scsi: core: Replace scsi_target_block() with scsi_block_targets()

All callers (fc_remote_port_delete(), __iscsi_block_session(),
__srp_start_tl_fail_timers(), srp_reconnect_rport(), snic_tgt_del()) pass
parent devices of scsi_target devices to scsi_target_block().

Rename the function to scsi_block_targets(), and simplify it by assuming
that it is always passed a parent device. Also, have callers pass the
Scsi_Host pointer to scsi_block_targets(), as every caller has this pointer
readily available.

Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Link: https://lore.kernel.org/r/20230614103616.31857-7-mwilck@suse.com
Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 16 insertions, 10 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b98750028044..55a327b2dd8b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2890,20 +2890,26 @@ target_block(struct device *dev, void *data)
 	return 0;
 }
 
+/**
+ * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state
+ * @dev: a parent device of one or more scsi_target devices
+ * @shost: the Scsi_Host to which this device belongs
+ *
+ * Iterate over all children of @dev, which should be scsi_target devices,
+ * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for
+ * ongoing scsi_queue_rq() calls to finish. May sleep.
+ *
+ * Note:
+ * @dev must not itself be a scsi_target device.
+ */
 void
-scsi_target_block(struct device *dev)
+scsi_block_targets(struct Scsi_Host *shost, struct device *dev)
 {
-	struct Scsi_Host *shost = dev_to_shost(dev);
-
-	if (scsi_is_target_device(dev))
-		starget_for_each_device(to_scsi_target(dev), NULL,
-					scsi_device_block);
-	else
-		device_for_each_child(dev, NULL, target_block);
-
+	WARN_ON_ONCE(scsi_is_target_device(dev));
+	device_for_each_child(dev, NULL, target_block);
 	blk_mq_wait_quiesce_done(&shost->tag_set);
 }
-EXPORT_SYMBOL_GPL(scsi_target_block);
+EXPORT_SYMBOL_GPL(scsi_block_targets);
 
 static void
 device_unblock(struct scsi_device *sdev, void *data)