diff options
| -rw-r--r-- | block/blk-core.c | 3 | ||||
| -rw-r--r-- | block/blk-mq.c | 9 |
2 files changed, 9 insertions, 3 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 24ee7785a5ad..ebb7a1689b26 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1140,8 +1140,7 @@ void __blk_flush_plug(struct blk_plug *plug, bool from_schedule) { if (!list_empty(&plug->cb_list)) flush_plug_callbacks(plug, from_schedule); - if (!rq_list_empty(plug->mq_list)) - blk_mq_flush_plug_list(plug, from_schedule); + blk_mq_flush_plug_list(plug, from_schedule); /* * Unconditionally flush out cached requests, even if the unplug * event came from schedule. Since we know hold references to the diff --git a/block/blk-mq.c b/block/blk-mq.c index add013d5bbda..100fb0c3114f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2749,7 +2749,14 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct request *rq; - if (rq_list_empty(plug->mq_list)) + /* + * We may have been called recursively midway through handling + * plug->mq_list via a schedule() in the driver's queue_rq() callback. + * To avoid mq_list changing under our feet, clear rq_count early and + * bail out specifically if rq_count is 0 rather than checking + * whether the mq_list is empty. + */ + if (plug->rq_count == 0) return; plug->rq_count = 0; |