[PATCH AUTOSEL 5.15 36/41] scsi: megaraid_sas: Target with invalid LUN ID is deleted during scan

[Sasha Levin]

From: Chandrakanth patil <chandrakanth.patil@xxxxxxxxxxxx>

[ Upstream commit 56495f295d8e021f77d065b890fc0100e3f9f6d8 ]

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@xxxxxxxxxxxx
Signed-off-by: Chandrakanth patil <chandrakanth.patil@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/megaraid/megaraid_sas.h      | 3 +++
 drivers/scsi/megaraid/megaraid_sas_base.c | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 7af2c23652b0..650210d2abb4 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -2558,6 +2558,9 @@ 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)
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 39d8754e63ac..bb3f78013a13 100644
--- 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 scsi_device *sdev)
 			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 scsi_device *sdev)
 	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)
-- 
2.35.1