1 files changed, 154 insertions, 0 deletions
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
new file mode 100644
index 00000000..eac30d6b
--- /dev/null
+++ b/include/linux/nfs_page.h
@@ -0,0 +1,154 @@
+/*
+ * 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/sunrpc/auth.h>
+#include <linux/nfs_xdr.h>
+
+#include <linux/kref.h>
+
+/*
+ * Valid flags for a dirty buffer
+ */
+enum {
+	PG_BUSY = 0,
+	PG_MAPPED,
+	PG_CLEAN,
+	PG_NEED_COMMIT,
+	PG_NEED_RESCHED,
+	PG_PARTIAL_READ_FAILED,
+	PG_COMMIT_TO_DS,
+};
+
+struct nfs_inode;
+struct nfs_page {
+	struct list_head	wb_list;	/* Defines state of page: */
+	struct page		*wb_page;	/* page to read in/write out */
+	struct nfs_open_context	*wb_context;	/* File state context info */
+	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
+	atomic_t		wb_complete;	/* i/os we're waiting for */
+	pgoff_t			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 */
+	struct kref		wb_kref;	/* reference count */
+	unsigned long		wb_flags;
+	struct nfs_writeverf	wb_verf;	/* Commit cookie */
+};
+
+struct nfs_pageio_descriptor;
+struct nfs_pageio_ops {
+	void	(*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
+	bool	(*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
+	int	(*pg_doio)(struct nfs_pageio_descriptor *);
+};
+
+struct nfs_pageio_descriptor {
+	struct list_head	pg_list;
+	unsigned long		pg_bytes_written;
+	size_t			pg_count;
+	size_t			pg_bsize;
+	unsigned int		pg_base;
+	unsigned char		pg_moreio : 1,
+				pg_recoalesce : 1;
+
+	struct inode		*pg_inode;
+	const struct nfs_pageio_ops *pg_ops;
+	int 			pg_ioflags;
+	int			pg_error;
+	const struct rpc_call_ops *pg_rpc_callops;
+	struct pnfs_layout_segment *pg_lseg;
+};
+
+#define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(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_release_request(struct nfs_page *req);
+
+
+extern	void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
+			     struct inode *inode,
+			     const struct nfs_pageio_ops *pg_ops,
+			     size_t bsize,
+			     int how);
+extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
+				   struct nfs_page *);
+extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
+extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
+extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
+				struct nfs_page *prev,
+				struct nfs_page *req);
+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 getting a new reference
+ */
+static inline int
+nfs_lock_request_dontget(struct nfs_page *req)
+{
+	return !test_and_set_bit(PG_BUSY, &req->wb_flags);
+}
+
+static inline int
+nfs_lock_request(struct nfs_page *req)
+{
+	if (test_and_set_bit(PG_BUSY, &req->wb_flags))
+		return 0;
+	kref_get(&req->wb_kref);
+	return 1;
+}
+
+
+/**
+ * nfs_list_add_request - Insert a request into a list
+ * @req: request
+ * @head: head of list into which to insert the request.
+ */
+static inline void
+nfs_list_add_request(struct nfs_page *req, struct list_head *head)
+{
+	list_add_tail(&req->wb_list, head);
+}
+
+
+/**
+ * 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;
+	list_del_init(&req->wb_list);
+}
+
+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 */