From 738a07c8216412f649a816d685d5b3d4d81a4286 Mon Sep 17 00:00:00 2001
From: Adam Rutkowski <adam.j.rutkowski@intel.com>
Date: Mon, 27 Jun 2022 16:21:44 +0200
Subject: [PATCH] avoid overflow in disk openers counter

Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
---
 modules/cas_disk/exp_obj.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/modules/cas_disk/exp_obj.c b/modules/cas_disk/exp_obj.c
index 0636242..8f4faa7 100644
--- a/modules/cas_disk/exp_obj.c
+++ b/modules/cas_disk/exp_obj.c
@@ -347,8 +347,12 @@ static int _casdsk_exp_obj_open(struct block_device *bdev, fmode_t mode)
 	mutex_lock(&dsk->openers_lock);
 
 	if (!dsk->claimed) {
-		dsk->openers++;
-		result = 0;
+		if (unlikely(dsk->openers == UINT_MAX)) {
+			result = -EBUSY;
+		} else {
+			dsk->openers++;
+			result = 0;
+		}
 	}
 
 	mutex_unlock(&dsk->openers_lock);