[precise/trusty/utopic SRU] [1/1] drivers:scsi:storvsc: Fix a bug in handling ring buffer failures that may result in I/O freeze

[Andy Whitcroft]

From: Long Li <longli at microsoft.com>

When ring buffer returns an error indicating retry, storvsc may not return a proper error code to SCSI when bounce buffer is not used. This has introduced I/O freeze on RAID running atop storvsc devices. This patch fixes it by always returning a proper error code.

Signed-off-by: Long Li <longli at microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Cc: stable at vger.kernel.org
BugLink: http://bugs.launchpad.net/bugs/1400289
Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 drivers/scsi/storvsc_drv.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index a3b4ce9..d73b740 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1379,13 +1379,12 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	if (ret == -EAGAIN) {
 		/* no more space */
 
-		if (cmd_request->bounce_sgl_count) {
+		if (cmd_request->bounce_sgl_count)
 			destroy_bounce_buffer(cmd_request->bounce_sgl,
 					cmd_request->bounce_sgl_count);
 
-			ret = SCSI_MLQUEUE_DEVICE_BUSY;
-			goto queue_error;
-		}
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+		goto queue_error;
 	}
 
 	return 0;
-- 
1.9.1