This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / fs / fscache / fsdef.c

diff --git a/fs/fscache/fsdef.c b/fs/fscache/fsdef.c
new file mode 100644 (file)
index 0000000..495f633
--- /dev/null
+++ b/fs/fscache/fsdef.c
@@ -0,0 +1,110 @@
+/* fsdef.c: filesystem index definition
+ *
+ * Copyright (C) 2004 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/module.h>
+#include "fscache-int.h"
+
+static uint16_t fscache_fsdef_netfs_get_key(const void *cookie_netfs_data,
+                                           void *buffer, uint16_t bufmax);
+
+static uint16_t fscache_fsdef_netfs_get_aux(const void *cookie_netfs_data,
+                                           void *buffer, uint16_t bufmax);
+
+static fscache_checkaux_t fscache_fsdef_netfs_check_aux(void *cookie_netfs_data,
+                                                       const void *data,
+                                                       uint16_t datalen);
+
+struct fscache_cookie_def fscache_fsdef_netfs_def = {
+       .name           = "FSDEF.netfs",
+       .type           = FSCACHE_COOKIE_TYPE_INDEX,
+       .get_key        = fscache_fsdef_netfs_get_key,
+       .get_aux        = fscache_fsdef_netfs_get_aux,
+       .check_aux      = fscache_fsdef_netfs_check_aux,
+};
+
+struct fscache_cookie fscache_fsdef_index = {
+       .usage          = ATOMIC_INIT(1),
+       .def            = NULL,
+       .sem            = __RWSEM_INITIALIZER(fscache_fsdef_index.sem),
+       .backing_objects = HLIST_HEAD_INIT,
+};
+
+EXPORT_SYMBOL(fscache_fsdef_index);
+
+/*****************************************************************************/
+/*
+ * get the key data for an FSDEF index record
+ */
+static uint16_t fscache_fsdef_netfs_get_key(const void *cookie_netfs_data,
+                                           void *buffer, uint16_t bufmax)
+{
+       const struct fscache_netfs *netfs = cookie_netfs_data;
+       unsigned klen;
+
+       _enter("{%s.%u},", netfs->name, netfs->version);
+
+       klen = strlen(netfs->name);
+       if (klen > bufmax)
+               return 0;
+
+       memcpy(buffer, netfs->name, klen);
+       return klen;
+}
+
+/*****************************************************************************/
+/*
+ * get the auxilliary data for an FSDEF index record
+ */
+static uint16_t fscache_fsdef_netfs_get_aux(const void *cookie_netfs_data,
+                                           void *buffer, uint16_t bufmax)
+{
+       const struct fscache_netfs *netfs = cookie_netfs_data;
+       unsigned dlen;
+
+       _enter("{%s.%u},", netfs->name, netfs->version);
+
+       dlen = sizeof(uint32_t);
+       if (dlen > bufmax)
+               return 0;
+
+       memcpy(buffer, &netfs->version, dlen);
+       return dlen;
+}
+
+/*****************************************************************************/
+/*
+ * check that the version stored in the auxilliary data is correct
+ */
+static fscache_checkaux_t fscache_fsdef_netfs_check_aux(void *cookie_netfs_data,
+                                                       const void *data,
+                                                       uint16_t datalen)
+{
+       struct fscache_netfs *netfs = cookie_netfs_data;
+       uint32_t version;
+
+       _enter("{%s},,%hu", netfs->name, datalen);
+
+       if (datalen != sizeof(version)) {
+               _leave(" = OBSOLETE [dl=%d v=%d]",
+                      datalen, sizeof(version));
+               return FSCACHE_CHECKAUX_OBSOLETE;
+       }
+
+       memcpy(&version, data, sizeof(version));
+       if (version != netfs->version) {
+               _leave(" = OBSOLETE [ver=%x net=%x]",
+                      version, netfs->version);
+               return FSCACHE_CHECKAUX_OBSOLETE;
+       }
+
+       _leave(" = OKAY");
+       return FSCACHE_CHECKAUX_OKAY;
+}