linux/fs/nfs/fscache.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* NFS filesystem cache interface definitions
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#ifndef _NFS_FSCACHE_H
#define _NFS_FSCACHE_H

#include <linux/swap.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/fscache.h>
#include <linux/iversion.h>

#ifdef CONFIG_NFS_FSCACHE

/*
 * Definition of the auxiliary data attached to NFS inode storage objects
 * within the cache.
 *
 * The contents of this struct are recorded in the on-disk local cache in the
 * auxiliary data attached to the data storage object backing an inode.  This
 * permits coherency to be managed when a new inode binds to an already extant
 * cache object.
 */
struct nfs_fscache_inode_auxdata { … };

struct nfs_netfs_io_data { … };

static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
{ … }

static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
{ … }
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
{ … }
extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
extern int nfs_netfs_folio_unlock(struct folio *folio);

/*
 * fscache.c
 */
extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
extern void nfs_fscache_release_super_cookie(struct super_block *);

extern void nfs_fscache_init_inode(struct inode *);
extern void nfs_fscache_clear_inode(struct inode *);
extern void nfs_fscache_open_file(struct inode *, struct file *);
extern void nfs_fscache_release_file(struct inode *, struct file *);
extern int nfs_netfs_readahead(struct readahead_control *ractl);
extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);

static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
{ … }

static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
					      struct inode *inode)
{ … }

/*
 * Invalidate the contents of fscache for this inode.  This will not sleep.
 */
static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
{ … }

/*
 * indicate the client caching state as readable text
 */
static inline const char *nfs_server_fscache_state(struct nfs_server *server)
{ … }

static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
					     struct nfs_pageio_descriptor *desc)
{ … }
static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
						   struct nfs_pgio_header *hdr)
{ … }
static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc)
{ … }
#else /* CONFIG_NFS_FSCACHE */
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
static inline int nfs_netfs_folio_unlock(struct folio *folio)
{
	return 1;
}
static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}

static inline void nfs_fscache_init_inode(struct inode *inode) {}
static inline void nfs_fscache_clear_inode(struct inode *inode) {}
static inline void nfs_fscache_open_file(struct inode *inode,
					 struct file *filp) {}
static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {}
static inline int nfs_netfs_readahead(struct readahead_control *ractl)
{
	return -ENOBUFS;
}
static inline int nfs_netfs_read_folio(struct file *file, struct folio *folio)
{
	return -ENOBUFS;
}

static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
{
	return true; /* may release folio */
}
static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}

static inline const char *nfs_server_fscache_state(struct nfs_server *server)
{
	return "no ";
}
static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
					     struct nfs_pageio_descriptor *desc) {}
static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
						   struct nfs_pgio_header *hdr) {}
static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {}
#endif /* CONFIG_NFS_FSCACHE */
#endif /* _NFS_FSCACHE_H */