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/sunrpc/auth.h>
17 #include <linux/nfs_xdr.h>
19 #include <linux/kref.h>
22 * Valid flags for the radix tree
24 #define NFS_PAGE_TAG_LOCKED 0
25 #define NFS_PAGE_TAG_COMMIT 1
28 * Valid flags for a dirty buffer
31 #define PG_NEED_COMMIT 1
32 #define PG_NEED_RESCHED 2
33 #define PG_NEED_FLUSH 3
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 pgoff_t 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 struct kref wb_kref; /* reference count */
47 unsigned long wb_flags;
48 struct nfs_writeverf wb_verf; /* Commit cookie */
51 struct nfs_pageio_descriptor {
52 struct list_head pg_list;
53 unsigned long pg_bytes_written;
58 struct inode *pg_inode;
59 int (*pg_doio)(struct inode *, struct list_head *, unsigned int, size_t, int);
64 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
66 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
71 extern void nfs_clear_request(struct nfs_page *req);
72 extern void nfs_release_request(struct nfs_page *req);
75 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
76 pgoff_t idx_start, unsigned int npages, int tag);
77 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
79 int (*doio)(struct inode *, struct list_head *, unsigned int, size_t, int),
82 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
84 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
85 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
86 extern int nfs_wait_on_request(struct nfs_page *);
87 extern void nfs_unlock_request(struct nfs_page *req);
88 extern void nfs_clear_page_tag_locked(struct nfs_page *req);
92 * Lock the page of an asynchronous request without getting a new reference
95 nfs_lock_request_dontget(struct nfs_page *req)
97 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
101 * Lock the page of an asynchronous request and take a reference
104 nfs_lock_request(struct nfs_page *req)
106 if (test_and_set_bit(PG_BUSY, &req->wb_flags))
108 kref_get(&req->wb_kref);
113 * nfs_list_add_request - Insert a request into a list
115 * @head: head of list into which to insert the request.
118 nfs_list_add_request(struct nfs_page *req, struct list_head *head)
120 list_add_tail(&req->wb_list, head);
121 req->wb_list_head = head;
126 * nfs_list_remove_request - Remove a request from its wb_list
130 nfs_list_remove_request(struct nfs_page *req)
132 if (list_empty(&req->wb_list))
134 list_del_init(&req->wb_list);
135 req->wb_list_head = NULL;
138 static inline struct nfs_page *
139 nfs_list_entry(struct list_head *head)
141 return list_entry(head, struct nfs_page, wb_list);
145 loff_t req_offset(struct nfs_page *req)
147 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
150 #endif /* _LINUX_NFS_PAGE_H */