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
40 struct list_head wb_list; /* Defines state of page: */
41 struct page *wb_page; /* page to read in/write out */
42 struct nfs_open_context *wb_context; /* File state context info */
43 struct nfs_lock_context *wb_lock_context; /* lock context info */
44 atomic_t wb_complete; /* i/os we're waiting for */
45 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
46 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
47 wb_pgbase, /* Start of page data */
48 wb_bytes; /* Length of request */
49 struct kref wb_kref; /* reference count */
50 unsigned long wb_flags;
51 struct nfs_writeverf wb_verf; /* Commit cookie */
54 struct nfs_pageio_descriptor {
55 struct list_head pg_list;
56 unsigned long pg_bytes_written;
61 struct inode *pg_inode;
62 int (*pg_doio)(struct nfs_pageio_descriptor *);
65 struct pnfs_layout_segment *pg_lseg;
66 int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
69 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
71 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
76 extern void nfs_clear_request(struct nfs_page *req);
77 extern void nfs_release_request(struct nfs_page *req);
80 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
81 pgoff_t idx_start, unsigned int npages, int tag);
82 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
84 int (*doio)(struct nfs_pageio_descriptor *desc),
87 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
89 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
90 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
91 extern int nfs_wait_on_request(struct nfs_page *);
92 extern void nfs_unlock_request(struct nfs_page *req);
93 extern int nfs_set_page_tag_locked(struct nfs_page *req);
94 extern void nfs_clear_page_tag_locked(struct nfs_page *req);
98 * Lock the page of an asynchronous request without getting a new reference
101 nfs_lock_request_dontget(struct nfs_page *req)
103 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
107 * nfs_list_add_request - Insert a request into a list
109 * @head: head of list into which to insert the request.
112 nfs_list_add_request(struct nfs_page *req, struct list_head *head)
114 list_add_tail(&req->wb_list, head);
119 * nfs_list_remove_request - Remove a request from its wb_list
123 nfs_list_remove_request(struct nfs_page *req)
125 if (list_empty(&req->wb_list))
127 list_del_init(&req->wb_list);
130 static inline struct nfs_page *
131 nfs_list_entry(struct list_head *head)
133 return list_entry(head, struct nfs_page, wb_list);
137 loff_t req_offset(struct nfs_page *req)
139 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
142 #endif /* _LINUX_NFS_PAGE_H */