[PATCH 3.18 45/85] libata: Fix command retry decision

Greg Kroah-Hartman
2018-08-07T18:58:10Z

From: Damien Le Moal <damien.lemoal@wdc.com>

[ 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 | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2173,12 +2173,16 @@ static void ata_eh_link_autopsy(struct a
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 */