Re: [PATCH] scsi: libsas: set tf to normal in sas_ata_device_link_abort()

From: yangxingui
Date: Mon Apr 17 2023 - 04:21:23 EST


Hi Jason

On 2023/4/14 15:36, Jason Yan wrote:
On 2023/4/7 11:56, Xingui Yang wrote:
If the disk returns UNC for more than five times within a short period, the
number of retry times for other I/Os may reach scmd->allowed, and the
default error "Illegal Request" is returned for other I/Os, as follows:

[  273.801770] hisi_sas_v3_hw 0000:b4:02.0: erroneous completion disk err dev id=2 sas_addr=0x5000000000000605 CQ hdr: 0x400903 0x20103 0x0 0x80470000
[  273.875286] sas: Enter sas_scsi_recover_host busy: 30 failed: 30
[  273.879895] sas: trying to find task 0x00000000d9cfc893
[  273.879896] sas: sas_scsi_find_task: aborting task 0x00000000d9cfc893
[  273.880054] sas: sas_scsi_find_task: task 0x00000000d9cfc893 is done
[  273.880055] sas: sas_eh_handle_sas_errors: task 0x00000000d9cfc893 is done
[  273.880236] ata6.00: failed command: READ FPDMA QUEUED
[  273.880238] ata6.00: cmd 60/08:00:59:27:00/00:00:00:00:00/40 tag 22 ncq dma 4096 in
                         res 41/04:00:20:00:00/00:00:00:00:00/00 Emask 0x1 (device error)
[  273.880239] ata6.00: status: { DRDY ERR }
[  273.880240] ata6.00: error: { ABRT }
[  273.880241] ata6.00: failed command: READ FPDMA QUEUED
[  273.880243] ata6.00: cmd 60/90:00:d1:26:00/00:00:00:00:00/40 tag 23 ncq dma 73728 in
                         res 41/40:90:10:27:00/00:00:00:00:00/00 Emask 0x409 (media error) <F>
[  273.880245] ata6.00: status: { DRDY ERR }
[  273.880246] ata6.00: error: { UNC }
[  273.880247] ata6.00: failed command: READ FPDMA QUEUED
[  273.880249] ata6.00: cmd 60/08:00:19:27:00/00:00:00:00:00/40 tag 24 ncq dma 4096 in
                         res 41/04:00:20:00:00/00:00:00:00:00/00 Emask 0x1 (device error)
[  273.880250] ata6.00: status: { DRDY ERR }
[  273.880251] ata6.00: error: { ABRT }
[  274.199477] scmd->retries: 3, scmd->allowed: 5
[  274.199478] scmd->retries: 3, scmd->allowed: 5
[  274.199479] scmd->retries: 3, scmd->allowed: 5
[  274.199481] scmd->retries: 3, scmd->allowed: 5
[  274.199482] scmd->retries: 3, scmd->allowed: 5
[  274.199483] scmd->retries: 2, scmd->allowed: 5
[  274.199484] scmd->retries: 3, scmd->allowed: 5
[  274.199485] scmd->retries: 3, scmd->allowed: 5
[  274.199486] scmd->retries: 5, scmd->allowed: 5
[  274.199487] scmd->retries: 2, scmd->allowed: 5
[  274.199488] scmd->retries: 2, scmd->allowed: 5
[  274.199524] sd 6:0:1:0: [sdb] tag#258 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[  274.199527] sd 6:0:1:0: [sdb] tag#258 Sense Key : Illegal Request [current]
[  274.199530] sd 6:0:1:0: [sdb] tag#258 Add. Sense: Unaligned write command
[  274.199532] sd 6:0:1:0: [sdb] tag#258 CDB: Read(10) 28 00 00 00 27 59 00 00 08 00
[  274.199535] print_req_error: I/O error, dev sdb, sector 10073
[  274.199573] sd 6:0:1:0: [sdb] tag#259 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[  274.199574] sd 6:0:1:0: [sdb] tag#259 Sense Key : Medium Error [current]
[  274.199576] sd 6:0:1:0: [sdb] tag#259 Add. Sense: Unrecovered read error - auto reallocate failed
[  274.199578] sd 6:0:1:0: [sdb] tag#259 CDB: Read(10) 28 00 00 00 26 d1 00 00 90 00
[  274.199579] print_req_error: I/O error, dev sdb, sector 10000
[  274.199608] ata6: EH complete
[  274.199615] sas: --- Exit sas_scsi_recover_host: busy: 0 failed: 30 tries: 1

As mentioned in ata_eh_qc_retry(), if qc->err_mask is zero then increment
scmd->allowed. So set tf to normal may be better.

Hi Xingui,

If we increase scmd->allowed every time, and the device returns UNC for too many times, will the other IO pending for too long and cause hungtask? And also the runtime check in scsi_cmd_runtime_exceeced() will not trigger since cmd->allowed is extended.

Thank you for your reply. In scenarios similar to UNC error, where a disk returns an error through D2H or SDB, no error is reported for other I/Os in the disk. In this case, AHCI will increase the number of retry times for other I/Os, and AHCI may face similar problems you say, but default failures may not be very good for users.

In addition, for commands with pass through type, other I/Os are immediately returned with default errors and are not retried, but AHCI only report one single error I/O.

Thanks,
Xingui

Thanks,
Jason


Signed-off-by: Xingui Yang <yangxingui@xxxxxxxxxx>
---
  drivers/scsi/libsas/sas_ata.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 77714a495cbb..f5047e8dcb59 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -949,8 +949,8 @@ void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
      unsigned long flags;
      spin_lock_irqsave(ap->lock, flags);
-    device->sata_dev.fis[2] = ATA_ERR | ATA_DRDY; /* tf status */
-    device->sata_dev.fis[3] = ATA_ABORTED; /* tf error */
+    device->sata_dev.fis[2] = ATA_DRDY; /* tf status */
+    device->sata_dev.fis[3] = 0;        /* tf error */
      link->eh_info.err_mask |= AC_ERR_DEV;
      if (force_reset)

.