[PATCH] libata-eh-fw: implement new EH scheduling via error completion

There are several ways a qc can get schedule for EH in new EH.  This
patch implements one of them - completing a qc with ATA_QCFLAG_FAILED
set or with non-zero qc->err_mask.  ALL such qc's are examined by EH.

New EH schedules a qc for EH from completion iff ->error_handler is
implemented, qc is marked as failed or qc->err_mask is non-zero and
the command is not an internal command (internal cmd is handled via
->post_internal_cmd).  The EH scheduling itself is performed by asking
SCSI midlayer to schedule EH for the specified scmd.

For drivers implementing old-EH, nothing changes.  As this change
makes ata_qc_complete() rather large, it's not inlined anymore and
__ata_qc_complete() is exported to other parts of libata for later
use.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 959a1cdffac2..471846fe4b73 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -210,6 +210,33 @@ void ata_eng_timeout(struct ata_port *ap)
         DPRINTK("EXIT\n");
 }
 
+/**
+ *      ata_qc_schedule_eh - schedule qc for error handling
+ *      @qc: command to schedule error handling for
+ *
+ *      Schedule error handling for @qc.  EH will kick in as soon as
+ *      other commands are drained.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ */
+void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+
+        WARN_ON(!ap->ops->error_handler);
+
+        qc->flags |= ATA_QCFLAG_FAILED;
+        qc->ap->flags |= ATA_FLAG_EH_PENDING;
+
+        /* The following will fail if timeout has already expired.
+         * ata_scsi_error() takes care of such scmds on EH entry.
+         * Note that ATA_QCFLAG_FAILED is unconditionally set after
+         * this function completes.
+         */
+        scsi_req_abort_cmd(qc->scsicmd);
+}
+
 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
 {
         /* nada */