linux-stable/fs/cifs/cache.c
Arnd Bergmann cbedeadf9c cifs: use 64-bit timestamps for fscache
In the fscache, we just need the timestamps as cookies to check for
changes, so we don't really care about the overflow, but it's better
to stop using the deprecated timespec so we don't have to go through
explicit conversion functions.

To avoid comparing uninitialized padding values that are copied
while assigning the timespec values, this rearranges the members of
cifs_fscache_inode_auxdata to avoid padding, and assigns them
individually.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-08-07 14:15:41 -05:00

146 lines
3.8 KiB
C

/*
* fs/cifs/cache.c - CIFS filesystem cache index structure definitions
*
* Copyright (c) 2010 Novell, Inc.
* Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "fscache.h"
#include "cifs_debug.h"
/*
* CIFS filesystem definition for FS-Cache
*/
struct fscache_netfs cifs_fscache_netfs = {
.name = "cifs",
.version = 0,
};
/*
* Register CIFS for caching with FS-Cache
*/
int cifs_fscache_register(void)
{
return fscache_register_netfs(&cifs_fscache_netfs);
}
/*
* Unregister CIFS for caching
*/
void cifs_fscache_unregister(void)
{
fscache_unregister_netfs(&cifs_fscache_netfs);
}
/*
* Server object for FS-Cache
*/
const struct fscache_cookie_def cifs_fscache_server_index_def = {
.name = "CIFS.server",
.type = FSCACHE_COOKIE_TYPE_INDEX,
};
/*
* Auxiliary data attached to CIFS superblock within the cache
*/
struct cifs_fscache_super_auxdata {
u64 resource_id; /* unique server resource id */
};
char *extract_sharename(const char *treename)
{
const char *src;
char *delim, *dst;
int len;
/* skip double chars at the beginning */
src = treename + 2;
/* share name is always preceded by '\\' now */
delim = strchr(src, '\\');
if (!delim)
return ERR_PTR(-EINVAL);
delim++;
len = strlen(delim);
/* caller has to free the memory */
dst = kstrndup(delim, len, GFP_KERNEL);
if (!dst)
return ERR_PTR(-ENOMEM);
return dst;
}
static enum
fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size)
{
struct cifs_fscache_super_auxdata auxdata;
const struct cifs_tcon *tcon = cookie_netfs_data;
if (datalen != sizeof(auxdata))
return FSCACHE_CHECKAUX_OBSOLETE;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.resource_id = tcon->resource_id;
if (memcmp(data, &auxdata, datalen) != 0)
return FSCACHE_CHECKAUX_OBSOLETE;
return FSCACHE_CHECKAUX_OKAY;
}
/*
* Superblock object for FS-Cache
*/
const struct fscache_cookie_def cifs_fscache_super_index_def = {
.name = "CIFS.super",
.type = FSCACHE_COOKIE_TYPE_INDEX,
.check_aux = cifs_fscache_super_check_aux,
};
static enum
fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size)
{
struct cifs_fscache_inode_auxdata auxdata;
struct cifsInodeInfo *cifsi = cookie_netfs_data;
if (datalen != sizeof(auxdata))
return FSCACHE_CHECKAUX_OBSOLETE;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.eof = cifsi->server_eof;
auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
if (memcmp(data, &auxdata, datalen) != 0)
return FSCACHE_CHECKAUX_OBSOLETE;
return FSCACHE_CHECKAUX_OKAY;
}
const struct fscache_cookie_def cifs_fscache_inode_object_def = {
.name = "CIFS.uniqueid",
.type = FSCACHE_COOKIE_TYPE_DATAFILE,
.check_aux = cifs_fscache_inode_check_aux,
};