mmc: block: Delete gendisk before cleaning up the request queue

dd if=/dev/urandom of=/dev/mmcblk1 bs=4k count=10000
with a SD card hotplug during transfer reports a warning below
introduced by commit a063057d7c73 ("block: Fix a race between
request queue removal and the block cgroup controller"). So we
should now remove the disk, partition and bdi sysfs attributes
before cleaning up the request queue associated with the disk.

[  410.331226] mmc1: card 59b4 removed
[  410.348583] WARNING: CPU: 0 PID: 5 at block/blk-core.c:785
blk_cleanup_queue+0x138/0x140
[  410.349294] Modules linked in:
[  410.349570] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted
4.16.0-rc6-next-20180321-00004-gc2ad6a7 #263
[  410.350363] Hardware name: Excavator-RK3399 Board (DT)
[  410.350819] Workqueue: events_freezable mmc_rescan
[  410.351242] pstate: 60000005 (nZCv daif -PAN -UAO)
[  410.351663] pc : blk_cleanup_queue+0x138/0x140
[  410.352054] lr : blk_cleanup_queue+0xac/0x140
[  410.352436] sp : ffff0000092cbb90
[  410.352727] x29: ffff0000092cbb90 x28: 0000000000000000
[  410.353195] x27: ffff8000f6f23030 x26: ffff00000904e610
[  410.353662] x25: ffff8000f17cc808 x24: ffff8000f1038200
[  410.354128] x23: 0000000000000060 x22: 0000000000000000
[  410.354595] x21: ffff8000f11748d8 x20: ffff8000f1038200
[  410.355061] x19: ffff8000f1174200 x18: 0000ffff936347d8
[  410.355528] x17: 0000ffff935b93c0 x16: ffff0000081263f8
[  410.355994] x15: 0000000000000000 x14: 0000000000000400
[  410.356461] x13: 0000000000000001 x12: 0000000000000001
[  410.356927] x11: 0000000000000040 x10: ffff8000f2400028
[  410.357393] x9 : ffff8000f2400040 x8 : 0000000000000000
[  410.357860] x7 : ffff8000f6f3a340 x6 : ffff8000f6f3a340
[  410.358326] x5 : ffff8000f2400000 x4 : ffff8000f6f3a340
[  410.358792] x3 : 0000000000000000 x2 : 39c1333e45670800
[  410.359259] x1 : 0000000000000000 x0 : 0000000000000003
[  410.359726] Call trace:
[  410.359943]  blk_cleanup_queue+0x138/0x140
[  410.360305]  mmc_cleanup_queue+0x2c/0x48
[  410.360652]  mmc_blk_remove_req+0x1c/0x98
[  410.361005]  mmc_blk_remove+0x180/0x1c0
[  410.361343]  mmc_bus_remove+0x1c/0x28
[  410.361670]  device_release_driver_internal+0x154/0x1f0
[  410.362128]  device_release_driver+0x14/0x20
[  410.362504]  bus_remove_device+0xc8/0x108
[  410.362858]  device_del+0x120/0x350
[  410.363167]  mmc_remove_card+0x5c/0xb8
[  410.363498]  mmc_sd_detect+0x40/0x78
[  410.363813]  mmc_rescan+0x19c/0x368
[  410.364123]  process_one_work+0x1ac/0x318
[  410.364477]  worker_thread+0x50/0x450
[  410.364801]  kthread+0xf8/0x128
[  410.365081]  ret_from_fork+0x10/0x18
[  410.365395] ---[ end trace 268e87a46c28968c ]---

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/mmc/core/block.c

@@ -2647,7 +2647,6 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
 		 * from being accepted.
 		 */
 		card = md->queue.card;
-		mmc_cleanup_queue(&md->queue);
 		if (md->disk->flags & GENHD_FL_UP) {
 			device_remove_file(disk_to_dev(md->disk), &md->force_ro);
 			if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
@@ -2657,6 +2656,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
 
 			del_gendisk(md->disk);
 		}
+		mmc_cleanup_queue(&md->queue);
 		mmc_blk_put(md);
 	}
 }