libata: Fix command retry decision
authorDamien Le Moal <damien.lemoal@wdc.com>
Wed, 9 May 2018 00:28:12 +0000 (09:28 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 3 Aug 2018 05:50:35 +0000 (07:50 +0200)
[ Upstream commit 804689ad2d9b66d0d3920b48cf05881049d44589 ]

For failed commands with valid sense data (e.g. NCQ commands),
scsi_check_sense() is used in ata_analyze_tf() to determine if the
command can be retried. In such case, rely on this decision and ignore
the command error mask based decision done in ata_worth_retry().

This fixes useless retries of commands such as unaligned writes on zoned
disks (TYPE_ZAC).

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/ata/libata-eh.c

index 711dd91..2651c81 100644 (file)
@@ -2217,12 +2217,16 @@ static void ata_eh_link_autopsy(struct ata_link *link)
                if (qc->err_mask & ~AC_ERR_OTHER)
                        qc->err_mask &= ~AC_ERR_OTHER;
 
-               /* SENSE_VALID trumps dev/unknown error and revalidation */
+               /*
+                * SENSE_VALID trumps dev/unknown error and revalidation. Upper
+                * layers will determine whether the command is worth retrying
+                * based on the sense data and device class/type. Otherwise,
+                * determine directly if the command is worth retrying using its
+                * error mask and flags.
+                */
                if (qc->flags & ATA_QCFLAG_SENSE_VALID)
                        qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
-
-               /* determine whether the command is worth retrying */
-               if (ata_eh_worth_retry(qc))
+               else if (ata_eh_worth_retry(qc))
                        qc->flags |= ATA_QCFLAG_RETRY;
 
                /* accumulate error info */