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 <asm/atomic.h>
22 * Valid flags for the radix tree
24 #define NFS_PAGE_TAG_WRITEBACK 0
27 * Valid flags for a dirty buffer
30 #define PG_NEED_COMMIT 1
31 #define PG_NEED_RESCHED 2
32 #define PG_NEED_FLUSH 3
36 struct list_head wb_list
, /* Defines state of page: */
37 *wb_list_head
; /* read/write/commit */
38 struct page
*wb_page
; /* page to read in/write out */
39 struct nfs_open_context
*wb_context
; /* File state context info */
40 atomic_t wb_complete
; /* i/os we're waiting for */
41 pgoff_t wb_index
; /* Offset >> PAGE_CACHE_SHIFT */
42 unsigned int wb_offset
, /* Offset & ~PAGE_CACHE_MASK */
43 wb_pgbase
, /* Start of page data */
44 wb_bytes
; /* Length of request */
45 atomic_t wb_count
; /* reference count */
46 unsigned long wb_flags
;
47 struct nfs_writeverf wb_verf
; /* Commit cookie */
50 struct nfs_pageio_descriptor
{
51 struct list_head pg_list
;
52 unsigned long pg_bytes_written
;
57 struct inode
*pg_inode
;
58 int (*pg_doio
)(struct inode
*, struct list_head
*, unsigned int, size_t, int);
63 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
65 extern struct nfs_page
*nfs_create_request(struct nfs_open_context
*ctx
,
70 extern void nfs_clear_request(struct nfs_page
*req
);
71 extern void nfs_release_request(struct nfs_page
*req
);
74 extern int nfs_scan_list(struct nfs_inode
*nfsi
, struct list_head
*head
, struct list_head
*dst
,
75 pgoff_t idx_start
, unsigned int npages
);
76 extern void nfs_pageio_init(struct nfs_pageio_descriptor
*desc
,
78 int (*doio
)(struct inode
*, struct list_head
*, unsigned int, size_t, int),
81 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor
*,
83 extern void nfs_pageio_complete(struct nfs_pageio_descriptor
*desc
);
84 extern int nfs_wait_on_request(struct nfs_page
*);
85 extern void nfs_unlock_request(struct nfs_page
*req
);
86 extern int nfs_set_page_writeback_locked(struct nfs_page
*req
);
87 extern void nfs_clear_page_writeback(struct nfs_page
*req
);
91 * Lock the page of an asynchronous request without incrementing the wb_count
94 nfs_lock_request_dontget(struct nfs_page
*req
)
96 return !test_and_set_bit(PG_BUSY
, &req
->wb_flags
);
100 * Lock the page of an asynchronous request
103 nfs_lock_request(struct nfs_page
*req
)
105 if (test_and_set_bit(PG_BUSY
, &req
->wb_flags
))
107 atomic_inc(&req
->wb_count
);
112 * nfs_list_add_request - Insert a request into a list
114 * @head: head of list into which to insert the request.
117 nfs_list_add_request(struct nfs_page
*req
, struct list_head
*head
)
119 list_add_tail(&req
->wb_list
, head
);
120 req
->wb_list_head
= head
;
125 * nfs_list_remove_request - Remove a request from its wb_list
129 nfs_list_remove_request(struct nfs_page
*req
)
131 if (list_empty(&req
->wb_list
))
133 list_del_init(&req
->wb_list
);
134 req
->wb_list_head
= NULL
;
137 static inline struct nfs_page
*
138 nfs_list_entry(struct list_head
*head
)
140 return list_entry(head
, struct nfs_page
, wb_list
);
144 loff_t
req_offset(struct nfs_page
*req
)
146 return (((loff_t
)req
->wb_index
) << PAGE_CACHE_SHIFT
) + req
->wb_offset
;
149 #endif /* _LINUX_NFS_PAGE_H */