| Message ID | 1508224276-130348-1-git-send-email-hare@suse.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Tue, 2017-10-17 at 09:11 +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. This will lock up the system if some ALUA initiator gets into a state where it always returns transitioning and never completes, which doesn't look like the best way to handle problem devices. I thought after the ALUA transition the LUN gives a unit attention ... can't you use that some way to trigger the capacity re-read, so do asynchronous event notification instead of polling forever. James
On 10/17/2017 03:57 PM, James Bottomley wrote: > On Tue, 2017-10-17 at 09:11 +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. > > This will lock up the system if some ALUA initiator gets into a state > where it always returns transitioning and never completes, which > doesn't look like the best way to handle problem devices. > > I thought after the ALUA transition the LUN gives a unit attention ... > can't you use that some way to trigger the capacity re-read, so do > asynchronous event notification instead of polling forever. > Hmm. Will give it a try. Cheers, Hannes
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 37daf9a..b4647f5 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2333,6 +2333,11 @@ 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--; @@ -2418,6 +2423,11 @@ 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--;
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@suse.de> --- drivers/scsi/sd.c | 10 ++++++++++ 1 file changed, 10 insertions(+)