[PATCH] libata-eh-fw: implement ata_port_schedule_eh() and ata_port_abort()

ata_port_schedule_eh() directly schedules EH for @ap without
associated qc.  Once EH scheduled, no further qc is allowed and EH
kicks in as soon as all currently active qc's are drained.

ata_port_abort() schedules all currently active commands for EH by
qc_completing them with ATA_QCFLAG_FAILED set.  If ata_port_abort()
doesn't find any qc to abort, it directly schedule EH using
ata_port_schedule_eh().

These two functions provide ways to invoke EH for conditions which
aren't directly related to any specfic qc.

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

4 files changed, 80 insertions, 0 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 1f5c3270992a..9c97783462d6 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5383,5 +5383,7 @@ EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
 EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
 
 EXPORT_SYMBOL_GPL(ata_eng_timeout);
+EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
+EXPORT_SYMBOL_GPL(ata_port_abort);
 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 471846fe4b73..037a561809f5 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -237,6 +237,60 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
         scsi_req_abort_cmd(qc->scsicmd);
 }
 
+/**
+ *      ata_port_schedule_eh - schedule error handling without a qc
+ *      @ap: ATA port to schedule EH for
+ *
+ *      Schedule error handling for @ap.  EH will kick in as soon as
+ *      all commands are drained.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ */
+void ata_port_schedule_eh(struct ata_port *ap)
+{
+        WARN_ON(!ap->ops->error_handler);
+
+        ap->flags |= ATA_FLAG_EH_PENDING;
+        ata_schedule_scsi_eh(ap->host);
+
+        DPRINTK("port EH scheduled\n");
+}
+
+/**
+ *      ata_port_abort - abort all qc's on the port
+ *      @ap: ATA port to abort qc's for
+ *
+ *      Abort all active qc's of @ap and schedule EH.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      Number of aborted qc's.
+ */
+int ata_port_abort(struct ata_port *ap)
+{
+        int tag, nr_aborted = 0;
+
+        WARN_ON(!ap->ops->error_handler);
+
+        for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
+                struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
+
+                if (qc) {
+                        qc->flags |= ATA_QCFLAG_FAILED;
+                        ata_qc_complete(qc);
+                        nr_aborted++;
+                }
+        }
+
+        if (!nr_aborted)
+                ata_port_schedule_eh(ap);
+
+        return nr_aborted;
+}
+
 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
 {
         /* nada */
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index a9b4083a4f67..fd7064b9697d 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2596,3 +2596,26 @@ void ata_scsi_scan_host(struct ata_port *ap)
         }
 }
 
+/**
+ *      ata_schedule_scsi_eh - schedule EH for SCSI host
+ *      @shost: SCSI host to invoke error handling on.
+ *
+ *      Schedule SCSI EH without scmd.  This is a hack.
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ **/
+void ata_schedule_scsi_eh(struct Scsi_Host *shost)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(shost->host_lock, flags);
+
+        if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
+            scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
+                shost->host_eh_scheduled++;
+                scsi_eh_wakeup(shost);
+        }
+
+        spin_unlock_irqrestore(shost->host_lock, flags);
+}
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index 52622b7f8a9e..b76ad7d7062a 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -98,6 +98,7 @@ extern void ata_scsi_set_sense(struct scsi_cmnd *cmd,
 extern void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
                         unsigned int (*actor) (struct ata_scsi_args *args,
                                            u8 *rbuf, unsigned int buflen));
+extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
 
 /* libata-eh.c */
 extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);