[mirror_ubuntu-bionic-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 the radix tree
 */
#define NFS_PAGE_TAG_LOCKED	0
#define NFS_PAGE_TAG_COMMIT	1

/*
 * Valid flags for a dirty buffer
 */
enum {
	PG_BUSY = 0,
	PG_MAPPED,
	PG_CLEAN,
	PG_NEED_COMMIT,
	PG_NEED_RESCHED,
	PG_PNFS_COMMIT,
	PG_PARTIAL_READ_FAILED,
};

struct nfs_inode;
struct nfs_page {
	union {
		struct list_head	wb_list;	/* Defines state of page: */
		struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
	};
	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	int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
			  pgoff_t idx_start, unsigned int npages, int tag);
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);
extern	int nfs_set_page_tag_locked(struct nfs_page *req);
extern  void nfs_clear_page_tag_locked(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);
}

/**
 * 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	20
c6a556b8 TM	21	/*
	22	* Valid flags for the radix tree
	23	*/
9fd367f0	24	#define NFS_PAGE_TAG_LOCKED 0
5c369683	25	#define NFS_PAGE_TAG_COMMIT 1
c6a556b8	26
1da177e4 LT	27	/*
	28	* Valid flags for a dirty buffer
	29	*/
e468bae9 TM	30	enum {
e468bae9 TM	31	PG_BUSY = 0,
2df485a7	32	PG_MAPPED,
e468bae9 TM	33	PG_CLEAN,
	34	PG_NEED_COMMIT,
	35	PG_NEED_RESCHED,
a861a1e1	36	PG_PNFS_COMMIT,
fba73005	37	PG_PARTIAL_READ_FAILED,
e468bae9	38	};
1da177e4	39
3da28eb1	40	struct nfs_inode;
1da177e4	41	struct nfs_page {
a861a1e1 FI	42	union {
	43	struct list_head wb_list; /* Defines state of page: */
	44	struct pnfs_layout_segment wb_commit_lseg; / Used when PG_PNFS_COMMIT set */
	45	};
1da177e4 LT	46	struct page wb_page; / page to read in/write out */
1da177e4 LT	47	struct nfs_open_context wb_context; / File state context info */
f11ac8db	48	struct nfs_lock_context wb_lock_context; / lock context info */
1da177e4	49	atomic_t wb_complete; /* i/os we're waiting for */
ca52fec1	50	pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
1da177e4 LT	51	unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
	52	wb_pgbase, /* Start of page data */
	53	wb_bytes; /* Length of request */
c03b4024	54	struct kref wb_kref; /* reference count */
1da177e4 LT	55	unsigned long wb_flags;
	56	struct nfs_writeverf wb_verf; /* Commit cookie */
	57	};
	58
1751c363 TM	59	struct nfs_pageio_descriptor;
1751c363 TM	60	struct nfs_pageio_ops {
d8007d4d	61	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
1751c363 TM	62	bool (pg_test)(struct nfs_pageio_descriptor , struct nfs_page , struct nfs_page );
	63	int (pg_doio)(struct nfs_pageio_descriptor );
	64	};
	65
d8a5ad75 TM	66	struct nfs_pageio_descriptor {
d8a5ad75 TM	67	struct list_head pg_list;
bcb71bba	68	unsigned long pg_bytes_written;
d8a5ad75 TM	69	size_t pg_count;
	70	size_t pg_bsize;
	71	unsigned int pg_base;
d9156f9f TM	72	unsigned char pg_moreio : 1,
d9156f9f TM	73	pg_recoalesce : 1;
bcb71bba TM	74
bcb71bba TM	75	struct inode *pg_inode;
1751c363	76	const struct nfs_pageio_ops *pg_ops;
bcb71bba TM	77	int pg_ioflags;
bcb71bba TM	78	int pg_error;
50828d7e	79	const struct rpc_call_ops *pg_rpc_callops;
94ad1c80	80	struct pnfs_layout_segment *pg_lseg;
d8a5ad75 TM	81	};
d8a5ad75 TM	82
1da177e4	83	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	84
	85	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
	86	struct inode *inode,
	87	struct page *page,
	88	unsigned int offset,
	89	unsigned int count);
1da177e4 LT	90	extern void nfs_release_request(struct nfs_page *req);
	91
	92
5c369683 TM	93	extern int nfs_scan_list(struct nfs_inode nfsi, struct list_head dst,
5c369683 TM	94	pgoff_t idx_start, unsigned int npages, int tag);
bcb71bba TM	95	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	96	struct inode *inode,
1751c363	97	const struct nfs_pageio_ops *pg_ops,
bcb71bba TM	98	size_t bsize,
bcb71bba TM	99	int how);
8b09bee3 TM	100	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	101	struct nfs_page *);
bcb71bba	102	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	103	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
19345cb2 BH	104	extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
	105	struct nfs_page *prev,
	106	struct nfs_page *req);
1da177e4 LT	107	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	108	extern void nfs_unlock_request(struct nfs_page *req);
acee478a	109	extern int nfs_set_page_tag_locked(struct nfs_page *req);
9fd367f0	110	extern void nfs_clear_page_tag_locked(struct nfs_page *req);
c6a556b8	111
1da177e4	112	/*
c03b4024	113	* Lock the page of an asynchronous request without getting a new reference
1da177e4 LT	114	*/
	115	static inline int
	116	nfs_lock_request_dontget(struct nfs_page *req)
	117	{
a911fd9a	118	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
1da177e4 LT	119	}
1da177e4 LT	120
3da28eb1 TM	121	/**
	122	* nfs_list_add_request - Insert a request into a list
	123	* @req: request
	124	* @head: head of list into which to insert the request.
	125	*/
	126	static inline void
	127	nfs_list_add_request(struct nfs_page req, struct list_head head)
	128	{
	129	list_add_tail(&req->wb_list, head);
3da28eb1 TM	130	}
3da28eb1 TM	131
1da177e4 LT	132
	133	/**
	134	* nfs_list_remove_request - Remove a request from its wb_list
	135	* @req: request
	136	*/
	137	static inline void
	138	nfs_list_remove_request(struct nfs_page *req)
	139	{
	140	if (list_empty(&req->wb_list))
	141	return;
1da177e4	142	list_del_init(&req->wb_list);
1da177e4 LT	143	}
1da177e4 LT	144
1da177e4 LT	145	static inline struct nfs_page *
	146	nfs_list_entry(struct list_head *head)
	147	{
	148	return list_entry(head, struct nfs_page, wb_list);
	149	}
	150
	151	static inline
	152	loff_t req_offset(struct nfs_page *req)
	153	{
	154	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
	155	}
	156
	157	#endif /* _LINUX_NFS_PAGE_H */