scsi: core: Fix shost->cmd_per_lun calculation in scsi_add_host_with_dma()

After commit ea2f0f7 ("scsi: core: Cap scsi_host cmd_per_lun at
can_queue"), a 416-CPU VM running on Hyper-V hangs during boot because the
hv_storvsc driver sets scsi_driver.can_queue to an integer value that
exceeds SHRT_MAX, and hence scsi_add_host_with_dma() sets
shost->cmd_per_lun to a negative "short" value.

Use min_t(int, ...) to work around the issue.

Link: https://lore.kernel.org/r/[email protected]
Fixes: ea2f0f7 ("scsi: core: Cap scsi_host cmd_per_lun at can_queue")
Cc: [email protected]
Reviewed-by: Haiyang Zhang <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: John Garry <[email protected]>
Signed-off-by: Dexuan Cui <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: dcui

drivers/scsi/hosts.c

@@ -220,7 +220,8 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 		goto fail;
 	}
 
-	shost->cmd_per_lun = min_t(short, shost->cmd_per_lun,
+	/* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
+	shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
 				   shost->can_queue);
 
 	error = scsi_init_sense_cache(shost);