drivers:scsi:storvsc: Fix a bug in handling ring buffer failures that may result in I/O freeze

From: Long Li
Date: Fri Dec 05 2014 - 21:36:20 EST


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@xxxxxxxxxxxxx>
Reviewed-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
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 e3ba251..4cff0dd 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1688,13 +1688,12 @@ 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;
--
2.1.0

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