From: Christoph Hellwig Date: Tue, 16 Sep 2014 21:44:07 +0000 (-0700) Subject: blk-mq: avoid infinite recursion with the FUA flag X-Git-Tag: firefly_0821_release~176^2~3186^2~3 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a57a178a490345c7236b0077b3de005754389ed6;p=firefly-linux-kernel-4.4.55.git 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 --- 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);