
|
dir = d_inode_rcu(parent);
|
|
if (!dir)
|
|
return -ECHILD;
|
|
ret = reval(dir, dentry, flags);
|
|
if (parent != READ_ONCE(dentry->d_parent))
|
|
return -ECHILD;
|
|
} else {
|
|
/* Wait for unlink to complete */
|
|
wait_var_event(&dentry->d_fsdata,
|
|
dentry->d_fsdata != NFS_FSDATA_BLOCKED);
|
|
parent = dget_parent(dentry);
|
|
ret = reval(d_inode(parent), dentry, flags);
|
|
dput(parent);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
int error = 0;
|
|
|
|
/*
|
|
* 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_lookup_verify_inode(inode, flags);
|
|
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 & SB_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 > 0)
|
|
drop_nlink(inode);
|
|
NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter();
|
|
nfs_set_cache_invalid(
|
|
inode, NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
|
|
NFS_INO_INVALID_NLINK);
|
|
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 (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 inode *inode = NULL;
|
|
struct nfs_fh *fhandle = NULL;
|
|
struct nfs_fattr *fattr = NULL;
|
|
unsigned long dir_verifier;
|
|
int error;
|
|
|
|
dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
|
|
nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
|
|
|
|
if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen))
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
/*
|
|
* If we're doing an exclusive create, optimize away the lookup
|
|
* but don't hash the dentry.
|
|
*/
|
|
if (nfs_is_exclusive_create(dir, flags) || flags & LOOKUP_RENAME_TARGET)
|
|
return NULL;
|
|
|
|
res = ERR_PTR(-ENOMEM);
|
|
fhandle = nfs_alloc_fhandle();
|
|
fattr = nfs_alloc_fattr_with_label(NFS_SERVER(dir));
|
|
if (fhandle == NULL || fattr == NULL)
|
|
goto out;
|
|
|
|
dir_verifier = nfs_save_change_attribute(dir);
|
|
trace_nfs_lookup_enter(dir, dentry, flags);
|
|
error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr);
|
|
if (error == -ENOENT) {
|
|
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
|
|
dir_verifier = inode_peek_iversion_raw(dir);
|
|
goto no_entry;
|
|
}
|
|
if (error < 0) {
|
|
res = ERR_PTR(error);
|
|
goto out;
|
|
}
|
|
inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
|
|
res = ERR_CAST(inode);
|
|
if (IS_ERR(res))
|
|
goto out;
|
|
|
|
/* Notify readdir to use READDIRPLUS */
|
|
nfs_lookup_advise_force_readdirplus(dir, flags);
|
|
|
|
no_entry:
|
|
res = d_splice_alias(inode, dentry);
|
|
if (res != NULL) {
|
|
if (IS_ERR(res))
|
|
goto out;
|
|
dentry = res;
|
|
}
|
|
nfs_set_verifier(dentry, dir_verifier);
|
|
out:
|
|
trace_nfs_lookup_exit(dir, dentry, flags, PTR_ERR_OR_ZERO(res));
|
|
nfs_free_fattr(fattr);
|
|
nfs_free_fhandle(fhandle);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_lookup);
|
|
|
|
void nfs_d_prune_case_insensitive_aliases(struct inode *inode)
|
|
{
|
|
/* Case insensitive server? Revalidate dentries */
|
|
if (inode && nfs_server_capable(inode, NFS_CAP_CASE_INSENSITIVE))
|
|
d_prune_aliases(inode);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_d_prune_case_insensitive_aliases);
|
|
|
|
#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_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(nfs4_dentry_operations);
|
|
|
|
static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp)
|
|
{
|
|
return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp);
|
|
}
|
|
|
|
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 err;
|
|
|
|
err = finish_open(file, dentry, do_open);
|
|
if (err)
|
|
goto out;
|
|
if (S_ISREG(file_inode(file)->i_mode))
|
|
nfs_file_set_open_context(file, ctx);
|
|
else
|
|
err = -EOPENSTALE;
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
|
|
struct file *file, unsigned open_flags,
|
|
umode_t mode)
|
|
{
|
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
|
|
struct nfs_open_context *ctx;
|
|
struct dentry *res;
|
|
struct iattr attr = { .ia_valid = ATTR_OPEN };
|
|
struct inode *inode;
|
|
unsigned int lookup_flags = 0;
|
|
unsigned long dir_verifier;
|
|
bool switched = false;
|
|
int created = 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_in_lookup(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) {
|
|
struct nfs_server *server = NFS_SERVER(dir);
|
|
|
|
if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
|
|
mode &= ~current_umask();
|
|
|
|
attr.ia_valid |= ATTR_MODE;
|
|
attr.ia_mode = mode;
|
|
}
|
|
if (open_flags & O_TRUNC) {
|
|
attr.ia_valid |= ATTR_SIZE;
|
|
attr.ia_size = 0;
|
|
}
|
|
|
|
if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) {
|
|
d_drop(dentry);
|
|
switched = true;
|
|
dentry = d_alloc_parallel(dentry->d_parent,
|
|
&dentry->d_name, &wq);
|
|
if (IS_ERR(dentry))
|
|
return PTR_ERR(dentry);
|
|
if (unlikely(!d_in_lookup(dentry)))
|
|
return finish_no_open(file, dentry);
|
|
}
|
|
|
|
ctx = create_nfs_open_context(dentry, open_flags, file);
|
|
err = PTR_ERR(ctx);
|
|
if (IS_ERR(ctx))
|
|
goto out;
|
|
|
|
trace_nfs_atomic_open_enter(dir, ctx, open_flags);
|
|
inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, &created);
|
|
if (created)
|
|
file->f_mode |= FMODE_CREATED;
|
|
if (IS_ERR(inode)) {
|
|
err = PTR_ERR(inode);
|
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
|
|
put_nfs_open_context(ctx);
|
|
d_drop(dentry);
|
|
switch (err) {
|
|
case -ENOENT:
|
|
d_splice_alias(NULL, dentry);
|
|
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
|
|
dir_verifier = inode_peek_iversion_raw(dir);
|
|
else
|
|
dir_verifier = nfs_save_change_attribute(dir);
|
|
nfs_set_verifier(dentry, dir_verifier);
|
|
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;
|
|
}
|
|
file->f_mode |= FMODE_CAN_ODIRECT;
|
|
|
|
err = nfs_finish_open(ctx, ctx->dentry, file, open_flags);
|
|
trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
|
|
put_nfs_open_context(ctx);
|
|
out:
|
|
if (unlikely(switched)) {
|
|
d_lookup_done(dentry);
|
|
dput(dentry);
|
|
}
|
|
return err;
|
|
|
|
no_open:
|
|
res = nfs_lookup(dir, dentry, lookup_flags);
|
|
if (!res) {
|
|
inode = d_inode(dentry);
|
|
if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
|
|
!(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
|
|
res = ERR_PTR(-ENOTDIR);
|
|
else if (inode && S_ISREG(inode->i_mode))
|
|
res = ERR_PTR(-EOPENSTALE);
|
|
} else if (!IS_ERR(res)) {
|
|
inode = d_inode(res);
|
|
if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
|
|
!(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) {
|
|
dput(res);
|
|
res = ERR_PTR(-ENOTDIR);
|
|
} else if (inode && S_ISREG(inode->i_mode)) {
|
|
dput(res);
|
|
res = ERR_PTR(-EOPENSTALE);
|
|
}
|
|
}
|
|
if (switched) {
|
|
d_lookup_done(dentry);
|
|
if (!res)
|
|
res = dentry;
|
|
else
|
|
dput(dentry);
|
|
}
|
|
if (IS_ERR(res))
|
|
return PTR_ERR(res);
|
|
return finish_no_open(file, res);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_atomic_open);
|
|
|
|
static int
|
|
nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
|
|
unsigned int flags)
|
|
{
|
|
struct inode *inode;
|
|
|
|
if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
|
|
goto full_reval;
|
|
if (d_mountpoint(dentry))
|
|
goto full_reval;
|
|
|
|
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)
|
|
goto full_reval;
|
|
|
|
if (nfs_verifier_is_delegated(dentry))
|
|
return nfs_lookup_revalidate_delegated(dir, dentry, inode);
|
|
|
|
/* NFS only supports OPEN on regular files */
|
|
if (!S_ISREG(inode->i_mode))
|
|
goto full_reval;
|
|
|
|
/* We cannot do exclusive creation on a positive dentry */
|
|
if (flags & (LOOKUP_EXCL | LOOKUP_REVAL))
|
|
goto reval_dentry;
|
|
|
|
/* Check if the directory changed */
|
|
if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU))
|
|
goto reval_dentry;
|
|
|
|
/* Let f_op->open() actually open (and revalidate) the file */
|
|
return 1;
|
|
reval_dentry:
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags);
|
|
|
|
full_reval:
|
|
return nfs_do_lookup_revalidate(dir, dentry, flags);
|
|
}
|
|
|
|
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
|
|
{
|
|
return __nfs_lookup_revalidate(dentry, flags,
|
|
nfs4_do_lookup_revalidate);
|
|
}
|
|
|
|
#endif /* CONFIG_NFSV4 */
|
|
|
|
struct dentry *
|
|
nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fhandle,
|
|
struct nfs_fattr *fattr)
|
|
{
|
|
struct dentry *parent = dget_parent(dentry);
|
|
struct inode *dir = d_inode(parent);
|
|
struct inode *inode;
|
|
struct dentry *d;
|
|
int error;
|
|
|
|
d_drop(dentry);
|
|
|
|
if (fhandle->size == 0) {
|
|
error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr);
|
|
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);
|
|
d = d_splice_alias(inode, dentry);
|
|
out:
|
|
dput(parent);
|
|
return d;
|
|
out_error:
|
|
d = ERR_PTR(error);
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_add_or_obtain);
|
|
|
|
/*
|
|
* Code common to create, mkdir, and mknod.
|
|
*/
|
|
int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
|
|
struct nfs_fattr *fattr)
|
|
{
|
|
struct dentry *d;
|
|
|
|
d = nfs_add_or_obtain(dentry, fhandle, fattr);
|
|
if (IS_ERR(d))
|
|
return PTR_ERR(d);
|
|
|
|
/* Callers don't care */
|
|
dput(d);
|
|
return 0;
|
|
}
|
|
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 mnt_idmap *idmap, 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 mnt_idmap *idmap, 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);
|
|
|
|
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 mnt_idmap *idmap, 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);
|
|
}
|
|
|
|
static void nfs_dentry_remove_handle_error(struct inode *dir,
|
|
struct dentry *dentry, int error)
|
|
{
|
|
switch (error) {
|
|
case -ENOENT:
|
|
if (d_really_is_positive(dentry))
|
|
d_delete(dentry);
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
break;
|
|
case 0:
|
|
nfs_d_prune_case_insensitive_aliases(d_inode(dentry));
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
}
|
|
}
|
|
|
|
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)) {
|
|
down_write(&NFS_I(d_inode(dentry))->rmdir_sem);
|
|
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);
|
|
}
|
|
up_write(&NFS_I(d_inode(dentry))->rmdir_sem);
|
|
} else
|
|
error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
|
|
nfs_dentry_remove_handle_error(dir, dentry, error);
|
|
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) {
|
|
error = NFS_PROTO(dir)->remove(dir, dentry);
|
|
if (error == 0)
|
|
nfs_drop_nlink(inode);
|
|
} else
|
|
error = NFS_PROTO(dir)->remove(dir, dentry);
|
|
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;
|
|
|
|
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 && !test_bit(NFS_INO_PRESERVE_UNLINKED,
|
|
&NFS_I(d_inode(dentry))->flags)) {
|
|
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;
|
|
}
|
|
/* We must prevent any concurrent open until the unlink
|
|
* completes. ->d_revalidate will wait for ->d_fsdata
|
|
* to clear. We set it here to ensure no lookup succeeds until
|
|
* the unlink is complete on the server.
|
|
*/
|
|
error = -ETXTBSY;
|
|
if (WARN_ON(dentry->d_flags & DCACHE_NFSFS_RENAMED) ||
|
|
WARN_ON(dentry->d_fsdata == NFS_FSDATA_BLOCKED)) {
|
|
spin_unlock(&dentry->d_lock);
|
|
goto out;
|
|
}
|
|
/* old devname */
|
|
kfree(dentry->d_fsdata);
|
|
dentry->d_fsdata = NFS_FSDATA_BLOCKED;
|
|
|
|
spin_unlock(&dentry->d_lock);
|
|
error = nfs_safe_remove(dentry);
|
|
nfs_dentry_remove_handle_error(dir, dentry, error);
|
|
dentry->d_fsdata = NULL;
|
|
wake_up_var(&dentry->d_fsdata);
|
|
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 mnt_idmap *idmap, 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_USER);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
kaddr = page_address(page);
|
|
memcpy(kaddr, symname, pathlen);
|
|
if (pathlen < PAGE_SIZE)
|
|
memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
|
|
|
|
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;
|
|
}
|
|
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
put_page(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);
|
|
d_drop(dentry);
|
|
if (S_ISREG(inode->i_mode))
|
|
nfs_sync_inode(inode);
|
|
error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
|
|
if (error == 0) {
|
|
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
|
|
ihold(inode);
|
|
d_add(dentry, inode);
|
|
}
|
|
trace_nfs_link_exit(inode, dir, dentry, error);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_link);
|
|
|
|
static void
|
|
nfs_unblock_rename(struct rpc_task *task, struct nfs_renamedata *data)
|
|
{
|
|
struct dentry *new_dentry = data->new_dentry;
|
|
|
|
new_dentry->d_fsdata = NULL;
|
|
wake_up_var(&new_dentry->d_fsdata);
|
|
}
|
|
|
|
/*
|
|
* 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 mnt_idmap *idmap, struct inode *old_dir,
|
|
struct dentry *old_dentry, struct inode *new_dir,
|
|
struct dentry *new_dentry, unsigned int flags)
|
|
{
|
|
struct inode *old_inode = d_inode(old_dentry);
|
|
struct inode *new_inode = d_inode(new_dentry);
|
|
struct dentry *dentry = NULL;
|
|
struct rpc_task *task;
|
|
bool must_unblock = false;
|
|
int error = -EBUSY;
|
|
|
|
if (flags)
|
|
return -EINVAL;
|
|
|
|
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)) {
|
|
/* We must prevent any concurrent open until the unlink
|
|
* completes. ->d_revalidate will wait for ->d_fsdata
|
|
* to clear. We set it here to ensure no lookup succeeds until
|
|
* the unlink is complete on the server.
|
|
*/
|
|
error = -ETXTBSY;
|
|
if (WARN_ON(new_dentry->d_flags & DCACHE_NFSFS_RENAMED) ||
|
|
WARN_ON(new_dentry->d_fsdata == NFS_FSDATA_BLOCKED))
|
|
goto out;
|
|
if (new_dentry->d_fsdata) {
|
|
/* old devname */
|
|
kfree(new_dentry->d_fsdata);
|
|
new_dentry->d_fsdata = NULL;
|
|
}
|
|
|
|
spin_lock(&new_dentry->d_lock);
|
|
if (d_count(new_dentry) > 2) {
|
|
int err;
|
|
|
|
spin_unlock(&new_dentry->d_lock);
|
|
|
|
/* 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;
|
|
new_inode = NULL;
|
|
} else {
|
|
new_dentry->d_fsdata = NFS_FSDATA_BLOCKED;
|
|
must_unblock = true;
|
|
spin_unlock(&new_dentry->d_lock);
|
|
}
|
|
|
|
}
|
|
|
|
if (S_ISREG(old_inode->i_mode))
|
|
nfs_sync_inode(old_inode);
|
|
task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry,
|
|
must_unblock ? nfs_unblock_rename : NULL);
|
|
if (IS_ERR(task)) {
|
|
error = PTR_ERR(task);
|
|
goto out;
|
|
}
|
|
|
|
error = rpc_wait_for_completion_task(task);
|
|
if (error != 0) {
|
|
((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1;
|
|
/* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */
|
|
smp_wmb();
|
|
} else
|
|
error = task->tk_status;
|
|
rpc_put_task(task);
|
|
/* Ensure the inode attributes are revalidated */
|
|
if (error == 0) {
|
|
spin_lock(&old_inode->i_lock);
|
|
NFS_I(old_inode)->attr_gencount = nfs_inc_attr_generation_counter();
|
|
nfs_set_cache_invalid(old_inode, NFS_INO_INVALID_CHANGE |
|
|
NFS_INO_INVALID_CTIME |
|
|
NFS_INO_REVAL_FORCED);
|
|
spin_unlock(&old_inode->i_lock);
|
|
}
|
|
out:
|
|
trace_nfs_rename_exit(old_dir, old_dentry,
|
|
new_dir, new_dentry, error);
|
|
if (!error) {
|
|
if (new_inode != NULL)
|
|
nfs_drop_nlink(new_inode);
|
|
/*
|
|
* The d_move() should be here instead of in an async RPC completion
|
|
* handler because we need the proper locks to move the dentry. If
|
|
* we're interrupted by a signal, the async RPC completion handler
|
|
* should mark the directories for revalidation.
|
|
*/
|
|
d_move(old_dentry, new_dentry);
|
|
nfs_set_verifier(old_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 = 4*1024*1024;
|
|
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_group_info(entry->group_info);
|
|
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 int access_cmp(const struct cred *a, const struct nfs_access_entry *b)
|
|
{
|
|
struct group_info *ga, *gb;
|
|
int g;
|
|
|
|
if (uid_lt(a->fsuid, b->fsuid))
|
|
return -1;
|
|
if (uid_gt(a->fsuid, b->fsuid))
|
|
return 1;
|
|
|
|
if (gid_lt(a->fsgid, b->fsgid))
|
|
return -1;
|
|
if (gid_gt(a->fsgid, b->fsgid))
|
|
return 1;
|
|
|
|
ga = a->group_info;
|
|
gb = b->group_info;
|
|
if (ga == gb)
|
|
return 0;
|
|
if (ga == NULL)
|
|
return -1;
|
|
if (gb == NULL)
|
|
return 1;
|
|
if (ga->ngroups < gb->ngroups)
|
|
return -1;
|
|
if (ga->ngroups > gb->ngroups)
|
|
return 1;
|
|
|
|
for (g = 0; g < ga->ngroups; g++) {
|
|
if (gid_lt(ga->gid[g], gb->gid[g]))
|
|
return -1;
|
|
if (gid_gt(ga->gid[g], gb->gid[g]))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, const struct cred *cred)
|
|
{
|
|
struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
|
|
|
|
while (n != NULL) {
|
|
struct nfs_access_entry *entry =
|
|
rb_entry(n, struct nfs_access_entry, rb_node);
|
|
int cmp = access_cmp(cred, entry);
|
|
|
|
if (cmp < 0)
|
|
n = n->rb_left;
|
|
else if (cmp > 0)
|
|
n = n->rb_right;
|
|
else
|
|
return entry;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static u64 nfs_access_login_time(const struct task_struct *task,
|
|
const struct cred *cred)
|
|
{
|
|
const struct task_struct *parent;
|
|
const struct cred *pcred;
|
|
u64 ret;
|
|
|
|
rcu_read_lock();
|
|
for (;;) {
|
|
parent = rcu_dereference(task->real_parent);
|
|
pcred = rcu_dereference(parent->cred);
|
|
if (parent == task || cred_fscmp(pcred, cred) != 0)
|
|
break;
|
|
task = parent;
|
|
}
|
|
ret = task->start_time;
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block)
|
|
{
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
u64 login_time = nfs_access_login_time(current, cred);
|
|
struct nfs_access_entry *cache;
|
|
bool retry = true;
|
|
int err;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
for(;;) {
|
|
if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
|
|
goto out_zap;
|
|
cache = nfs_access_search_rbtree(inode, cred);
|
|
err = -ENOENT;
|
|
if (cache == NULL)
|
|
goto out;
|
|
/* Found an entry, is our attribute cache valid? */
|
|
if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
|
|
break;
|
|
if (!retry)
|
|
break;
|
|
err = -ECHILD;
|
|
if (!may_block)
|
|
goto out;
|
|
spin_unlock(&inode->i_lock);
|
|
err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
|
|
if (err)
|
|
return err;
|
|
spin_lock(&inode->i_lock);
|
|
retry = false;
|
|
}
|
|
err = -ENOENT;
|
|
if ((s64)(login_time - cache->timestamp) > 0)
|
|
goto out;
|
|
*mask = cache->mask;
|
|
list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
|
|
err = 0;
|
|
out:
|
|
spin_unlock(&inode->i_lock);
|
|
return err;
|
|
out_zap:
|
|
spin_unlock(&inode->i_lock);
|
|
nfs_access_zap_cache(inode);
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, u32 *mask)
|
|
{
|
|
/* Only check the most recently returned cache entry,
|
|
* but do it without locking.
|
|
*/
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
u64 login_time = nfs_access_login_time(current, cred);
|
|
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(list_tail_rcu(&nfsi->access_cache_entry_lru));
|
|
cache = list_entry(lh, struct nfs_access_entry, lru);
|
|
if (lh == &nfsi->access_cache_entry_lru ||
|
|
access_cmp(cred, cache) != 0)
|
|
cache = NULL;
|
|
if (cache == NULL)
|
|
goto out;
|
|
if ((s64)(login_time - cache->timestamp) > 0)
|
|
goto out;
|
|
if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
|
|
goto out;
|
|
*mask = cache->mask;
|
|
err = 0;
|
|
out:
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
|
|
int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
|
|
u32 *mask, bool may_block)
|
|
{
|
|
int status;
|
|
|
|
status = nfs_access_get_cached_rcu(inode, cred, mask);
|
|
if (status != 0)
|
|
status = nfs_access_get_cached_locked(inode, cred, mask,
|
|
may_block);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_access_get_cached);
|
|
|
|
static void nfs_access_add_rbtree(struct inode *inode,
|
|
struct nfs_access_entry *set,
|
|
const struct cred *cred)
|
|
{
|
|
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;
|
|
int cmp;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
while (*p != NULL) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct nfs_access_entry, rb_node);
|
|
cmp = access_cmp(cred, entry);
|
|
|
|
if (cmp < 0)
|
|
p = &parent->rb_left;
|
|
else if (cmp > 0)
|
|
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,
|
|
const struct cred *cred)
|
|
{
|
|
struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
|
|
if (cache == NULL)
|
|
return;
|
|
RB_CLEAR_NODE(&cache->rb_node);
|
|
cache->fsuid = cred->fsuid;
|
|
cache->fsgid = cred->fsgid;
|
|
cache->group_info = get_group_info(cred->group_info);
|
|
cache->mask = set->mask;
|
|
cache->timestamp = ktime_get_ns();
|
|
|
|
/* 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, cred);
|
|
|
|
/* 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);
|
|
|
|
#define NFS_MAY_READ (NFS_ACCESS_READ)
|
|
#define NFS_MAY_WRITE (NFS_ACCESS_MODIFY | \
|
|
NFS_ACCESS_EXTEND | \
|
|
NFS_ACCESS_DELETE)
|
|
#define NFS_FILE_MAY_WRITE (NFS_ACCESS_MODIFY | \
|
|
NFS_ACCESS_EXTEND)
|
|
#define NFS_DIR_MAY_WRITE NFS_MAY_WRITE
|
|
#define NFS_MAY_LOOKUP (NFS_ACCESS_LOOKUP)
|
|
#define NFS_MAY_EXECUTE (NFS_ACCESS_EXECUTE)
|
|
static int
|
|
nfs_access_calc_mask(u32 access_result, umode_t umode)
|
|
{
|
|
int mask = 0;
|
|
|
|
if (access_result & NFS_MAY_READ)
|
|
mask |= MAY_READ;
|
|
if (S_ISDIR(umode)) {
|
|
if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE)
|
|
mask |= MAY_WRITE;
|
|
if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP)
|
|
mask |= MAY_EXEC;
|
|
} else if (S_ISREG(umode)) {
|
|
if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE)
|
|
mask |= MAY_WRITE;
|
|
if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE)
|
|
mask |= MAY_EXEC;
|
|
} else if (access_result & NFS_MAY_WRITE)
|
|
mask |= MAY_WRITE;
|
|
return mask;
|
|
}
|
|
|
|
void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
|
|
{
|
|
entry->mask = access_result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_access_set_mask);
|
|
|
|
static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
|
|
{
|
|
struct nfs_access_entry cache;
|
|
bool may_block = (mask & MAY_NOT_BLOCK) == 0;
|
|
int cache_mask = -1;
|
|
int status;
|
|
|
|
trace_nfs_access_enter(inode);
|
|
|
|
status = nfs_access_get_cached(inode, cred, &cache.mask, may_block);
|
|
if (status == 0)
|
|
goto out_cached;
|
|
|
|
status = -ECHILD;
|
|
if (!may_block)
|
|
goto out;
|
|
|
|
/*
|
|
* Determine which access bits we want to ask for...
|
|
*/
|
|
cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND |
|
|
nfs_access_xattr_mask(NFS_SERVER(inode));
|
|
if (S_ISDIR(inode->i_mode))
|
|
cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
|
|
else
|
|
cache.mask |= NFS_ACCESS_EXECUTE;
|
|
status = NFS_PROTO(inode)->access(inode, &cache, cred);
|
|
if (status != 0) {
|
|
if (status == -ESTALE) {
|
|
if (!S_ISDIR(inode->i_mode))
|
|
nfs_set_inode_stale(inode);
|
|
else
|
|
nfs_zap_caches(inode);
|
|
}
|
|
goto out;
|
|
}
|
|
nfs_access_add_cache(inode, &cache, cred);
|
|
out_cached:
|
|
cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
|
|
if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
|
|
status = -EACCES;
|
|
out:
|
|
trace_nfs_access_exit(inode, mask, cache_mask, 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, const struct cred *cred, int openflags)
|
|
{
|
|
return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_may_open);
|
|
|
|
static int nfs_execute_ok(struct inode *inode, int mask)
|
|
{
|
|
struct nfs_server *server = NFS_SERVER(inode);
|
|
int ret = 0;
|
|
|
|
if (S_ISDIR(inode->i_mode))
|
|
return 0;
|
|
if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_MODE)) {
|
|
if (mask & MAY_NOT_BLOCK)
|
|
return -ECHILD;
|
|
ret = __nfs_revalidate_inode(server, inode);
|
|
}
|
|
if (ret == 0 && !execute_ok(inode))
|
|
ret = -EACCES;
|
|
return ret;
|
|
}
|
|
|
|
int nfs_permission(struct mnt_idmap *idmap,
|
|
struct inode *inode,
|
|
int mask)
|
|
{
|
|
const struct cred *cred = current_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:
|
|
if ((mask & MAY_OPEN) &&
|
|
nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN))
|
|
return 0;
|
|
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;
|
|
|
|
res = nfs_do_access(inode, cred, mask);
|
|
out:
|
|
if (!res && (mask & MAY_EXEC))
|
|
res = nfs_execute_ok(inode, mask);
|
|
|
|
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(inode, NFS_INO_INVALID_MODE |
|
|
NFS_INO_INVALID_OTHER);
|
|
if (res == 0)
|
|
res = generic_permission(&nop_mnt_idmap, inode, mask);
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_permission);
|