release 6.16.3 (preliminary)

debian/patches/patchset-pf/steady/0037-block-restore-default-wbt-enablement.patch

@@ -0,0 +1,56 @@
+From ca0b04683be7bba50703eaec260167ec494d80b8 Mon Sep 17 00:00:00 2001
+From: Julian Sun <sunjunchao2870@gmail.com>
+Date: Tue, 12 Aug 2025 23:42:57 +0800
+Subject: block: restore default wbt enablement
+
+The commit 245618f8e45f ("block: protect wbt_lat_usec using
+q->elevator_lock") protected wbt_enable_default() with
+q->elevator_lock; however, it also placed wbt_enable_default()
+before blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);, resulting
+in wbt failing to be enabled.
+
+Moreover, the protection of wbt_enable_default() by q->elevator_lock
+was removed in commit 78c271344b6f ("block: move wbt_enable_default()
+out of queue freezing from sched ->exit()"), so we can directly fix
+this issue by placing wbt_enable_default() after
+blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);.
+
+Additionally, this issue also causes the inability to read the
+wbt_lat_usec file, and the scenario is as follows:
+
+root@q:/sys/block/sda/queue# cat wbt_lat_usec
+cat: wbt_lat_usec: Invalid argument
+
+root@q:/data00/sjc/linux# ls /sys/kernel/debug/block/sda/rqos
+cannot access '/sys/kernel/debug/block/sda/rqos': No such file or directory
+
+root@q:/data00/sjc/linux# find /sys -name wbt
+/sys/kernel/debug/tracing/events/wbt
+
+After testing with this patch, wbt can be enabled normally.
+
+Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
+Cc: stable@vger.kernel.org
+Fixes: 245618f8e45f ("block: protect wbt_lat_usec using q->elevator_lock")
+Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
+Reviewed-by: Yu Kuai <yukuai3@huawei.com>
+Reviewed-by: Ming Lei <ming.lei@redhat.com>
+Link: https://lore.kernel.org/r/20250812154257.57540-1-sunjunchao@bytedance.com
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+---
+ block/blk-sysfs.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/block/blk-sysfs.c
++++ b/block/blk-sysfs.c
+@@ -876,9 +876,9 @@ int blk_register_queue(struct gendisk *d
+ 
+ 	if (queue_is_mq(q))
+ 		elevator_set_default(q);
+-	wbt_enable_default(disk);
+ 
+ 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
++	wbt_enable_default(disk);
+ 
+ 	/* Now everything is ready and send out KOBJ_ADD uevent */
+ 	kobject_uevent(&disk->queue_kobj, KOBJ_ADD);