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/nfs_fs_sb.h>
17 #include <linux/sunrpc/auth.h>
18 #include <linux/nfs_xdr.h>
20 #include <asm/atomic.h>
23 * Valid flags for a dirty buffer
26 #define PG_NEED_COMMIT 1
27 #define PG_NEED_RESCHED 2
30 struct list_head wb_list, /* Defines state of page: */
31 *wb_list_head; /* read/write/commit */
33 fl_owner_t wb_lockowner;
34 struct inode *wb_inode;
35 struct rpc_cred *wb_cred;
36 struct nfs4_state *wb_state;
37 struct page *wb_page; /* page to read in/write out */
38 atomic_t wb_complete; /* i/os we're waiting for */
39 wait_queue_head_t wb_wait; /* wait queue */
40 unsigned long 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 wb_count; /* reference count */
45 unsigned long wb_flags;
46 struct nfs_writeverf wb_verf; /* Commit cookie */
49 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
50 #define NFS_NEED_COMMIT(req) (test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
51 #define NFS_NEED_RESCHED(req) (test_bit(PG_NEED_RESCHED,&(req)->wb_flags))
53 extern struct nfs_page *nfs_create_request(struct file *, struct inode *,
55 unsigned int, unsigned int);
56 extern void nfs_clear_request(struct nfs_page *req);
57 extern void nfs_release_request(struct nfs_page *req);
60 extern void nfs_list_add_request(struct nfs_page *, struct list_head *);
62 extern int nfs_scan_list(struct list_head *, struct list_head *,
63 unsigned long, unsigned int);
64 extern int nfs_coalesce_requests(struct list_head *, struct list_head *,
66 extern int nfs_wait_on_request(struct nfs_page *);
68 extern spinlock_t nfs_wreq_lock;
71 * Lock the page of an asynchronous request without incrementing the wb_count
74 nfs_lock_request_dontget(struct nfs_page *req)
76 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
82 * Lock the page of an asynchronous request
85 nfs_lock_request(struct nfs_page *req)
87 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
94 nfs_unlock_request(struct nfs_page *req)
96 if (!NFS_WBACK_BUSY(req)) {
97 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
100 smp_mb__before_clear_bit();
101 clear_bit(PG_BUSY, &req->wb_flags);
102 smp_mb__after_clear_bit();
103 wake_up_all(&req->wb_wait);
104 nfs_release_request(req);
108 * nfs_list_remove_request - Remove a request from its wb_list
112 nfs_list_remove_request(struct nfs_page *req)
114 if (list_empty(&req->wb_list))
116 if (!NFS_WBACK_BUSY(req)) {
117 printk(KERN_ERR "NFS: unlocked request attempted removed from list!\n");
120 list_del_init(&req->wb_list);
121 req->wb_list_head = NULL;
125 nfs_defer_commit(struct nfs_page *req)
127 if (test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags))
133 nfs_clear_commit(struct nfs_page *req)
135 smp_mb__before_clear_bit();
136 clear_bit(PG_NEED_COMMIT, &req->wb_flags);
137 smp_mb__after_clear_bit();
141 nfs_defer_reschedule(struct nfs_page *req)
143 if (test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags))
149 nfs_clear_reschedule(struct nfs_page *req)
151 smp_mb__before_clear_bit();
152 clear_bit(PG_NEED_RESCHED, &req->wb_flags);
153 smp_mb__after_clear_bit();
156 static inline struct nfs_page *
157 nfs_list_entry(struct list_head *head)
159 return list_entry(head, struct nfs_page, wb_list);
163 loff_t req_offset(struct nfs_page *req)
165 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
168 #endif /* _LINUX_NFS_PAGE_H */