From 08802ed665e47243393f43501bdafa032112eb1c Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Thu, 5 Dec 2019 20:53:11 +0800 Subject: [PATCH] bfq-iosched: Ensure bio->bi_blkg is valid before using it bio->bi_blkg will be NULL when the issue of the request has bypassed the block layer as shown in the following oops: Internal error: Oops: 96000005 [#1] SMP CPU: 17 PID: 2996 Comm: scsi_id Not tainted 5.4.0 #4 Call trace: percpu_counter_add_batch+0x38/0x4c8 bfqg_stats_update_legacy_io+0x9c/0x280 bfq_insert_requests+0xbac/0x2190 blk_mq_sched_insert_request+0x288/0x670 blk_execute_rq_nowait+0x140/0x178 blk_execute_rq+0x8c/0x140 sg_io+0x604/0x9c0 scsi_cmd_ioctl+0xe38/0x10a8 scsi_cmd_blk_ioctl+0xac/0xe8 sd_ioctl+0xe4/0x238 blkdev_ioctl+0x590/0x20e0 block_ioctl+0x60/0x98 do_vfs_ioctl+0xe0/0x1b58 ksys_ioctl+0x80/0xd8 __arm64_sys_ioctl+0x40/0x78 el0_svc_handler+0xc4/0x270 so ensure its validity before using it. Fixes: fd41e60331b1 ("bfq-iosched: stop using blkg->stat_bytes and ->stat_ios") Signed-off-by: Hou Tao Signed-off-by: Jens Axboe --- block/bfq-cgroup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index cea0ae12f937..e1419edde2ec 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -351,6 +351,9 @@ void bfqg_stats_update_legacy_io(struct request_queue *q, struct request *rq) { struct bfq_group *bfqg = blkg_to_bfqg(rq->bio->bi_blkg); + if (!bfqg) + return; + blkg_rwstat_add(&bfqg->stats.bytes, rq->cmd_flags, blk_rq_bytes(rq)); blkg_rwstat_add(&bfqg->stats.ios, rq->cmd_flags, 1); }