From a57a178a490345c7236b0077b3de005754389ed6 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 16 Sep 2014 14:44:07 -0700 Subject: [PATCH] blk-mq: avoid infinite recursion with the FUA flag We should not insert requests into the flush state machine from blk_mq_insert_request. All incoming flush requests come through blk_{m,s}q_make_request and are handled there, while blk_execute_rq_nowait should only be called for BLOCK_PC requests. All other callers deal with requests that already went through the flush statemchine and shouldn't be reinserted into it. Reported-by: Robert Elliott Debugged-by: Ming Lei Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-exec.c | 1 + block/blk-mq.c | 11 +++-------- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/block/blk-exec.c b/block/blk-exec.c index f4d27b12c90b..9924725fa50d 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -56,6 +56,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, bool is_pm_resume; WARN_ON(irqs_disabled()); + WARN_ON(rq->cmd_type == REQ_TYPE_FS); rq->rq_disk = bd_disk; rq->end_io = done; diff --git a/block/blk-mq.c b/block/blk-mq.c index 1583ed28ea03..a7d70a1bbf36 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -963,14 +963,9 @@ void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, hctx = q->mq_ops->map_queue(q, ctx->cpu); - if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA) && - !(rq->cmd_flags & (REQ_FLUSH_SEQ))) { - blk_insert_flush(rq); - } else { - spin_lock(&ctx->lock); - __blk_mq_insert_request(hctx, rq, at_head); - spin_unlock(&ctx->lock); - } + spin_lock(&ctx->lock); + __blk_mq_insert_request(hctx, rq, at_head); + spin_unlock(&ctx->lock); if (run_queue) blk_mq_run_hw_queue(hctx, async); -- 2.34.1