kernel-packages team mailing list archive

[Andy Whitcroft <apw@xxxxxxxxxxxxx>]

Public bug reported:

As requested by Microsoft.

===

Andy,

Could you pick up this patch. Customers are hitting this issue on Azure
(on Canonical images).

Regards,

K. Y

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

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;

** Affects: linux (Ubuntu)
     Importance: High
     Assignee: Andy Whitcroft (apw)
         Status: Confirmed

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1400289

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

Status in linux package in Ubuntu:
  Confirmed

Bug description:
  As requested by Microsoft.

  ===

  Andy,

  Could you pick up this patch. Customers are hitting this issue on
  Azure (on Canonical images).

  Regards,

  K. Y

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

  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;

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