original development tree for Linux kernel GTP module; now long in mainline.
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/*
* 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);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server, server->fscache);
}
void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
{
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server, server->fscache);
fscache_relinquish_cookie(server->fscache, 0);
server->fscache = NULL;
}
void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
{
struct TCP_Server_Info *server = tcon->ses->server;
tcon->fscache =
fscache_acquire_cookie(server->fscache,
&cifs_fscache_super_index_def, tcon);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, server->fscache, tcon->fscache);
}
void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
{
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, 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 cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
if (cifsi->fscache)
return;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE) {
cifsi->fscache = fscache_acquire_cookie(tcon->fscache,
&cifs_fscache_inode_object_def, cifsi);
cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
__func__, tcon->fscache, cifsi->fscache);
}
}
void cifs_fscache_release_inode_cookie(struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
if (cifsi->fscache) {
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, 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) {
cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
fscache_uncache_all_inode_pages(cifsi->fscache, inode);
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);
}
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);
cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
__func__, 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);
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
__func__, 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)
{
cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, 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;
cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
__func__, 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 */
cifs_dbg(FYI, "%s: submitted\n", __func__);
return ret;
case -ENOBUFS: /* page won't be cached */
case -ENODATA: /* page not in cache */
cifs_dbg(FYI, "%s: %d\n", __func__, ret);
return 1;
default:
cifs_dbg(VFS, "unknown error ret = %d\n", 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;
cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
__func__, 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 */
cifs_dbg(FYI, "%s: submitted\n", __func__);
return ret;
case -ENOBUFS: /* some pages are not cached and can't be */
case -ENODATA: /* some pages are not cached */
cifs_dbg(FYI, "%s: no page\n", __func__);
return 1;
default:
cifs_dbg(FYI, "unknown error ret = %d\n", ret);
}
return ret;
}
void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
{
int ret;
cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
__func__, 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_readpages_cancel(struct inode *inode, struct list_head *pages)
{
cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
__func__, CIFS_I(inode)->fscache, inode);
fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
}
void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
{
struct cifsInodeInfo *cifsi = CIFS_I(inode);
struct fscache_cookie *cookie = cifsi->fscache;
cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
fscache_wait_on_page_write(cookie, page);
fscache_uncache_page(cookie, page);
}