Thanks for the fix. Tested-by: Yi Zhang <yi.zhang@xxxxxxxxxx> On Wed, Jun 9, 2021 at 9:58 AM Ming Lei <ming.lei@xxxxxxxxxx> wrote: > > Hello, > > Yi reported several kernel panics on: > > [16687.001777] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 > ... > [16687.163549] pc : __rq_qos_track+0x38/0x60 > > or > > [ 997.690455] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 > ... > [ 997.850347] pc : __rq_qos_done+0x2c/0x50 > > Turns out it is caused by race between adding wbt and normal IO. > > Fix the issue by freezing request queue when adding/deleting rq qos. > > V3: > - use ->queue_lock for protecting concurrent adding/deleting rqos on > same queue > > V2: > - switch to the approach of freezing queue, which is more generic > than V1. > > > > Ming Lei (2): > block: fix race between adding/removing rq qos and normal IO > block: mark queue init done at the end of blk_register_queue > > block/blk-rq-qos.h | 24 ++++++++++++++++++++++++ > block/blk-sysfs.c | 29 +++++++++++++++-------------- > 2 files changed, 39 insertions(+), 14 deletions(-) > > Cc: Yi Zhang <yi.zhang@xxxxxxxxxx> > Cc: Bart Van Assche <bvanassche@xxxxxxx> > -- > 2.31.1 > -- Best Regards, Yi Zhang
