From bdf7a0bd8a26ccdd94aaf972d469976563a0c0d7 Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: Apr 20 2023 11:01:00 +0000
Subject: cgroup/cpuset: Wake up cpuset_attach_wq tasks in

cpuset_cancel_attach() (bsc#1012628).

---

diff --git a/patches.kernel.org/6.2.12-117-cgroup-cpuset-Wake-up-cpuset_attach_wq-tasks-i.patch b/patches.kernel.org/6.2.12-117-cgroup-cpuset-Wake-up-cpuset_attach_wq-tasks-i.patch
new file mode 100644
index 0000000..5bbe2c4
--- /dev/null
+++ b/patches.kernel.org/6.2.12-117-cgroup-cpuset-Wake-up-cpuset_attach_wq-tasks-i.patch
@@ -0,0 +1,56 @@
+From: Waiman Long <longman@redhat.com>
+Date: Tue, 11 Apr 2023 09:35:57 -0400
+Subject: [PATCH] cgroup/cpuset: Wake up cpuset_attach_wq tasks in
+ cpuset_cancel_attach()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+References: bsc#1012628
+Patch-mainline: 6.2.12
+Git-commit: ba9182a89626d5f83c2ee4594f55cb9c1e60f0e2
+
+commit ba9182a89626d5f83c2ee4594f55cb9c1e60f0e2 upstream.
+
+After a successful cpuset_can_attach() call which increments the
+attach_in_progress flag, either cpuset_cancel_attach() or cpuset_attach()
+will be called later. In cpuset_attach(), tasks in cpuset_attach_wq,
+if present, will be woken up at the end. That is not the case in
+cpuset_cancel_attach(). So missed wakeup is possible if the attach
+operation is somehow cancelled. Fix that by doing the wakeup in
+cpuset_cancel_attach() as well.
+
+Fixes: e44193d39e8d ("cpuset: let hotplug propagation work wait for task attaching")
+Signed-off-by: Waiman Long <longman@redhat.com>
+Reviewed-by: Michal Koutný <mkoutny@suse.com>
+Cc: stable@vger.kernel.org # v3.11+
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Jiri Slaby <jslaby@suse.cz>
+---
+ kernel/cgroup/cpuset.c | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
+index 56fb79a4..86cd79e8 100644
+--- a/kernel/cgroup/cpuset.c
++++ b/kernel/cgroup/cpuset.c
+@@ -2502,11 +2502,15 @@ static int cpuset_can_attach(struct cgroup_taskset *tset)
+ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
+ {
+ 	struct cgroup_subsys_state *css;
++	struct cpuset *cs;
+ 
+ 	cgroup_taskset_first(tset, &css);
++	cs = css_cs(css);
+ 
+ 	percpu_down_write(&cpuset_rwsem);
+-	css_cs(css)->attach_in_progress--;
++	cs->attach_in_progress--;
++	if (!cs->attach_in_progress)
++		wake_up(&cpuset_attach_wq);
+ 	percpu_up_write(&cpuset_rwsem);
+ }
+ 
+-- 
+2.35.3
+
diff --git a/series.conf b/series.conf
index c9e11ad..ab30977 100644
--- a/series.conf
+++ b/series.conf
@@ -2344,6 +2344,7 @@
 	patches.kernel.org/6.2.12-114-x86-PCI-Add-quirk-for-AMD-XHCI-controller-that.patch
 	patches.kernel.org/6.2.12-115-cgroup-fix-display-of-forceidle-time-at-root.patch
 	patches.kernel.org/6.2.12-116-cgroup-cpuset-Fix-partition-root-s-cpuset.cpus.patch
+	patches.kernel.org/6.2.12-117-cgroup-cpuset-Wake-up-cpuset_attach_wq-tasks-i.patch
 
 	########################################################
 	# Build fixes that apply to the vanilla kernel too.