linux/fs/cifs/fscache.c
Jeff Layton 0d424ad0a4 cifs: add cifs_sb_master_tcon and convert some callers to use it
At mount time, we'll always need to create a tcon that will serve as a
template for others that are associated with the mount. This tcon is
known as the "master" tcon.

In some cases, we'll need to use that tcon regardless of who's accessing
the mount. Add an accessor function for the master tcon and go ahead and
switch the appropriate places to use it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-09-29 19:04:33 +00:00

238 lines
6.6 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);
struct cifsTconInfo *tcon = cifs_sb_master_tcon(cifs_sb);
if (cifsi->fscache)
return;
cifsi->fscache = fscache_acquire_cookie(tcon->fscache,
&cifs_fscache_inode_object_def, cifsi);
cFYI(1, "CIFS: got FH cookie (0x%p/0x%p)", 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_master_tcon(cifs_sb)->fscache,
&cifs_fscache_inode_object_def,
cifsi);
cFYI(1, "CIFS: new cookie 0x%p oldcookie 0x%p",
cifsi->fscache, old);
}
}
int cifs_fscache_release_page(struct page *page, gfp_t gfp)
{
if (PageFsCache(page)) {
struct inode *inode = page->mapping->host;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
cFYI(1, "CIFS: fscache release page (0x%p/0x%p)",
page, cifsi->fscache);
if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
return 0;
}
return 1;
}
static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
int error)
{
cFYI(1, "CFS: readpage_from_fscache_complete (0x%p/%d)",
page, error);
if (!error)
SetPageUptodate(page);
unlock_page(page);
}
/*
* Retrieve a page from FS-Cache
*/
int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
{
int ret;
cFYI(1, "CIFS: readpage_from_fscache(fsc:%p, p:%p, i:0x%p",
CIFS_I(inode)->fscache, page, inode);
ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
cifs_readpage_from_fscache_complete,
NULL,
GFP_KERNEL);
switch (ret) {
case 0: /* page found in fscache, read submitted */
cFYI(1, "CIFS: readpage_from_fscache: submitted");
return ret;
case -ENOBUFS: /* page won't be cached */
case -ENODATA: /* page not in cache */
cFYI(1, "CIFS: readpage_from_fscache %d", ret);
return 1;
default:
cERROR(1, "unknown error ret = %d", ret);
}
return ret;
}
/*
* Retrieve a set of pages from FS-Cache
*/
int __cifs_readpages_from_fscache(struct inode *inode,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages)
{
int ret;
cFYI(1, "CIFS: __cifs_readpages_from_fscache (0x%p/%u/0x%p)",
CIFS_I(inode)->fscache, *nr_pages, inode);
ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
pages, nr_pages,
cifs_readpage_from_fscache_complete,
NULL,
mapping_gfp_mask(mapping));
switch (ret) {
case 0: /* read submitted to the cache for all pages */
cFYI(1, "CIFS: readpages_from_fscache: submitted");
return ret;
case -ENOBUFS: /* some pages are not cached and can't be */
case -ENODATA: /* some pages are not cached */
cFYI(1, "CIFS: readpages_from_fscache: no page");
return 1;
default:
cFYI(1, "unknown error ret = %d", ret);
}
return ret;
}
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
int ret;
cFYI(1, "CIFS: readpage_to_fscache(fsc: %p, p: %p, i: %p",
CIFS_I(inode)->fscache, page, inode);
ret = fscache_write_page(CIFS_I(inode)->fscache, page, GFP_KERNEL);
if (ret != 0)
fscache_uncache_page(CIFS_I(inode)->fscache, page);
}
void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct fscache_cookie *cookie = cifsi->fscache;
cFYI(1, "CIFS: fscache invalidatepage (0x%p/0x%p)", page, cookie);
fscache_wait_on_page_write(cookie, page);
fscache_uncache_page(cookie, page);
}