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-rw-r--r--include/linux/nfs_page.h151
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 00000000000..39e4895bcdb
--- /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 */