Patch "elevator: add new field flags in struct elevator_queue" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    elevator: add new field flags in struct elevator_queue

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     elevator-add-new-field-flags-in-struct-elevator_queu.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 85ad0276e21822aca9c6a80d8a03247daa354d1c
Author: Yu Kuai <yukuai3@xxxxxxxxxx>
Date:   Wed Oct 19 20:15:17 2022 +0800

    elevator: add new field flags in struct elevator_queue
    
    [ Upstream commit 181d06637451b5348d746039478e71fa53dfbff6 ]
    
    There are only one flag to indicate that elevator is registered currently,
    prepare to add a flag to disable wbt if default elevator is bfq.
    
    Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
    Reviewed-by: Christoph Hellwig <hch@xxxxxx>
    Link: https://lore.kernel.org/r/20221019121518.3865235-6-yukuai1@xxxxxxxxxxxxxxx
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Stable-dep-of: f814bdda774c ("blk-wbt: Fix detection of dirty-throttled tasks")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/block/elevator.c b/block/elevator.c
index 20e70fd3f77f9..9e12706e8d8cb 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -512,7 +512,7 @@ int elv_register_queue(struct request_queue *q, bool uevent)
 		if (uevent)
 			kobject_uevent(&e->kobj, KOBJ_ADD);
 
-		e->registered = 1;
+		set_bit(ELEVATOR_FLAG_REGISTERED, &e->flags);
 	}
 	return error;
 }
@@ -523,11 +523,9 @@ void elv_unregister_queue(struct request_queue *q)
 
 	lockdep_assert_held(&q->sysfs_lock);
 
-	if (e && e->registered) {
+	if (e && test_and_clear_bit(ELEVATOR_FLAG_REGISTERED, &e->flags)) {
 		kobject_uevent(&e->kobj, KOBJ_REMOVE);
 		kobject_del(&e->kobj);
-
-		e->registered = 0;
 	}
 }
 
diff --git a/block/elevator.h b/block/elevator.h
index 3f0593b3bf9d3..ed574bf3e629e 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -100,10 +100,12 @@ struct elevator_queue
 	void *elevator_data;
 	struct kobject kobj;
 	struct mutex sysfs_lock;
-	unsigned int registered:1;
+	unsigned long flags;
 	DECLARE_HASHTABLE(hash, ELV_HASH_BITS);
 };
 
+#define ELEVATOR_FLAG_REGISTERED 0
+
 /*
  * block elevator interface
  */