1 files changed, 151 insertions, 0 deletions
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
new file mode 100644
index 000000000000..39e4895bcdb4
--- /dev/null
+++ b/include/linux/nfs_page.h
@@ -0,0 +1,151 @@
+/*
+ * linux/include/linux/nfs_page.h
+ *
+ * Copyright (C) 2000 Trond Myklebust
+ *
+ * NFS page cache wrapper.
+ */
+
+#ifndef _LINUX_NFS_PAGE_H
+#define _LINUX_NFS_PAGE_H
+
+
+#include <linux/list.h>
+#include <linux/pagemap.h>
+#include <linux/wait.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/nfs_xdr.h>
+
+#include <asm/atomic.h>
+
+/*
+ * Valid flags for a dirty buffer
+ */
+#define PG_BUSY			0
+#define PG_NEED_COMMIT		1
+#define PG_NEED_RESCHED		2
+
+struct nfs_page {
+	struct list_head	wb_list,	/* Defines state of page: */
+				*wb_list_head;	/*      read/write/commit */
+	struct page		*wb_page;	/* page to read in/write out */
+	struct nfs_open_context	*wb_context;	/* File state context info */
+	atomic_t		wb_complete;	/* i/os we're waiting for */
+	unsigned long		wb_index;	/* Offset >> PAGE_CACHE_SHIFT */
+	unsigned int		wb_offset,	/* Offset & ~PAGE_CACHE_MASK */
+				wb_pgbase,	/* Start of page data */
+				wb_bytes;	/* Length of request */
+	atomic_t		wb_count;	/* reference count */
+	unsigned long		wb_flags;
+	struct nfs_writeverf	wb_verf;	/* Commit cookie */
+};
+
+#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
+#define NFS_NEED_COMMIT(req)	(test_bit(PG_NEED_COMMIT,&(req)->wb_flags))
+#define NFS_NEED_RESCHED(req)	(test_bit(PG_NEED_RESCHED,&(req)->wb_flags))
+
+extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
+					    struct inode *inode,
+					    struct page *page,
+					    unsigned int offset,
+					    unsigned int count);
+extern	void nfs_clear_request(struct nfs_page *req);
+extern	void nfs_release_request(struct nfs_page *req);
+
+
+extern	void nfs_list_add_request(struct nfs_page *, struct list_head *);
+
+extern	int nfs_scan_list(struct list_head *, struct list_head *,
+			  unsigned long, unsigned int);
+extern	int nfs_coalesce_requests(struct list_head *, struct list_head *,
+				  unsigned int);
+extern  int nfs_wait_on_request(struct nfs_page *);
+extern	void nfs_unlock_request(struct nfs_page *req);
+
+/*
+ * Lock the page of an asynchronous request without incrementing the wb_count
+ */
+static inline int
+nfs_lock_request_dontget(struct nfs_page *req)
+{
+	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
+		return 0;
+	return 1;
+}
+
+/*
+ * Lock the page of an asynchronous request
+ */
+static inline int
+nfs_lock_request(struct nfs_page *req)
+{
+	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
+		return 0;
+	atomic_inc(&req->wb_count);
+	return 1;
+}
+
+
+/**
+ * nfs_list_remove_request - Remove a request from its wb_list
+ * @req: request
+ */
+static inline void
+nfs_list_remove_request(struct nfs_page *req)
+{
+	if (list_empty(&req->wb_list))
+		return;
+	if (!NFS_WBACK_BUSY(req)) {
+		printk(KERN_ERR "NFS: unlocked request attempted removed from list!\n");
+		BUG();
+	}
+	list_del_init(&req->wb_list);
+	req->wb_list_head = NULL;
+}
+
+static inline int
+nfs_defer_commit(struct nfs_page *req)
+{
+	if (test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags))
+		return 0;
+	return 1;
+}
+
+static inline void
+nfs_clear_commit(struct nfs_page *req)
+{
+	smp_mb__before_clear_bit();
+	clear_bit(PG_NEED_COMMIT, &req->wb_flags);
+	smp_mb__after_clear_bit();
+}
+
+static inline int
+nfs_defer_reschedule(struct nfs_page *req)
+{
+	if (test_and_set_bit(PG_NEED_RESCHED, &req->wb_flags))
+		return 0;
+	return 1;
+}
+
+static inline void
+nfs_clear_reschedule(struct nfs_page *req)
+{
+	smp_mb__before_clear_bit();
+	clear_bit(PG_NEED_RESCHED, &req->wb_flags);
+	smp_mb__after_clear_bit();
+}
+
+static inline struct nfs_page *
+nfs_list_entry(struct list_head *head)
+{
+	return list_entry(head, struct nfs_page, wb_list);
+}
+
+static inline
+loff_t req_offset(struct nfs_page *req)
+{
+	return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
+}
+
+#endif /* _LINUX_NFS_PAGE_H */