linux/fs/cifs/fscache.h
Shyam Prasad N 18d04062f8 cifs: enable fscache usage even for files opened as rw
So far, the fscache implementation we had supports only
a small set of use cases. Particularly for files opened
with O_RDONLY.

This commit enables it even for rw based file opens. It
also enables the reuse of cached data in case of mount
option (cache=singleclient) where it is guaranteed that
this is the only client (and server) which operates on
the files. There's also a single line change in fscache.c
to get around a bug seen in fscache.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-25 15:45:10 -05:00

184 lines
5.4 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 */
/*
* fs/cifs/fscache.h - CIFS filesystem cache interface definitions
*
* Copyright (c) 2010 Novell, Inc.
* Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
*
*/
#ifndef _CIFS_FSCACHE_H
#define _CIFS_FSCACHE_H
#include <linux/fscache.h>
#include "cifsglob.h"
#ifdef CONFIG_CIFS_FSCACHE
/*
* Auxiliary data attached to CIFS superblock within the cache
*/
struct cifs_fscache_super_auxdata {
u64 resource_id; /* unique server resource id */
__le64 vol_create_time;
u32 vol_serial_number;
} __packed;
/*
* Auxiliary data attached to CIFS inode within the cache
*/
struct cifs_fscache_inode_auxdata {
u64 last_write_time_sec;
u64 last_change_time_sec;
u32 last_write_time_nsec;
u32 last_change_time_nsec;
u64 eof;
};
/*
* cache.c
*/
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_update_inode_cookie(struct inode *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 void __cifs_fscache_wait_on_page_write(struct inode *inode, struct page *page);
extern void __cifs_fscache_uncache_page(struct inode *inode, struct page *page);
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 void cifs_fscache_wait_on_page_write(struct inode *inode,
struct page *page)
{
if (PageFsCache(page))
__cifs_fscache_wait_on_page_write(inode, page);
}
static inline void cifs_fscache_uncache_page(struct inode *inode,
struct page *page)
{
if (PageFsCache(page))
__cifs_fscache_uncache_page(inode, page);
}
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_update_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 void cifs_fscache_wait_on_page_write(struct inode *inode,
struct page *page) {}
static inline void cifs_fscache_uncache_page(struct inode *inode,
struct page *page) {}
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 */