[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 <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

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 */
};

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;

	struct inode		*pg_inode;
	int			(*pg_doio)(struct inode *, struct list_head *, size_t, int);
	int 			pg_ioflags;
	int			pg_error;
};

#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_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	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
			     struct inode *inode,
			     int (*doio)(struct inode *, struct list_head *, size_t, int),
			     size_t bsize,
			     int how);
extern	void nfs_pageio_add_list(struct nfs_pageio_descriptor *,
				 struct list_head *);
extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
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 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
1da177e4	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
d8a5ad75 TM	51	struct nfs_pageio_descriptor {
d8a5ad75 TM	52	struct list_head pg_list;
bcb71bba	53	unsigned long pg_bytes_written;
d8a5ad75 TM	54	size_t pg_count;
	55	size_t pg_bsize;
	56	unsigned int pg_base;
bcb71bba TM	57
	58	struct inode *pg_inode;
	59	int (pg_doio)(struct inode , struct list_head *, size_t, int);
	60	int pg_ioflags;
	61	int pg_error;
d8a5ad75 TM	62	};
d8a5ad75 TM	63
1da177e4	64	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	65
	66	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	67	struct inode *inode,
	68	struct page *page,
	69	unsigned int offset,
	70	unsigned int count);
	71	extern void nfs_clear_request(struct nfs_page *req);
	72	extern void nfs_release_request(struct nfs_page *req);
	73
	74
3f442547 TM	75	extern long nfs_scan_dirty(struct address_space *mapping,
	76	struct writeback_control *wbc,
	77	struct list_head *dst);
d2ccddf0 TM	78	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head head, struct list_head *dst,
d2ccddf0 TM	79	unsigned long idx_start, unsigned int npages);
bcb71bba TM	80	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
	81	struct inode *inode,
	82	int (doio)(struct inode , struct list_head *, size_t, int),
	83	size_t bsize,
	84	int how);
d8a5ad75 TM	85	extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *,
d8a5ad75 TM	86	struct list_head *);
bcb71bba	87	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
1da177e4 LT	88	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	89	extern void nfs_unlock_request(struct nfs_page *req);
c6a556b8 TM	90	extern int nfs_set_page_writeback_locked(struct nfs_page *req);
	91	extern void nfs_clear_page_writeback(struct nfs_page *req);
	92
1da177e4 LT	93
	94	/*
	95	* Lock the page of an asynchronous request without incrementing the wb_count
	96	*/
	97	static inline int
	98	nfs_lock_request_dontget(struct nfs_page *req)
	99	{
a911fd9a	100	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	101	}
	102
	103	/*
	104	* Lock the page of an asynchronous request
	105	*/
	106	static inline int
	107	nfs_lock_request(struct nfs_page *req)
	108	{
	109	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
	110	return 0;
	111	atomic_inc(&req->wb_count);
	112	return 1;
	113	}
	114
3da28eb1 TM	115	/**
	116	* nfs_list_add_request - Insert a request into a list
	117	* @req: request
	118	* @head: head of list into which to insert the request.
	119	*/
	120	static inline void
	121	nfs_list_add_request(struct nfs_page req, struct list_head head)
	122	{
	123	list_add_tail(&req->wb_list, head);
	124	req->wb_list_head = head;
	125	}
	126
1da177e4 LT	127
	128	/**
	129	* nfs_list_remove_request - Remove a request from its wb_list
	130	* @req: request
	131	*/
	132	static inline void
	133	nfs_list_remove_request(struct nfs_page *req)
	134	{
	135	if (list_empty(&req->wb_list))
	136	return;
1da177e4 LT	137	list_del_init(&req->wb_list);
	138	req->wb_list_head = NULL;
	139	}
	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 */