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 <Elliott@hp.com>
Debugged-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-exec.c b/block/blk-exec.c
index f4d27b1..9924725 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -56,6 +56,7 @@
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 1583ed2..a7d70a1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -963,14 +963,9 @@
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);
