tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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 <asm/atomic.h>
20
21/*
22 * Valid flags for the radix tree
23 */
24#define NFS_PAGE_TAG_DIRTY 0
25#define NFS_PAGE_TAG_WRITEBACK 1
26
27/*
28 * Valid flags for a dirty buffer
29 */
30#define PG_BUSY 0
31#define PG_NEED_COMMIT 1
32#define PG_NEED_RESCHED 2
33#define PG_NEED_FLUSH 3
34#define PG_FLUSHING 4
35
36struct nfs_inode;
37struct nfs_page {
38 struct list_head wb_list, /* Defines state of page: */
39 *wb_list_head; /* read/write/commit */
40 struct page *wb_page; /* page to read in/write out */
41 struct nfs_open_context *wb_context; /* File state context info */
42 atomic_t wb_complete; /* i/os we're waiting for */
43 unsigned long wb_index; /* Offset >> PAGE_CACHE_SHIFT */
44 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
45 wb_pgbase, /* Start of page data */
46 wb_bytes; /* Length of request */
47 atomic_t wb_count; /* reference count */
48 unsigned long wb_flags;
49 struct nfs_writeverf wb_verf; /* Commit cookie */
50};
51
52#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
53#define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
54#define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags))
55
56extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
57 struct inode *inode,
58 struct page *page,
59 unsigned int offset,
60 unsigned int count);
61extern void nfs_clear_request(struct nfs_page *req);
62extern void nfs_release_request(struct nfs_page *req);
63
64
65extern long nfs_scan_dirty(struct address_space *mapping,
66 struct writeback_control *wbc,
67 struct list_head *dst);
68extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst,
69 unsigned long idx_start, unsigned int npages);
70extern int nfs_coalesce_requests(struct list_head *, struct list_head *,
71 unsigned int);
72extern int nfs_wait_on_request(struct nfs_page *);
73extern void nfs_unlock_request(struct nfs_page *req);
74extern int nfs_set_page_writeback_locked(struct nfs_page *req);
75extern void nfs_clear_page_writeback(struct nfs_page *req);
76
77
78/*
79 * Lock the page of an asynchronous request without incrementing the wb_count
80 */
81static inline int
82nfs_lock_request_dontget(struct nfs_page *req)
83{
84 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
85}
86
87/*
88 * Lock the page of an asynchronous request
89 */
90static inline int
91nfs_lock_request(struct nfs_page *req)
92{
93 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
94 return 0;
95 atomic_inc(&req->wb_count);
96 return 1;
97}
98
99/**
100 * nfs_list_add_request - Insert a request into a list
101 * @req: request
102 * @head: head of list into which to insert the request.
103 */
104static inline void
105nfs_list_add_request(struct nfs_page *req, struct list_head *head)
106{
107 list_add_tail(&req->wb_list, head);
108 req->wb_list_head = head;
109}
110
111
112/**
113 * nfs_list_remove_request - Remove a request from its wb_list
114 * @req: request
115 */
116static inline void
117nfs_list_remove_request(struct nfs_page *req)
118{
119 if (list_empty(&req->wb_list))
120 return;
121 list_del_init(&req->wb_list);
122 req->wb_list_head = NULL;
123}
124
125static inline int
126nfs_defer_commit(struct nfs_page *req)
127{
128 return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags);
129}
130
131static inline void
132nfs_clear_commit(struct nfs_page *req)
133{
134 smp_mb__before_clear_bit();
135 clear_bit(PG_NEED_COMMIT, &req->wb_flags);
136 smp_mb__after_clear_bit();
137}
138
139static inline int
140nfs_defer_reschedule(struct nfs_page *req)
141{
142 return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags);
143}
144
145static inline void
146nfs_clear_reschedule(struct nfs_page *req)
147{
148 smp_mb__before_clear_bit();
149 clear_bit(PG_NEED_RESCHED, &req->wb_flags);
150 smp_mb__after_clear_bit();
151}
152
153static inline struct nfs_page *
154nfs_list_entry(struct list_head *head)
155{
156 return list_entry(head, struct nfs_page, wb_list);
157}
158
159static inline
160loff_t req_offset(struct nfs_page *req)
161{
162 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
163}
164
165#endif /* _LINUX_NFS_PAGE_H */