From: Sarthak Garg sartgarg@codeaurora.org
commit 39a22f73744d5baee30b5f134ae2e30b668b66ed upstream.
Consider the following stack trace
-001|raw_spin_lock_irqsave -002|mmc_blk_cqe_complete_rq -003|__blk_mq_complete_request(inline) -003|blk_mq_complete_request(rq) -004|mmc_cqe_timed_out(inline) -004|mmc_mq_timed_out
mmc_mq_timed_out acquires the queue_lock for the first time. The mmc_blk_cqe_complete_rq function also tries to acquire the same queue lock resulting in recursive locking where the task is spinning for the same lock which it has already acquired leading to watchdog bark.
Fix this issue with the lock only for the required critical section.
Cc: stable@vger.kernel.org Fixes: 1e8e55b67030 ("mmc: block: Add CQE support") Suggested-by: Sahitya Tummala stummala@codeaurora.org Signed-off-by: Sarthak Garg sartgarg@codeaurora.org Acked-by: Adrian Hunter adrian.hunter@intel.com Link: https://lore.kernel.org/r/1588868135-31783-1-git-send-email-vbadigan@codeaur... Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/core/queue.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)
--- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -108,7 +108,7 @@ static enum blk_eh_timer_return mmc_cqe_ case MMC_ISSUE_DCMD: if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) { if (recovery_needed) - __mmc_cqe_recovery_notifier(mq); + mmc_cqe_recovery_notifier(mrq); return BLK_EH_RESET_TIMER; } /* The request has gone already */ @@ -125,18 +125,13 @@ static enum blk_eh_timer_return mmc_mq_t struct request_queue *q = req->q; struct mmc_queue *mq = q->queuedata; unsigned long flags; - int ret; + bool ignore_tout;
spin_lock_irqsave(q->queue_lock, flags); - - if (mq->recovery_needed || !mq->use_cqe) - ret = BLK_EH_RESET_TIMER; - else - ret = mmc_cqe_timed_out(req); - + ignore_tout = mq->recovery_needed || !mq->use_cqe; spin_unlock_irqrestore(q->queue_lock, flags);
- return ret; + return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req); }
static void mmc_mq_recovery_handler(struct work_struct *work)