[PATCH] libata: implement and apply ata_eh_qc_complete/retry()

Implement ata_eh_qc_complete/retry() using scsi_eh_finish_cmd() and
scsi_eh_flush_done_q().  This removes all eh scsicmd finish hacks from
low level drivers.

This change was first suggested by Jeff Garzik.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 53 insertions, 6 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 95e3c278dd43..ab6b53349d6f 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -738,17 +738,64 @@ int ata_scsi_error(struct Scsi_Host *host)
         ap = (struct ata_port *) &host->hostdata[0];
         ap->ops->eng_timeout(ap);
 
-        /* TODO: this is per-command; when queueing is supported
-         * this code will either change or move to a more
-         * appropriate place
-         */
-        host->host_failed--;
-        INIT_LIST_HEAD(&host->eh_cmd_q);
+        assert(host->host_failed == 0 && list_empty(&host->eh_cmd_q));
+
+        scsi_eh_flush_done_q(&ap->eh_done_q);
 
         DPRINTK("EXIT\n");
         return 0;
 }
 
+static void ata_eh_scsidone(struct scsi_cmnd *scmd)
+{
+        /* nada */
+}
+
+static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+        struct scsi_cmnd *scmd = qc->scsicmd;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ap->host_set->lock, flags);
+        qc->scsidone = ata_eh_scsidone;
+        ata_qc_complete(qc);
+        assert(!ata_tag_valid(qc->tag));
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+        scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
+}
+
+/**
+ *      ata_eh_qc_complete - Complete an active ATA command from EH
+ *      @qc: Command to complete
+ *
+ *      Indicate to the mid and upper layers that an ATA command has
+ *      completed.  To be used from EH.
+ */
+void ata_eh_qc_complete(struct ata_queued_cmd *qc)
+{
+        struct scsi_cmnd *scmd = qc->scsicmd;
+        scmd->retries = scmd->allowed;
+        __ata_eh_qc_complete(qc);
+}
+
+/**
+ *      ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
+ *      @qc: Command to retry
+ *
+ *      Indicate to the mid and upper layers that an ATA command
+ *      should be retried.  To be used from EH.
+ *
+ *      SCSI midlayer limits the number of retries to scmd->allowed.
+ *      This function might need to adjust scmd->retries for commands
+ *      which get retried due to unrelated NCQ failures.
+ */
+void ata_eh_qc_retry(struct ata_queued_cmd *qc)
+{
+        __ata_eh_qc_complete(qc);
+}
+
 /**
  *      ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
  *      @qc: Storage for translated ATA taskfile