original development tree for Linux kernel GTP module; now long in mainline.
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/*
* 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);
}
/*
* Key layout of CIFS server cache index object
*/
struct cifs_server_key {
uint16_t family; /* address family */
__be16 port; /* IP port */
union {
struct in_addr ipv4_addr;
struct in6_addr ipv6_addr;
} addr[0];
};
/*
* Server object keyed by {IPaddress,port,family} tuple
*/
static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
void *buffer, uint16_t maxbuf)
{
const struct TCP_Server_Info *server = cookie_netfs_data;
const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
struct cifs_server_key *key = buffer;
uint16_t key_len = sizeof(struct cifs_server_key);
memset(key, 0, key_len);
/*
* Should not be a problem as sin_family/sin6_family overlays
* sa_family field
*/
switch (sa->sa_family) {
case AF_INET:
key->family = sa->sa_family;
key->port = addr->sin_port;
key->addr[0].ipv4_addr = addr->sin_addr;
key_len += sizeof(key->addr[0].ipv4_addr);
break;
case AF_INET6:
key->family = sa->sa_family;
key->port = addr6->sin6_port;
key->addr[0].ipv6_addr = addr6->sin6_addr;
key_len += sizeof(key->addr[0].ipv6_addr);
break;
default:
cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
key_len = 0;
break;
}
return key_len;
}
/*
* Server object for FS-Cache
*/
const struct fscache_cookie_def cifs_fscache_server_index_def = {
.name = "CIFS.server",
.type = FSCACHE_COOKIE_TYPE_INDEX,
.get_key = cifs_server_get_key,
};
/*
* Auxiliary data attached to CIFS superblock within the cache
*/
struct cifs_fscache_super_auxdata {
u64 resource_id; /* unique server resource id */
};
static 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;
}
/*
* Superblock object currently keyed by share name
*/
static uint16_t cifs_super_get_key(const void *cookie_netfs_data, void *buffer,
uint16_t maxbuf)
{
const struct cifs_tcon *tcon = cookie_netfs_data;
char *sharename;
uint16_t len;
sharename = extract_sharename(tcon->treeName);
if (IS_ERR(sharename)) {
cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
sharename = NULL;
return 0;
}
len = strlen(sharename);
if (len > maxbuf)
return 0;
memcpy(buffer, sharename, len);
kfree(sharename);
return len;
}
static uint16_t
cifs_fscache_super_get_aux(const void *cookie_netfs_data, void *buffer,
uint16_t maxbuf)
{
struct cifs_fscache_super_auxdata auxdata;
const struct cifs_tcon *tcon = cookie_netfs_data;
memset(&auxdata, 0, sizeof(auxdata));
auxdata.resource_id = tcon->resource_id;
if (maxbuf > sizeof(auxdata))
maxbuf = sizeof(auxdata);
memcpy(buffer, &auxdata, maxbuf);
return maxbuf;
}
static enum
fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen)
{
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,
.get_key = cifs_super_get_key,
.get_aux = cifs_fscache_super_get_aux,
.check_aux = cifs_fscache_super_check_aux,
};
/*
* Auxiliary data attached to CIFS inode within the cache
*/
struct cifs_fscache_inode_auxdata {
struct timespec last_write_time;
struct timespec last_change_time;
u64 eof;
};
static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
void *buffer, uint16_t maxbuf)
{
const struct cifsInodeInfo *cifsi = cookie_netfs_data;
uint16_t keylen;
/* use the UniqueId as the key */
keylen = sizeof(cifsi->uniqueid);
if (keylen > maxbuf)
keylen = 0;
else
memcpy(buffer, &cifsi->uniqueid, keylen);
return keylen;
}
static void
cifs_fscache_inode_get_attr(const void *cookie_netfs_data, uint64_t *size)
{
const struct cifsInodeInfo *cifsi = cookie_netfs_data;
*size = cifsi->vfs_inode.i_size;
}
static uint16_t
cifs_fscache_inode_get_aux(const void *cookie_netfs_data, void *buffer,
uint16_t maxbuf)
{
struct cifs_fscache_inode_auxdata auxdata;
const struct cifsInodeInfo *cifsi = cookie_netfs_data;
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 (maxbuf > sizeof(auxdata))
maxbuf = sizeof(auxdata);
memcpy(buffer, &auxdata, maxbuf);
return maxbuf;
}
static enum
fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen)
{
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;
}
static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
{
struct cifsInodeInfo *cifsi = cookie_netfs_data;
struct pagevec pvec;
pgoff_t first;
int loop, nr_pages;
pagevec_init(&pvec, 0);
first = 0;
cifs_dbg(FYI, "%s: cifs inode 0x%p now uncached\n", __func__, cifsi);
for (;;) {
nr_pages = pagevec_lookup(&pvec,
cifsi->vfs_inode.i_mapping, first,
PAGEVEC_SIZE - pagevec_count(&pvec));
if (!nr_pages)
break;
for (loop = 0; loop < nr_pages; loop++)
ClearPageFsCache(pvec.pages[loop]);
first = pvec.pages[nr_pages - 1]->index + 1;
pvec.nr = nr_pages;
pagevec_release(&pvec);
cond_resched();
}
}
const struct fscache_cookie_def cifs_fscache_inode_object_def = {
.name = "CIFS.uniqueid",
.type = FSCACHE_COOKIE_TYPE_DATAFILE,
.get_key = cifs_fscache_inode_get_key,
.get_attr = cifs_fscache_inode_get_attr,
.get_aux = cifs_fscache_inode_get_aux,
.check_aux = cifs_fscache_inode_check_aux,
.now_uncached = cifs_fscache_inode_now_uncached,
};