LXR linux/fs/cifs/cache.c

   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
  56char *extract_sharename(const char *treename)
  57{
  58        const char *src;
  59        char *delim, *dst;
  60        int len;
  61
  62        /* skip double chars at the beginning */
  63        src = treename + 2;
  64
  65        /* share name is always preceded by '\\' now */
  66        delim = strchr(src, '\\');
  67        if (!delim)
  68                return ERR_PTR(-EINVAL);
  69        delim++;
  70        len = strlen(delim);
  71
  72        /* caller has to free the memory */
  73        dst = kstrndup(delim, len, GFP_KERNEL);
  74        if (!dst)
  75                return ERR_PTR(-ENOMEM);
  76
  77        return dst;
  78}
  79
  80static enum
  81fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
  82                                              const void *data,
  83                                              uint16_t datalen,
  84                                              loff_t object_size)
  85{
  86        struct cifs_fscache_super_auxdata auxdata;
  87        const struct cifs_tcon *tcon = cookie_netfs_data;
  88
  89        if (datalen != sizeof(auxdata))
  90                return FSCACHE_CHECKAUX_OBSOLETE;
  91
  92        memset(&auxdata, 0, sizeof(auxdata));
  93        auxdata.resource_id = tcon->resource_id;
  94        auxdata.vol_create_time = tcon->vol_create_time;
  95        auxdata.vol_serial_number = tcon->vol_serial_number;
  96
  97        if (memcmp(data, &auxdata, datalen) != 0)
  98                return FSCACHE_CHECKAUX_OBSOLETE;
  99
 100        return FSCACHE_CHECKAUX_OKAY;
 101}
 102
 103/*
 104 * Superblock object for FS-Cache
 105 */
 106const struct fscache_cookie_def cifs_fscache_super_index_def = {
 107        .name = "CIFS.super",
 108        .type = FSCACHE_COOKIE_TYPE_INDEX,
 109        .check_aux = cifs_fscache_super_check_aux,
 110};
 111
 112static enum
 113fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
 114                                              const void *data,
 115                                              uint16_t datalen,
 116                                              loff_t object_size)
 117{
 118        struct cifs_fscache_inode_auxdata auxdata;
 119        struct cifsInodeInfo *cifsi = cookie_netfs_data;
 120
 121        if (datalen != sizeof(auxdata))
 122                return FSCACHE_CHECKAUX_OBSOLETE;
 123
 124        memset(&auxdata, 0, sizeof(auxdata));
 125        auxdata.eof = cifsi->server_eof;
 126        auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
 127        auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
 128        auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
 129        auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
 130
 131        if (memcmp(data, &auxdata, datalen) != 0)
 132                return FSCACHE_CHECKAUX_OBSOLETE;
 133
 134        return FSCACHE_CHECKAUX_OKAY;
 135}
 136
 137const struct fscache_cookie_def cifs_fscache_inode_object_def = {
 138        .name           = "CIFS.uniqueid",
 139        .type           = FSCACHE_COOKIE_TYPE_DATAFILE,
 140        .check_aux      = cifs_fscache_inode_check_aux,
 141};
 142