[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 <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 when in writeback */
	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 */
	PG_CONTENDED1,		/* Is someone waiting for a lock? */
	PG_CONTENDED2,		/* Is someone waiting for a lock? */
};

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_SHIFT */
	unsigned int		wb_offset,	/* Offset & ~PAGE_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 *);
	unsigned int	(*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
				       struct nfs_page *);
	void	(*pg_cleanup)(struct nfs_pageio_descriptor *);
};

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

struct nfs_pgio_mirror {
	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_recoalesce : 1;
};

struct nfs_pageio_descriptor {
	unsigned char		pg_moreio : 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_io_completion *pg_io_completion;
	struct nfs_direct_req	*pg_dreq;
	unsigned int		pg_bsize;	/* default bsize for mirrors */

	u32			pg_mirror_count;
	struct nfs_pgio_mirror	*pg_mirrors;
	struct nfs_pgio_mirror	pg_mirrors_static[1];
	struct nfs_pgio_mirror	*pg_mirrors_dynamic;
	u32			pg_mirror_idx;	/* current mirror */
};

/* arbitrarily selected limit to number of mirrors */
#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16

#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,
			     gfp_t gfp_flags);
extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
				   struct nfs_page *);
extern  int nfs_pageio_resend(struct nfs_pageio_descriptor *,
			      struct nfs_pgio_header *);
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 int nfs_page_group_lock(struct nfs_page *, bool);
extern void nfs_page_group_lock_wait(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);
extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);

/*
 * 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_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 LT	20
	21	/*
	22	* Valid flags for a dirty buffer
	23	*/
e468bae9	24	enum {
12c05792 WAA	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 */
b412ddf0	29	PG_INODE_REF, /* extra ref held by inode when in writeback */
2bfc6e56 WAA	30	PG_HEADLOCK, /* page group lock of wb_head */
2bfc6e56 WAA	31	PG_TEARDOWN, /* page group sync for destroy */
67d0338e WAA	32	PG_UNLOCKPAGE, /* page group sync bit in read path */
67d0338e WAA	33	PG_UPTODATE, /* page group sync bit in read path */
20633f04 WAA	34	PG_WB_END, /* page group sync bit in write path */
20633f04 WAA	35	PG_REMOVE, /* page group sync bit in write path */
b4f937cf TM	36	PG_CONTENDED1, /* Is someone waiting for a lock? */
b4f937cf TM	37	PG_CONTENDED2, /* Is someone waiting for a lock? */
e468bae9	38	};
1da177e4	39
3da28eb1	40	struct nfs_inode;
1da177e4	41	struct nfs_page {
d6d6dc7c	42	struct list_head wb_list; /* Defines state of page: */
1da177e4 LT	43	struct page wb_page; / page to read in/write out */
1da177e4 LT	44	struct nfs_open_context wb_context; / File state context info */
f11ac8db	45	struct nfs_lock_context wb_lock_context; / lock context info */
ea1754a0 KS	46	pgoff_t wb_index; /* Offset >> PAGE_SHIFT */
ea1754a0 KS	47	unsigned int wb_offset, /* Offset & ~PAGE_MASK */
1da177e4 LT	48	wb_pgbase, /* Start of page data */
1da177e4 LT	49	wb_bytes; /* Length of request */
c03b4024	50	struct kref wb_kref; /* reference count */
1da177e4	51	unsigned long wb_flags;
2f2c63bc	52	struct nfs_write_verifier wb_verf; /* Commit cookie */
2bfc6e56 WAA	53	struct nfs_page wb_this_page; / list of reqs for this page */
2bfc6e56 WAA	54	struct nfs_page wb_head; / head pointer for req list */
1da177e4 LT	55	};
1da177e4 LT	56
1751c363 TM	57	struct nfs_pageio_descriptor;
1751c363 TM	58	struct nfs_pageio_ops {
d8007d4d	59	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
b4fdac1a WAA	60	size_t (pg_test)(struct nfs_pageio_descriptor , struct nfs_page *,
b4fdac1a WAA	61	struct nfs_page *);
1751c363	62	int (pg_doio)(struct nfs_pageio_descriptor );
a7d42ddb WAA	63	unsigned int (pg_get_mirror_count)(struct nfs_pageio_descriptor ,
a7d42ddb WAA	64	struct nfs_page *);
2176bf42	65	void (pg_cleanup)(struct nfs_pageio_descriptor );
1751c363 TM	66	};
1751c363 TM	67
4a0de55c	68	struct nfs_rw_ops {
1e7f3a48 WAA	69	struct nfs_pgio_header (rw_alloc_header)(void);
1e7f3a48 WAA	70	void (rw_free_header)(struct nfs_pgio_header );
d45f60c6 WAA	71	int (rw_done)(struct rpc_task , struct nfs_pgio_header *,
	72	struct inode *);
	73	void (rw_result)(struct rpc_task , struct nfs_pgio_header *);
	74	void (rw_initiate)(struct nfs_pgio_header , struct rpc_message *,
abde71f4	75	const struct nfs_rpc_ops *,
1ed26f33	76	struct rpc_task_setup *, int);
4a0de55c AS	77	};
4a0de55c AS	78
a7d42ddb	79	struct nfs_pgio_mirror {
d8a5ad75	80	struct list_head pg_list;
bcb71bba	81	unsigned long pg_bytes_written;
d8a5ad75 TM	82	size_t pg_count;
	83	size_t pg_bsize;
	84	unsigned int pg_base;
a7d42ddb WAA	85	unsigned char pg_recoalesce : 1;
a7d42ddb WAA	86	};
bcb71bba	87
a7d42ddb WAA	88	struct nfs_pageio_descriptor {
a7d42ddb WAA	89	unsigned char pg_moreio : 1;
bcb71bba	90	struct inode *pg_inode;
1751c363	91	const struct nfs_pageio_ops *pg_ops;
4a0de55c	92	const struct nfs_rw_ops *pg_rw_ops;
bcb71bba TM	93	int pg_ioflags;
bcb71bba TM	94	int pg_error;
50828d7e	95	const struct rpc_call_ops *pg_rpc_callops;
061ae2ed	96	const struct nfs_pgio_completion_ops *pg_completion_ops;
94ad1c80	97	struct pnfs_layout_segment *pg_lseg;
919e3bd9	98	struct nfs_io_completion *pg_io_completion;
584aa810	99	struct nfs_direct_req *pg_dreq;
a7d42ddb WAA	100	unsigned int pg_bsize; /* default bsize for mirrors */
	101
	102	u32 pg_mirror_count;
	103	struct nfs_pgio_mirror *pg_mirrors;
	104	struct nfs_pgio_mirror pg_mirrors_static[1];
	105	struct nfs_pgio_mirror *pg_mirrors_dynamic;
	106	u32 pg_mirror_idx; /* current mirror */
d8a5ad75 TM	107	};
d8a5ad75 TM	108
a7d42ddb WAA	109	/* arbitrarily selected limit to number of mirrors */
	110	#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
	111
1da177e4	112	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
1da177e4 LT	113
1da177e4 LT	114	extern struct nfs_page nfs_create_request(struct nfs_open_context ctx,
1da177e4	115	struct page *page,
2bfc6e56	116	struct nfs_page *last,
1da177e4 LT	117	unsigned int offset,
1da177e4 LT	118	unsigned int count);
2bfc6e56	119	extern void nfs_release_request(struct nfs_page *);
1da177e4 LT	120
1da177e4 LT	121
bcb71bba TM	122	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
bcb71bba TM	123	struct inode *inode,
1751c363	124	const struct nfs_pageio_ops *pg_ops,
061ae2ed	125	const struct nfs_pgio_completion_ops *compl_ops,
4a0de55c	126	const struct nfs_rw_ops *rw_ops,
bcb71bba	127	size_t bsize,
fbe77c30 BC	128	int how,
fbe77c30 BC	129	gfp_t gfp_flags);
8b09bee3 TM	130	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
8b09bee3 TM	131	struct nfs_page *);
53113ad3 WAA	132	extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
53113ad3 WAA	133	struct nfs_pgio_header *);
bcb71bba	134	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
7fe7f848	135	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
b4fdac1a	136	extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
19345cb2 BH	137	struct nfs_page *prev,
19345cb2 BH	138	struct nfs_page *req);
1da177e4 LT	139	extern int nfs_wait_on_request(struct nfs_page *);
1da177e4 LT	140	extern void nfs_unlock_request(struct nfs_page *req);
2bfc6e56	141	extern void nfs_unlock_and_release_request(struct nfs_page *);
e7029206	142	extern int nfs_page_group_lock(struct nfs_page *, bool);
7c3af975	143	extern void nfs_page_group_lock_wait(struct nfs_page *);
2bfc6e56 WAA	144	extern void nfs_page_group_unlock(struct nfs_page *);
2bfc6e56 WAA	145	extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
7d6ddf88	146	extern bool nfs_async_iocounter_wait(struct rpc_task , struct nfs_lock_context );
c6a556b8	147
1da177e4	148	/*
7ad84aa9	149	* Lock the page of an asynchronous request
1da177e4	150	*/
8dd37758 TM	151	static inline int
	152	nfs_lock_request(struct nfs_page *req)
	153	{
7ad84aa9	154	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
8dd37758 TM	155	}
8dd37758 TM	156
3da28eb1 TM	157	/**
	158	* nfs_list_add_request - Insert a request into a list
	159	* @req: request
	160	* @head: head of list into which to insert the request.
	161	*/
	162	static inline void
	163	nfs_list_add_request(struct nfs_page req, struct list_head head)
	164	{
	165	list_add_tail(&req->wb_list, head);
3da28eb1 TM	166	}
3da28eb1 TM	167
1da177e4 LT	168
	169	/**
	170	* nfs_list_remove_request - Remove a request from its wb_list
	171	* @req: request
	172	*/
	173	static inline void
	174	nfs_list_remove_request(struct nfs_page *req)
	175	{
	176	if (list_empty(&req->wb_list))
	177	return;
1da177e4	178	list_del_init(&req->wb_list);
1da177e4 LT	179	}
1da177e4 LT	180
1da177e4 LT	181	static inline struct nfs_page *
	182	nfs_list_entry(struct list_head *head)
	183	{
	184	return list_entry(head, struct nfs_page, wb_list);
	185	}
	186
	187	static inline
	188	loff_t req_offset(struct nfs_page *req)
	189	{
09cbfeaf	190	return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
1da177e4 LT	191	}
	192
	193	#endif /* _LINUX_NFS_PAGE_H */