[thirdparty/kernel/stable.git] / include / linux / nfs_page.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * linux/include/linux/nfs_page.h
 *
 * Copyright (C) 2000 Trond Myklebust
 *
 * NFS page cache wrapper.
 */

#ifndef _LINUX_NFS_PAGE_H
#define _LINUX_NFS_PAGE_H


#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>

#include <linux/kref.h>

/*
 * Valid flags for a dirty buffer
 */
enum {
	PG_BUSY = 0,		/* nfs_{un}lock_request */
	PG_MAPPED,		/* page private set for buffered io */
	PG_FOLIO,		/* Tracking a folio (unset for O_DIRECT) */
	PG_CLEAN,		/* write succeeded */
	PG_COMMIT_TO_DS,	/* used by pnfs layouts */
	PG_INODE_REF,		/* extra ref held by inode when in writeback */
	PG_HEADLOCK,		/* page group lock of wb_head */
	PG_TEARDOWN,		/* page group sync for destroy */
	PG_UNLOCKPAGE,		/* page group sync bit in read path */
	PG_UPTODATE,		/* page group sync bit in read path */
	PG_WB_END,		/* page group sync bit in write path */
	PG_REMOVE,		/* page group sync bit in write path */
	PG_CONTENDED1,		/* Is someone waiting for a lock? */
	PG_CONTENDED2,		/* Is someone waiting for a lock? */
};

struct nfs_inode;
struct nfs_page {
	struct list_head	wb_list;	/* Defines state of page: */
	union {
		struct page	*wb_page;	/* page to read in/write out */
		struct folio	*wb_folio;
	};
	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
	pgoff_t			wb_index;	/* Offset >> PAGE_SHIFT */
	unsigned int		wb_offset,	/* Offset & ~PAGE_MASK */
				wb_pgbase,	/* Start of page data */
				wb_bytes;	/* Length of request */
	struct kref		wb_kref;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_write_verifier	wb_verf;	/* Commit cookie */
	struct nfs_page		*wb_this_page;  /* list of reqs for this page */
	struct nfs_page		*wb_head;       /* head pointer for req list */
	unsigned short		wb_nio;		/* Number of I/O attempts */
};

struct nfs_pgio_mirror;
struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
	void	(*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
	size_t	(*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
			   struct nfs_page *);
	int	(*pg_doio)(struct nfs_pageio_descriptor *);
	unsigned int	(*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
				       struct nfs_page *);
	void	(*pg_cleanup)(struct nfs_pageio_descriptor *);
	struct nfs_pgio_mirror *
		(*pg_get_mirror)(struct nfs_pageio_descriptor *, u32);
	u32	(*pg_set_mirror)(struct nfs_pageio_descriptor *, u32);
};

struct nfs_rw_ops {
	struct nfs_pgio_header *(*rw_alloc_header)(void);
	void (*rw_free_header)(struct nfs_pgio_header *);
	int  (*rw_done)(struct rpc_task *, struct nfs_pgio_header *,
			struct inode *);
	void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *);
	void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *,
			    const struct nfs_rpc_ops *,
			    struct rpc_task_setup *, int);
};

struct nfs_pgio_mirror {
	struct list_head	pg_list;
	unsigned long		pg_bytes_written;
	size_t			pg_count;
	size_t			pg_bsize;
	unsigned int		pg_base;
	unsigned char		pg_recoalesce : 1;
};

struct nfs_pageio_descriptor {
	struct inode		*pg_inode;
	const struct nfs_pageio_ops *pg_ops;
	const struct nfs_rw_ops *pg_rw_ops;
	int 			pg_ioflags;
	int			pg_error;
	const struct rpc_call_ops *pg_rpc_callops;
	const struct nfs_pgio_completion_ops *pg_completion_ops;
	struct pnfs_layout_segment *pg_lseg;
	struct nfs_io_completion *pg_io_completion;
	struct nfs_direct_req	*pg_dreq;
#ifdef CONFIG_NFS_FSCACHE
	void			*pg_netfs;
#endif
	unsigned int		pg_bsize;	/* default bsize for mirrors */

	u32			pg_mirror_count;
	struct nfs_pgio_mirror	*pg_mirrors;
	struct nfs_pgio_mirror	pg_mirrors_static[1];
	struct nfs_pgio_mirror	*pg_mirrors_dynamic;
	u32			pg_mirror_idx;	/* current mirror */
	unsigned short		pg_maxretrans;
	unsigned char		pg_moreio : 1;
};

/* arbitrarily selected limit to number of mirrors */
#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16

#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))

extern struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
						  struct page *page,
						  unsigned int pgbase,
						  loff_t offset,
						  unsigned int count);
extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
						   struct folio *folio,
						   unsigned int offset,
						   unsigned int count);
extern	void nfs_release_request(struct nfs_page *);


extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
			     struct inode *inode,
			     const struct nfs_pageio_ops *pg_ops,
			     const struct nfs_pgio_completion_ops *compl_ops,
			     const struct nfs_rw_ops *rw_ops,
			     size_t bsize,
			     int how);
extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
				   struct nfs_page *);
extern  int nfs_pageio_resend(struct nfs_pageio_descriptor *,
			      struct nfs_pgio_header *);
extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
				struct nfs_page *prev,
				struct nfs_page *req);
extern  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern	void nfs_unlock_and_release_request(struct nfs_page *);
extern	struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req);
extern	int nfs_page_group_lock_subrequests(struct nfs_page *head);
extern void nfs_join_page_group(struct nfs_page *head,
				struct nfs_commit_info *cinfo,
				struct inode *inode);
extern int nfs_page_group_lock(struct nfs_page *);
extern void nfs_page_group_unlock(struct nfs_page *);
extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
extern	int nfs_page_set_headlock(struct nfs_page *req);
extern void nfs_page_clear_headlock(struct nfs_page *req);
extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);

/**
 * nfs_page_to_folio - Retrieve a struct folio for the request
 * @req: pointer to a struct nfs_page
 *
 * If a folio was assigned to @req, then return it, otherwise return NULL.
 */
static inline struct folio *nfs_page_to_folio(const struct nfs_page *req)
{
	if (test_bit(PG_FOLIO, &req->wb_flags))
		return req->wb_folio;
	return NULL;
}

/**
 * nfs_page_to_page - Retrieve a struct page for the request
 * @req: pointer to a struct nfs_page
 * @pgbase: folio byte offset
 *
 * Return the page containing the byte that is at offset @pgbase relative
 * to the start of the folio.
 * Note: The request starts at offset @req->wb_pgbase.
 */
static inline struct page *nfs_page_to_page(const struct nfs_page *req,
					    size_t pgbase)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return req->wb_page;
	return folio_page(folio, pgbase >> PAGE_SHIFT);
}

/**
 * nfs_page_to_inode - Retrieve an inode for the request
 * @req: pointer to a struct nfs_page
 */
static inline struct inode *nfs_page_to_inode(const struct nfs_page *req)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return page_file_mapping(req->wb_page)->host;
	return folio_file_mapping(folio)->host;
}

/**
 * nfs_page_max_length - Retrieve the maximum possible length for a request
 * @req: pointer to a struct nfs_page
 *
 * Returns the maximum possible length of a request
 */
static inline size_t nfs_page_max_length(const struct nfs_page *req)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return PAGE_SIZE;
	return folio_size(folio);
}

/*
 * Lock the page of an asynchronous request
 */
static inline int
nfs_lock_request(struct nfs_page *req)
{
	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}

/**
 * nfs_list_add_request - Insert a request into a list
 * @req: request
 * @head: head of list into which to insert the request.
 */
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
	list_add_tail(&req->wb_list, head);
}

/**
 * nfs_list_move_request - Move a request to a new list
 * @req: request
 * @head: head of list into which to insert the request.
 */
static inline void
nfs_list_move_request(struct nfs_page *req, struct list_head *head)
{
	list_move_tail(&req->wb_list, head);
}

/**
 * nfs_list_remove_request - Remove a request from its wb_list
 * @req: request
 */
static inline void
nfs_list_remove_request(struct nfs_page *req)
{
	if (list_empty(&req->wb_list))
		return;
	list_del_init(&req->wb_list);
}

static inline struct nfs_page *
nfs_list_entry(struct list_head *head)
{
	return list_entry(head, struct nfs_page, wb_list);
}

static inline loff_t req_offset(const struct nfs_page *req)
{
	return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
}

static inline struct nfs_open_context *
nfs_req_openctx(struct nfs_page *req)
{
	return req->wb_lock_context->open_context;
}

#endif /* _LINUX_NFS_PAGE_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	/*
	3	* linux/include/linux/nfs_page.h
	4	*
	5	* Copyright (C) 2000 Trond Myklebust
	6	*
	7	* NFS page cache wrapper.
	8	*/
	9
	10	#ifndef _LINUX_NFS_PAGE_H
	11	#define _LINUX_NFS_PAGE_H
	12
	13
	14	#include <linux/list.h>
	15	#include <linux/pagemap.h>
	16	#include <linux/wait.h>
1da177e4 LT	17	#include <linux/sunrpc/auth.h>
	18	#include <linux/nfs_xdr.h>
	19
c03b4024	20	#include <linux/kref.h>
1da177e4 LT	21
	22	/*
	23	* Valid flags for a dirty buffer
	24	*/
e468bae9	25	enum {
12c05792 WAA	26	PG_BUSY = 0, /* nfs_{un}lock_request */
12c05792 WAA	27	PG_MAPPED, /* page private set for buffered io */
35c5db0e	28	PG_FOLIO, /* Tracking a folio (unset for O_DIRECT) */
12c05792 WAA	29	PG_CLEAN, /* write succeeded */
12c05792 WAA	30	PG_COMMIT_TO_DS, /* used by pnfs layouts */
b412ddf0	31	PG_INODE_REF, /* extra ref held by inode when in writeback */
2bfc6e56 WAA	32	PG_HEADLOCK, /* page group lock of wb_head */
2bfc6e56 WAA	33	PG_TEARDOWN, /* page group sync for destroy */
67d0338e WAA	34	PG_UNLOCKPAGE, /* page group sync bit in read path */
67d0338e WAA	35	PG_UPTODATE, /* page group sync bit in read path */
20633f04 WAA	36	PG_WB_END, /* page group sync bit in write path */
20633f04 WAA	37	PG_REMOVE, /* page group sync bit in write path */
b4f937cf TM	38	PG_CONTENDED1, /* Is someone waiting for a lock? */
b4f937cf TM	39	PG_CONTENDED2, /* Is someone waiting for a lock? */
e468bae9	40	};
1da177e4	41
3da28eb1	42	struct nfs_inode;
1da177e4	43	struct nfs_page {
d6d6dc7c	44	struct list_head wb_list; /* Defines state of page: */
35c5db0e TM	45	union {
	46	struct page wb_page; / page to read in/write out */
	47	struct folio *wb_folio;
	48	};
f11ac8db	49	struct nfs_lock_context wb_lock_context; / lock context info */
ea1754a0 KS	50	pgoff_t wb_index; /* Offset >> PAGE_SHIFT */
ea1754a0 KS	51	unsigned int wb_offset, /* Offset & ~PAGE_MASK */
1da177e4 LT	52	wb_pgbase, /* Start of page data */
1da177e4 LT	53	wb_bytes; /* Length of request */
c03b4024	54	struct kref wb_kref; /* reference count */
1da177e4	55	unsigned long wb_flags;
2f2c63bc	56	struct nfs_write_verifier wb_verf; /* Commit cookie */
2bfc6e56 WAA	57	struct nfs_page wb_this_page; / list of reqs for this page */
2bfc6e56 WAA	58	struct nfs_page wb_head; / head pointer for req list */
33344e0f	59	unsigned short wb_nio; /* Number of I/O attempts */
1da177e4 LT	60	};
1da177e4 LT	61
63e2fffa	62	struct nfs_pgio_mirror;
1751c363 TM	63	struct nfs_pageio_descriptor;
1751c363 TM	64	struct nfs_pageio_ops {
d8007d4d	65	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
b4fdac1a WAA	66	size_t (pg_test)(struct nfs_pageio_descriptor , struct nfs_page *,
b4fdac1a WAA	67	struct nfs_page *);
1751c363	68	int (pg_doio)(struct nfs_pageio_descriptor );
a7d42ddb WAA	69	unsigned int (pg_get_mirror_count)(struct nfs_pageio_descriptor ,
a7d42ddb WAA	70	struct nfs_page *);
2176bf42	71	void (pg_cleanup)(struct nfs_pageio_descriptor );
63e2fffa TM	72	struct nfs_pgio_mirror *
	73	(pg_get_mirror)(struct nfs_pageio_descriptor , u32);
	74	u32 (pg_set_mirror)(struct nfs_pageio_descriptor , u32);
1751c363 TM	75	};
1751c363 TM	76
4a0de55c	77	struct nfs_rw_ops {
1e7f3a48 WAA	78	struct nfs_pgio_header (rw_alloc_header)(void);
1e7f3a48 WAA	79	void (rw_free_header)(struct nfs_pgio_header );
d45f60c6 WAA	80	int (rw_done)(struct rpc_task , struct nfs_pgio_header *,
	81	struct inode *);
	82	void (rw_result)(struct rpc_task , struct nfs_pgio_header *);
	83	void (rw_initiate)(struct nfs_pgio_header , struct rpc_message *,
abde71f4	84	const struct nfs_rpc_ops *,
1ed26f33	85	struct rpc_task_setup *, int);
4a0de55c AS	86	};
4a0de55c AS	87
a7d42ddb	88	struct nfs_pgio_mirror {
d8a5ad75	89	struct list_head pg_list;
bcb71bba	90	unsigned long pg_bytes_written;
d8a5ad75 TM	91	size_t pg_count;
	92	size_t pg_bsize;
	93	unsigned int pg_base;
a7d42ddb WAA	94	unsigned char pg_recoalesce : 1;
a7d42ddb WAA	95	};
bcb71bba	96
a7d42ddb	97	struct nfs_pageio_descriptor {
bcb71bba	98	struct inode *pg_inode;
1751c363	99	const struct nfs_pageio_ops *pg_ops;
4a0de55c	100	const struct nfs_rw_ops *pg_rw_ops;
bcb71bba TM	101	int pg_ioflags;
bcb71bba TM	102	int pg_error;
50828d7e	103	const struct rpc_call_ops *pg_rpc_callops;
061ae2ed	104	const struct nfs_pgio_completion_ops *pg_completion_ops;
94ad1c80	105	struct pnfs_layout_segment *pg_lseg;
919e3bd9	106	struct nfs_io_completion *pg_io_completion;
584aa810	107	struct nfs_direct_req *pg_dreq;
000dbe0b DW	108	#ifdef CONFIG_NFS_FSCACHE
	109	void *pg_netfs;
	110	#endif
a7d42ddb WAA	111	unsigned int pg_bsize; /* default bsize for mirrors */
	112
	113	u32 pg_mirror_count;
	114	struct nfs_pgio_mirror *pg_mirrors;
	115	struct nfs_pgio_mirror pg_mirrors_static[1];
	116	struct nfs_pgio_mirror *pg_mirrors_dynamic;
	117	u32 pg_mirror_idx; /* current mirror */
33344e0f TM	118	unsigned short pg_maxretrans;
33344e0f TM	119	unsigned char pg_moreio : 1;
d8a5ad75 TM	120	};
d8a5ad75 TM	121
a7d42ddb WAA	122	/* arbitrarily selected limit to number of mirrors */
	123	#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
	124
1da177e4	125	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4	126
70e9db69 TM	127	extern struct nfs_page nfs_page_create_from_page(struct nfs_open_context ctx,
	128	struct page *page,
	129	unsigned int pgbase,
	130	loff_t offset,
	131	unsigned int count);
ab75bff1 TM	132	extern struct nfs_page nfs_page_create_from_folio(struct nfs_open_context ctx,
	133	struct folio *folio,
	134	unsigned int offset,
	135	unsigned int count);
2bfc6e56	136	extern void nfs_release_request(struct nfs_page *);
1da177e4 LT	137
1da177e4 LT	138
bcb71bba TM	139	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	140	struct inode *inode,
1751c363	141	const struct nfs_pageio_ops *pg_ops,
061ae2ed	142	const struct nfs_pgio_completion_ops *compl_ops,
4a0de55c	143	const struct nfs_rw_ops *rw_ops,
bcb71bba	144	size_t bsize,
3bde7afd	145	int how);
8b09bee3 TM	146	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	147	struct nfs_page *);
53113ad3 WAA	148	extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
53113ad3 WAA	149	struct nfs_pgio_header *);
bcb71bba	150	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	151	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
b4fdac1a	152	extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
19345cb2 BH	153	struct nfs_page *prev,
19345cb2 BH	154	struct nfs_page *req);
1da177e4 LT	155	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	156	extern void nfs_unlock_request(struct nfs_page *req);
2bfc6e56	157	extern void nfs_unlock_and_release_request(struct nfs_page *);
e00ed89d	158	extern struct nfs_page nfs_page_group_lock_head(struct nfs_page req);
a62f8e3b	159	extern int nfs_page_group_lock_subrequests(struct nfs_page *head);
b193a78d TM	160	extern void nfs_join_page_group(struct nfs_page *head,
	161	struct nfs_commit_info *cinfo,
	162	struct inode *inode);
1344b7ea	163	extern int nfs_page_group_lock(struct nfs_page *);
2bfc6e56 WAA	164	extern void nfs_page_group_unlock(struct nfs_page *);
2bfc6e56 WAA	165	extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
08ca8b21 TM	166	extern int nfs_page_set_headlock(struct nfs_page *req);
08ca8b21 TM	167	extern void nfs_page_clear_headlock(struct nfs_page *req);
7d6ddf88	168	extern bool nfs_async_iocounter_wait(struct rpc_task , struct nfs_lock_context );
c6a556b8	169
35c5db0e TM	170	/**
	171	* nfs_page_to_folio - Retrieve a struct folio for the request
	172	* @req: pointer to a struct nfs_page
	173	*
	174	* If a folio was assigned to @req, then return it, otherwise return NULL.
	175	*/
	176	static inline struct folio nfs_page_to_folio(const struct nfs_page req)
	177	{
	178	if (test_bit(PG_FOLIO, &req->wb_flags))
	179	return req->wb_folio;
	180	return NULL;
	181	}
	182
	183	/**
	184	* nfs_page_to_page - Retrieve a struct page for the request
	185	* @req: pointer to a struct nfs_page
	186	* @pgbase: folio byte offset
	187	*
	188	* Return the page containing the byte that is at offset @pgbase relative
	189	* to the start of the folio.
	190	* Note: The request starts at offset @req->wb_pgbase.
	191	*/
	192	static inline struct page nfs_page_to_page(const struct nfs_page req,
	193	size_t pgbase)
	194	{
	195	struct folio *folio = nfs_page_to_folio(req);
	196
	197	if (folio == NULL)
	198	return req->wb_page;
	199	return folio_page(folio, pgbase >> PAGE_SHIFT);
	200	}
	201
6dd85e83 TM	202	/**
	203	* nfs_page_to_inode - Retrieve an inode for the request
	204	* @req: pointer to a struct nfs_page
	205	*/
	206	static inline struct inode nfs_page_to_inode(const struct nfs_page req)
	207	{
	208	struct folio *folio = nfs_page_to_folio(req);
	209
	210	if (folio == NULL)
	211	return page_file_mapping(req->wb_page)->host;
	212	return folio_file_mapping(folio)->host;
	213	}
	214
8e0bdc70 TM	215	/**
	216	* nfs_page_max_length - Retrieve the maximum possible length for a request
	217	* @req: pointer to a struct nfs_page
	218	*
	219	* Returns the maximum possible length of a request
	220	*/
	221	static inline size_t nfs_page_max_length(const struct nfs_page *req)
	222	{
	223	struct folio *folio = nfs_page_to_folio(req);
	224
	225	if (folio == NULL)
	226	return PAGE_SIZE;
	227	return folio_size(folio);
	228	}
	229
1da177e4	230	/*
7ad84aa9	231	* Lock the page of an asynchronous request
1da177e4	232	*/
8dd37758 TM	233	static inline int
	234	nfs_lock_request(struct nfs_page *req)
	235	{
7ad84aa9	236	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
8dd37758 TM	237	}
8dd37758 TM	238
3da28eb1 TM	239	/**
	240	* nfs_list_add_request - Insert a request into a list
	241	* @req: request
	242	* @head: head of list into which to insert the request.
	243	*/
	244	static inline void
	245	nfs_list_add_request(struct nfs_page req, struct list_head head)
	246	{
	247	list_add_tail(&req->wb_list, head);
3da28eb1 TM	248	}
3da28eb1 TM	249
078b5fd9 TM	250	/**
	251	* nfs_list_move_request - Move a request to a new list
	252	* @req: request
	253	* @head: head of list into which to insert the request.
	254	*/
	255	static inline void
	256	nfs_list_move_request(struct nfs_page req, struct list_head head)
	257	{
	258	list_move_tail(&req->wb_list, head);
	259	}
1da177e4 LT	260
	261	/**
	262	* nfs_list_remove_request - Remove a request from its wb_list
	263	* @req: request
	264	*/
	265	static inline void
	266	nfs_list_remove_request(struct nfs_page *req)
	267	{
	268	if (list_empty(&req->wb_list))
	269	return;
1da177e4	270	list_del_init(&req->wb_list);
1da177e4 LT	271	}
1da177e4 LT	272
1da177e4 LT	273	static inline struct nfs_page *
	274	nfs_list_entry(struct list_head *head)
	275	{
	276	return list_entry(head, struct nfs_page, wb_list);
	277	}
	278
af887e43	279	static inline loff_t req_offset(const struct nfs_page *req)
1da177e4	280	{
09cbfeaf	281	return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
1da177e4 LT	282	}
1da177e4 LT	283
9fcd5960 TM	284	static inline struct nfs_open_context *
	285	nfs_req_openctx(struct nfs_page *req)
	286	{
c79d183e	287	return req->wb_lock_context->open_context;
9fcd5960 TM	288	}
9fcd5960 TM	289
1da177e4	290	#endif /* _LINUX_NFS_PAGE_H */