From: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Date: Thu, 24 Mar 2022 02:47:11 -0700
Subject: scsi: megaraid_sas: Target with invalid LUN ID is deleted during scan
Patch-mainline: v5.18-rc2
Git-commit: 56495f295d8e021f77d065b890fc0100e3f9f6d8
References: jsc#PED-1490

The megaraid_sas driver supports single LUN for RAID devices. That is LUN
0. All other LUNs are unsupported. When a device scan on a logical target
with invalid LUN number is invoked through sysfs, that target ends up
getting removed.

Add LUN ID validation in the slave destroy function to avoid the target
deletion.

Link: https://lore.kernel.org/r/20220324094711.48833-1-chandrakanth.patil@broadcom.com
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Martin Wilck <mwilck@suse.com>
---
 drivers/scsi/megaraid/megaraid_sas.h      |    3 +++
 drivers/scsi/megaraid/megaraid_sas_base.c |    7 +++++++
 2 files changed, 10 insertions(+)

--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -2560,6 +2560,9 @@ struct megasas_instance_template {
 #define MEGASAS_IS_LOGICAL(sdev)					\
 	((sdev->channel < MEGASAS_MAX_PD_CHANNELS) ? 0 : 1)
 
+#define MEGASAS_IS_LUN_VALID(sdev)					\
+	(((sdev)->lun == 0) ? 1 : 0)
+
 #define MEGASAS_DEV_INDEX(scp)						\
 	(((scp->device->channel % 2) * MEGASAS_MAX_DEV_PER_CHANNEL) +	\
 	scp->device->id)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2126,6 +2126,9 @@ static int megasas_slave_alloc(struct sc
 			goto scan_target;
 		}
 		return -ENXIO;
+	} else if (!MEGASAS_IS_LUN_VALID(sdev)) {
+		sdev_printk(KERN_INFO, sdev, "%s: invalid LUN\n", __func__);
+		return -ENXIO;
 	}
 
 scan_target:
@@ -2156,6 +2159,10 @@ static void megasas_slave_destroy(struct
 	instance = megasas_lookup_instance(sdev->host->host_no);
 
 	if (MEGASAS_IS_LOGICAL(sdev)) {
+		if (!MEGASAS_IS_LUN_VALID(sdev)) {
+			sdev_printk(KERN_INFO, sdev, "%s: invalid LUN\n", __func__);
+			return;
+		}
 		ld_tgt_id = MEGASAS_TARGET_ID(sdev);
 		instance->ld_tgtid_status[ld_tgt_id] = LD_TARGET_ID_DELETED;
 		if (megasas_dbg_lvl & LD_PD_DEBUG)