From: Gerd Hoffmann <kraxel@redhat.com>
Subject: [RHEL-5.1 PATCH 5/10] xen: blktap: kill bogous flush
Date: Fri, 15 Jun 2007 10:41:12 +0200
Bugzilla: 222128
Message-Id: <467250A8.2060505@redhat.com>
Changelog: [xen] blktap: kill bogous flush


  Hi,

This patch fixes one error path in the blktap driver.

cheers,

  Gerd

# HG changeset patch
# User kfraser@localhost.localdomain
# Date 1161332666 -3600
# Node ID bb76521fdcb34fb10247f335b9e3836d9779321f
# Parent  1467ae6622288069016fd0a12010fa9e737f6f17
[BLKTAP]: Kill bogus fast_flush_area

The function dispatch_rw_block_io may call fast_flush_area even before
a pending request has been initialised.  This patch deletes that call.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

---
 drivers/xen/blktap/blktapmain.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Index: linux-2.6.18.noarch/drivers/xen/blktap/blktapmain.c
===================================================================
--- linux-2.6.18.noarch.orig/drivers/xen/blktap/blktapmain.c
+++ linux-2.6.18.noarch/drivers/xen/blktap/blktapmain.c
@@ -1143,9 +1143,10 @@ static void dispatch_rw_block_io(blkif_t
 	int usr_idx = GET_NEXT_REQ(info->idx_map);
 	uint16_t mmap_idx = pending_req->mem_idx;
 
-	/*Check we have space on user ring - should never fail*/
-	if(usr_idx == INVALID_REQ) goto fail_flush;
-	
+	/* Check we have space on user ring - should never fail. */
+	if (usr_idx == INVALID_REQ)
+		goto fail_response;
+
 	/* Check that number of segments is sane. */
 	nseg = req->nr_segments;
 	if ( unlikely(nseg == 0) ||