2 * linux/include/linux/nfs_page.h
4 * Copyright (C) 2000 Trond Myklebust
6 * NFS page cache wrapper.
9 #ifndef _LINUX_NFS_PAGE_H
10 #define _LINUX_NFS_PAGE_H
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>
19 #include <linux/kref.h>
22 * Valid flags for a dirty buffer
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 */
40 struct list_head wb_list
; /* Defines state of page: */
41 struct page
*wb_page
; /* page to read in/write out */
42 struct nfs_open_context
*wb_context
; /* File state context info */
43 struct nfs_lock_context
*wb_lock_context
; /* lock context info */
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_write_verifier wb_verf
; /* Commit cookie */
51 struct nfs_page
*wb_this_page
; /* list of reqs for this page */
52 struct nfs_page
*wb_head
; /* head pointer for req list */
55 struct nfs_pageio_descriptor
;
56 struct nfs_pageio_ops
{
57 void (*pg_init
)(struct nfs_pageio_descriptor
*, struct nfs_page
*);
58 size_t (*pg_test
)(struct nfs_pageio_descriptor
*, struct nfs_page
*,
60 int (*pg_doio
)(struct nfs_pageio_descriptor
*);
61 unsigned int (*pg_get_mirror_count
)(struct nfs_pageio_descriptor
*,
63 void (*pg_cleanup
)(struct nfs_pageio_descriptor
*);
67 const fmode_t rw_mode
;
68 struct nfs_pgio_header
*(*rw_alloc_header
)(void);
69 void (*rw_free_header
)(struct nfs_pgio_header
*);
70 void (*rw_release
)(struct nfs_pgio_header
*);
71 int (*rw_done
)(struct rpc_task
*, struct nfs_pgio_header
*,
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);
79 struct nfs_pgio_mirror
{
80 struct list_head pg_list
;
81 unsigned long pg_bytes_written
;
85 unsigned char pg_recoalesce
: 1;
88 struct 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
;
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_direct_req
*pg_dreq
;
99 void *pg_layout_private
;
100 unsigned int pg_bsize
; /* default bsize for mirrors */
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 */
109 /* arbitrarily selected limit to number of mirrors */
110 #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
112 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
114 extern struct nfs_page
*nfs_create_request(struct nfs_open_context
*ctx
,
116 struct nfs_page
*last
,
119 extern void nfs_release_request(struct nfs_page
*);
122 extern void nfs_pageio_init(struct nfs_pageio_descriptor
*desc
,
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
,
129 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor
*,
131 extern int nfs_pageio_resend(struct nfs_pageio_descriptor
*,
132 struct nfs_pgio_header
*);
133 extern void nfs_pageio_complete(struct nfs_pageio_descriptor
*desc
);
134 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor
*, pgoff_t
);
135 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor
*desc
,
136 struct nfs_page
*prev
,
137 struct nfs_page
*req
);
138 extern int nfs_wait_on_request(struct nfs_page
*);
139 extern void nfs_unlock_request(struct nfs_page
*req
);
140 extern void nfs_unlock_and_release_request(struct nfs_page
*);
141 extern int nfs_page_group_lock(struct nfs_page
*, bool);
142 extern void nfs_page_group_lock_wait(struct nfs_page
*);
143 extern void nfs_page_group_unlock(struct nfs_page
*);
144 extern bool nfs_page_group_sync_on_bit(struct nfs_page
*, unsigned int);
147 * Lock the page of an asynchronous request
150 nfs_lock_request(struct nfs_page
*req
)
152 return !test_and_set_bit(PG_BUSY
, &req
->wb_flags
);
156 * nfs_list_add_request - Insert a request into a list
158 * @head: head of list into which to insert the request.
161 nfs_list_add_request(struct nfs_page
*req
, struct list_head
*head
)
163 list_add_tail(&req
->wb_list
, head
);
168 * nfs_list_remove_request - Remove a request from its wb_list
172 nfs_list_remove_request(struct nfs_page
*req
)
174 if (list_empty(&req
->wb_list
))
176 list_del_init(&req
->wb_list
);
179 static inline struct nfs_page
*
180 nfs_list_entry(struct list_head
*head
)
182 return list_entry(head
, struct nfs_page
, wb_list
);
186 loff_t
req_offset(struct nfs_page
*req
)
188 return (((loff_t
)req
->wb_index
) << PAGE_CACHE_SHIFT
) + req
->wb_offset
;
191 #endif /* _LINUX_NFS_PAGE_H */