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
|
/*
* 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/mm.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>
/*
* Valid flags for a dirty buffer
*/
#define PG_BUSY 0
struct nfs_page {
struct list_head wb_hash, /* Inode */
wb_list, /* Defines state of page: */
*wb_list_head; /* read/write/commit */
struct file *wb_file;
struct dentry *wb_dentry;
struct rpc_cred *wb_cred;
struct page *wb_page; /* page to read in/write out */
wait_queue_head_t wb_wait; /* wait queue */
unsigned long wb_timeout; /* when to read/write/commit */
unsigned int wb_offset, /* Offset of read/write */
wb_bytes, /* Length of request */
wb_count, /* reference count */
wb_flags;
struct nfs_writeverf wb_verf; /* Commit cookie */
};
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
extern struct nfs_page *nfs_create_request(struct file *file,
struct page *page,
unsigned int offset,
unsigned int count);
extern void nfs_release_request(struct nfs_page *req);
extern void nfs_list_add_request(struct nfs_page *req,
struct list_head *head);
extern void nfs_list_remove_request(struct nfs_page *req);
extern int nfs_scan_list_timeout(struct list_head *head,
struct list_head *dst,
struct inode *inode);
extern int nfs_scan_list(struct list_head *src, struct list_head *dst,
struct file *file, unsigned long idx_start,
unsigned int npages);
extern int nfs_coalesce_requests(struct list_head *src, struct list_head *dst,
unsigned int maxpages);
extern spinlock_t nfs_wreq_lock;
/*
* 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;
req->wb_count++;
return 1;
}
static __inline__ void
nfs_unlock_request(struct nfs_page *req)
{
if (!NFS_WBACK_BUSY(req)) {
printk(KERN_ERR "NFS: Invalid unlock attempted\n");
BUG();
}
smp_mb__before_clear_bit();
clear_bit(PG_BUSY, &req->wb_flags);
smp_mb__after_clear_bit();
if (waitqueue_active(&req->wb_wait))
wake_up(&req->wb_wait);
nfs_release_request(req);
}
static __inline__ struct nfs_page *
nfs_list_entry(struct list_head *head)
{
return list_entry(head, struct nfs_page, wb_list);
}
static __inline__ struct nfs_page *
nfs_inode_wb_entry(struct list_head *head)
{
return list_entry(head, struct nfs_page, wb_hash);
}
#endif /* _LINUX_NFS_PAGE_H */
|
