linux_kernel/fs/cifs/cache.c
Steve French 5865985416 smb3: extend fscache mount volume coherency check
It is better to check volume id and creation time, not just
the root inode number to verify if the volume has changed
when remounting.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-06 11:16:25 -05:00

142 lines
3.7 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,
};
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;
auxdata.vol_create_time = tcon->vol_create_time;
auxdata.vol_serial_number = tcon->vol_serial_number;
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,
};