blob: 3ef8e0441473db0d62c377e84409a47fca2de710 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/sunrpc/auth.h>
17#include <linux/nfs_xdr.h>
18
19#include <asm/atomic.h>
20
21/*
Trond Myklebustc6a556b2005-06-22 17:16:30 +000022 * Valid flags for the radix tree
23 */
Trond Myklebust3da28eb2005-06-22 17:16:31 +000024#define NFS_PAGE_TAG_DIRTY 0
Trond Myklebustc6a556b2005-06-22 17:16:30 +000025#define NFS_PAGE_TAG_WRITEBACK 1
26
27/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 * Valid flags for a dirty buffer
29 */
30#define PG_BUSY 0
31#define PG_NEED_COMMIT 1
32#define PG_NEED_RESCHED 2
Trond Myklebust1a545332006-12-05 00:35:40 -050033#define PG_NEED_FLUSH 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Trond Myklebust3da28eb2005-06-22 17:16:31 +000035struct nfs_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036struct nfs_page {
37 struct list_head wb_list, /* Defines state of page: */
38 *wb_list_head; /* read/write/commit */
39 struct page *wb_page; /* page to read in/write out */
40 struct nfs_open_context *wb_context; /* File state context info */
41 atomic_t wb_complete; /* i/os we're waiting for */
42 unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
43 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
44 wb_pgbase, /* Start of page data */
45 wb_bytes; /* Length of request */
46 atomic_t wb_count; /* reference count */
47 unsigned long wb_flags;
48 struct nfs_writeverf wb_verf; /* Commit cookie */
49};
50
Trond Myklebustd8a5ad72007-04-02 18:48:28 -040051struct nfs_pageio_descriptor {
52 struct list_head pg_list;
53 size_t pg_count;
54 size_t pg_bsize;
55 unsigned int pg_base;
56};
57
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
61 struct inode *inode,
62 struct page *page,
63 unsigned int offset,
64 unsigned int count);
65extern void nfs_clear_request(struct nfs_page *req);
66extern void nfs_release_request(struct nfs_page *req);
67
68
Trond Myklebust3f442542006-09-17 14:46:44 -040069extern long nfs_scan_dirty(struct address_space *mapping,
70 struct writeback_control *wbc,
71 struct list_head *dst);
Trond Myklebustd2ccddf2006-05-31 01:13:38 -040072extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
73 unsigned long idx_start, unsigned int npages);
Trond Myklebustd8a5ad72007-04-02 18:48:28 -040074extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
75 size_t iosize);
76extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *,
77 struct list_head *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078extern int nfs_wait_on_request(struct nfs_page *);
79extern void nfs_unlock_request(struct nfs_page *req);
Trond Myklebustc6a556b2005-06-22 17:16:30 +000080extern int nfs_set_page_writeback_locked(struct nfs_page *req);
81extern void nfs_clear_page_writeback(struct nfs_page *req);
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84/*
85 * Lock the page of an asynchronous request without incrementing the wb_count
86 */
87static inline int
88nfs_lock_request_dontget(struct nfs_page *req)
89{
Chuck Levera911fd92005-11-30 18:08:59 -050090 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091}
92
93/*
94 * Lock the page of an asynchronous request
95 */
96static inline int
97nfs_lock_request(struct nfs_page *req)
98{
99 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
100 return 0;
101 atomic_inc(&req->wb_count);
102 return 1;
103}
104
Trond Myklebust3da28eb2005-06-22 17:16:31 +0000105/**
106 * nfs_list_add_request - Insert a request into a list
107 * @req: request
108 * @head: head of list into which to insert the request.
109 */
110static inline void
111nfs_list_add_request(struct nfs_page *req, struct list_head *head)
112{
113 list_add_tail(&req->wb_list, head);
114 req->wb_list_head = head;
115}
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118/**
119 * nfs_list_remove_request - Remove a request from its wb_list
120 * @req: request
121 */
122static inline void
123nfs_list_remove_request(struct nfs_page *req)
124{
125 if (list_empty(&req->wb_list))
126 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 list_del_init(&req->wb_list);
128 req->wb_list_head = NULL;
129}
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131static inline struct nfs_page *
132nfs_list_entry(struct list_head *head)
133{
134 return list_entry(head, struct nfs_page, wb_list);
135}
136
137static inline
138loff_t req_offset(struct nfs_page *req)
139{
140 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
141}
142
143#endif /* _LINUX_NFS_PAGE_H */