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1da177e4 LT |
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/nfs_fs_sb.h> | |
17 | #include <linux/sunrpc/auth.h> | |
18 | #include <linux/nfs_xdr.h> | |
19 | ||
20 | #include <asm/atomic.h> | |
21 | ||
c6a556b8 TM |
22 | /* |
23 | * Valid flags for the radix tree | |
24 | */ | |
3da28eb1 | 25 | #define NFS_PAGE_TAG_DIRTY 0 |
c6a556b8 TM |
26 | #define NFS_PAGE_TAG_WRITEBACK 1 |
27 | ||
1da177e4 LT |
28 | /* |
29 | * Valid flags for a dirty buffer | |
30 | */ | |
31 | #define PG_BUSY 0 | |
32 | #define PG_NEED_COMMIT 1 | |
33 | #define PG_NEED_RESCHED 2 | |
34 | ||
3da28eb1 | 35 | struct nfs_inode; |
1da177e4 LT |
36 | struct 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 | ||
51 | #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) | |
52 | #define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags)) | |
53 | #define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags)) | |
54 | ||
55 | extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, | |
56 | struct inode *inode, | |
57 | struct page *page, | |
58 | unsigned int offset, | |
59 | unsigned int count); | |
60 | extern void nfs_clear_request(struct nfs_page *req); | |
61 | extern void nfs_release_request(struct nfs_page *req); | |
62 | ||
63 | ||
3da28eb1 TM |
64 | extern int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst, |
65 | unsigned long idx_start, unsigned int npages); | |
1da177e4 LT |
66 | extern int nfs_scan_list(struct list_head *, struct list_head *, |
67 | unsigned long, unsigned int); | |
68 | extern int nfs_coalesce_requests(struct list_head *, struct list_head *, | |
69 | unsigned int); | |
70 | extern int nfs_wait_on_request(struct nfs_page *); | |
71 | extern void nfs_unlock_request(struct nfs_page *req); | |
c6a556b8 TM |
72 | extern int nfs_set_page_writeback_locked(struct nfs_page *req); |
73 | extern void nfs_clear_page_writeback(struct nfs_page *req); | |
74 | ||
1da177e4 LT |
75 | |
76 | /* | |
77 | * Lock the page of an asynchronous request without incrementing the wb_count | |
78 | */ | |
79 | static inline int | |
80 | nfs_lock_request_dontget(struct nfs_page *req) | |
81 | { | |
82 | if (test_and_set_bit(PG_BUSY, &req->wb_flags)) | |
83 | return 0; | |
84 | return 1; | |
85 | } | |
86 | ||
87 | /* | |
88 | * Lock the page of an asynchronous request | |
89 | */ | |
90 | static inline int | |
91 | nfs_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 | ||
3da28eb1 TM |
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 | */ | |
104 | static inline void | |
105 | nfs_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 | ||
1da177e4 LT |
111 | |
112 | /** | |
113 | * nfs_list_remove_request - Remove a request from its wb_list | |
114 | * @req: request | |
115 | */ | |
116 | static inline void | |
117 | nfs_list_remove_request(struct nfs_page *req) | |
118 | { | |
119 | if (list_empty(&req->wb_list)) | |
120 | return; | |
1da177e4 LT |
121 | list_del_init(&req->wb_list); |
122 | req->wb_list_head = NULL; | |
123 | } | |
124 | ||
125 | static inline int | |
126 | nfs_defer_commit(struct nfs_page *req) | |
127 | { | |
128 | if (test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) | |
129 | return 0; | |
130 | return 1; | |
131 | } | |
132 | ||
133 | static inline void | |
134 | nfs_clear_commit(struct nfs_page *req) | |
135 | { | |
136 | smp_mb__before_clear_bit(); | |
137 | clear_bit(PG_NEED_COMMIT, &req->wb_flags); | |
138 | smp_mb__after_clear_bit(); | |
139 | } | |
140 | ||
141 | static inline int | |
142 | nfs_defer_reschedule(struct nfs_page *req) | |
143 | { | |
144 | if (test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags)) | |
145 | return 0; | |
146 | return 1; | |
147 | } | |
148 | ||
149 | static inline void | |
150 | nfs_clear_reschedule(struct nfs_page *req) | |
151 | { | |
152 | smp_mb__before_clear_bit(); | |
153 | clear_bit(PG_NEED_RESCHED, &req->wb_flags); | |
154 | smp_mb__after_clear_bit(); | |
155 | } | |
156 | ||
157 | static inline struct nfs_page * | |
158 | nfs_list_entry(struct list_head *head) | |
159 | { | |
160 | return list_entry(head, struct nfs_page, wb_list); | |
161 | } | |
162 | ||
163 | static inline | |
164 | loff_t req_offset(struct nfs_page *req) | |
165 | { | |
166 | return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; | |
167 | } | |
168 | ||
169 | #endif /* _LINUX_NFS_PAGE_H */ |