404 lines
11 KiB
C
404 lines
11 KiB
C
/* AFS caching stuff
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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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include "internal.h"
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static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
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const void *buffer,
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uint16_t buflen);
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static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static enum fscache_checkaux afs_vlocation_cache_check_aux(
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void *cookie_netfs_data, const void *buffer, uint16_t buflen);
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static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
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uint64_t *size);
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static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t buflen);
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static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
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const void *buffer,
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uint16_t buflen);
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static void afs_vnode_cache_now_uncached(void *cookie_netfs_data);
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struct fscache_netfs afs_cache_netfs = {
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.name = "afs",
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.version = 0,
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};
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struct fscache_cookie_def afs_cell_cache_index_def = {
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.name = "AFS.cell",
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.type = FSCACHE_COOKIE_TYPE_INDEX,
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.get_key = afs_cell_cache_get_key,
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.get_aux = afs_cell_cache_get_aux,
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.check_aux = afs_cell_cache_check_aux,
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};
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struct fscache_cookie_def afs_vlocation_cache_index_def = {
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.name = "AFS.vldb",
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.type = FSCACHE_COOKIE_TYPE_INDEX,
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.get_key = afs_vlocation_cache_get_key,
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.get_aux = afs_vlocation_cache_get_aux,
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.check_aux = afs_vlocation_cache_check_aux,
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};
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struct fscache_cookie_def afs_volume_cache_index_def = {
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.name = "AFS.volume",
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.type = FSCACHE_COOKIE_TYPE_INDEX,
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.get_key = afs_volume_cache_get_key,
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};
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struct fscache_cookie_def afs_vnode_cache_index_def = {
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.name = "AFS.vnode",
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.type = FSCACHE_COOKIE_TYPE_DATAFILE,
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.get_key = afs_vnode_cache_get_key,
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.get_attr = afs_vnode_cache_get_attr,
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.get_aux = afs_vnode_cache_get_aux,
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.check_aux = afs_vnode_cache_check_aux,
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.now_uncached = afs_vnode_cache_now_uncached,
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};
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/*
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* set the key for the index entry
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*/
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static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_cell *cell = cookie_netfs_data;
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uint16_t klen;
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_enter("%p,%p,%u", cell, buffer, bufmax);
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klen = strlen(cell->name);
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if (klen > bufmax)
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return 0;
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memcpy(buffer, cell->name, klen);
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return klen;
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}
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/*
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* provide new auxilliary cache data
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*/
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static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_cell *cell = cookie_netfs_data;
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uint16_t dlen;
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_enter("%p,%p,%u", cell, buffer, bufmax);
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dlen = cell->vl_naddrs * sizeof(cell->vl_addrs[0]);
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dlen = min(dlen, bufmax);
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dlen &= ~(sizeof(cell->vl_addrs[0]) - 1);
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memcpy(buffer, cell->vl_addrs, dlen);
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return dlen;
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}
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/*
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* check that the auxilliary data indicates that the entry is still valid
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*/
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static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
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const void *buffer,
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uint16_t buflen)
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{
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_leave(" = OKAY");
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return FSCACHE_CHECKAUX_OKAY;
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}
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/*****************************************************************************/
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/*
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* set the key for the index entry
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*/
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static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_vlocation *vlocation = cookie_netfs_data;
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uint16_t klen;
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_enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
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klen = strnlen(vlocation->vldb.name, sizeof(vlocation->vldb.name));
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if (klen > bufmax)
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return 0;
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memcpy(buffer, vlocation->vldb.name, klen);
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_leave(" = %u", klen);
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return klen;
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}
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/*
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* provide new auxilliary cache data
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*/
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static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_vlocation *vlocation = cookie_netfs_data;
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uint16_t dlen;
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_enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
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dlen = sizeof(struct afs_cache_vlocation);
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dlen -= offsetof(struct afs_cache_vlocation, nservers);
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if (dlen > bufmax)
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return 0;
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memcpy(buffer, (uint8_t *)&vlocation->vldb.nservers, dlen);
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_leave(" = %u", dlen);
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return dlen;
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}
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/*
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* check that the auxilliary data indicates that the entry is still valid
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*/
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static
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enum fscache_checkaux afs_vlocation_cache_check_aux(void *cookie_netfs_data,
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const void *buffer,
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uint16_t buflen)
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{
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const struct afs_cache_vlocation *cvldb;
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struct afs_vlocation *vlocation = cookie_netfs_data;
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uint16_t dlen;
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_enter("{%s},%p,%u", vlocation->vldb.name, buffer, buflen);
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/* check the size of the data is what we're expecting */
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dlen = sizeof(struct afs_cache_vlocation);
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dlen -= offsetof(struct afs_cache_vlocation, nservers);
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if (dlen != buflen)
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return FSCACHE_CHECKAUX_OBSOLETE;
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cvldb = container_of(buffer, struct afs_cache_vlocation, nservers);
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/* if what's on disk is more valid than what's in memory, then use the
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* VL record from the cache */
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if (!vlocation->valid || vlocation->vldb.rtime == cvldb->rtime) {
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memcpy((uint8_t *)&vlocation->vldb.nservers, buffer, dlen);
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vlocation->valid = 1;
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_leave(" = SUCCESS [c->m]");
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return FSCACHE_CHECKAUX_OKAY;
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}
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/* need to update the cache if the cached info differs */
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if (memcmp(&vlocation->vldb, buffer, dlen) != 0) {
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/* delete if the volume IDs for this name differ */
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if (memcmp(&vlocation->vldb.vid, &cvldb->vid,
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sizeof(cvldb->vid)) != 0
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) {
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_leave(" = OBSOLETE");
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return FSCACHE_CHECKAUX_OBSOLETE;
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}
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_leave(" = UPDATE");
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return FSCACHE_CHECKAUX_NEEDS_UPDATE;
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}
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_leave(" = OKAY");
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return FSCACHE_CHECKAUX_OKAY;
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}
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/*****************************************************************************/
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/*
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* set the key for the volume index entry
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*/
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static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_volume *volume = cookie_netfs_data;
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uint16_t klen;
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_enter("{%u},%p,%u", volume->type, buffer, bufmax);
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klen = sizeof(volume->type);
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if (klen > bufmax)
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return 0;
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memcpy(buffer, &volume->type, sizeof(volume->type));
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_leave(" = %u", klen);
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return klen;
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}
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/*****************************************************************************/
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/*
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* set the key for the index entry
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*/
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static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_vnode *vnode = cookie_netfs_data;
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uint16_t klen;
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_enter("{%x,%x,%llx},%p,%u",
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vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
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buffer, bufmax);
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klen = sizeof(vnode->fid.vnode);
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if (klen > bufmax)
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return 0;
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memcpy(buffer, &vnode->fid.vnode, sizeof(vnode->fid.vnode));
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_leave(" = %u", klen);
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return klen;
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}
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/*
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* provide updated file attributes
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*/
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static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
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uint64_t *size)
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{
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const struct afs_vnode *vnode = cookie_netfs_data;
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_enter("{%x,%x,%llx},",
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vnode->fid.vnode, vnode->fid.unique,
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vnode->status.data_version);
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*size = vnode->status.size;
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}
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/*
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* provide new auxilliary cache data
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*/
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static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
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void *buffer, uint16_t bufmax)
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{
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const struct afs_vnode *vnode = cookie_netfs_data;
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uint16_t dlen;
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_enter("{%x,%x,%Lx},%p,%u",
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vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
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buffer, bufmax);
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dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
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if (dlen > bufmax)
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return 0;
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memcpy(buffer, &vnode->fid.unique, sizeof(vnode->fid.unique));
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buffer += sizeof(vnode->fid.unique);
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memcpy(buffer, &vnode->status.data_version,
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sizeof(vnode->status.data_version));
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_leave(" = %u", dlen);
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return dlen;
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}
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/*
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* check that the auxilliary data indicates that the entry is still valid
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*/
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static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
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const void *buffer,
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uint16_t buflen)
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{
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struct afs_vnode *vnode = cookie_netfs_data;
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uint16_t dlen;
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_enter("{%x,%x,%llx},%p,%u",
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vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
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buffer, buflen);
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/* check the size of the data is what we're expecting */
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dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
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if (dlen != buflen) {
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_leave(" = OBSOLETE [len %hx != %hx]", dlen, buflen);
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return FSCACHE_CHECKAUX_OBSOLETE;
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}
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if (memcmp(buffer,
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&vnode->fid.unique,
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sizeof(vnode->fid.unique)
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) != 0) {
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unsigned unique;
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memcpy(&unique, buffer, sizeof(unique));
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_leave(" = OBSOLETE [uniq %x != %x]",
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unique, vnode->fid.unique);
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return FSCACHE_CHECKAUX_OBSOLETE;
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}
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if (memcmp(buffer + sizeof(vnode->fid.unique),
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&vnode->status.data_version,
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sizeof(vnode->status.data_version)
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) != 0) {
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afs_dataversion_t version;
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memcpy(&version, buffer + sizeof(vnode->fid.unique),
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sizeof(version));
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_leave(" = OBSOLETE [vers %llx != %llx]",
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version, vnode->status.data_version);
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return FSCACHE_CHECKAUX_OBSOLETE;
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}
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_leave(" = SUCCESS");
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return FSCACHE_CHECKAUX_OKAY;
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}
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/*
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* indication the cookie is no longer uncached
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* - this function is called when the backing store currently caching a cookie
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* is removed
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* - the netfs should use this to clean up any markers indicating cached pages
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* - this is mandatory for any object that may have data
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*/
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static void afs_vnode_cache_now_uncached(void *cookie_netfs_data)
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{
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struct afs_vnode *vnode = cookie_netfs_data;
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struct pagevec pvec;
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pgoff_t first;
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int loop, nr_pages;
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_enter("{%x,%x,%Lx}",
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vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version);
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pagevec_init(&pvec, 0);
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first = 0;
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for (;;) {
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/* grab a bunch of pages to clean */
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nr_pages = pagevec_lookup(&pvec, vnode->vfs_inode.i_mapping,
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first,
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PAGEVEC_SIZE - pagevec_count(&pvec));
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if (!nr_pages)
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break;
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for (loop = 0; loop < nr_pages; loop++)
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ClearPageFsCache(pvec.pages[loop]);
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first = pvec.pages[nr_pages - 1]->index + 1;
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pvec.nr = nr_pages;
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pagevec_release(&pvec);
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cond_resched();
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}
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_leave("");
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}
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