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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 a dirty buffer
23 */
24enum {
25 PG_BUSY = 0,
26 PG_MAPPED,
27 PG_CLEAN,
28 PG_NEED_COMMIT,
29 PG_NEED_RESCHED,
30 PG_COMMIT_TO_DS,
31};
32
33struct nfs_inode;
34struct nfs_page {
35 struct list_head wb_list; /* Defines state of page: */
36 struct page *wb_page; /* page to read in/write out */
37 struct nfs_open_context *wb_context; /* File state context info */
38 struct nfs_lock_context *wb_lock_context; /* lock context info */
39 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
40 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
41 wb_pgbase, /* Start of page data */
42 wb_bytes; /* Length of request */
43 struct kref wb_kref; /* reference count */
44 unsigned long wb_flags;
45 struct nfs_write_verifier wb_verf; /* Commit cookie */
46};
47
48struct nfs_pageio_descriptor;
49struct nfs_pageio_ops {
50 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
51 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
52 int (*pg_doio)(struct nfs_pageio_descriptor *);
53};
54
55struct nfs_pageio_descriptor {
56 struct list_head pg_list;
57 unsigned long pg_bytes_written;
58 size_t pg_count;
59 size_t pg_bsize;
60 unsigned int pg_base;
61 unsigned char pg_moreio : 1,
62 pg_recoalesce : 1;
63
64 struct inode *pg_inode;
65 const struct nfs_pageio_ops *pg_ops;
66 int pg_ioflags;
67 int pg_error;
68 const struct rpc_call_ops *pg_rpc_callops;
69 const struct nfs_pgio_completion_ops *pg_completion_ops;
70 struct pnfs_layout_segment *pg_lseg;
71 struct nfs_direct_req *pg_dreq;
72 void *pg_layout_private;
73};
74
75#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
76
77extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
78 struct inode *inode,
79 struct page *page,
80 unsigned int offset,
81 unsigned int count);
82extern void nfs_release_request(struct nfs_page *req);
83
84
85extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
86 struct inode *inode,
87 const struct nfs_pageio_ops *pg_ops,
88 const struct nfs_pgio_completion_ops *compl_ops,
89 size_t bsize,
90 int how);
91extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
92 struct nfs_page *);
93extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
94extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
95extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
96 struct nfs_page *prev,
97 struct nfs_page *req);
98extern int nfs_wait_on_request(struct nfs_page *);
99extern void nfs_unlock_request(struct nfs_page *req);
100extern void nfs_unlock_and_release_request(struct nfs_page *req);
101
102/*
103 * Lock the page of an asynchronous request
104 */
105static inline int
106nfs_lock_request(struct nfs_page *req)
107{
108 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
109}
110
111/**
112 * nfs_list_add_request - Insert a request into a list
113 * @req: request
114 * @head: head of list into which to insert the request.
115 */
116static inline void
117nfs_list_add_request(struct nfs_page *req, struct list_head *head)
118{
119 list_add_tail(&req->wb_list, head);
120}
121
122
123/**
124 * nfs_list_remove_request - Remove a request from its wb_list
125 * @req: request
126 */
127static inline void
128nfs_list_remove_request(struct nfs_page *req)
129{
130 if (list_empty(&req->wb_list))
131 return;
132 list_del_init(&req->wb_list);
133}
134
135static inline struct nfs_page *
136nfs_list_entry(struct list_head *head)
137{
138 return list_entry(head, struct nfs_page, wb_list);
139}
140
141static inline
142loff_t req_offset(struct nfs_page *req)
143{
144 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
145}
146
147#endif /* _LINUX_NFS_PAGE_H */