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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 <asm/atomic.h>
20
21/*
22 * Valid flags for the radix tree
23 */
24#define NFS_PAGE_TAG_WRITEBACK 0
25
26/*
27 * Valid flags for a dirty buffer
28 */
29#define PG_BUSY 0
30#define PG_NEED_COMMIT 1
31#define PG_NEED_RESCHED 2
32#define PG_NEED_FLUSH 3
33
34struct nfs_inode;
35struct nfs_page {
36 struct list_head wb_list, /* Defines state of page: */
37 *wb_list_head; /* read/write/commit */
38 struct page *wb_page; /* page to read in/write out */
39 struct nfs_open_context *wb_context; /* File state context info */
40 atomic_t wb_complete; /* i/os we're waiting for */
41 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
42 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
43 wb_pgbase, /* Start of page data */
44 wb_bytes; /* Length of request */
45 atomic_t wb_count; /* reference count */
46 unsigned long wb_flags;
47 struct nfs_writeverf wb_verf; /* Commit cookie */
48};
49
50struct nfs_pageio_descriptor {
51 struct list_head pg_list;
52 unsigned long pg_bytes_written;
53 size_t pg_count;
54 size_t pg_bsize;
55 unsigned int pg_base;
56
57 struct inode *pg_inode;
58 int (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
59 int pg_ioflags;
60 int pg_error;
61};
62
63#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
64
65extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
66 struct inode *inode,
67 struct page *page,
68 unsigned int offset,
69 unsigned int count);
70extern void nfs_clear_request(struct nfs_page *req);
71extern void nfs_release_request(struct nfs_page *req);
72
73
74extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
75 pgoff_t idx_start, unsigned int npages);
76extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
77 struct inode *inode,
78 int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
79 size_t bsize,
80 int how);
81extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
82 struct nfs_page *);
83extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
84extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
85extern int nfs_wait_on_request(struct nfs_page *);
86extern void nfs_unlock_request(struct nfs_page *req);
87extern int nfs_set_page_writeback_locked(struct nfs_page *req);
88extern void nfs_clear_page_writeback(struct nfs_page *req);
89
90
91/*
92 * Lock the page of an asynchronous request without incrementing the wb_count
93 */
94static inline int
95nfs_lock_request_dontget(struct nfs_page *req)
96{
97 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
98}
99
100/*
101 * Lock the page of an asynchronous request
102 */
103static inline int
104nfs_lock_request(struct nfs_page *req)
105{
106 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
107 return 0;
108 atomic_inc(&req->wb_count);
109 return 1;
110}
111
112/**
113 * nfs_list_add_request - Insert a request into a list
114 * @req: request
115 * @head: head of list into which to insert the request.
116 */
117static inline void
118nfs_list_add_request(struct nfs_page *req, struct list_head *head)
119{
120 list_add_tail(&req->wb_list, head);
121 req->wb_list_head = head;
122}
123
124
125/**
126 * nfs_list_remove_request - Remove a request from its wb_list
127 * @req: request
128 */
129static inline void
130nfs_list_remove_request(struct nfs_page *req)
131{
132 if (list_empty(&req->wb_list))
133 return;
134 list_del_init(&req->wb_list);
135 req->wb_list_head = NULL;
136}
137
138static inline struct nfs_page *
139nfs_list_entry(struct list_head *head)
140{
141 return list_entry(head, struct nfs_page, wb_list);
142}
143
144static inline
145loff_t req_offset(struct nfs_page *req)
146{
147 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
148}
149
150#endif /* _LINUX_NFS_PAGE_H */