Hi Tejun,
在 2018/2/13 0:51, Tejun Heo 写道:
Hello,
On Wed, Jan 24, 2018 at 09:20:25PM +0800, chenxiang wrote:
In ata_eh_reset, it will reset three times at most for sata disk. For
some drivers through libsas, it calls sas_ata_hard_reset at last. When
device is gone, function sas_ata_hard_reset will return -ENODEV. But
it will still try to reset three times for offline device. This process
lasts a long time:
[11248.344323] ata13.00: status: { ERR }
[11248.344324] ata13.00: error: { ABRT }
[11248.344327] ata13: hard resetting link
[11248.503557] sas: ata: ex 500e004aaaaaaa1f phy02:U:A attached:0000000000000000 (no device)
[11249.359524] sas: ata13: end_device-1:0:2: reset failed (errno=-19)[eta03d:19h:35m:17s]
[11249.365692] ata13: reset failed (errno=-19), retrying in 9 secs
[11258.451402] ata13: hard resetting linkKB/0KB/0KB /s] [0/0/0 iops][eta 03d:22h:10m:48s]
[11259.411508] sas: ata13: end_device-1:0:2: reset failed (errno=-19)[eta 03d:22h:28m:05s]
[11259.417683] ata13: reset failed (errno=-19), retrying in 10 secs
[11268.695401] ata13: hard resetting linkKB/0KB/0KB /s] [0/0/0 iops] [eta 04d:01h:03m:37s]
[11269.699513] sas: ata13: end_device-1:0:2: reset failed (errno=-19)[eta 04d:01h:20m:54s]
[11269.705689] ata13: reset failed (errno=-19), retrying in 34 secs
[11304.275393] ata13: hard resetting linkKB/0KB/0KB /s] [0/0/0 iops] [eta 04d:11h:25m:43s]
[11305.283516] sas: ata13: end_device-1:0:2: reset failed (errno=-19)[eta 04d:11h:43m:00s]
[11305.289692] ata13: reset failed, giving up
[11305.293785] ata13.00: disabled
Actually it is no need to reset three times for this scenario. So add
a check to avoid it.
I'm a bit reluctant in changing this per-driver. Does this actually
hurt something?
For those drivers using libsas, i think they have the same issue. It
takes about 1 minute to
recover but actually device is gone, so this recover is useless for this
scenario (when enter EH,
all normal IOs are blocked actually, so it will cause normal IOs are
blocked one more minute which
user doesn't want to).
Actually in sas_ata_hard_reset, there are two situations returned
-ENODEV which represent device is gone:
- LLDD directly returns -ENODEV through lldd_I_T_nexus_reset;
- It sends SMP DISCOVER to check local phy in smp_ata_check_ready, and
find it is gone;
Thanks.
