[mirror_ubuntu-artful-kernel.git] / include / linux / nfs_page.h

/*
 * 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,
	PG_MAPPED,
	PG_CLEAN,
	PG_NEED_COMMIT,
	PG_NEED_RESCHED,
	PG_COMMIT_TO_DS,
};

struct nfs_inode;
struct nfs_page {
	struct list_head	wb_list;	/* Defines state of page: */
	struct page		*wb_page;	/* page to read in/write out */
	struct nfs_open_context	*wb_context;	/* File state context info */
	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
	atomic_t		wb_complete;	/* i/os we're waiting for */
	pgoff_t			wb_index;	/* Offset >> PAGE_CACHE_SHIFT */
	unsigned int		wb_offset,	/* Offset & ~PAGE_CACHE_MASK */
				wb_pgbase,	/* Start of page data */
				wb_bytes;	/* Length of request */
	struct kref		wb_kref;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_writeverf	wb_verf;	/* Commit cookie */
};

struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
	void	(*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
	bool	(*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
	int	(*pg_doio)(struct nfs_pageio_descriptor *);
};

struct nfs_pageio_descriptor {
	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_moreio : 1,
				pg_recoalesce : 1;

	struct inode		*pg_inode;
	const struct nfs_pageio_ops *pg_ops;
	int 			pg_ioflags;
	int			pg_error;
	const struct rpc_call_ops *pg_rpc_callops;
	struct pnfs_layout_segment *pg_lseg;
};

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

extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
					    struct inode *inode,
					    struct page *page,
					    unsigned int offset,
					    unsigned int count);
extern	void nfs_release_request(struct nfs_page *req);


extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
			     struct inode *inode,
			     const struct nfs_pageio_ops *pg_ops,
			     size_t bsize,
			     int how);
extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
				   struct nfs_page *);
extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern bool 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);

/*
 * Lock the page of an asynchronous request without getting a new reference
 */
static inline int
nfs_lock_request_dontget(struct nfs_page *req)
{
	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}

static inline int
nfs_lock_request(struct nfs_page *req)
{
	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
		return 0;
	kref_get(&req->wb_kref);
	return 1;
}


/**
 * 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_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(struct nfs_page *req)
{
	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
}

#endif /* _LINUX_NFS_PAGE_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/linux/nfs_page.h
	3	*
	4	* Copyright (C) 2000 Trond Myklebust
	5	*
	6	* NFS page cache wrapper.
	7	*/
	8
	9	#ifndef _LINUX_NFS_PAGE_H
	10	#define _LINUX_NFS_PAGE_H
	11
	12
	13	#include <linux/list.h>
	14	#include <linux/pagemap.h>
	15	#include <linux/wait.h>
1da177e4 LT	16	#include <linux/sunrpc/auth.h>
	17	#include <linux/nfs_xdr.h>
	18
c03b4024	19	#include <linux/kref.h>
1da177e4 LT	20
	21	/*
	22	* Valid flags for a dirty buffer
	23	*/
e468bae9 TM	24	enum {
e468bae9 TM	25	PG_BUSY = 0,
2df485a7	26	PG_MAPPED,
e468bae9 TM	27	PG_CLEAN,
	28	PG_NEED_COMMIT,
	29	PG_NEED_RESCHED,
8dd37758	30	PG_COMMIT_TO_DS,
e468bae9	31	};
1da177e4	32
3da28eb1	33	struct nfs_inode;
1da177e4	34	struct nfs_page {
d6d6dc7c	35	struct list_head wb_list; /* Defines state of page: */
1da177e4 LT	36	struct page wb_page; / page to read in/write out */
1da177e4 LT	37	struct nfs_open_context wb_context; / File state context info */
f11ac8db	38	struct nfs_lock_context wb_lock_context; / lock context info */
1da177e4	39	atomic_t wb_complete; /* i/os we're waiting for */
ca52fec1	40	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
1da177e4 LT	41	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	42	wb_pgbase, /* Start of page data */
	43	wb_bytes; /* Length of request */
c03b4024	44	struct kref wb_kref; /* reference count */
1da177e4 LT	45	unsigned long wb_flags;
	46	struct nfs_writeverf wb_verf; /* Commit cookie */
	47	};
	48
1751c363 TM	49	struct nfs_pageio_descriptor;
1751c363 TM	50	struct nfs_pageio_ops {
d8007d4d	51	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
1751c363 TM	52	bool (pg_test)(struct nfs_pageio_descriptor , struct nfs_page , struct nfs_page );
	53	int (pg_doio)(struct nfs_pageio_descriptor );
	54	};
	55
d8a5ad75 TM	56	struct nfs_pageio_descriptor {
d8a5ad75 TM	57	struct list_head pg_list;
bcb71bba	58	unsigned long pg_bytes_written;
d8a5ad75 TM	59	size_t pg_count;
	60	size_t pg_bsize;
	61	unsigned int pg_base;
d9156f9f TM	62	unsigned char pg_moreio : 1,
d9156f9f TM	63	pg_recoalesce : 1;
bcb71bba TM	64
bcb71bba TM	65	struct inode *pg_inode;
1751c363	66	const struct nfs_pageio_ops *pg_ops;
bcb71bba TM	67	int pg_ioflags;
bcb71bba TM	68	int pg_error;
50828d7e	69	const struct rpc_call_ops *pg_rpc_callops;
94ad1c80	70	struct pnfs_layout_segment *pg_lseg;
d8a5ad75 TM	71	};
d8a5ad75 TM	72
1da177e4	73	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	74
	75	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	76	struct inode *inode,
	77	struct page *page,
	78	unsigned int offset,
	79	unsigned int count);
1da177e4 LT	80	extern void nfs_release_request(struct nfs_page *req);
	81
	82
bcb71bba TM	83	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	84	struct inode *inode,
1751c363	85	const struct nfs_pageio_ops *pg_ops,
bcb71bba TM	86	size_t bsize,
bcb71bba TM	87	int how);
8b09bee3 TM	88	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	89	struct nfs_page *);
bcb71bba	90	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	91	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
19345cb2 BH	92	extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
	93	struct nfs_page *prev,
	94	struct nfs_page *req);
1da177e4 LT	95	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	96	extern void nfs_unlock_request(struct nfs_page *req);
c6a556b8	97
1da177e4	98	/*
c03b4024	99	* Lock the page of an asynchronous request without getting a new reference
1da177e4 LT	100	*/
	101	static inline int
	102	nfs_lock_request_dontget(struct nfs_page *req)
	103	{
a911fd9a	104	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	105	}
1da177e4 LT	106
8dd37758 TM	107	static inline int
	108	nfs_lock_request(struct nfs_page *req)
	109	{
	110	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	111	return 0;
	112	kref_get(&req->wb_kref);
	113	return 1;
	114	}
	115
	116
3da28eb1 TM	117	/**
	118	* nfs_list_add_request - Insert a request into a list
	119	* @req: request
	120	* @head: head of list into which to insert the request.
	121	*/
	122	static inline void
	123	nfs_list_add_request(struct nfs_page req, struct list_head head)
	124	{
	125	list_add_tail(&req->wb_list, head);
3da28eb1 TM	126	}
3da28eb1 TM	127
1da177e4 LT	128
	129	/**
	130	* nfs_list_remove_request - Remove a request from its wb_list
	131	* @req: request
	132	*/
	133	static inline void
	134	nfs_list_remove_request(struct nfs_page *req)
	135	{
	136	if (list_empty(&req->wb_list))
	137	return;
1da177e4	138	list_del_init(&req->wb_list);
1da177e4 LT	139	}
1da177e4 LT	140
1da177e4 LT	141	static inline struct nfs_page *
	142	nfs_list_entry(struct list_head *head)
	143	{
	144	return list_entry(head, struct nfs_page, wb_list);
	145	}
	146
	147	static inline
	148	loff_t req_offset(struct nfs_page *req)
	149	{
	150	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	151	}
	152
	153	#endif /* _LINUX_NFS_PAGE_H */