[net-next-2.6.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/nfs_fs_sb.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>

#include <asm/atomic.h>

/*
 * Valid flags for the radix tree
 */
#define NFS_PAGE_TAG_DIRTY	0
#define NFS_PAGE_TAG_WRITEBACK	1

/*
 * Valid flags for a dirty buffer
 */
#define PG_BUSY			0
#define PG_NEED_COMMIT		1
#define PG_NEED_RESCHED		2

struct nfs_inode;
struct nfs_page {
	struct list_head	wb_list,	/* Defines state of page: */
				*wb_list_head;	/*      read/write/commit */
	struct page		*wb_page;	/* page to read in/write out */
	struct nfs_open_context	*wb_context;	/* File state context info */
	atomic_t		wb_complete;	/* i/os we're waiting for */
	unsigned long		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 */
	atomic_t		wb_count;	/* reference count */
	unsigned long		wb_flags;
	struct nfs_writeverf	wb_verf;	/* Commit cookie */
};

#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
#define NFS_NEED_COMMIT(req)	(test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
#define NFS_NEED_RESCHED(req)	(test_bit(PG_NEED_RESCHED,&(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_clear_request(struct nfs_page *req);
extern	void nfs_release_request(struct nfs_page *req);


extern  int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
				unsigned long idx_start, unsigned int npages);
extern	int nfs_scan_list(struct list_head *, struct list_head *,
			  unsigned long, unsigned int);
extern	int nfs_coalesce_requests(struct list_head *, struct list_head *,
				  unsigned int);
extern  int nfs_wait_on_request(struct nfs_page *);
extern	void nfs_unlock_request(struct nfs_page *req);
extern  int nfs_set_page_writeback_locked(struct nfs_page *req);
extern  void nfs_clear_page_writeback(struct nfs_page *req);


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

/*
 * Lock the page of an asynchronous request
 */
static inline int
nfs_lock_request(struct nfs_page *req)
{
	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
		return 0;
	atomic_inc(&req->wb_count);
	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);
	req->wb_list_head = 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);
	req->wb_list_head = NULL;
}

static inline int
nfs_defer_commit(struct nfs_page *req)
{
	return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags);
}

static inline void
nfs_clear_commit(struct nfs_page *req)
{
	smp_mb__before_clear_bit();
	clear_bit(PG_NEED_COMMIT, &req->wb_flags);
	smp_mb__after_clear_bit();
}

static inline int
nfs_defer_reschedule(struct nfs_page *req)
{
	return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags);
}

static inline void
nfs_clear_reschedule(struct nfs_page *req)
{
	smp_mb__before_clear_bit();
	clear_bit(PG_NEED_RESCHED, &req->wb_flags);
	smp_mb__after_clear_bit();
}

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>
	16	#include <linux/nfs_fs_sb.h>
	17	#include <linux/sunrpc/auth.h>
	18	#include <linux/nfs_xdr.h>
	19
	20	#include <asm/atomic.h>
	21
c6a556b8 TM	22	/*
	23	* Valid flags for the radix tree
	24	*/
3da28eb1	25	#define NFS_PAGE_TAG_DIRTY 0
c6a556b8 TM	26	#define NFS_PAGE_TAG_WRITEBACK 1
c6a556b8 TM	27
1da177e4 LT	28	/*
	29	* Valid flags for a dirty buffer
	30	*/
	31	#define PG_BUSY 0
	32	#define PG_NEED_COMMIT 1
	33	#define PG_NEED_RESCHED 2
	34
3da28eb1	35	struct nfs_inode;
1da177e4 LT	36	struct nfs_page {
	37	struct list_head wb_list, /* Defines state of page: */
	38	wb_list_head; / read/write/commit */
	39	struct page wb_page; / page to read in/write out */
	40	struct nfs_open_context wb_context; / File state context info */
	41	atomic_t wb_complete; /* i/os we're waiting for */
	42	unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
	43	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	44	wb_pgbase, /* Start of page data */
	45	wb_bytes; /* Length of request */
	46	atomic_t wb_count; /* reference count */
	47	unsigned long wb_flags;
	48	struct nfs_writeverf wb_verf; /* Commit cookie */
	49	};
	50
	51	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
	52	#define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
	53	#define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags))
	54
	55	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	56	struct inode *inode,
	57	struct page *page,
	58	unsigned int offset,
	59	unsigned int count);
	60	extern void nfs_clear_request(struct nfs_page *req);
	61	extern void nfs_release_request(struct nfs_page *req);
	62
	63
3da28eb1 TM	64	extern int nfs_scan_lock_dirty(struct nfs_inode nfsi, struct list_head dst,
3da28eb1 TM	65	unsigned long idx_start, unsigned int npages);
1da177e4 LT	66	extern int nfs_scan_list(struct list_head , struct list_head ,
	67	unsigned long, unsigned int);
	68	extern int nfs_coalesce_requests(struct list_head , struct list_head ,
	69	unsigned int);
	70	extern int nfs_wait_on_request(struct nfs_page *);
	71	extern void nfs_unlock_request(struct nfs_page *req);
c6a556b8 TM	72	extern int nfs_set_page_writeback_locked(struct nfs_page *req);
	73	extern void nfs_clear_page_writeback(struct nfs_page *req);
	74
1da177e4 LT	75
	76	/*
	77	* Lock the page of an asynchronous request without incrementing the wb_count
	78	*/
	79	static inline int
	80	nfs_lock_request_dontget(struct nfs_page *req)
	81	{
a911fd9a	82	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	83	}
	84
	85	/*
	86	* Lock the page of an asynchronous request
	87	*/
	88	static inline int
	89	nfs_lock_request(struct nfs_page *req)
	90	{
	91	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	92	return 0;
	93	atomic_inc(&req->wb_count);
	94	return 1;
	95	}
	96
3da28eb1 TM	97	/**
	98	* nfs_list_add_request - Insert a request into a list
	99	* @req: request
	100	* @head: head of list into which to insert the request.
	101	*/
	102	static inline void
	103	nfs_list_add_request(struct nfs_page req, struct list_head head)
	104	{
	105	list_add_tail(&req->wb_list, head);
	106	req->wb_list_head = head;
	107	}
	108
1da177e4 LT	109
	110	/**
	111	* nfs_list_remove_request - Remove a request from its wb_list
	112	* @req: request
	113	*/
	114	static inline void
	115	nfs_list_remove_request(struct nfs_page *req)
	116	{
	117	if (list_empty(&req->wb_list))
	118	return;
1da177e4 LT	119	list_del_init(&req->wb_list);
	120	req->wb_list_head = NULL;
	121	}
	122
	123	static inline int
	124	nfs_defer_commit(struct nfs_page *req)
	125	{
a911fd9a	126	return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags);
1da177e4 LT	127	}
	128
	129	static inline void
	130	nfs_clear_commit(struct nfs_page *req)
	131	{
	132	smp_mb__before_clear_bit();
	133	clear_bit(PG_NEED_COMMIT, &req->wb_flags);
	134	smp_mb__after_clear_bit();
	135	}
	136
	137	static inline int
	138	nfs_defer_reschedule(struct nfs_page *req)
	139	{
a911fd9a	140	return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags);
1da177e4 LT	141	}
	142
	143	static inline void
	144	nfs_clear_reschedule(struct nfs_page *req)
	145	{
	146	smp_mb__before_clear_bit();
	147	clear_bit(PG_NEED_RESCHED, &req->wb_flags);
	148	smp_mb__after_clear_bit();
	149	}
	150
	151	static inline struct nfs_page *
	152	nfs_list_entry(struct list_head *head)
	153	{
	154	return list_entry(head, struct nfs_page, wb_list);
	155	}
	156
	157	static inline
	158	loff_t req_offset(struct nfs_page *req)
	159	{
	160	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	161	}
	162
	163	#endif /* _LINUX_NFS_PAGE_H */