linux_dsm_epyc7002/fs/nfs/fscache-index.c
Arnd Bergmann 6e31ded689 nfs: fscache: use timespec64 in inode auxdata
nfs currently behaves differently on 32-bit and 64-bit kernels regarding
the on-disk format of nfs_fscache_inode_auxdata.

That format should really be the same on any kernel, and we should avoid
the 'timespec' type in order to remove that from the kernel later on.

Using plain 'timespec64' would not be good here, since that includes
implied padding and would possibly leak kernel stack data to the on-disk
format on 32-bit architectures.

struct __kernel_timespec would work as a replacement, but open-coding
the two struct members in nfs_fscache_inode_auxdata makes it more
obvious what's going on here, and keeps the current format for 64-bit
architectures.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-18 18:07:33 +01:00

141 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* NFS FS-Cache index structure definition
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/in6.h>
#include <linux/iversion.h>
#include "internal.h"
#include "fscache.h"
#define NFSDBG_FACILITY NFSDBG_FSCACHE
/*
* Define the NFS filesystem for FS-Cache. Upon registration FS-Cache sticks
* the cookie for the top-level index object for NFS into here. The top-level
* index can than have other cache objects inserted into it.
*/
struct fscache_netfs nfs_fscache_netfs = {
.name = "nfs",
.version = 0,
};
/*
* Register NFS for caching
*/
int nfs_fscache_register(void)
{
return fscache_register_netfs(&nfs_fscache_netfs);
}
/*
* Unregister NFS for caching
*/
void nfs_fscache_unregister(void)
{
fscache_unregister_netfs(&nfs_fscache_netfs);
}
/*
* Define the server object for FS-Cache. This is used to describe a server
* object to fscache_acquire_cookie(). It is keyed by the NFS protocol and
* server address parameters.
*/
const struct fscache_cookie_def nfs_fscache_server_index_def = {
.name = "NFS.server",
.type = FSCACHE_COOKIE_TYPE_INDEX,
};
/*
* Define the superblock object for FS-Cache. This is used to describe a
* superblock object to fscache_acquire_cookie(). It is keyed by all the NFS
* parameters that might cause a separate superblock.
*/
const struct fscache_cookie_def nfs_fscache_super_index_def = {
.name = "NFS.super",
.type = FSCACHE_COOKIE_TYPE_INDEX,
};
/*
* Consult the netfs about the state of an object
* - This function can be absent if the index carries no state data
* - The netfs data from the cookie being used as the target is
* presented, as is the auxiliary data
*/
static
enum fscache_checkaux nfs_fscache_inode_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size)
{
struct nfs_fscache_inode_auxdata auxdata;
struct nfs_inode *nfsi = cookie_netfs_data;
if (datalen != sizeof(auxdata))
return FSCACHE_CHECKAUX_OBSOLETE;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec;
auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
auxdata.ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec;
auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
if (memcmp(data, &auxdata, datalen) != 0)
return FSCACHE_CHECKAUX_OBSOLETE;
return FSCACHE_CHECKAUX_OKAY;
}
/*
* Get an extra reference on a read context.
* - This function can be absent if the completion function doesn't require a
* context.
* - The read context is passed back to NFS in the event that a data read on the
* cache fails with EIO - in which case the server must be contacted to
* retrieve the data, which requires the read context for security.
*/
static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
{
get_nfs_open_context(context);
}
/*
* Release an extra reference on a read context.
* - This function can be absent if the completion function doesn't require a
* context.
*/
static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
{
if (context)
put_nfs_open_context(context);
}
/*
* Define the inode object for FS-Cache. This is used to describe an inode
* object to fscache_acquire_cookie(). It is keyed by the NFS file handle for
* an inode.
*
* Coherency is managed by comparing the copies of i_size, i_mtime and i_ctime
* held in the cache auxiliary data for the data storage object with those in
* the inode struct in memory.
*/
const struct fscache_cookie_def nfs_fscache_inode_object_def = {
.name = "NFS.fh",
.type = FSCACHE_COOKIE_TYPE_DATAFILE,
.check_aux = nfs_fscache_inode_check_aux,
.get_context = nfs_fh_get_context,
.put_context = nfs_fh_put_context,
};