linux/fs/cifs/cache.c
David Howells ee1235a9a0 fscache: Pass object size in rather than calling back for it
Pass the object size in to fscache_acquire_cookie() and
fscache_write_page() rather than the netfs providing a callback by which it
can be received.  This makes it easier to update the size of the object
when a new page is written that extends the object.

The current object size is also passed by fscache to the check_aux
function, obviating the need to store it in the aux data.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
2018-04-06 14:05:14 +01:00

144 lines
3.6 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 = cifsi->vfs_inode.i_mtime;
auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
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,
};