[PATCH] NFS: Make searching and waiting on busy writeback requests more efficient.

 Basically copies the VFS's method for tracking writebacks and applies
 it to the struct nfs_page.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 39e4895bcdb4..db40e4590ba2 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -20,6 +20,11 @@
 #include <asm/atomic.h>
 
 /*
+ * Valid flags for the radix tree
+ */
+#define NFS_PAGE_TAG_WRITEBACK  1
+
+/*
  * Valid flags for a dirty buffer
  */
 #define PG_BUSY                 0
@@ -62,6 +67,9 @@ 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);
+extern  int nfs_set_page_writeback_locked(struct nfs_page *req);
+extern  void nfs_clear_page_writeback(struct nfs_page *req);
+
 
 /*
  * Lock the page of an asynchronous request without incrementing the wb_count
@@ -96,10 +104,6 @@ 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;
 }