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Linux kernel mirror (for testing)
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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_writeverf 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};
73
74#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
75
76extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
77 struct inode *inode,
78 struct page *page,
79 unsigned int offset,
80 unsigned int count);
81extern void nfs_release_request(struct nfs_page *req);
82
83
84extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
85 struct inode *inode,
86 const struct nfs_pageio_ops *pg_ops,
87 const struct nfs_pgio_completion_ops *compl_ops,
88 size_t bsize,
89 int how);
90extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
91 struct nfs_page *);
92extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
93extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
94extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
95 struct nfs_page *prev,
96 struct nfs_page *req);
97extern int nfs_wait_on_request(struct nfs_page *);
98extern void nfs_unlock_request(struct nfs_page *req);
99extern void nfs_unlock_and_release_request(struct nfs_page *req);
100
101/*
102 * Lock the page of an asynchronous request
103 */
104static inline int
105nfs_lock_request(struct nfs_page *req)
106{
107 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
108}
109
110/**
111 * nfs_list_add_request - Insert a request into a list
112 * @req: request
113 * @head: head of list into which to insert the request.
114 */
115static inline void
116nfs_list_add_request(struct nfs_page *req, struct list_head *head)
117{
118 list_add_tail(&req->wb_list, head);
119}
120
121
122/**
123 * nfs_list_remove_request - Remove a request from its wb_list
124 * @req: request
125 */
126static inline void
127nfs_list_remove_request(struct nfs_page *req)
128{
129 if (list_empty(&req->wb_list))
130 return;
131 list_del_init(&req->wb_list);
132}
133
134static inline struct nfs_page *
135nfs_list_entry(struct list_head *head)
136{
137 return list_entry(head, struct nfs_page, wb_list);
138}
139
140static inline
141loff_t req_offset(struct nfs_page *req)
142{
143 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
144}
145
146#endif /* _LINUX_NFS_PAGE_H */