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