From: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
To: adrian.hunter@intel.com, ulf.hansson@linaro.org
Cc: stummala@codeaurora.org, linux-mmc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
Sarthak Garg <sartgarg@codeaurora.org>, <stable@vger.kernel.org>,
Baolin Wang <baolin.wang@linaro.org>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Andreas Koop <andreas.koop@zf.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH V1 2/2] mmc: core: Fix recursive locking issue in CQE recovery path
Date: Wed, 6 May 2020 20:04:03 +0530 [thread overview]
Message-ID: <1588775643-18037-3-git-send-email-vbadigan@codeaurora.org> (raw)
In-Reply-To: <1588775643-18037-1-git-send-email-vbadigan@codeaurora.org>
From: Sarthak Garg <sartgarg@codeaurora.org>
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> # v4.19+
Suggested-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>
---
drivers/mmc/core/queue.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 25bee3d..72bef39 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -107,7 +107,7 @@ 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;
}
/* No timeout (XXX: huh? comment doesn't make much sense) */
@@ -131,12 +131,13 @@ static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req,
spin_lock_irqsave(&mq->lock, flags);
- if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled)
+ if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled) {
ret = BLK_EH_RESET_TIMER;
- else
+ spin_unlock_irqrestore(&mq->lock, flags);
+ } else {
+ spin_unlock_irqrestore(&mq->lock, flags);
ret = mmc_cqe_timed_out(req);
-
- spin_unlock_irqrestore(&mq->lock, flags);
+ }
return ret;
}
--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-05-06 14:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-06 14:34 [PATCH V1 0/2] CQE fixes Veerabhadrarao Badiganti
2020-05-06 14:34 ` [PATCH V1 1/2] mmc: core: Check request type before completing the request Veerabhadrarao Badiganti
2020-05-06 17:06 ` Adrian Hunter
2020-05-08 8:12 ` Ulf Hansson
2020-05-06 14:34 ` Veerabhadrarao Badiganti [this message]
2020-05-07 11:48 ` [PATCH V1 2/2] mmc: core: Fix recursive locking issue in CQE recovery path Adrian Hunter
2020-05-07 14:06 ` [PATCH] mmc: block: Fix request completion in the CQE timeout path Adrian Hunter
2020-05-08 5:25 ` Ulf Hansson
2020-05-08 6:22 ` [PATCH RESEND] " Adrian Hunter
2020-05-08 8:17 ` Ulf Hansson
2020-05-07 16:15 ` [PATCH V2] mmc: core: Fix recursive locking issue in CQE recovery path Veerabhadrarao Badiganti
2020-05-07 17:21 ` Adrian Hunter
2020-05-08 8:12 ` Ulf Hansson
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