Re: [PATCH] sd: always retry READ CAPACITY for ALUA state transition

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 4/30/2015 5:56 PM, Hannes Reinecke wrote:
On 04/28/2015 11:18 PM, James Bottomley wrote:
On Mon, 2015-04-27 at 11:35 +0200, Hannes Reinecke wrote:
During ALUA state transitions the device might return
a sense code 02/04/0a (Logical unit not accessible, asymmetric
access state transition). As this is a transient error
we should just retry the READ CAPACITY call until
the state transition finishes and the correct
capacity can be returned.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
  drivers/scsi/sd.c | 10 ++++++++++
  1 file changed, 10 insertions(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 79beebf..7178b05 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1987,6 +1987,11 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
  				 * give it one more chance */
  				if (--reset_retries > 0)
  					continue;
+			if (sense_valid &&
+			    sshdr.sense_key == NOT_READY &&
+			    sshdr.asc == 0x04 && sshdr.ascq == 0x0A)
+				/* ALUA state transition; always retry */
+				continue;
  		}
  		retries--;

@@ -2069,6 +2074,11 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
  				 * give it one more chance */
  				if (--reset_retries > 0)
  					continue;
+			if (sense_valid &&
+			    sshdr.sense_key == NOT_READY &&
+			    sshdr.asc == 0x04 && sshdr.ascq == 0x0A)
+				/* ALUA state transition; always retry */
+				continue;
  		}
  		retries--;


Got to say I really don't like this infinite retry possibility.  How
long does the ALUA transition take?  Would increasing retries work (or
even hijacking reset_retries)?

Well ... transitioning could be quite long (NetApp FAS has a
transition timeout of 30 _minutes_ ...).

Well, actually NetApp FAS has a transition timeout of 2 minutes, and not 30 minutes - as reported in the IMPLICIT TRANSITION TIMEOUT value in the extended RTPG data.

-Martin
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux