[deliverable/linux.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 <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
#define PG_NEED_FLUSH		3
#define PG_FLUSHING		4

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	long nfs_scan_dirty(struct address_space *mapping,
				struct writeback_control *wbc,
				struct list_head *dst);
extern	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
			  unsigned long idx_start, unsigned int npages);
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>
1da177e4 LT	16	#include <linux/sunrpc/auth.h>
	17	#include <linux/nfs_xdr.h>
	18
	19	#include <asm/atomic.h>
	20
c6a556b8 TM	21	/*
	22	* Valid flags for the radix tree
	23	*/
3da28eb1	24	#define NFS_PAGE_TAG_DIRTY 0
c6a556b8 TM	25	#define NFS_PAGE_TAG_WRITEBACK 1
c6a556b8 TM	26
1da177e4 LT	27	/*
	28	* Valid flags for a dirty buffer
	29	*/
	30	#define PG_BUSY 0
	31	#define PG_NEED_COMMIT 1
	32	#define PG_NEED_RESCHED 2
1a54533e	33	#define PG_NEED_FLUSH 3
e261f51f	34	#define PG_FLUSHING 4
1da177e4	35
3da28eb1	36	struct nfs_inode;
1da177e4 LT	37	struct nfs_page {
	38	struct list_head wb_list, /* Defines state of page: */
	39	wb_list_head; / read/write/commit */
	40	struct page wb_page; / page to read in/write out */
	41	struct nfs_open_context wb_context; / File state context info */
	42	atomic_t wb_complete; /* i/os we're waiting for */
	43	unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
	44	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	45	wb_pgbase, /* Start of page data */
	46	wb_bytes; /* Length of request */
	47	atomic_t wb_count; /* reference count */
	48	unsigned long wb_flags;
	49	struct nfs_writeverf wb_verf; /* Commit cookie */
	50	};
	51
	52	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
	53	#define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
	54	#define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags))
	55
	56	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	57	struct inode *inode,
	58	struct page *page,
	59	unsigned int offset,
	60	unsigned int count);
	61	extern void nfs_clear_request(struct nfs_page *req);
	62	extern void nfs_release_request(struct nfs_page *req);
	63
	64
3f442547 TM	65	extern long nfs_scan_dirty(struct address_space *mapping,
	66	struct writeback_control *wbc,
	67	struct list_head *dst);
d2ccddf0 TM	68	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head head, struct list_head *dst,
d2ccddf0 TM	69	unsigned long idx_start, unsigned int npages);
1da177e4 LT	70	extern int nfs_coalesce_requests(struct list_head , struct list_head ,
	71	unsigned int);
	72	extern int nfs_wait_on_request(struct nfs_page *);
	73	extern void nfs_unlock_request(struct nfs_page *req);
c6a556b8 TM	74	extern int nfs_set_page_writeback_locked(struct nfs_page *req);
	75	extern void nfs_clear_page_writeback(struct nfs_page *req);
	76
1da177e4 LT	77
	78	/*
	79	* Lock the page of an asynchronous request without incrementing the wb_count
	80	*/
	81	static inline int
	82	nfs_lock_request_dontget(struct nfs_page *req)
	83	{
a911fd9a	84	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	85	}
	86
	87	/*
	88	* Lock the page of an asynchronous request
	89	*/
	90	static inline int
	91	nfs_lock_request(struct nfs_page *req)
	92	{
	93	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	94	return 0;
	95	atomic_inc(&req->wb_count);
	96	return 1;
	97	}
	98
3da28eb1 TM	99	/**
	100	* nfs_list_add_request - Insert a request into a list
	101	* @req: request
	102	* @head: head of list into which to insert the request.
	103	*/
	104	static inline void
	105	nfs_list_add_request(struct nfs_page req, struct list_head head)
	106	{
	107	list_add_tail(&req->wb_list, head);
	108	req->wb_list_head = head;
	109	}
	110
1da177e4 LT	111
	112	/**
	113	* nfs_list_remove_request - Remove a request from its wb_list
	114	* @req: request
	115	*/
	116	static inline void
	117	nfs_list_remove_request(struct nfs_page *req)
	118	{
	119	if (list_empty(&req->wb_list))
	120	return;
1da177e4 LT	121	list_del_init(&req->wb_list);
	122	req->wb_list_head = NULL;
	123	}
	124
	125	static inline int
	126	nfs_defer_commit(struct nfs_page *req)
	127	{
a911fd9a	128	return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags);
1da177e4 LT	129	}
	130
	131	static inline void
	132	nfs_clear_commit(struct nfs_page *req)
	133	{
	134	smp_mb__before_clear_bit();
	135	clear_bit(PG_NEED_COMMIT, &req->wb_flags);
	136	smp_mb__after_clear_bit();
	137	}
	138
	139	static inline int
	140	nfs_defer_reschedule(struct nfs_page *req)
	141	{
a911fd9a	142	return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags);
1da177e4 LT	143	}
	144
	145	static inline void
	146	nfs_clear_reschedule(struct nfs_page *req)
	147	{
	148	smp_mb__before_clear_bit();
	149	clear_bit(PG_NEED_RESCHED, &req->wb_flags);
	150	smp_mb__after_clear_bit();
	151	}
	152
	153	static inline struct nfs_page *
	154	nfs_list_entry(struct list_head *head)
	155	{
	156	return list_entry(head, struct nfs_page, wb_list);
	157	}
	158
	159	static inline
	160	loff_t req_offset(struct nfs_page *req)
	161	{
	162	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	163	}
	164
	165	#endif /* _LINUX_NFS_PAGE_H */