From: Hannes Reinecke <hare@suse.de>
Date: Fri, 28 Feb 2020 08:53:07 +0100
Subject: scsi: core: add scsi_host_complete_all_commands() helper
Git-commit: 466552b9f3730f06fee75776a208f5fa9c06c6a3
Patch-mainline: v5.7-rc1
References: jsc#SLE-15152

Add a helper scsi_host_complete_all_commands() to terminate all outstanding
commands on a SCSI host.

[ld: I added the include of scsi_cmnd.h. Not sure why it was needed.]

Link: https://lore.kernel.org/r/20200228075318.91255-3-hare@suse.de
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/hosts.c     |   29 +++++++++++++++++++++++++++++
 include/scsi/scsi_host.h |    2 ++
 2 files changed, 31 insertions(+)

--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -38,6 +38,7 @@
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_transport.h>
+#include <scsi/scsi_cmnd.h>
 
 #include "scsi_priv.h"
 #include "scsi_logging.h"
@@ -633,3 +634,31 @@ void scsi_flush_work(struct Scsi_Host *s
 	flush_workqueue(shost->work_q);
 }
 EXPORT_SYMBOL_GPL(scsi_flush_work);
+
+static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
+{
+	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
+	int status = *(int *)data;
+
+	scsi_dma_unmap(scmd);
+	scmd->result = status << 16;
+	scmd->scsi_done(scmd);
+	return true;
+}
+
+/**
+ * scsi_host_complete_all_commands - Terminate all running commands
+ * @shost:	Scsi Host on which commands should be terminated
+ * @status:	Status to be set for the terminated commands
+ *
+ * There is no protection against modification of the number
+ * of outstanding commands. It is the responsibility of the
+ * caller to ensure that concurrent I/O submission and/or
+ * completion is stopped when calling this function.
+ */
+void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
+{
+	blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
+				&status);
+}
+EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -746,6 +746,8 @@ extern int scsi_host_busy(struct Scsi_Ho
 extern void scsi_host_put(struct Scsi_Host *t);
 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
 extern const char *scsi_host_state_name(enum scsi_host_state);
+extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
+					    int status);
 
 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
 					     struct device *dev)