On 22/03/18 10:43, Shawn Lin wrote:
> On 2018/3/22 16:26, Adrian Hunter wrote:
>> On 22/03/18 09:49, Shawn Lin wrote:
>>> dd if=/dev/urandom of=/dev/mmcblk1 bs=4k count=10000
>>> with a SD card hotplug during transfer reports a warning below:
>>
>> What kernel version / commit was it?
>
> Actually the log below has it, it is clean : 4.16.0-rc6-next-20180321
Ok so it seems to be coming from this patch in next:
commit a063057d7c731cffa7d10740e8ebc2970df8dbb3
Author: Bart Van Assche <bart.vanassche at wdc.com>
Date: Wed Feb 28 10:15:33 2018 -0800
block: Fix a race between request queue removal and the block cgroup controller
Avoid that the following race can occur:
blk_cleanup_queue() blkcg_print_blkgs()
spin_lock_irq(lock) (1) spin_lock_irq(blkg->q->queue_lock) (2,5)
q->queue_lock = &q->__queue_lock (3)
spin_unlock_irq(lock) (4)
spin_unlock_irq(blkg->q->queue_lock) (6)
(1) take driver lock;
(2) busy loop for driver lock;
(3) override driver lock with internal lock;
(4) unlock driver lock;
(5) can take driver lock now;
(6) but unlock internal lock.
This change is safe because only the SCSI core and the NVME core keep
a reference on a request queue after having called blk_cleanup_queue().
Neither driver accesses any of the removed data structures between its
blk_cleanup_queue() and blk_put_queue() calls.
Reported-by: Joseph Qi <joseph.qi at linux.alibaba.com>
Signed-off-by: Bart Van Assche <bart.vanassche at wdc.com>
Reviewed-by: Joseph Qi <joseph.qi at linux.alibaba.com>
Cc: Jan Kara <jack at suse.com>
Signed-off-by: Jens Axboe <axboe at kernel.dk>
>
>>
>>>
>>> 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);
>>> ????? }
>>> ? }
>>>
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