linux/fs/cifs/fscache.c
Suresh Jayaraman 9451a9a52f cifs: define inode-level cache object and register them
Define inode-level data storage objects (managed by cifsInodeInfo structs).
Each inode-level object is created in a super-block level object and is itself
a data storage object in to which pages from the inode are stored.

The inode object is keyed by UniqueId. The coherency data being used is
LastWriteTime, LastChangeTime and end of file reported by the server.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-02 12:40:36 +00:00

127 lines
3.7 KiB
C

/*
* fs/cifs/fscache.c - CIFS filesystem cache interface
*
* Copyright (c) 2010 Novell, Inc.
* Author(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 "cifsglob.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
{
server->fscache =
fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
&cifs_fscache_server_index_def, server);
cFYI(1, "CIFS: get client cookie (0x%p/0x%p)", server,
server->fscache);
}
void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
{
cFYI(1, "CIFS: release client cookie (0x%p/0x%p)", server,
server->fscache);
fscache_relinquish_cookie(server->fscache, 0);
server->fscache = NULL;
}
void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon)
{
struct TCP_Server_Info *server = tcon->ses->server;
tcon->fscache =
fscache_acquire_cookie(server->fscache,
&cifs_fscache_super_index_def, tcon);
cFYI(1, "CIFS: get superblock cookie (0x%p/0x%p)",
server->fscache, tcon->fscache);
}
void cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon)
{
cFYI(1, "CIFS: releasing superblock cookie (0x%p)", tcon->fscache);
fscache_relinquish_cookie(tcon->fscache, 0);
tcon->fscache = NULL;
}
static void cifs_fscache_enable_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
if (cifsi->fscache)
return;
cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
&cifs_fscache_inode_object_def,
cifsi);
cFYI(1, "CIFS: got FH cookie (0x%p/0x%p)",
cifs_sb->tcon->fscache, cifsi->fscache);
}
void cifs_fscache_release_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cFYI(1, "CIFS releasing inode cookie (0x%p)",
cifsi->fscache);
fscache_relinquish_cookie(cifsi->fscache, 0);
cifsi->fscache = NULL;
}
}
static void cifs_fscache_disable_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cFYI(1, "CIFS disabling inode cookie (0x%p)",
cifsi->fscache);
fscache_relinquish_cookie(cifsi->fscache, 1);
cifsi->fscache = NULL;
}
}
void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
{
if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
cifs_fscache_disable_inode_cookie(inode);
else {
cifs_fscache_enable_inode_cookie(inode);
cFYI(1, "CIFS: fscache inode cookie set");
}
}
void cifs_fscache_reset_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct fscache_cookie *old = cifsi->fscache;
if (cifsi->fscache) {
/* retire the current fscache cache and get a new one */
fscache_relinquish_cookie(cifsi->fscache, 1);
cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
&cifs_fscache_inode_object_def,
cifsi);
cFYI(1, "CIFS: new cookie 0x%p oldcookie 0x%p",
cifsi->fscache, old);
}
}