[PATCH] separate bdi congestion functions from queue congestion functions

Separate out the concept of "queue congestion" from "backing-dev congestion".
Congestion is a backing-dev concept, not a queue concept.

The blk_* congestion functions are retained, as wrappers around the core
backing-dev congestion functions.

This proper layering is needed so that NFS can cleanly use the congestion
functions, and so that CONFIG_BLOCK=n actually links.

Cc: "Thomas Maier" <balagi@justmail.de>
Cc: "Jens Axboe" <jens.axboe@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: David Howells <dhowells@redhat.com>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/lib/usercopy.c b/arch/i386/lib/usercopy.c
index 258df6b..d22cfc9 100644
--- a/arch/i386/lib/usercopy.c
+++ b/arch/i386/lib/usercopy.c
@@ -9,6 +9,7 @@
 #include <linux/highmem.h>
 #include <linux/blkdev.h>
 #include <linux/module.h>
+#include <linux/backing-dev.h>
 #include <asm/uaccess.h>
 #include <asm/mmx.h>
 
@@ -741,7 +742,7 @@
 
 			if (retval == -ENOMEM && is_init(current)) {
 				up_read(&current->mm->mmap_sem);
-				blk_congestion_wait(WRITE, HZ/50);
+				congestion_wait(WRITE, HZ/50);
 				goto survive;
 			}