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
42 struct list_head wb_list; /* Defines state of page: */
43 struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
45 struct page *wb_page; /* page to read in/write out */
46 struct nfs_open_context *wb_context; /* File state context info */
47 struct nfs_lock_context *wb_lock_context; /* lock context info */
48 atomic_t wb_complete; /* i/os we're waiting for */
49 pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
50 unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
51 wb_pgbase, /* Start of page data */
52 wb_bytes; /* Length of request */
53 struct kref wb_kref; /* reference count */
54 unsigned long wb_flags;
55 struct nfs_writeverf wb_verf; /* Commit cookie */
58 struct nfs_pageio_descriptor {
59 struct list_head pg_list;
60 unsigned long pg_bytes_written;
66 struct inode *pg_inode;
67 int (*pg_doio)(struct nfs_pageio_descriptor *);
70 struct pnfs_layout_segment *pg_lseg;
71 bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
74 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
76 extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
81 extern void nfs_release_request(struct nfs_page *req);
84 extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
85 pgoff_t idx_start, unsigned int npages, int tag);
86 extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
88 int (*doio)(struct nfs_pageio_descriptor *desc),
91 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
93 extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
94 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
95 extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
96 struct nfs_page *prev,
97 struct nfs_page *req);
98 extern int nfs_wait_on_request(struct nfs_page *);
99 extern void nfs_unlock_request(struct nfs_page *req);
100 extern int nfs_set_page_tag_locked(struct nfs_page *req);
101 extern void nfs_clear_page_tag_locked(struct nfs_page *req);
105 * Lock the page of an asynchronous request without getting a new reference
108 nfs_lock_request_dontget(struct nfs_page *req)
110 return !test_and_set_bit(PG_BUSY, &req->wb_flags);
114 * nfs_list_add_request - Insert a request into a list
116 * @head: head of list into which to insert the request.
119 nfs_list_add_request(struct nfs_page *req, struct list_head *head)
121 list_add_tail(&req->wb_list, 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);
137 static inline struct nfs_page *
138 nfs_list_entry(struct list_head *head)
140 return list_entry(head, struct nfs_page, wb_list);
144 loff_t req_offset(struct nfs_page *req)
146 return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
149 #endif /* _LINUX_NFS_PAGE_H */