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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 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};
37
38struct nfs_inode;
39struct nfs_page {
40 struct list_head wb_list; /* Defines state of page: */
41 struct page *wb_page; /* page to read in/write out */
42 struct nfs_open_context *wb_context; /* File state context info */
43 struct nfs_lock_context *wb_lock_context; /* lock context info */
44 atomic_t wb_complete; /* i/os we're waiting for */
45 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
46 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
47 wb_pgbase, /* Start of page data */
48 wb_bytes; /* Length of request */
49 struct kref wb_kref; /* reference count */
50 unsigned long wb_flags;
51 struct nfs_writeverf wb_verf; /* Commit cookie */
52};
53
54struct nfs_pageio_descriptor {
55 struct list_head pg_list;
56 unsigned long pg_bytes_written;
57 size_t pg_count;
58 size_t pg_bsize;
59 unsigned int pg_base;
60
61 struct inode *pg_inode;
62 int (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
63 int pg_ioflags;
64 int pg_error;
65};
66
67#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
68
69extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
70 struct inode *inode,
71 struct page *page,
72 unsigned int offset,
73 unsigned int count);
74extern void nfs_clear_request(struct nfs_page *req);
75extern void nfs_release_request(struct nfs_page *req);
76
77
78extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
79 pgoff_t idx_start, unsigned int npages, int tag);
80extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
81 struct inode *inode,
82 int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
83 size_t bsize,
84 int how);
85extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
86 struct nfs_page *);
87extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
88extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
89extern int nfs_wait_on_request(struct nfs_page *);
90extern void nfs_unlock_request(struct nfs_page *req);
91extern int nfs_set_page_tag_locked(struct nfs_page *req);
92extern void nfs_clear_page_tag_locked(struct nfs_page *req);
93
94
95/*
96 * Lock the page of an asynchronous request without getting a new reference
97 */
98static inline int
99nfs_lock_request_dontget(struct nfs_page *req)
100{
101 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
102}
103
104/**
105 * nfs_list_add_request - Insert a request into a list
106 * @req: request
107 * @head: head of list into which to insert the request.
108 */
109static inline void
110nfs_list_add_request(struct nfs_page *req, struct list_head *head)
111{
112 list_add_tail(&req->wb_list, head);
113}
114
115
116/**
117 * nfs_list_remove_request - Remove a request from its wb_list
118 * @req: request
119 */
120static inline void
121nfs_list_remove_request(struct nfs_page *req)
122{
123 if (list_empty(&req->wb_list))
124 return;
125 list_del_init(&req->wb_list);
126}
127
128static inline struct nfs_page *
129nfs_list_entry(struct list_head *head)
130{
131 return list_entry(head, struct nfs_page, wb_list);
132}
133
134static inline
135loff_t req_offset(struct nfs_page *req)
136{
137 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
138}
139
140#endif /* _LINUX_NFS_PAGE_H */