linux/fs/cifs/fscache.h
David Howells 54afa99057 CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them
In cifs_readpages(), we may decide we don't want to read a page after all -
but the page may already have passed through fscache_read_or_alloc_pages() and
thus have marks and reservations set.  Thus we have to call
fscache_readpages_cancel() or fscache_uncache_page() on the pages we're
returning to clear the marks.

NFS, AFS and 9P should be unaffected by this as they call read_cache_pages()
which does the cleanup for you.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-18 10:17:03 -05:00

149 lines
4.8 KiB
C

/*
* fs/cifs/fscache.h - CIFS filesystem cache interface 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
*/
#ifndef _CIFS_FSCACHE_H
#define _CIFS_FSCACHE_H
#include <linux/fscache.h>
#include "cifsglob.h"
#ifdef CONFIG_CIFS_FSCACHE
extern struct fscache_netfs cifs_fscache_netfs;
extern const struct fscache_cookie_def cifs_fscache_server_index_def;
extern const struct fscache_cookie_def cifs_fscache_super_index_def;
extern const struct fscache_cookie_def cifs_fscache_inode_object_def;
extern int cifs_fscache_register(void);
extern void cifs_fscache_unregister(void);
/*
* fscache.c
*/
extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);
extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);
extern void cifs_fscache_get_super_cookie(struct cifs_tcon *);
extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);
extern void cifs_fscache_release_inode_cookie(struct inode *);
extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
extern void cifs_fscache_reset_inode_cookie(struct inode *);
extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
extern int __cifs_readpages_from_fscache(struct inode *,
struct address_space *,
struct list_head *,
unsigned *);
extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);
extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
static inline void cifs_fscache_invalidate_page(struct page *page,
struct inode *inode)
{
if (PageFsCache(page))
__cifs_fscache_invalidate_page(page, inode);
}
static inline int cifs_readpage_from_fscache(struct inode *inode,
struct page *page)
{
if (CIFS_I(inode)->fscache)
return __cifs_readpage_from_fscache(inode, page);
return -ENOBUFS;
}
static inline int cifs_readpages_from_fscache(struct inode *inode,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages)
{
if (CIFS_I(inode)->fscache)
return __cifs_readpages_from_fscache(inode, mapping, pages,
nr_pages);
return -ENOBUFS;
}
static inline void cifs_readpage_to_fscache(struct inode *inode,
struct page *page)
{
if (PageFsCache(page))
__cifs_readpage_to_fscache(inode, page);
}
static inline void cifs_fscache_readpages_cancel(struct inode *inode,
struct list_head *pages)
{
if (CIFS_I(inode)->fscache)
return __cifs_fscache_readpages_cancel(inode, pages);
}
#else /* CONFIG_CIFS_FSCACHE */
static inline int cifs_fscache_register(void) { return 0; }
static inline void cifs_fscache_unregister(void) {}
static inline void
cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}
static inline void
cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) {}
static inline void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) {}
static inline void
cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}
static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
struct file *filp) {}
static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
{
return 1; /* May release page */
}
static inline void cifs_fscache_invalidate_page(struct page *page,
struct inode *inode) {}
static inline int
cifs_readpage_from_fscache(struct inode *inode, struct page *page)
{
return -ENOBUFS;
}
static inline int cifs_readpages_from_fscache(struct inode *inode,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages)
{
return -ENOBUFS;
}
static inline void cifs_readpage_to_fscache(struct inode *inode,
struct page *page) {}
static inline void cifs_fscache_readpages_cancel(struct inode *inode,
struct list_head *pages)
{
}
#endif /* CONFIG_CIFS_FSCACHE */
#endif /* _CIFS_FSCACHE_H */