block: ublk: move ublk_chr_class destroying after devices are removed

The 'ublk_chr_class' is needed when deleting ublk char devices in
ublk_exit(), so move it after devices(idle) are removed.

Fixes the following warning reported by Harris, James R:

[  859.178950] sysfs group 'power' not found for kobject 'ublkc0'
[  859.178962] WARNING: CPU: 3 PID: 1109 at fs/sysfs/group.c:278 sysfs_remove_group+0x9c/0xb0

Reported-by: "Harris, James R" <james.r.harris@intel.com>
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Link: https://lore.kernel.org/linux-block/Y9JlFmSgDl3+zy3N@T590/T/#t
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Jim Harris <james.r.harris@intel.com>
Link: https://lore.kernel.org/r/20230126115346.263344-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 17b677b5d3b221fac658268958730dbc71dade52..e546932046309a66f63e2fcaf771e9d41c20ffc3 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2092,13 +2092,12 @@ static void __exit ublk_exit(void)
        struct ublk_device *ub;
        int id;
 
-       class_destroy(ublk_chr_class);
-
-       misc_deregister(&ublk_misc);
-
        idr_for_each_entry(&ublk_index_idr, ub, id)
                ublk_remove(ub);
 
+       class_destroy(ublk_chr_class);
+       misc_deregister(&ublk_misc);
+
        idr_destroy(&ublk_index_idr);
        unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS);
 }