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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> | |
1da177e4 LT |
16 | #include <linux/sunrpc/auth.h> |
17 | #include <linux/nfs_xdr.h> | |
18 | ||
19 | #include <asm/atomic.h> | |
20 | ||
c6a556b8 TM |
21 | /* |
22 | * Valid flags for the radix tree | |
23 | */ | |
3da28eb1 | 24 | #define NFS_PAGE_TAG_DIRTY 0 |
c6a556b8 TM |
25 | #define NFS_PAGE_TAG_WRITEBACK 1 |
26 | ||
1da177e4 LT |
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 | ||
3da28eb1 | 34 | struct nfs_inode; |
1da177e4 LT |
35 | struct nfs_page { |
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 | unsigned long 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 */ | |
48 | }; | |
49 | ||
50 | #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags)) | |
51 | #define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags)) | |
52 | #define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags)) | |
53 | ||
54 | extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx, | |
55 | struct inode *inode, | |
56 | struct page *page, | |
57 | unsigned int offset, | |
58 | unsigned int count); | |
59 | extern void nfs_clear_request(struct nfs_page *req); | |
60 | extern void nfs_release_request(struct nfs_page *req); | |
61 | ||
62 | ||
3da28eb1 TM |
63 | extern int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst, |
64 | unsigned long idx_start, unsigned int npages); | |
d2ccddf0 TM |
65 | extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst, |
66 | unsigned long idx_start, unsigned int npages); | |
1da177e4 LT |
67 | extern int nfs_coalesce_requests(struct list_head *, struct list_head *, |
68 | unsigned int); | |
69 | extern int nfs_wait_on_request(struct nfs_page *); | |
70 | extern void nfs_unlock_request(struct nfs_page *req); | |
c6a556b8 TM |
71 | extern int nfs_set_page_writeback_locked(struct nfs_page *req); |
72 | extern void nfs_clear_page_writeback(struct nfs_page *req); | |
73 | ||
1da177e4 LT |
74 | |
75 | /* | |
76 | * Lock the page of an asynchronous request without incrementing the wb_count | |
77 | */ | |
78 | static inline int | |
79 | nfs_lock_request_dontget(struct nfs_page *req) | |
80 | { | |
a911fd9a | 81 | return !test_and_set_bit(PG_BUSY, &req->wb_flags); |
1da177e4 LT |
82 | } |
83 | ||
84 | /* | |
85 | * Lock the page of an asynchronous request | |
86 | */ | |
87 | static inline int | |
88 | nfs_lock_request(struct nfs_page *req) | |
89 | { | |
90 | if (test_and_set_bit(PG_BUSY, &req->wb_flags)) | |
91 | return 0; | |
92 | atomic_inc(&req->wb_count); | |
93 | return 1; | |
94 | } | |
95 | ||
3da28eb1 TM |
96 | /** |
97 | * nfs_list_add_request - Insert a request into a list | |
98 | * @req: request | |
99 | * @head: head of list into which to insert the request. | |
100 | */ | |
101 | static inline void | |
102 | nfs_list_add_request(struct nfs_page *req, struct list_head *head) | |
103 | { | |
104 | list_add_tail(&req->wb_list, head); | |
105 | req->wb_list_head = head; | |
106 | } | |
107 | ||
1da177e4 LT |
108 | |
109 | /** | |
110 | * nfs_list_remove_request - Remove a request from its wb_list | |
111 | * @req: request | |
112 | */ | |
113 | static inline void | |
114 | nfs_list_remove_request(struct nfs_page *req) | |
115 | { | |
116 | if (list_empty(&req->wb_list)) | |
117 | return; | |
1da177e4 LT |
118 | list_del_init(&req->wb_list); |
119 | req->wb_list_head = NULL; | |
120 | } | |
121 | ||
122 | static inline int | |
123 | nfs_defer_commit(struct nfs_page *req) | |
124 | { | |
a911fd9a | 125 | return !test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags); |
1da177e4 LT |
126 | } |
127 | ||
128 | static inline void | |
129 | nfs_clear_commit(struct nfs_page *req) | |
130 | { | |
131 | smp_mb__before_clear_bit(); | |
132 | clear_bit(PG_NEED_COMMIT, &req->wb_flags); | |
133 | smp_mb__after_clear_bit(); | |
134 | } | |
135 | ||
136 | static inline int | |
137 | nfs_defer_reschedule(struct nfs_page *req) | |
138 | { | |
a911fd9a | 139 | return !test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags); |
1da177e4 LT |
140 | } |
141 | ||
142 | static inline void | |
143 | nfs_clear_reschedule(struct nfs_page *req) | |
144 | { | |
145 | smp_mb__before_clear_bit(); | |
146 | clear_bit(PG_NEED_RESCHED, &req->wb_flags); | |
147 | smp_mb__after_clear_bit(); | |
148 | } | |
149 | ||
150 | static inline struct nfs_page * | |
151 | nfs_list_entry(struct list_head *head) | |
152 | { | |
153 | return list_entry(head, struct nfs_page, wb_list); | |
154 | } | |
155 | ||
156 | static inline | |
157 | loff_t req_offset(struct nfs_page *req) | |
158 | { | |
159 | return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset; | |
160 | } | |
161 | ||
162 | #endif /* _LINUX_NFS_PAGE_H */ |