v4.19.13 snapshot.
diff --git a/fs/afs/cache.c b/fs/afs/cache.c
new file mode 100644
index 0000000..b1c31ec
--- /dev/null
+++ b/fs/afs/cache.c
@@ -0,0 +1,72 @@
+/* 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 enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
+ const void *buffer,
+ uint16_t buflen,
+ loff_t object_size);
+
+struct fscache_netfs afs_cache_netfs = {
+ .name = "afs",
+ .version = 2,
+};
+
+struct fscache_cookie_def afs_cell_cache_index_def = {
+ .name = "AFS.cell",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+struct fscache_cookie_def afs_volume_cache_index_def = {
+ .name = "AFS.volume",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+struct fscache_cookie_def afs_vnode_cache_index_def = {
+ .name = "AFS.vnode",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .check_aux = afs_vnode_cache_check_aux,
+};
+
+/*
+ * 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,
+ loff_t object_size)
+{
+ struct afs_vnode *vnode = cookie_netfs_data;
+ struct afs_vnode_cache_aux aux;
+
+ _enter("{%x,%x,%llx},%p,%u",
+ vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
+ buffer, buflen);
+
+ memcpy(&aux, buffer, sizeof(aux));
+
+ /* check the size of the data is what we're expecting */
+ if (buflen != sizeof(aux)) {
+ _leave(" = OBSOLETE [len %hx != %zx]", buflen, sizeof(aux));
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ if (vnode->status.data_version != aux.data_version) {
+ _leave(" = OBSOLETE [vers %llx != %llx]",
+ aux.data_version, vnode->status.data_version);
+ return FSCACHE_CHECKAUX_OBSOLETE;
+ }
+
+ _leave(" = SUCCESS");
+ return FSCACHE_CHECKAUX_OKAY;
+}