[linux-block.git] / include / linux / nfs_page.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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_FOLIO,		/* Tracking a folio (unset for O_DIRECT) */
	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: */
	union {
		struct page	*wb_page;	/* page to read in/write out */
		struct folio	*wb_folio;
	};
	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 */
	unsigned short		wb_nio;		/* Number of I/O attempts */
};

struct nfs_pgio_mirror;
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_pgio_mirror *
		(*pg_get_mirror)(struct nfs_pageio_descriptor *, u32);
	u32	(*pg_set_mirror)(struct nfs_pageio_descriptor *, u32);
};

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 {
	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 */
	unsigned short		pg_maxretrans;
	unsigned char		pg_moreio : 1;
};

/* 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_page_create_from_page(struct nfs_open_context *ctx,
						  struct page *page,
						  unsigned int pgbase,
						  loff_t offset,
						  unsigned int count);
extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
						   struct folio *folio,
						   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  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	struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req);
extern	int nfs_page_group_lock_subrequests(struct nfs_page *head);
extern	void nfs_join_page_group(struct nfs_page *head, struct inode *inode);
extern int 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);
extern	int nfs_page_set_headlock(struct nfs_page *req);
extern void nfs_page_clear_headlock(struct nfs_page *req);
extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);

/**
 * nfs_page_to_folio - Retrieve a struct folio for the request
 * @req: pointer to a struct nfs_page
 *
 * If a folio was assigned to @req, then return it, otherwise return NULL.
 */
static inline struct folio *nfs_page_to_folio(const struct nfs_page *req)
{
	if (test_bit(PG_FOLIO, &req->wb_flags))
		return req->wb_folio;
	return NULL;
}

/**
 * nfs_page_to_page - Retrieve a struct page for the request
 * @req: pointer to a struct nfs_page
 * @pgbase: folio byte offset
 *
 * Return the page containing the byte that is at offset @pgbase relative
 * to the start of the folio.
 * Note: The request starts at offset @req->wb_pgbase.
 */
static inline struct page *nfs_page_to_page(const struct nfs_page *req,
					    size_t pgbase)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return req->wb_page;
	return folio_page(folio, pgbase >> PAGE_SHIFT);
}

/**
 * nfs_page_to_inode - Retrieve an inode for the request
 * @req: pointer to a struct nfs_page
 */
static inline struct inode *nfs_page_to_inode(const struct nfs_page *req)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return page_file_mapping(req->wb_page)->host;
	return folio_file_mapping(folio)->host;
}

/**
 * nfs_page_max_length - Retrieve the maximum possible length for a request
 * @req: pointer to a struct nfs_page
 *
 * Returns the maximum possible length of a request
 */
static inline size_t nfs_page_max_length(const struct nfs_page *req)
{
	struct folio *folio = nfs_page_to_folio(req);

	if (folio == NULL)
		return PAGE_SIZE;
	return folio_size(folio);
}

/*
 * 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_move_request - Move a request to a new list
 * @req: request
 * @head: head of list into which to insert the request.
 */
static inline void
nfs_list_move_request(struct nfs_page *req, struct list_head *head)
{
	list_move_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(const struct nfs_page *req)
{
	return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
}

static inline struct nfs_open_context *
nfs_req_openctx(struct nfs_page *req)
{
	return req->wb_lock_context->open_context;
}

#endif /* _LINUX_NFS_PAGE_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* linux/include/linux/nfs_page.h
	4	*
	5	* Copyright (C) 2000 Trond Myklebust
	6	*
	7	* NFS page cache wrapper.
	8	*/
	9
	10	#ifndef _LINUX_NFS_PAGE_H
	11	#define _LINUX_NFS_PAGE_H
	12
	13
	14	#include <linux/list.h>
	15	#include <linux/pagemap.h>
	16	#include <linux/wait.h>
	17	#include <linux/sunrpc/auth.h>
	18	#include <linux/nfs_xdr.h>
	19
	20	#include <linux/kref.h>
	21
	22	/*
	23	* Valid flags for a dirty buffer
	24	*/
	25	enum {
	26	PG_BUSY = 0, /* nfs_{un}lock_request */
	27	PG_MAPPED, /* page private set for buffered io */
	28	PG_FOLIO, /* Tracking a folio (unset for O_DIRECT) */
	29	PG_CLEAN, /* write succeeded */
	30	PG_COMMIT_TO_DS, /* used by pnfs layouts */
	31	PG_INODE_REF, /* extra ref held by inode when in writeback */
	32	PG_HEADLOCK, /* page group lock of wb_head */
	33	PG_TEARDOWN, /* page group sync for destroy */
	34	PG_UNLOCKPAGE, /* page group sync bit in read path */
	35	PG_UPTODATE, /* page group sync bit in read path */
	36	PG_WB_END, /* page group sync bit in write path */
	37	PG_REMOVE, /* page group sync bit in write path */
	38	PG_CONTENDED1, /* Is someone waiting for a lock? */
	39	PG_CONTENDED2, /* Is someone waiting for a lock? */
	40	};
	41
	42	struct nfs_inode;
	43	struct nfs_page {
	44	struct list_head wb_list; /* Defines state of page: */
	45	union {
	46	struct page wb_page; / page to read in/write out */
	47	struct folio *wb_folio;
	48	};
	49	struct nfs_lock_context wb_lock_context; / lock context info */
	50	pgoff_t wb_index; /* Offset >> PAGE_SHIFT */
	51	unsigned int wb_offset, /* Offset & ~PAGE_MASK */
	52	wb_pgbase, /* Start of page data */
	53	wb_bytes; /* Length of request */
	54	struct kref wb_kref; /* reference count */
	55	unsigned long wb_flags;
	56	struct nfs_write_verifier wb_verf; /* Commit cookie */
	57	struct nfs_page wb_this_page; / list of reqs for this page */
	58	struct nfs_page wb_head; / head pointer for req list */
	59	unsigned short wb_nio; /* Number of I/O attempts */
	60	};
	61
	62	struct nfs_pgio_mirror;
	63	struct nfs_pageio_descriptor;
	64	struct nfs_pageio_ops {
	65	void (pg_init)(struct nfs_pageio_descriptor , struct nfs_page *);
	66	size_t (pg_test)(struct nfs_pageio_descriptor , struct nfs_page *,
	67	struct nfs_page *);
	68	int (pg_doio)(struct nfs_pageio_descriptor );
	69	unsigned int (pg_get_mirror_count)(struct nfs_pageio_descriptor ,
	70	struct nfs_page *);
	71	void (pg_cleanup)(struct nfs_pageio_descriptor );
	72	struct nfs_pgio_mirror *
	73	(pg_get_mirror)(struct nfs_pageio_descriptor , u32);
	74	u32 (pg_set_mirror)(struct nfs_pageio_descriptor , u32);
	75	};
	76
	77	struct nfs_rw_ops {
	78	struct nfs_pgio_header (rw_alloc_header)(void);
	79	void (rw_free_header)(struct nfs_pgio_header );
	80	int (rw_done)(struct rpc_task , struct nfs_pgio_header *,
	81	struct inode *);
	82	void (rw_result)(struct rpc_task , struct nfs_pgio_header *);
	83	void (rw_initiate)(struct nfs_pgio_header , struct rpc_message *,
	84	const struct nfs_rpc_ops *,
	85	struct rpc_task_setup *, int);
	86	};
	87
	88	struct nfs_pgio_mirror {
	89	struct list_head pg_list;
	90	unsigned long pg_bytes_written;
	91	size_t pg_count;
	92	size_t pg_bsize;
	93	unsigned int pg_base;
	94	unsigned char pg_recoalesce : 1;
	95	};
	96
	97	struct nfs_pageio_descriptor {
	98	struct inode *pg_inode;
	99	const struct nfs_pageio_ops *pg_ops;
	100	const struct nfs_rw_ops *pg_rw_ops;
	101	int pg_ioflags;
	102	int pg_error;
	103	const struct rpc_call_ops *pg_rpc_callops;
	104	const struct nfs_pgio_completion_ops *pg_completion_ops;
	105	struct pnfs_layout_segment *pg_lseg;
	106	struct nfs_io_completion *pg_io_completion;
	107	struct nfs_direct_req *pg_dreq;
	108	unsigned int pg_bsize; /* default bsize for mirrors */
	109
	110	u32 pg_mirror_count;
	111	struct nfs_pgio_mirror *pg_mirrors;
	112	struct nfs_pgio_mirror pg_mirrors_static[1];
	113	struct nfs_pgio_mirror *pg_mirrors_dynamic;
	114	u32 pg_mirror_idx; /* current mirror */
	115	unsigned short pg_maxretrans;
	116	unsigned char pg_moreio : 1;
	117	};
	118
	119	/* arbitrarily selected limit to number of mirrors */
	120	#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
	121
	122	#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
	123
	124	extern struct nfs_page nfs_page_create_from_page(struct nfs_open_context ctx,
	125	struct page *page,
	126	unsigned int pgbase,
	127	loff_t offset,
	128	unsigned int count);
	129	extern struct nfs_page nfs_page_create_from_folio(struct nfs_open_context ctx,
	130	struct folio *folio,
	131	unsigned int offset,
	132	unsigned int count);
	133	extern void nfs_release_request(struct nfs_page *);
	134
	135
	136	extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
	137	struct inode *inode,
	138	const struct nfs_pageio_ops *pg_ops,
	139	const struct nfs_pgio_completion_ops *compl_ops,
	140	const struct nfs_rw_ops *rw_ops,
	141	size_t bsize,
	142	int how);
	143	extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
	144	struct nfs_page *);
	145	extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
	146	struct nfs_pgio_header *);
	147	extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
	148	extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
	149	extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
	150	struct nfs_page *prev,
	151	struct nfs_page *req);
	152	extern int nfs_wait_on_request(struct nfs_page *);
	153	extern void nfs_unlock_request(struct nfs_page *req);
	154	extern void nfs_unlock_and_release_request(struct nfs_page *);
	155	extern struct nfs_page nfs_page_group_lock_head(struct nfs_page req);
	156	extern int nfs_page_group_lock_subrequests(struct nfs_page *head);
	157	extern void nfs_join_page_group(struct nfs_page head, struct inode inode);
	158	extern int nfs_page_group_lock(struct nfs_page *);
	159	extern void nfs_page_group_unlock(struct nfs_page *);
	160	extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
	161	extern int nfs_page_set_headlock(struct nfs_page *req);
	162	extern void nfs_page_clear_headlock(struct nfs_page *req);
	163	extern bool nfs_async_iocounter_wait(struct rpc_task , struct nfs_lock_context );
	164
	165	/**
	166	* nfs_page_to_folio - Retrieve a struct folio for the request
	167	* @req: pointer to a struct nfs_page
	168	*
	169	* If a folio was assigned to @req, then return it, otherwise return NULL.
	170	*/
	171	static inline struct folio nfs_page_to_folio(const struct nfs_page req)
	172	{
	173	if (test_bit(PG_FOLIO, &req->wb_flags))
	174	return req->wb_folio;
	175	return NULL;
	176	}
	177
	178	/**
	179	* nfs_page_to_page - Retrieve a struct page for the request
	180	* @req: pointer to a struct nfs_page
	181	* @pgbase: folio byte offset
	182	*
	183	* Return the page containing the byte that is at offset @pgbase relative
	184	* to the start of the folio.
	185	* Note: The request starts at offset @req->wb_pgbase.
	186	*/
	187	static inline struct page nfs_page_to_page(const struct nfs_page req,
	188	size_t pgbase)
	189	{
	190	struct folio *folio = nfs_page_to_folio(req);
	191
	192	if (folio == NULL)
	193	return req->wb_page;
	194	return folio_page(folio, pgbase >> PAGE_SHIFT);
	195	}
	196
	197	/**
	198	* nfs_page_to_inode - Retrieve an inode for the request
	199	* @req: pointer to a struct nfs_page
	200	*/
	201	static inline struct inode nfs_page_to_inode(const struct nfs_page req)
	202	{
	203	struct folio *folio = nfs_page_to_folio(req);
	204
	205	if (folio == NULL)
	206	return page_file_mapping(req->wb_page)->host;
	207	return folio_file_mapping(folio)->host;
	208	}
	209
	210	/**
	211	* nfs_page_max_length - Retrieve the maximum possible length for a request
	212	* @req: pointer to a struct nfs_page
	213	*
	214	* Returns the maximum possible length of a request
	215	*/
	216	static inline size_t nfs_page_max_length(const struct nfs_page *req)
	217	{
	218	struct folio *folio = nfs_page_to_folio(req);
	219
	220	if (folio == NULL)
	221	return PAGE_SIZE;
	222	return folio_size(folio);
	223	}
	224
	225	/*
	226	* Lock the page of an asynchronous request
	227	*/
	228	static inline int
	229	nfs_lock_request(struct nfs_page *req)
	230	{
	231	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
	232	}
	233
	234	/**
	235	* nfs_list_add_request - Insert a request into a list
	236	* @req: request
	237	* @head: head of list into which to insert the request.
	238	*/
	239	static inline void
	240	nfs_list_add_request(struct nfs_page req, struct list_head head)
	241	{
	242	list_add_tail(&req->wb_list, head);
	243	}
	244
	245	/**
	246	* nfs_list_move_request - Move a request to a new list
	247	* @req: request
	248	* @head: head of list into which to insert the request.
	249	*/
	250	static inline void
	251	nfs_list_move_request(struct nfs_page req, struct list_head head)
	252	{
	253	list_move_tail(&req->wb_list, head);
	254	}
	255
	256	/**
	257	* nfs_list_remove_request - Remove a request from its wb_list
	258	* @req: request
	259	*/
	260	static inline void
	261	nfs_list_remove_request(struct nfs_page *req)
	262	{
	263	if (list_empty(&req->wb_list))
	264	return;
	265	list_del_init(&req->wb_list);
	266	}
	267
	268	static inline struct nfs_page *
	269	nfs_list_entry(struct list_head *head)
	270	{
	271	return list_entry(head, struct nfs_page, wb_list);
	272	}
	273
	274	static inline loff_t req_offset(const struct nfs_page *req)
	275	{
	276	return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
	277	}
	278
	279	static inline struct nfs_open_context *
	280	nfs_req_openctx(struct nfs_page *req)
	281	{
	282	return req->wb_lock_context->open_context;
	283	}
	284
	285	#endif /* _LINUX_NFS_PAGE_H */