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Linux kernel mirror (for testing)
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linux
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_CLEAN,
33 PG_NEED_COMMIT,
34 PG_NEED_RESCHED,
35};
36
37struct nfs_inode;
38struct nfs_page {
39 struct list_head wb_list; /* Defines state of page: */
40 struct page *wb_page; /* page to read in/write out */
41 struct nfs_open_context *wb_context; /* File state context info */
42 struct nfs_lock_context *wb_lock_context; /* lock context info */
43 atomic_t wb_complete; /* i/os we're waiting for */
44 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
45 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
46 wb_pgbase, /* Start of page data */
47 wb_bytes; /* Length of request */
48 struct kref wb_kref; /* reference count */
49 unsigned long wb_flags;
50 struct nfs_writeverf wb_verf; /* Commit cookie */
51};
52
53struct nfs_pageio_descriptor {
54 struct list_head pg_list;
55 unsigned long pg_bytes_written;
56 size_t pg_count;
57 size_t pg_bsize;
58 unsigned int pg_base;
59
60 struct inode *pg_inode;
61 int (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
62 int pg_ioflags;
63 int pg_error;
64};
65
66#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
67
68extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
69 struct inode *inode,
70 struct page *page,
71 unsigned int offset,
72 unsigned int count);
73extern void nfs_clear_request(struct nfs_page *req);
74extern void nfs_release_request(struct nfs_page *req);
75
76
77extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
78 pgoff_t idx_start, unsigned int npages, int tag);
79extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
80 struct inode *inode,
81 int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
82 size_t bsize,
83 int how);
84extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
85 struct nfs_page *);
86extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
87extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
88extern int nfs_wait_on_request(struct nfs_page *);
89extern void nfs_unlock_request(struct nfs_page *req);
90extern int nfs_set_page_tag_locked(struct nfs_page *req);
91extern void nfs_clear_page_tag_locked(struct nfs_page *req);
92
93
94/*
95 * Lock the page of an asynchronous request without getting a new reference
96 */
97static inline int
98nfs_lock_request_dontget(struct nfs_page *req)
99{
100 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
101}
102
103/**
104 * nfs_list_add_request - Insert a request into a list
105 * @req: request
106 * @head: head of list into which to insert the request.
107 */
108static inline void
109nfs_list_add_request(struct nfs_page *req, struct list_head *head)
110{
111 list_add_tail(&req->wb_list, head);
112}
113
114
115/**
116 * nfs_list_remove_request - Remove a request from its wb_list
117 * @req: request
118 */
119static inline void
120nfs_list_remove_request(struct nfs_page *req)
121{
122 if (list_empty(&req->wb_list))
123 return;
124 list_del_init(&req->wb_list);
125}
126
127static inline struct nfs_page *
128nfs_list_entry(struct list_head *head)
129{
130 return list_entry(head, struct nfs_page, wb_list);
131}
132
133static inline
134loff_t req_offset(struct nfs_page *req)
135{
136 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
137}
138
139#endif /* _LINUX_NFS_PAGE_H */