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blk-mq: setup queue ->tag_set before initializing hctx

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Commit 7b815817aa ("blk-mq: add helper for checking if one CPU is mapped to specified hctx")
needs to check queue mapping via tag set in hctx's cpuhp handler.

However, q->tag_set may not be setup yet when the cpuhp handler is
enabled, then kernel oops is triggered.

Fix the issue by setup queue tag_set before initializing hctx.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Rick Koch <mr.rickkoch@gmail.com>
Closes: https://lore.kernel.org/linux-block/CANa58eeNDozLaBHKPLxSAhEy__FPfJT_F71W=sEQw49UCrC9PQ@mail.gmail.com
Fixes: 7b815817aa ("blk-mq: add helper for checking if one CPU is mapped to specified hctx")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241014005115.2699642-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2024-10-14 08:51:15 +08:00 committed by Jens Axboe
parent ee7ff15bf5
commit c25c0c9035
1 changed files with 6 additions and 2 deletions
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8
block/blk-mq.c
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@ -4310,6 +4310,12 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
/* mark the queue as mq asap */
q->mq_ops = set->ops;
/*
* ->tag_set has to be setup before initialize hctx, which cpuphp
* handler needs it for checking queue mapping
*/
q->tag_set = set;
if (blk_mq_alloc_ctxs(q))
goto err_exit;
@ -4328,8 +4334,6 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
q->tag_set = set;
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);