[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 <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_CLEAN,		/* write succeeded */
	PG_COMMIT_TO_DS,	/* used by pnfs layouts */
	PG_INODE_REF,		/* extra ref held by inode (head req only) */
	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 */
};

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 */
	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_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 */
};

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 *);
};

struct nfs_rw_ops {
	const fmode_t rw_mode;
	struct nfs_pgio_header *(*rw_alloc_header)(void);
	void (*rw_free_header)(struct nfs_pgio_header *);
	void (*rw_release)(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 *,
			    struct rpc_task_setup *, int);
};

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;
	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_direct_req	*pg_dreq;
	void			*pg_layout_private;
};

#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 page *page,
					    struct nfs_page *last,
					    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	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 void 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);

/*
 * 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_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
	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/sunrpc/auth.h>
	17	#include <linux/nfs_xdr.h>
	18
	19	#include <linux/kref.h>
	20
	21	/*
	22	* Valid flags for a dirty buffer
	23	*/
	24	enum {
	25	PG_BUSY = 0, /* nfs_{un}lock_request */
	26	PG_MAPPED, /* page private set for buffered io */
	27	PG_CLEAN, /* write succeeded */
	28	PG_COMMIT_TO_DS, /* used by pnfs layouts */
	29	PG_INODE_REF, /* extra ref held by inode (head req only) */
	30	PG_HEADLOCK, /* page group lock of wb_head */
	31	PG_TEARDOWN, /* page group sync for destroy */
	32	PG_UNLOCKPAGE, /* page group sync bit in read path */
	33	PG_UPTODATE, /* page group sync bit in read path */
	34	PG_WB_END, /* page group sync bit in write path */
	35	PG_REMOVE, /* page group sync bit in write path */
	36	};
	37
	38	struct nfs_inode;
	39	struct nfs_page {
	40	struct list_head wb_list; /* Defines state of page: */
	41	struct page wb_page; / page to read in/write out */
	42	struct nfs_open_context wb_context; / File state context info */
	43	struct nfs_lock_context wb_lock_context; / lock context info */
	44	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
	45	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	46	wb_pgbase, /* Start of page data */
	47	wb_bytes; /* Length of request */
	48	struct kref wb_kref; /* reference count */
	49	unsigned long wb_flags;
	50	struct nfs_write_verifier wb_verf; /* Commit cookie */
	51	struct nfs_page wb_this_page; / list of reqs for this page */
	52	struct nfs_page wb_head; / head pointer for req list */
	53	};
	54
	55	struct nfs_pageio_descriptor;
	56	struct nfs_pageio_ops {
	57	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
	58	size_t (pg_test)(struct nfs_pageio_descriptor , struct nfs_page *,
	59	struct nfs_page *);
	60	int (pg_doio)(struct nfs_pageio_descriptor );
	61	};
	62
	63	struct nfs_rw_ops {
	64	const fmode_t rw_mode;
	65	struct nfs_pgio_header (rw_alloc_header)(void);
	66	void (rw_free_header)(struct nfs_pgio_header );
	67	void (rw_release)(struct nfs_pgio_header );
	68	int (rw_done)(struct rpc_task , struct nfs_pgio_header *,
	69	struct inode *);
	70	void (rw_result)(struct rpc_task , struct nfs_pgio_header *);
	71	void (rw_initiate)(struct nfs_pgio_header , struct rpc_message *,
	72	struct rpc_task_setup *, int);
	73	};
	74
	75	struct nfs_pageio_descriptor {
	76	struct list_head pg_list;
	77	unsigned long pg_bytes_written;
	78	size_t pg_count;
	79	size_t pg_bsize;
	80	unsigned int pg_base;
	81	unsigned char pg_moreio : 1,
	82	pg_recoalesce : 1;
	83
	84	struct inode *pg_inode;
	85	const struct nfs_pageio_ops *pg_ops;
	86	const struct nfs_rw_ops *pg_rw_ops;
	87	int pg_ioflags;
	88	int pg_error;
	89	const struct rpc_call_ops *pg_rpc_callops;
	90	const struct nfs_pgio_completion_ops *pg_completion_ops;
	91	struct pnfs_layout_segment *pg_lseg;
	92	struct nfs_direct_req *pg_dreq;
	93	void *pg_layout_private;
	94	};
	95
	96	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
	97
	98	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	99	struct page *page,
	100	struct nfs_page *last,
	101	unsigned int offset,
	102	unsigned int count);
	103	extern void nfs_release_request(struct nfs_page *);
	104
	105
	106	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
	107	struct inode *inode,
	108	const struct nfs_pageio_ops *pg_ops,
	109	const struct nfs_pgio_completion_ops *compl_ops,
	110	const struct nfs_rw_ops *rw_ops,
	111	size_t bsize,
	112	int how);
	113	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
	114	struct nfs_page *);
	115	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
	116	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
	117	extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
	118	struct nfs_page *prev,
	119	struct nfs_page *req);
	120	extern int nfs_wait_on_request(struct nfs_page *);
	121	extern void nfs_unlock_request(struct nfs_page *req);
	122	extern void nfs_unlock_and_release_request(struct nfs_page *);
	123	extern void nfs_page_group_lock(struct nfs_page *);
	124	extern void nfs_page_group_unlock(struct nfs_page *);
	125	extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
	126
	127	/*
	128	* Lock the page of an asynchronous request
	129	*/
	130	static inline int
	131	nfs_lock_request(struct nfs_page *req)
	132	{
	133	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
	134	}
	135
	136	/**
	137	* nfs_list_add_request - Insert a request into a list
	138	* @req: request
	139	* @head: head of list into which to insert the request.
	140	*/
	141	static inline void
	142	nfs_list_add_request(struct nfs_page req, struct list_head head)
	143	{
	144	list_add_tail(&req->wb_list, head);
	145	}
	146
	147
	148	/**
	149	* nfs_list_remove_request - Remove a request from its wb_list
	150	* @req: request
	151	*/
	152	static inline void
	153	nfs_list_remove_request(struct nfs_page *req)
	154	{
	155	if (list_empty(&req->wb_list))
	156	return;
	157	list_del_init(&req->wb_list);
	158	}
	159
	160	static inline struct nfs_page *
	161	nfs_list_entry(struct list_head *head)
	162	{
	163	return list_entry(head, struct nfs_page, wb_list);
	164	}
	165
	166	static inline
	167	loff_t req_offset(struct nfs_page *req)
	168	{
	169	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	170	}
	171
	172	#endif /* _LINUX_NFS_PAGE_H */