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| author | Ming Lei <ming.lei@redhat.com> | 2018-01-06 16:27:38 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-01-06 09:25:36 -0700 |
| commit | 24f5a90f0d13a97b51aa79f468143fafea4246bb (patch) | |
| tree | 4fe0235db1e0e32b1945933df172ca91456ced78 /block/elevator.c | |
| parent | c2856ae2f315d754a0b6a268e4c6745b332b42e7 (diff) | |
| download | linux-0-day-24f5a90f0d13a97b51aa79f468143fafea4246bb.tar.gz linux-0-day-24f5a90f0d13a97b51aa79f468143fafea4246bb.tar.xz | |
blk-mq: quiesce queue during switching io sched and updating nr_requests
Dispatch may still be in-progress after queue is frozen, so we have to
quiesce queue before switching IO scheduler and updating nr_requests.
Also when switching io schedulers, blk_mq_run_hw_queue() may still be
called somewhere(such as from nvme_reset_work()), and io scheduler's
per-hctx data may not be setup yet, so cause oops even inside
blk_mq_hctx_has_pending(), such as it can be run just between:
ret = e->ops.mq.init_sched(q, e);
AND
ret = e->ops.mq.init_hctx(hctx, i)
inside blk_mq_init_sched().
This reverts commit 7a148c2fcff8330(block: don't call blk_mq_quiesce_queue()
after queue is frozen) basically, and makes sure blk_mq_hctx_has_pending
won't be called if queue is quiesced.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 7a148c2fcff83309(block: don't call blk_mq_quiesce_queue() after queue is frozen)
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/elevator.c')
| -rw-r--r-- | block/elevator.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/block/elevator.c b/block/elevator.c index 7bda083d59684..138faeb08a7c3 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -968,6 +968,7 @@ static int elevator_switch_mq(struct request_queue *q, int ret; blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); if (q->elevator) { if (q->elevator->registered) @@ -994,6 +995,7 @@ static int elevator_switch_mq(struct request_queue *q, blk_add_trace_msg(q, "elv switch: none"); out: + blk_mq_unquiesce_queue(q); blk_mq_unfreeze_queue(q); return ret; } |