libata: make ata_eh_qc_retry() bump scmd->allowed on bogus failures

libata EH decrements scmd->retries when the command failed for reasons
unrelated to the command itself so that, for example, commands aborted
due to suspend / resume cycle don't get penalized; however,
decrementing scmd->retries isn't enough for ATA passthrough commands.

Without this fix, ATA passthrough commands are not resend to the
drive, and no error is signalled to the caller because:

- allowed retry count is 1
- ata_eh_qc_complete fill the sense data, so result is valid
- sense data is filled with untouched ATA registers.

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index c69fcce..370462f 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1322,14 +1322,14 @@ void ata_eh_qc_complete(struct ata_queued_cmd *qc)
  *     should be retried.  To be used from EH.
  *
  *     SCSI midlayer limits the number of retries to scmd->allowed.
- *     scmd->retries is decremented for commands which get retried
+ *     scmd->allowed is incremented for commands which get retried
  *     due to unrelated failures (qc->err_mask is zero).
  */
 void ata_eh_qc_retry(struct ata_queued_cmd *qc)
 {
        struct scsi_cmnd *scmd = qc->scsicmd;
-       if (!qc->err_mask && scmd->retries)
-               scmd->retries--;
+       if (!qc->err_mask)
+               scmd->allowed++;
        __ata_eh_qc_complete(qc);
 }