Message ID | 1590581942-24283-1-git-send-email-sartgarg@codeaurora.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [4.19.124,V1] mmc: core: Fix recursive locking issue in CQE recovery path | expand |
On Wed, May 27, 2020 at 05:49:02PM +0530, Sarthak Garg wrote: > [ Upstream commit 39a22f73744d5baee30b5f134ae2e30b668b66ed ] > > 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@codeaurora.org > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- Thanks for the backport, now queued up. greg k-h
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 03f3d9c..2a78816 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -108,7 +108,7 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req) 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_timed_out(struct request *req, 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)