[PATCH] mmc: block: Delete gendisk before cleaning up the request queue

[Shawn Lin]

dd if=/dev/urandom of=/dev/mmcblk1 bs=4k count=10000
with a SD card hotplug during transfer reports a warning below:

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 ]---

Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
---

 drivers/mmc/core/block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index a2b9c25..02485e3 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2659,7 +2659,6 @@ 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) &&
@@ -2669,6 +2668,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
 
 			del_gendisk(md->disk);
 		}
+		mmc_cleanup_queue(&md->queue);
 		mmc_blk_put(md);
 	}
 }
-- 
1.9.1