Messages in this thread Patch in this message | | | From | Tejun Heo <> | Subject | [PATCH 1/7] blk-mq: protect completion path with RCU | Date | Sat, 16 Dec 2017 04:07:20 -0800 |
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Currently, blk-mq protects only the issue path with RCU. This patch puts the completion path under the same RCU protection. This will be used to synchronize issue/completion against timeout by later patches, which will also add the comments.
Signed-off-by: Tejun Heo <tj@kernel.org> --- block/blk-mq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c index 1109747..acf4fbb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -568,11 +568,23 @@ static void __blk_mq_complete_request(struct request *rq) void blk_mq_complete_request(struct request *rq) { struct request_queue *q = rq->q; + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu); + int srcu_idx; if (unlikely(blk_should_fake_timeout(q))) return; - if (!blk_mark_rq_complete(rq)) - __blk_mq_complete_request(rq); + + if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { + rcu_read_lock(); + if (!blk_mark_rq_complete(rq)) + __blk_mq_complete_request(rq); + rcu_read_unlock(); + } else { + srcu_idx = srcu_read_lock(hctx->queue_rq_srcu); + if (!blk_mark_rq_complete(rq)) + __blk_mq_complete_request(rq); + srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx); + } } EXPORT_SYMBOL(blk_mq_complete_request); -- 2.9.5
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