139 строки
3.9 KiB
C
139 строки
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* NFS FS-Cache index structure definition
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*
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* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_fs_sb.h>
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#include <linux/in6.h>
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#include <linux/iversion.h>
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#include "internal.h"
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#include "fscache.h"
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#define NFSDBG_FACILITY NFSDBG_FSCACHE
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/*
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* Define the NFS filesystem for FS-Cache. Upon registration FS-Cache sticks
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* the cookie for the top-level index object for NFS into here. The top-level
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* index can than have other cache objects inserted into it.
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*/
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struct fscache_netfs nfs_fscache_netfs = {
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.name = "nfs",
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.version = 0,
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};
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/*
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* Register NFS for caching
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*/
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int nfs_fscache_register(void)
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{
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return fscache_register_netfs(&nfs_fscache_netfs);
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}
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/*
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* Unregister NFS for caching
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*/
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void nfs_fscache_unregister(void)
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{
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fscache_unregister_netfs(&nfs_fscache_netfs);
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}
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/*
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* Define the server object for FS-Cache. This is used to describe a server
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* object to fscache_acquire_cookie(). It is keyed by the NFS protocol and
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* server address parameters.
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*/
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const struct fscache_cookie_def nfs_fscache_server_index_def = {
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.name = "NFS.server",
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.type = FSCACHE_COOKIE_TYPE_INDEX,
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};
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/*
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* Define the superblock object for FS-Cache. This is used to describe a
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* superblock object to fscache_acquire_cookie(). It is keyed by all the NFS
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* parameters that might cause a separate superblock.
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*/
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const struct fscache_cookie_def nfs_fscache_super_index_def = {
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.name = "NFS.super",
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.type = FSCACHE_COOKIE_TYPE_INDEX,
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};
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/*
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* Consult the netfs about the state of an object
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* - This function can be absent if the index carries no state data
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* - The netfs data from the cookie being used as the target is
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* presented, as is the auxiliary data
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*/
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static
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enum fscache_checkaux nfs_fscache_inode_check_aux(void *cookie_netfs_data,
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const void *data,
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uint16_t datalen,
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loff_t object_size)
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{
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struct nfs_fscache_inode_auxdata auxdata;
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struct nfs_inode *nfsi = cookie_netfs_data;
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if (datalen != sizeof(auxdata))
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return FSCACHE_CHECKAUX_OBSOLETE;
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memset(&auxdata, 0, sizeof(auxdata));
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auxdata.mtime = timespec64_to_timespec(nfsi->vfs_inode.i_mtime);
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auxdata.ctime = timespec64_to_timespec(nfsi->vfs_inode.i_ctime);
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if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
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auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
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if (memcmp(data, &auxdata, datalen) != 0)
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return FSCACHE_CHECKAUX_OBSOLETE;
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return FSCACHE_CHECKAUX_OKAY;
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}
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/*
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* Get an extra reference on a read context.
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* - This function can be absent if the completion function doesn't require a
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* context.
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* - The read context is passed back to NFS in the event that a data read on the
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* cache fails with EIO - in which case the server must be contacted to
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* retrieve the data, which requires the read context for security.
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*/
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static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
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{
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get_nfs_open_context(context);
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}
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/*
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* Release an extra reference on a read context.
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* - This function can be absent if the completion function doesn't require a
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* context.
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*/
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static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
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{
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if (context)
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put_nfs_open_context(context);
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}
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/*
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* Define the inode object for FS-Cache. This is used to describe an inode
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* object to fscache_acquire_cookie(). It is keyed by the NFS file handle for
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* an inode.
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*
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* Coherency is managed by comparing the copies of i_size, i_mtime and i_ctime
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* held in the cache auxiliary data for the data storage object with those in
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* the inode struct in memory.
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*/
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const struct fscache_cookie_def nfs_fscache_inode_object_def = {
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.name = "NFS.fh",
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.type = FSCACHE_COOKIE_TYPE_DATAFILE,
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.check_aux = nfs_fscache_inode_check_aux,
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.get_context = nfs_fh_get_context,
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.put_context = nfs_fh_put_context,
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};
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