diff options
| -rw-r--r-- | block/blk-flush.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c index 968162579234..0d5a9c1da1fc 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -297,8 +297,14 @@ static bool blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq) if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending)) return false; - /* C2 and C3 */ + /* C2 and C3 + * + * For blk-mq + scheduling, we can risk having all driver tags + * assigned to empty flushes, and we deadlock if we are expecting + * other requests to make progress. Don't defer for that case. + */ if (!list_empty(&fq->flush_data_in_flight) && + !(q->mq_ops && q->elevator) && time_before(jiffies, fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return false; |