From 20e11dfb21ff12589ecc3df4301b333135e5a4fc Mon Sep 17 00:00:00 2001
From: Manuel Bentele
Date: Wed, 10 Feb 2021 10:02:51 +0100
Subject: Add support for AlmaLinux 8

---
 README.md               | 13 +++++++++++++
 src/kernel/xloop_main.c | 13 +++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index dc8f0b6..043b85b 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ and the user space utility **xlosetup** to configure xloop devices. The xloop Li
   - Ubuntu 20.04 with **Linux kernel 5.4.x**
   - Ubuntu 18.04 with **Linux kernel 4.19.x**
   - CentOS 8 with **Linux kernel 4.18.x**
+  - AlmaLinux 8 with **Linux kernel 4.18.x**
 
 
 ## Build
@@ -79,6 +80,18 @@ yum install git \
             rpm-build
 ```
 
+#### AlmaLinux 8 with Linux kernel 4.18.x
+```shell
+yum install git \
+            make \
+            cmake \
+            gcc \
+            kernel-devel \
+            elfutils-libelf-devel \
+            libcap-devel \  # required only in Debug build configuration
+            rpm-build
+```
+
 
 ### Preparation
 Before a build takes place, you should create a `build` directory inside the root folder of the repository. After that, change your working directory to that new directory as follows:
diff --git a/src/kernel/xloop_main.c b/src/kernel/xloop_main.c
index 441282a..aa75c41 100644
--- a/src/kernel/xloop_main.c
+++ b/src/kernel/xloop_main.c
@@ -95,6 +95,13 @@
 
 #include <linux/uaccess.h>
 
+/* define RHEL_CHECK_VERSION macro to check CentOS version */
+#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION)
+	#define RHEL_CHECK_VERSION(CONDITION) (CONDITION)
+#else
+	#define RHEL_CHECK_VERSION(CONDITION) (0)
+#endif
+
 static DEFINE_IDR(xloop_index_idr);
 static DEFINE_MUTEX(xloop_ctl_mutex);
 
@@ -358,7 +365,8 @@ static void xloop_reread_partitions(struct xloop_device *xlo,
 {
 	int rc;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)) || \
+		RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 3))
 	mutex_lock(&bdev->bd_mutex);
 	rc = bdev_disk_changed(bdev, false);
 	mutex_unlock(&bdev->bd_mutex);
@@ -1035,7 +1043,8 @@ out_unlock:
 		 * must be at least one and it can only become zero when the
 		 * current holder is released.
 		 */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0) || \
+		RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 3))
 		if (!release)
 			mutex_lock(&bdev->bd_mutex);
 		err = bdev_disk_changed(bdev, false);
-- 
cgit v1.2.3-55-g7522