[linux-block.git] / 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 (dhowells@redhat.com)
 */

#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 {
	s64	mtime_sec;
	s64	mtime_nsec;
	s64	ctime_sec;
	s64	ctime_nsec;
	u64	change_attr;
};

struct nfs_netfs_io_data {
	/*
	 * NFS may split a netfs_io_subrequest into multiple RPCs, each
	 * with their own read completion.  In netfs, we can only call
	 * netfs_subreq_terminated() once for each subrequest.  Use the
	 * refcount here to double as a marker of the last RPC completion,
	 * and only call netfs via netfs_subreq_terminated() once.
	 */
	refcount_t			refcount;
	struct netfs_io_subrequest	*sreq;

	/*
	 * Final disposition of the netfs_io_subrequest, sent in
	 * netfs_subreq_terminated()
	 */
	atomic64_t	transferred;
	int		error;
};

static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
{
	refcount_inc(&netfs->refcount);
}

static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
{
	ssize_t final_len;

	/* Only the last RPC completion should call netfs_subreq_terminated() */
	if (!refcount_dec_and_test(&netfs->refcount))
		return;

	/*
	 * The NFS pageio interface may read a complete page, even when netfs
	 * only asked for a partial page.  Specifically, this may be seen when
	 * one thread is truncating a file while another one is reading the last
	 * page of the file.
	 * Correct the final length here to be no larger than the netfs subrequest
	 * length, and thus avoid netfs's "Subreq overread" warning message.
	 */
	final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred));
	netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false);
	kfree(netfs);
}
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
{
	netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops);
}
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)
{
	if (folio_test_fscache(folio)) {
		if (current_is_kswapd() || !(gfp & __GFP_FS))
			return false;
		folio_wait_fscache(folio);
	}
	fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
	return true;
}

static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
					      struct inode *inode)
{
	memset(auxdata, 0, sizeof(*auxdata));
	auxdata->mtime_sec  = inode->i_mtime.tv_sec;
	auxdata->mtime_nsec = inode->i_mtime.tv_nsec;
	auxdata->ctime_sec  = inode->i_ctime.tv_sec;
	auxdata->ctime_nsec = inode->i_ctime.tv_nsec;

	if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4)
		auxdata->change_attr = inode_peek_iversion_raw(inode);
}

/*
 * Invalidate the contents of fscache for this inode.  This will not sleep.
 */
static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
{
	struct nfs_fscache_inode_auxdata auxdata;
	struct fscache_cookie *cookie =  netfs_i_cookie(&NFS_I(inode)->netfs);

	nfs_fscache_update_auxdata(&auxdata, inode);
	fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
}

/*
 * indicate the client caching state as readable text
 */
static inline const char *nfs_server_fscache_state(struct nfs_server *server)
{
	if (server->fscache)
		return "yes";
	return "no ";
}

static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
					     struct nfs_pageio_descriptor *desc)
{
	hdr->netfs = desc->pg_netfs;
}
static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
						   struct nfs_pgio_header *hdr)
{
	desc->pg_netfs = hdr->netfs;
}
static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc)
{
	desc->pg_netfs = NULL;
}
#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 */
Commit	Line	Data
b4d0d230	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
8ec442ae DH	2	/* NFS filesystem cache interface definitions
	3	*
	4	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
8ec442ae DH	6	*/
	7
	8	#ifndef _NFS_FSCACHE_H
	9	#define _NFS_FSCACHE_H
	10
d7bdba1c	11	#include <linux/swap.h>
8ec442ae DH	12	#include <linux/nfs_fs.h>
	13	#include <linux/nfs_mount.h>
	14	#include <linux/nfs4_mount.h>
	15	#include <linux/fscache.h>
a6b5a28e	16	#include <linux/iversion.h>
8ec442ae DH	17
	18	#ifdef CONFIG_NFS_FSCACHE
	19
402cb8dd DH	20	/*
	21	* Definition of the auxiliary data attached to NFS inode storage objects
	22	* within the cache.
	23	*
	24	* The contents of this struct are recorded in the on-disk local cache in the
	25	* auxiliary data attached to the data storage object backing an inode. This
	26	* permits coherency to be managed when a new inode binds to an already extant
	27	* cache object.
	28	*/
	29	struct nfs_fscache_inode_auxdata {
6e31ded6 AB	30	s64 mtime_sec;
	31	s64 mtime_nsec;
	32	s64 ctime_sec;
	33	s64 ctime_nsec;
	34	u64 change_attr;
402cb8dd DH	35	};
402cb8dd DH	36
000dbe0b DW	37	struct nfs_netfs_io_data {
	38	/*
	39	* NFS may split a netfs_io_subrequest into multiple RPCs, each
	40	* with their own read completion. In netfs, we can only call
	41	* netfs_subreq_terminated() once for each subrequest. Use the
	42	* refcount here to double as a marker of the last RPC completion,
	43	* and only call netfs via netfs_subreq_terminated() once.
	44	*/
	45	refcount_t refcount;
	46	struct netfs_io_subrequest *sreq;
	47
	48	/*
	49	* Final disposition of the netfs_io_subrequest, sent in
	50	* netfs_subreq_terminated()
	51	*/
	52	atomic64_t transferred;
	53	int error;
	54	};
	55
	56	static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
	57	{
	58	refcount_inc(&netfs->refcount);
	59	}
	60
	61	static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
	62	{
	63	ssize_t final_len;
	64
	65	/* Only the last RPC completion should call netfs_subreq_terminated() */
	66	if (!refcount_dec_and_test(&netfs->refcount))
	67	return;
	68
	69	/*
	70	* The NFS pageio interface may read a complete page, even when netfs
	71	* only asked for a partial page. Specifically, this may be seen when
	72	* one thread is truncating a file while another one is reading the last
	73	* page of the file.
	74	* Correct the final length here to be no larger than the netfs subrequest
	75	* length, and thus avoid netfs's "Subreq overread" warning message.
	76	*/
	77	final_len = min_t(s64, netfs->sreq->len, atomic64_read(&netfs->transferred));
	78	netfs_subreq_terminated(netfs->sreq, netfs->error ?: final_len, false);
	79	kfree(netfs);
	80	}
	81	static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
	82	{
	83	netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops);
	84	}
	85	extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
	86	extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
	87	extern int nfs_netfs_folio_unlock(struct folio *folio);
	88
14727281 DH	89	/*
	90	* fscache.c
	91	*/
a6b5a28e	92	extern int nfs_fscache_get_super_cookie(struct super_block , const char , int);
08734048 DH	93	extern void nfs_fscache_release_super_cookie(struct super_block *);
08734048 DH	94
f1fe29b4 DH	95	extern void nfs_fscache_init_inode(struct inode *);
	96	extern void nfs_fscache_clear_inode(struct inode *);
	97	extern void nfs_fscache_open_file(struct inode , struct file );
a6b5a28e	98	extern void nfs_fscache_release_file(struct inode , struct file );
000dbe0b DW	99	extern int nfs_netfs_readahead(struct readahead_control *ractl);
000dbe0b DW	100	extern int nfs_netfs_read_folio(struct file file, struct folio folio);
9a9fc1c0	101
3577da4a	102	static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
545db45f	103	{
3577da4a	104	if (folio_test_fscache(folio)) {
d7bdba1c	105	if (current_is_kswapd() \|\| !(gfp & __GFP_FS))
a6b5a28e	106	return false;
3577da4a	107	folio_wait_fscache(folio);
a6b5a28e	108	}
000dbe0b	109	fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
a6b5a28e	110	return true;
545db45f DH	111	}
545db45f DH	112
a6b5a28e	113	static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
45f3a70b	114	struct inode *inode)
de242c0b	115	{
a6b5a28e	116	memset(auxdata, 0, sizeof(*auxdata));
45f3a70b DW	117	auxdata->mtime_sec = inode->i_mtime.tv_sec;
	118	auxdata->mtime_nsec = inode->i_mtime.tv_nsec;
	119	auxdata->ctime_sec = inode->i_ctime.tv_sec;
	120	auxdata->ctime_nsec = inode->i_ctime.tv_nsec;
a6b5a28e	121
45f3a70b DW	122	if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4)
45f3a70b DW	123	auxdata->change_attr = inode_peek_iversion_raw(inode);
de242c0b DH	124	}
	125
	126	/*
a6b5a28e	127	* Invalidate the contents of fscache for this inode. This will not sleep.
de242c0b	128	*/
a6b5a28e	129	static inline void nfs_fscache_invalidate(struct inode *inode, int flags)
de242c0b	130	{
a6b5a28e	131	struct nfs_fscache_inode_auxdata auxdata;
88a4d7bd	132	struct fscache_cookie *cookie = netfs_i_cookie(&NFS_I(inode)->netfs);
a6b5a28e	133
88a4d7bd DW	134	nfs_fscache_update_auxdata(&auxdata, inode);
88a4d7bd DW	135	fscache_invalidate(cookie, &auxdata, i_size_read(inode), flags);
de242c0b DH	136	}
de242c0b DH	137
5d1acff1 DH	138	/*
	139	* indicate the client caching state as readable text
	140	*/
	141	static inline const char nfs_server_fscache_state(struct nfs_server server)
	142	{
dea1bb35	143	if (server->fscache)
5d1acff1 DH	144	return "yes";
	145	return "no ";
	146	}
	147
000dbe0b DW	148	static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
	149	struct nfs_pageio_descriptor *desc)
	150	{
	151	hdr->netfs = desc->pg_netfs;
	152	}
	153	static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
	154	struct nfs_pgio_header *hdr)
	155	{
	156	desc->pg_netfs = hdr->netfs;
	157	}
	158	static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc)
	159	{
	160	desc->pg_netfs = NULL;
	161	}
8ec442ae	162	#else /* CONFIG_NFS_FSCACHE */
000dbe0b DW	163	static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi) {}
	164	static inline void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr) {}
	165	static inline void nfs_netfs_read_completion(struct nfs_pgio_header *hdr) {}
	166	static inline int nfs_netfs_folio_unlock(struct folio *folio)
	167	{
	168	return 1;
	169	}
08734048 DH	170	static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
08734048 DH	171
f1fe29b4 DH	172	static inline void nfs_fscache_init_inode(struct inode *inode) {}
	173	static inline void nfs_fscache_clear_inode(struct inode *inode) {}
	174	static inline void nfs_fscache_open_file(struct inode *inode,
	175	struct file *filp) {}
a6b5a28e	176	static inline void nfs_fscache_release_file(struct inode inode, struct file file) {}
000dbe0b	177	static inline int nfs_netfs_readahead(struct readahead_control *ractl)
545db45f	178	{
000dbe0b	179	return -ENOBUFS;
545db45f	180	}
000dbe0b	181	static inline int nfs_netfs_read_folio(struct file file, struct folio folio)
9a9fc1c0 DH	182	{
	183	return -ENOBUFS;
	184	}
000dbe0b DW	185
	186	static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
	187	{
	188	return true; /* may release folio */
	189	}
a6b5a28e	190	static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {}
de242c0b	191
5d1acff1 DH	192	static inline const char nfs_server_fscache_state(struct nfs_server server)
	193	{
	194	return "no ";
	195	}
000dbe0b DW	196	static inline void nfs_netfs_set_pgio_header(struct nfs_pgio_header *hdr,
	197	struct nfs_pageio_descriptor *desc) {}
	198	static inline void nfs_netfs_set_pageio_descriptor(struct nfs_pageio_descriptor *desc,
	199	struct nfs_pgio_header *hdr) {}
	200	static inline void nfs_netfs_reset_pageio_descriptor(struct nfs_pageio_descriptor *desc) {}
8ec442ae DH	201	#endif /* CONFIG_NFS_FSCACHE */
8ec442ae DH	202	#endif /* _NFS_FSCACHE_H */