1/*
  2 *   fs/cifs/cache.c - CIFS filesystem cache index structure definitions
  3 *
  4 *   Copyright (c) 2010 Novell, Inc.
  5 *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
  6 *
  7 *   This library is free software; you can redistribute it and/or modify
  8 *   it under the terms of the GNU Lesser General Public License as published
  9 *   by the Free Software Foundation; either version 2.1 of the License, or
 10 *   (at your option) any later version.
 11 *
 12 *   This library is distributed in the hope that it will be useful,
 13 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 15 *   the GNU Lesser General Public License for more details.
 16 *
 17 *   You should have received a copy of the GNU Lesser General Public License
 18 *   along with this library; if not, write to the Free Software
 19 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 20 */
 21#include "fscache.h"
 22#include "cifs_debug.h"
 23
 24/*
 25 * CIFS filesystem definition for FS-Cache
 26 */
 27struct fscache_netfs cifs_fscache_netfs = {
 28	.name = "cifs",
 29	.version = 0,
 30};
 31
 32/*
 33 * Register CIFS for caching with FS-Cache
 34 */
 35int cifs_fscache_register(void)
 36{
 37	return fscache_register_netfs(&cifs_fscache_netfs);
 38}
 39
 40/*
 41 * Unregister CIFS for caching
 42 */
 43void cifs_fscache_unregister(void)
 44{
 45	fscache_unregister_netfs(&cifs_fscache_netfs);
 46}
 47
 48/*
 49 * Server object for FS-Cache
 50 */
 51const struct fscache_cookie_def cifs_fscache_server_index_def = {
 52	.name = "CIFS.server",
 53	.type = FSCACHE_COOKIE_TYPE_INDEX,
 54};
 55
 56/*
 57 * Auxiliary data attached to CIFS superblock within the cache
 58 */
 59struct cifs_fscache_super_auxdata {
 60	u64	resource_id;		/* unique server resource id */
 61};
 62
 63char *extract_sharename(const char *treename)
 64{
 65	const char *src;
 66	char *delim, *dst;
 67	int len;
 68
 69	/* skip double chars at the beginning */
 70	src = treename + 2;
 71
 72	/* share name is always preceded by '\\' now */
 73	delim = strchr(src, '\\');
 74	if (!delim)
 75		return ERR_PTR(-EINVAL);
 76	delim++;
 77	len = strlen(delim);
 78
 79	/* caller has to free the memory */
 80	dst = kstrndup(delim, len, GFP_KERNEL);
 81	if (!dst)
 82		return ERR_PTR(-ENOMEM);
 83
 84	return dst;
 85}
 86
 87static enum
 88fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
 89					      const void *data,
 90					      uint16_t datalen,
 91					      loff_t object_size)
 92{
 93	struct cifs_fscache_super_auxdata auxdata;
 94	const struct cifs_tcon *tcon = cookie_netfs_data;
 95
 96	if (datalen != sizeof(auxdata))
 97		return FSCACHE_CHECKAUX_OBSOLETE;
 98
 99	memset(&auxdata, 0, sizeof(auxdata));
100	auxdata.resource_id = tcon->resource_id;
101
102	if (memcmp(data, &auxdata, datalen) != 0)
103		return FSCACHE_CHECKAUX_OBSOLETE;
104
105	return FSCACHE_CHECKAUX_OKAY;
106}
107
108/*
109 * Superblock object for FS-Cache
110 */
111const struct fscache_cookie_def cifs_fscache_super_index_def = {
112	.name = "CIFS.super",
113	.type = FSCACHE_COOKIE_TYPE_INDEX,
114	.check_aux = cifs_fscache_super_check_aux,
115};
116
117static enum
118fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
119					      const void *data,
120					      uint16_t datalen,
121					      loff_t object_size)
122{
123	struct cifs_fscache_inode_auxdata auxdata;
124	struct cifsInodeInfo *cifsi = cookie_netfs_data;
125
126	if (datalen != sizeof(auxdata))
127		return FSCACHE_CHECKAUX_OBSOLETE;
128
129	memset(&auxdata, 0, sizeof(auxdata));
130	auxdata.eof = cifsi->server_eof;
131	auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
132	auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
133
134	if (memcmp(data, &auxdata, datalen) != 0)
135		return FSCACHE_CHECKAUX_OBSOLETE;
136
137	return FSCACHE_CHECKAUX_OKAY;
138}
139
140const struct fscache_cookie_def cifs_fscache_inode_object_def = {
141	.name		= "CIFS.uniqueid",
142	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
143	.check_aux	= cifs_fscache_inode_check_aux,
144};