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From:   Daniel Palmer <daniel@0x0f.com>
Date:   Tue, 25 Jan 2022 20:38:09 +0900
Message-ID: <CAFr9PXk0XxXN4rWhwe_hVc8npXcVc=vb7QEmiwYaydMhXrjquQ@mail.gmail.com>
Subject: Re: "blk-mq: fix tag_get wait task can't be awakened" causes hangs
To:     "Alex Xu (Hello71)" <alex_y_xu@yahoo.ca>
Cc:     Laibin Qiu <qiulaibin@huawei.com>, axboe@kernel.dk,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-block@vger.kernel.org, john.garry@huawei.com,
        ming.lei@redhat.com, martin.petersen@oracle.com, hare@suse.de,
        Andrew Morton <akpm@linux-foundation.org>, bvanassche@acm.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Alex,

Same issue here. I just spent an hour bisecting the issue and hit the
same commit you did.

If I try to dd from a USB card reader to null I can see a few commands
wake up the thread that usb storage uses and then nothing more.
The user process then blocks forever waiting for the data it asked for.

Cheers,

Daniel