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 a dirty buffer
23 */
24enum {
25 PG_BUSY = 0, /* nfs_{un}lock_request */
26 PG_MAPPED, /* page private set for buffered io */
27 PG_CLEAN, /* write succeeded */
28 PG_COMMIT_TO_DS, /* used by pnfs layouts */
29 PG_INODE_REF, /* extra ref held by inode when in writeback */
30 PG_HEADLOCK, /* page group lock of wb_head */
31 PG_TEARDOWN, /* page group sync for destroy */
32 PG_UNLOCKPAGE, /* page group sync bit in read path */
33 PG_UPTODATE, /* page group sync bit in read path */
34 PG_WB_END, /* page group sync bit in write path */
35 PG_REMOVE, /* page group sync bit in write path */
36 PG_CONTENDED1, /* Is someone waiting for a lock? */
37 PG_CONTENDED2, /* Is someone waiting for a lock? */
38};
39
40struct nfs_inode;
41struct nfs_page {
42 struct list_head wb_list; /* Defines state of page: */
43 struct page *wb_page; /* page to read in/write out */
44 struct nfs_open_context *wb_context; /* File state context info */
45 struct nfs_lock_context *wb_lock_context; /* lock context info */
46 pgoff_t wb_index; /* Offset >> PAGE_SHIFT */
47 unsigned int wb_offset, /* Offset & ~PAGE_MASK */
48 wb_pgbase, /* Start of page data */
49 wb_bytes; /* Length of request */
50 struct kref wb_kref; /* reference count */
51 unsigned long wb_flags;
52 struct nfs_write_verifier wb_verf; /* Commit cookie */
53 struct nfs_page *wb_this_page; /* list of reqs for this page */
54 struct nfs_page *wb_head; /* head pointer for req list */
55};
56
57struct nfs_pageio_descriptor;
58struct nfs_pageio_ops {
59 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
60 size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
61 struct nfs_page *);
62 int (*pg_doio)(struct nfs_pageio_descriptor *);
63 unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
64 struct nfs_page *);
65 void (*pg_cleanup)(struct nfs_pageio_descriptor *);
66};
67
68struct nfs_rw_ops {
69 struct nfs_pgio_header *(*rw_alloc_header)(void);
70 void (*rw_free_header)(struct nfs_pgio_header *);
71 int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *,
72 struct inode *);
73 void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *);
74 void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *,
75 const struct nfs_rpc_ops *,
76 struct rpc_task_setup *, int);
77};
78
79struct nfs_pgio_mirror {
80 struct list_head pg_list;
81 unsigned long pg_bytes_written;
82 size_t pg_count;
83 size_t pg_bsize;
84 unsigned int pg_base;
85 unsigned char pg_recoalesce : 1;
86};
87
88struct nfs_pageio_descriptor {
89 unsigned char pg_moreio : 1;
90 struct inode *pg_inode;
91 const struct nfs_pageio_ops *pg_ops;
92 const struct nfs_rw_ops *pg_rw_ops;
93 int pg_ioflags;
94 int pg_error;
95 const struct rpc_call_ops *pg_rpc_callops;
96 const struct nfs_pgio_completion_ops *pg_completion_ops;
97 struct pnfs_layout_segment *pg_lseg;
98 struct nfs_io_completion *pg_io_completion;
99 struct nfs_direct_req *pg_dreq;
100 unsigned int pg_bsize; /* default bsize for mirrors */
101
102 u32 pg_mirror_count;
103 struct nfs_pgio_mirror *pg_mirrors;
104 struct nfs_pgio_mirror pg_mirrors_static[1];
105 struct nfs_pgio_mirror *pg_mirrors_dynamic;
106 u32 pg_mirror_idx; /* current mirror */
107};
108
109/* arbitrarily selected limit to number of mirrors */
110#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
111
112#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
113
114extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
115 struct page *page,
116 struct nfs_page *last,
117 unsigned int offset,
118 unsigned int count);
119extern void nfs_release_request(struct nfs_page *);
120
121
122extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
123 struct inode *inode,
124 const struct nfs_pageio_ops *pg_ops,
125 const struct nfs_pgio_completion_ops *compl_ops,
126 const struct nfs_rw_ops *rw_ops,
127 size_t bsize,
128 int how,
129 gfp_t gfp_flags);
130extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
131 struct nfs_page *);
132extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
133 struct nfs_pgio_header *);
134extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
135extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
136extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
137 struct nfs_page *prev,
138 struct nfs_page *req);
139extern int nfs_wait_on_request(struct nfs_page *);
140extern void nfs_unlock_request(struct nfs_page *req);
141extern void nfs_unlock_and_release_request(struct nfs_page *);
142extern int nfs_page_group_lock(struct nfs_page *, bool);
143extern void nfs_page_group_lock_wait(struct nfs_page *);
144extern void nfs_page_group_unlock(struct nfs_page *);
145extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
146extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);
147
148/*
149 * Lock the page of an asynchronous request
150 */
151static inline int
152nfs_lock_request(struct nfs_page *req)
153{
154 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
155}
156
157/**
158 * nfs_list_add_request - Insert a request into a list
159 * @req: request
160 * @head: head of list into which to insert the request.
161 */
162static inline void
163nfs_list_add_request(struct nfs_page *req, struct list_head *head)
164{
165 list_add_tail(&req->wb_list, head);
166}
167
168
169/**
170 * nfs_list_remove_request - Remove a request from its wb_list
171 * @req: request
172 */
173static inline void
174nfs_list_remove_request(struct nfs_page *req)
175{
176 if (list_empty(&req->wb_list))
177 return;
178 list_del_init(&req->wb_list);
179}
180
181static inline struct nfs_page *
182nfs_list_entry(struct list_head *head)
183{
184 return list_entry(head, struct nfs_page, wb_list);
185}
186
187static inline
188loff_t req_offset(struct nfs_page *req)
189{
190 return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
191}
192
193#endif /* _LINUX_NFS_PAGE_H */