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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/*
* 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 <linux/kref.h>
/*
* Valid flags for a dirty buffer
*/
enum {
PG_BUSY = 0, /* nfs_{un}lock_request */
PG_MAPPED, /* page private set for buffered io */
PG_CLEAN, /* write succeeded */
PG_COMMIT_TO_DS, /* used by pnfs layouts */
PG_INODE_REF, /* extra ref held by inode when in writeback */
PG_HEADLOCK, /* page group lock of wb_head */
PG_TEARDOWN, /* page group sync for destroy */
PG_UNLOCKPAGE, /* page group sync bit in read path */
PG_UPTODATE, /* page group sync bit in read path */
PG_WB_END, /* page group sync bit in write path */
PG_REMOVE, /* page group sync bit in write path */
};
struct nfs_inode;
struct nfs_page {
struct list_head wb_list; /* Defines state of page: */
struct page *wb_page; /* page to read in/write out */
struct nfs_open_context *wb_context; /* File state context info */
struct nfs_lock_context *wb_lock_context; /* lock context info */
pgoff_t 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 */
struct kref wb_kref; /* reference count */
unsigned long wb_flags;
struct nfs_write_verifier wb_verf; /* Commit cookie */
struct nfs_page *wb_this_page; /* list of reqs for this page */
struct nfs_page *wb_head; /* head pointer for req list */
};
struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
struct nfs_page *);
int (*pg_doio)(struct nfs_pageio_descriptor *);
unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
struct nfs_page *);
void (*pg_cleanup)(struct nfs_pageio_descriptor *);
};
struct nfs_rw_ops {
const fmode_t rw_mode;
struct nfs_pgio_header *(*rw_alloc_header)(void);
void (*rw_free_header)(struct nfs_pgio_header *);
int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *,
struct inode *);
void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *);
void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *,
const struct nfs_rpc_ops *,
struct rpc_task_setup *, int);
};
struct nfs_pgio_mirror {
struct list_head pg_list;
unsigned long pg_bytes_written;
size_t pg_count;
size_t pg_bsize;
unsigned int pg_base;
unsigned char pg_recoalesce : 1;
};
struct nfs_pageio_descriptor {
unsigned char pg_moreio : 1;
struct inode *pg_inode;
const struct nfs_pageio_ops *pg_ops;
const struct nfs_rw_ops *pg_rw_ops;
int pg_ioflags;
int pg_error;
const struct rpc_call_ops *pg_rpc_callops;
const struct nfs_pgio_completion_ops *pg_completion_ops;
struct pnfs_layout_segment *pg_lseg;
struct nfs_direct_req *pg_dreq;
void *pg_layout_private;
unsigned int pg_bsize; /* default bsize for mirrors */
u32 pg_mirror_count;
struct nfs_pgio_mirror *pg_mirrors;
struct nfs_pgio_mirror pg_mirrors_static[1];
struct nfs_pgio_mirror *pg_mirrors_dynamic;
u32 pg_mirror_idx; /* current mirror */
};
/* arbitrarily selected limit to number of mirrors */
#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
#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 page *page,
struct nfs_page *last,
unsigned int offset,
unsigned int count);
extern void nfs_release_request(struct nfs_page *);
extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
struct inode *inode,
const struct nfs_pageio_ops *pg_ops,
const struct nfs_pgio_completion_ops *compl_ops,
const struct nfs_rw_ops *rw_ops,
size_t bsize,
int how);
extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
struct nfs_page *);
extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
struct nfs_pgio_header *);
extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
struct nfs_page *prev,
struct nfs_page *req);
extern int nfs_wait_on_request(struct nfs_page *);
extern void nfs_unlock_request(struct nfs_page *req);
extern void nfs_unlock_and_release_request(struct nfs_page *);
extern int nfs_page_group_lock(struct nfs_page *, bool);
extern void nfs_page_group_lock_wait(struct nfs_page *);
extern void nfs_page_group_unlock(struct nfs_page *);
extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
/*
* Lock the page of an asynchronous request
*/
static inline int
nfs_lock_request(struct nfs_page *req)
{
return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}
/**
* 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);
}
/**
* 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);
}
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 */
|
