On 1/20/22 11:52 AM, Daniel Wagner wrote: > The request queues can be freed while we operate on them. Make sure we > hold a reference when using blk_mq_queue_tag_busy_iter. > > RIP: blk_mq_queue_tag_busy_iter > Call Trace: > ? blk_mq_hctx_mark_pending > ? diskstats_show > ? blk_mq_hctx_mark_pending > blk_mq_in_flight > diskstats_show > ? klist_next > seq_read > proc_reg_read > vfs_read > ksys_read > do_syscall_64 > entry_SYSCALL_64_after_hwframe > > Signed-off-by: Daniel Wagner <dwagner@xxxxxxx> > --- > block/genhd.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/block/genhd.c b/block/genhd.c > index c9d4386dd177..0e163055a4e6 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -1167,10 +1167,13 @@ static int diskstats_show(struct seq_file *seqf, void *v) > if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) > continue; > part_stat_read_all(hd, &stat); > + if (blk_queue_enter(gp->queue, BLK_MQ_REQ_NOWAIT)) > + continue; > if (queue_is_mq(gp->queue)) > inflight = blk_mq_in_flight(gp->queue, hd); > else > inflight = part_in_flight(hd); > + blk_queue_exit(gp->queue); > > seq_printf(seqf, "%4d %7d %pg " > "%lu %lu %lu %u " > While this looks good, it seems to have been cut against an earlier branch; the code in question looks different in my copy. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer
