From a0bc45a83747afe7c82b8fda7438748fabe5a994 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Wed, 10 Apr 2024 15:30:36 +0200
Subject: [KERNEL] Fix build on CentOS 9.5-but-newer

So far, breaking changes were accompanied with a bump of the minor
version, but not this time. Bewetween -432 and-435, the signature of
disk_force_media_change() changed (haha), but the version number stayed
the same.

Pick the completely arbitrary macro QUEUE_FLAG_SYNCHRONOUS which only
exists in -435 to tell the versions apart.
---
 .github/workflows/build-kernel-modules.yml |  8 ++++----
 src/kernel/xloop_main_rhel_9.0.c           | 12 ++++++++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/build-kernel-modules.yml b/.github/workflows/build-kernel-modules.yml
index 85a54cc..7d51ee2 100644
--- a/.github/workflows/build-kernel-modules.yml
+++ b/.github/workflows/build-kernel-modules.yml
@@ -41,14 +41,14 @@ jobs:
             build-os: ubuntu-22.04
             kernel-type: centos-rpm
             kernel-source: https://vault.centos.org/8.5.2111/BaseOS/Source/SPackages/kernel-4.18.0-348.7.1.el8_5.src.rpm
-          - name: CentOS 9.4 [5.14.0]
-            build-os: ubuntu-22.04
-            kernel-type: centos-tar
-            kernel-source: https://files.bwlp.ks.uni-freiburg.de/stuff/centos/linux-5.14.0-427.el9.tar.xz
           - name: CentOS 9.5 [5.14.0]
             build-os: ubuntu-22.04
             kernel-type: centos-tar
             kernel-source: https://files.bwlp.ks.uni-freiburg.de/stuff/centos/linux-5.14.0-432.el9.tar.xz
+          - name: CentOS 9.5b [5.14.0]
+            build-os: ubuntu-22.04
+            kernel-type: centos-tar
+            kernel-source: https://files.bwlp.ks.uni-freiburg.de/stuff/centos/linux-5.14.0-435.el9.tar.xz
     name: Build xloop ${{ matrix.config.name }}
     runs-on: ${{ matrix.config.build-os }}
     steps:
diff --git a/src/kernel/xloop_main_rhel_9.0.c b/src/kernel/xloop_main_rhel_9.0.c
index e35284e..f654e8e 100644
--- a/src/kernel/xloop_main_rhel_9.0.c
+++ b/src/kernel/xloop_main_rhel_9.0.c
@@ -471,7 +471,11 @@ static int xloop_change_fd(struct xloop_device *xlo, struct block_device *bdev,
 		goto out_err;
 
 	/* and ... switch */
+#ifdef QUEUE_FLAG_SYNCHRONOUS
+	disk_force_media_change(xlo->xlo_disk);
+#else
 	disk_force_media_change(xlo->xlo_disk, DISK_EVENT_MEDIA_CHANGE);
+#endif
 	blk_mq_freeze_queue(xlo->xlo_queue);
 	mapping_set_gfp_mask(old_file->f_mapping, xlo->old_gfp_mask);
 	xlo->xlo_backing_file = file;
@@ -969,7 +973,11 @@ static int xloop_configure(struct xloop_device *xlo, fmode_t mode,
 		goto out_unlock;
 	}
 
+#ifdef QUEUE_FLAG_SYNCHRONOUS
+	disk_force_media_change(xlo->xlo_disk);
+#else
 	disk_force_media_change(xlo->xlo_disk, DISK_EVENT_MEDIA_CHANGE);
+#endif
 	set_disk_ro(xlo->xlo_disk, (xlo->xlo_flags & XLO_FLAGS_READ_ONLY) != 0);
 
 	INIT_WORK(&xlo->rootcg_work, xloop_rootcg_workfn);
@@ -1129,7 +1137,11 @@ static int __xloop_clr_fd(struct xloop_device *xlo, bool release)
 
 	partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN && bdev;
 	xlo_number = xlo->xlo_number;
+#ifdef QUEUE_FLAG_SYNCHRONOUS
+	disk_force_media_change(xlo->xlo_disk);
+#else
 	disk_force_media_change(xlo->xlo_disk, DISK_EVENT_MEDIA_CHANGE);
+#endif
 out_unlock:
 	mutex_unlock(&xlo->xlo_mutex);
 	if (partscan) {
-- 
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