? 2018/3/22 17:47, Ulf Hansson ??:
> On 22 March 2018 at 10:31, Adrian Hunter <adrian.hunter at intel.com> wrote:
>> 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>
>
> Looks like a reasonable analyze!
>
> Shawn, could you please re-post your patch to linux-block, Jens,
> cc:mmc-list, me and Adrian.
>
Sure, I have sent to Jens.
> I think the patch should be picked up by Jens and go via his tree.
>
> Kind regards
> Uffe
>
>>
>>
>>>
>>>>
>>>>>
>>>>> 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);
>>>>> }
>>>>> }
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
