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-rw-r--r--fs/afs/cache.c402
1 files changed, 402 insertions, 0 deletions
diff --git a/fs/afs/cache.c b/fs/afs/cache.c
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index 00000000..577763c3
--- /dev/null
+++ b/fs/afs/cache.c
@@ -0,0 +1,402 @@
+/* AFS caching stuff
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include "internal.h"
+
+static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen);
+
+static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_vlocation_cache_check_aux(
+ void *cookie_netfs_data, const void *buffer, uint16_t buflen);
+
+static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+
+static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
+ uint64_t *size);
+static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t buflen);
+static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen);
+static void afs_vnode_cache_now_uncached(void *cookie_netfs_data);
+
+struct fscache_netfs afs_cache_netfs = {
+ .name = "afs",
+ .version = 0,
+};
+
+struct fscache_cookie_def afs_cell_cache_index_def = {
+ .name = "AFS.cell",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_cell_cache_get_key,
+ .get_aux = afs_cell_cache_get_aux,
+ .check_aux = afs_cell_cache_check_aux,
+};
+
+struct fscache_cookie_def afs_vlocation_cache_index_def = {
+ .name = "AFS.vldb",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_vlocation_cache_get_key,
+ .get_aux = afs_vlocation_cache_get_aux,
+ .check_aux = afs_vlocation_cache_check_aux,
+};
+
+struct fscache_cookie_def afs_volume_cache_index_def = {
+ .name = "AFS.volume",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = afs_volume_cache_get_key,
+};
+
+struct fscache_cookie_def afs_vnode_cache_index_def = {
+ .name = "AFS.vnode",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .get_key = afs_vnode_cache_get_key,
+ .get_attr = afs_vnode_cache_get_attr,
+ .get_aux = afs_vnode_cache_get_aux,
+ .check_aux = afs_vnode_cache_check_aux,
+ .now_uncached = afs_vnode_cache_now_uncached,
+};
+
+/*
+ * set the key for the index entry
+ */
+static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_cell *cell = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("%p,%p,%u", cell, buffer, bufmax);
+
+ klen = strlen(cell->name);
+ if (klen > bufmax)
+ return 0;
+
+ memcpy(buffer, cell->name, klen);
+ return klen;
+}
+
+/*
+ * provide new auxiliary cache data
+ */
+static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_cell *cell = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("%p,%p,%u", cell, buffer, bufmax);
+
+ dlen = cell->vl_naddrs * sizeof(cell->vl_addrs[0]);
+ dlen = min(dlen, bufmax);
+ dlen &= ~(sizeof(cell->vl_addrs[0]) - 1);
+
+ memcpy(buffer, cell->vl_addrs, dlen);
+ return dlen;
+}
+
+/*
+ * check that the auxiliary data indicates that the entry is still valid
+ */
+static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
+{
+ _leave(" = OKAY");
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*****************************************************************************/
+/*
+ * set the key for the index entry
+ */
+static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
+
+ klen = strnlen(vlocation->vldb.name, sizeof(vlocation->vldb.name));
+ if (klen > bufmax)
+ return 0;
+
+ memcpy(buffer, vlocation->vldb.name, klen);
+
+ _leave(" = %u", klen);
+ return klen;
+}
+
+/*
+ * provide new auxiliary cache data
+ */
+static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);
+
+ dlen = sizeof(struct afs_cache_vlocation);
+ dlen -= offsetof(struct afs_cache_vlocation, nservers);
+ if (dlen > bufmax)
+ return 0;
+
+ memcpy(buffer, (uint8_t *)&vlocation->vldb.nservers, dlen);
+
+ _leave(" = %u", dlen);
+ return dlen;
+}
+
+/*
+ * check that the auxiliary data indicates that the entry is still valid
+ */
+static
+enum fscache_checkaux afs_vlocation_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
+{
+ const struct afs_cache_vlocation *cvldb;
+ struct afs_vlocation *vlocation = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%s},%p,%u", vlocation->vldb.name, buffer, buflen);
+
+ /* check the size of the data is what we're expecting */
+ dlen = sizeof(struct afs_cache_vlocation);
+ dlen -= offsetof(struct afs_cache_vlocation, nservers);
+ if (dlen != buflen)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ cvldb = container_of(buffer, struct afs_cache_vlocation, nservers);
+
+ /* if what's on disk is more valid than what's in memory, then use the
+ * VL record from the cache */
+ if (!vlocation->valid || vlocation->vldb.rtime == cvldb->rtime) {
+ memcpy((uint8_t *)&vlocation->vldb.nservers, buffer, dlen);
+ vlocation->valid = 1;
+ _leave(" = SUCCESS [c->m]");
+ return FSCACHE_CHECKAUX_OKAY;
+ }
+
+ /* need to update the cache if the cached info differs */
+ if (memcmp(&vlocation->vldb, buffer, dlen) != 0) {
+ /* delete if the volume IDs for this name differ */
+ if (memcmp(&vlocation->vldb.vid, &cvldb->vid,
+ sizeof(cvldb->vid)) != 0
+ ) {
+ _leave(" = OBSOLETE");
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ _leave(" = UPDATE");
+ return FSCACHE_CHECKAUX_NEEDS_UPDATE;
+ }
+
+ _leave(" = OKAY");
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*****************************************************************************/
+/*
+ * set the key for the volume index entry
+ */
+static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_volume *volume = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("{%u},%p,%u", volume->type, buffer, bufmax);
+
+ klen = sizeof(volume->type);
+ if (klen > bufmax)
+ return 0;
+
+ memcpy(buffer, &volume->type, sizeof(volume->type));
+
+ _leave(" = %u", klen);
+ return klen;
+
+}
+
+/*****************************************************************************/
+/*
+ * set the key for the index entry
+ */
+static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t klen;
+
+ _enter("{%x,%x,%llx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, bufmax);
+
+ klen = sizeof(vnode->fid.vnode);
+ if (klen > bufmax)
+ return 0;
+
+ memcpy(buffer, &vnode->fid.vnode, sizeof(vnode->fid.vnode));
+
+ _leave(" = %u", klen);
+ return klen;
+}
+
+/*
+ * provide updated file attributes
+ */
+static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
+ uint64_t *size)
+{
+ const struct afs_vnode *vnode = cookie_netfs_data;
+
+ _enter("{%x,%x,%llx},",
+ vnode->fid.vnode, vnode->fid.unique,
+ vnode->status.data_version);
+
+ *size = vnode->status.size;
+}
+
+/*
+ * provide new auxiliary cache data
+ */
+static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
+ void *buffer, uint16_t bufmax)
+{
+ const struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%x,%x,%Lx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, bufmax);
+
+ dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
+ if (dlen > bufmax)
+ return 0;
+
+ memcpy(buffer, &vnode->fid.unique, sizeof(vnode->fid.unique));
+ buffer += sizeof(vnode->fid.unique);
+ memcpy(buffer, &vnode->status.data_version,
+ sizeof(vnode->status.data_version));
+
+ _leave(" = %u", dlen);
+ return dlen;
+}
+
+/*
+ * check that the auxiliary data indicates that the entry is still valid
+ */
+static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen)
+{
+ struct afs_vnode *vnode = cookie_netfs_data;
+ uint16_t dlen;
+
+ _enter("{%x,%x,%llx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, buflen);
+
+ /* check the size of the data is what we're expecting */
+ dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
+ if (dlen != buflen) {
+ _leave(" = OBSOLETE [len %hx != %hx]", dlen, buflen);
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ if (memcmp(buffer,
+ &vnode->fid.unique,
+ sizeof(vnode->fid.unique)
+ ) != 0) {
+ unsigned unique;
+
+ memcpy(&unique, buffer, sizeof(unique));
+
+ _leave(" = OBSOLETE [uniq %x != %x]",
+ unique, vnode->fid.unique);
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ if (memcmp(buffer + sizeof(vnode->fid.unique),
+ &vnode->status.data_version,
+ sizeof(vnode->status.data_version)
+ ) != 0) {
+ afs_dataversion_t version;
+
+ memcpy(&version, buffer + sizeof(vnode->fid.unique),
+ sizeof(version));
+
+ _leave(" = OBSOLETE [vers %llx != %llx]",
+ version, vnode->status.data_version);
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ _leave(" = SUCCESS");
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*
+ * indication the cookie is no longer uncached
+ * - this function is called when the backing store currently caching a cookie
+ * is removed
+ * - the netfs should use this to clean up any markers indicating cached pages
+ * - this is mandatory for any object that may have data
+ */
+static void afs_vnode_cache_now_uncached(void *cookie_netfs_data)
+{
+ struct afs_vnode *vnode = cookie_netfs_data;
+ struct pagevec pvec;
+ pgoff_t first;
+ int loop, nr_pages;
+
+ _enter("{%x,%x,%Lx}",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version);
+
+ pagevec_init(&pvec, 0);
+ first = 0;
+
+ for (;;) {
+ /* grab a bunch of pages to clean */
+ nr_pages = pagevec_lookup(&pvec, vnode->vfs_inode.i_mapping,
+ first,
+ PAGEVEC_SIZE - pagevec_count(&pvec));
+ if (!nr_pages)
+ break;
+
+ for (loop = 0; loop < nr_pages; loop++)
+ ClearPageFsCache(pvec.pages[loop]);
+
+ first = pvec.pages[nr_pages - 1]->index + 1;
+
+ pvec.nr = nr_pages;
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+
+ _leave("");
+}
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