Adding debian version 4.19.249-2.debian/4.19.249-2debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/debian/patches-rt/0181-md-raid5-Make-raid5_percpu-handling-RT-aware.patch b/debian/patches-rt/0181-md-raid5-Make-raid5_percpu-handling-RT-aware.patch
new file mode 100644
index 000000000..e1f7c3fce
--- /dev/null
+++ b/debian/patches-rt/0181-md-raid5-Make-raid5_percpu-handling-RT-aware.patch
@@ -0,0 +1,77 @@
+From 17db75361d2ecbea4026acde76a744fdecc4c475 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Tue, 6 Apr 2010 16:51:31 +0200
+Subject: [PATCH 181/347] md: raid5: Make raid5_percpu handling RT aware
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+__raid_run_ops() disables preemption with get_cpu() around the access
+to the raid5_percpu variables. That causes scheduling while atomic
+spews on RT.
+
+Serialize the access to the percpu data with a lock and keep the code
+preemptible.
+
+Reported-by: Udo van den Heuvel <udovdh@xs4all.nl>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Tested-by: Udo van den Heuvel <udovdh@xs4all.nl>
+---
+ drivers/md/raid5.c | 8 +++++---
+ drivers/md/raid5.h | 1 +
+ 2 files changed, 6 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
+index c7bda4b0bced..8eb234732c9b 100644
+--- a/drivers/md/raid5.c
++++ b/drivers/md/raid5.c
+@@ -2069,8 +2069,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
+ 	struct raid5_percpu *percpu;
+ 	unsigned long cpu;
+ 
+-	cpu = get_cpu();
++	cpu = get_cpu_light();
+ 	percpu = per_cpu_ptr(conf->percpu, cpu);
++	spin_lock(&percpu->lock);
+ 	if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
+ 		ops_run_biofill(sh);
+ 		overlap_clear++;
+@@ -2129,7 +2130,8 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
+ 			if (test_and_clear_bit(R5_Overlap, &dev->flags))
+ 				wake_up(&sh->raid_conf->wait_for_overlap);
+ 		}
+-	put_cpu();
++	spin_unlock(&percpu->lock);
++	put_cpu_light();
+ }
+ 
+ static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
+@@ -6816,6 +6818,7 @@ static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
+ 			__func__, cpu);
+ 		return -ENOMEM;
+ 	}
++	spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
+ 	return 0;
+ }
+ 
+@@ -6826,7 +6829,6 @@ static int raid5_alloc_percpu(struct r5conf *conf)
+ 	conf->percpu = alloc_percpu(struct raid5_percpu);
+ 	if (!conf->percpu)
+ 		return -ENOMEM;
+-
+ 	err = cpuhp_state_add_instance(CPUHP_MD_RAID5_PREPARE, &conf->node);
+ 	if (!err) {
+ 		conf->scribble_disks = max(conf->raid_disks,
+diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
+index 8474c224127b..a3bf907ab2af 100644
+--- a/drivers/md/raid5.h
++++ b/drivers/md/raid5.h
+@@ -637,6 +637,7 @@ struct r5conf {
+ 	int			recovery_disabled;
+ 	/* per cpu variables */
+ 	struct raid5_percpu {
++		spinlock_t	lock;		/* Protection for -RT */
+ 		struct page	*spare_page; /* Used when checking P/Q in raid6 */
+ 		struct flex_array *scribble;   /* space for constructing buffer
+ 					      * lists and performing address
+-- 
+2.36.1
+