1 files changed, 43 insertions, 1 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index b007bb409382..9d67c6768335 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -717,6 +717,47 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
 }
 
 /**
+ *      ata_scsi_timed_out - SCSI layer time out callback
+ *      @cmd: timed out SCSI command
+ *
+ *      Handles SCSI layer timeout.  We race with normal completion of
+ *      the qc for @cmd.  If the qc is already gone, we lose and let
+ *      the scsi command finish (EH_HANDLED).  Otherwise, the qc has
+ *      timed out and EH should be invoked.  Prevent ata_qc_complete()
+ *      from finishing it by setting EH_SCHEDULED and return
+ *      EH_NOT_HANDLED.
+ *
+ *      LOCKING:
+ *      Called from timer context
+ *
+ *      RETURNS:
+ *      EH_HANDLED or EH_NOT_HANDLED
+ */
+enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
+{
+        struct Scsi_Host *host = cmd->device->host;
+        struct ata_port *ap = (struct ata_port *) &host->hostdata[0];
+        unsigned long flags;
+        struct ata_queued_cmd *qc;
+        enum scsi_eh_timer_return ret = EH_HANDLED;
+
+        DPRINTK("ENTER\n");
+
+        spin_lock_irqsave(&ap->host_set->lock, flags);
+        qc = ata_qc_from_tag(ap, ap->active_tag);
+        if (qc) {
+                assert(qc->scsicmd == cmd);
+                qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
+                qc->err_mask |= AC_ERR_TIMEOUT;
+                ret = EH_NOT_HANDLED;
+        }
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+        DPRINTK("EXIT, ret=%d\n", ret);
+        return ret;
+}
+
+/**
  *      ata_scsi_error - SCSI layer error handler callback
  *      @host: SCSI host on which error occurred
  *
@@ -741,6 +782,7 @@ int ata_scsi_error(struct Scsi_Host *host)
         spin_lock_irqsave(&ap->host_set->lock, flags);
         assert(!(ap->flags & ATA_FLAG_IN_EH));
         ap->flags |= ATA_FLAG_IN_EH;
+        assert(ata_qc_from_tag(ap, ap->active_tag) != NULL);
         spin_unlock_irqrestore(&ap->host_set->lock, flags);
 
         ap->ops->eng_timeout(ap);
@@ -770,7 +812,7 @@ static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
 
         spin_lock_irqsave(&ap->host_set->lock, flags);
         qc->scsidone = ata_eh_scsidone;
-        ata_qc_complete(qc);
+        __ata_qc_complete(qc);
         assert(!ata_tag_valid(qc->tag));
         spin_unlock_irqrestore(&ap->host_set->lock, flags);