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
35 struct list_head wb_list; /* Defines state of page: */
36 struct page *wb_page; /* page to read in/write out */
37 struct nfs_open_context *wb_context; /* File state context info */
38 struct nfs_lock_context *wb_lock_context; /* lock context info */
39 atomic_t wb_complete; /* i/os we're waiting for */
40 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
41 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
42 wb_pgbase, /* Start of page data */
43 wb_bytes; /* Length of request */
44 struct kref wb_kref; /* reference count */
45 unsigned long wb_flags;
46 struct nfs_writeverf wb_verf; /* Commit cookie */
49 struct nfs_pageio_descriptor;
50 struct nfs_pageio_ops {
51 void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
52 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
53 int (*pg_doio)(struct nfs_pageio_descriptor *);
56 struct nfs_pageio_descriptor {
57 struct list_head pg_list;
58 unsigned long pg_bytes_written;
62 unsigned char pg_moreio : 1,
65 struct inode *pg_inode;
66 const struct nfs_pageio_ops *pg_ops;
69 const struct rpc_call_ops *pg_rpc_callops;
70 struct pnfs_layout_segment *pg_lseg;
73 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
75 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
80 extern void nfs_release_request(struct nfs_page *req);
83 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
85 const struct nfs_pageio_ops *pg_ops,
88 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
90 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
91 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
92 extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
93 struct nfs_page *prev,
94 struct nfs_page *req);
95 extern int nfs_wait_on_request(struct nfs_page *);
96 extern void nfs_unlock_request(struct nfs_page *req);
99 * Lock the page of an asynchronous request without getting a new reference
102 nfs_lock_request_dontget(struct nfs_page *req)
104 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
108 nfs_lock_request(struct nfs_page *req)
110 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
112 kref_get(&req->wb_kref);
118 * nfs_list_add_request - Insert a request into a list
120 * @head: head of list into which to insert the request.
123 nfs_list_add_request(struct nfs_page *req, struct list_head *head)
125 list_add_tail(&req->wb_list, head);
130 * nfs_list_remove_request - Remove a request from its wb_list
134 nfs_list_remove_request(struct nfs_page *req)
136 if (list_empty(&req->wb_list))
138 list_del_init(&req->wb_list);
141 static inline struct nfs_page *
142 nfs_list_entry(struct list_head *head)
144 return list_entry(head, struct nfs_page, wb_list);
148 loff_t req_offset(struct nfs_page *req)
150 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
153 #endif /* _LINUX_NFS_PAGE_H */