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>
This commit is contained in:
Christoph Hellwig 2014-09-16 14:44:07 -07:00 committed by Jens Axboe
parent 683d0e1262
commit a57a178a49
2 changed files with 4 additions and 8 deletions

View file

@ -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;

View file

@ -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);
}
if (run_queue)
blk_mq_run_hw_queue(hctx, async);