1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
* linux/include/linux/nfs_page.h
*
* Copyright (C) 2000 Trond Myklebust
*
* NFS page cache wrapper.
*/
#ifndef _LINUX_NFS_PAGE_H
#define _LINUX_NFS_PAGE_H
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>
#include <asm/atomic.h>
/*
* Valid flags for the radix tree
*/
#define NFS_PAGE_TAG_DIRTY 0
#define NFS_PAGE_TAG_WRITEBACK 1
/*
* Valid flags for a dirty buffer
*/
#define PG_BUSY 0
#define PG_NEED_COMMIT 1
#define PG_NEED_RESCHED 2
#define PG_NEED_FLUSH 3
struct nfs_inode;
struct nfs_page {
struct list_head wb_list, /* Defines state of page: */
*wb_list_head; /* read/write/commit */
struct page *wb_page; /* page to read in/write out */
struct nfs_open_context *wb_context; /* File state context info */
atomic_t wb_complete; /* i/os we're waiting for */
unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
wb_pgbase, /* Start of page data */
wb_bytes; /* Length of request */
atomic_t wb_count; /* reference count */
unsigned long wb_flags;
struct nfs_writeverf wb_verf; /* Commit cookie */
};
struct nfs_pageio_descriptor {
struct list_head pg_list;
size_t pg_count;
size_t pg_bsize;
unsigned int pg_base;
};
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
struct inode *inode,
struct page *page,
unsigned int offset,
unsigned int count);
extern void nfs_clear_request(struct nfs_page *req);
extern void nfs_release_request(struct nfs_page *req);
extern long nfs_scan_dirty(struct address_space *mapping,
struct writeback_control *wbc,
struct list_head *dst);
extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
unsigned long idx_start, unsigned int npages);
extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
size_t iosize);
extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *,
struct list_head *);
extern int nfs_wait_on_request(struct nfs_page *);
extern void nfs_unlock_request(struct nfs_page *req);
extern int nfs_set_page_writeback_locked(struct nfs_page *req);
extern void nfs_clear_page_writeback(struct nfs_page *req);
/*
* Lock the page of an asynchronous request without incrementing the wb_count
*/
static inline int
nfs_lock_request_dontget(struct nfs_page *req)
{
return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}
/*
* Lock the page of an asynchronous request
*/
static inline int
nfs_lock_request(struct nfs_page *req)
{
if (test_and_set_bit(PG_BUSY, &req->wb_flags))
return 0;
atomic_inc(&req->wb_count);
return 1;
}
/**
* nfs_list_add_request - Insert a request into a list
* @req: request
* @head: head of list into which to insert the request.
*/
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
list_add_tail(&req->wb_list, head);
req->wb_list_head = head;
}
/**
* nfs_list_remove_request - Remove a request from its wb_list
* @req: request
*/
static inline void
nfs_list_remove_request(struct nfs_page *req)
{
if (list_empty(&req->wb_list))
return;
list_del_init(&req->wb_list);
req->wb_list_head = NULL;
}
static inline struct nfs_page *
nfs_list_entry(struct list_head *head)
{
return list_entry(head, struct nfs_page, wb_list);
}
static inline
loff_t req_offset(struct nfs_page *req)
{
return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
}
#endif /* _LINUX_NFS_PAGE_H */
|
