Messages in this thread | | | Subject | Re: [syzbot] possible deadlock in loop_add | From | Desmond Cheong Zhi Xi <> | Date | Sat, 17 Jul 2021 17:41:03 +0800 |
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On 16/7/21 7:00 am, Miquel Raynal wrote: > Hello, > > Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> wrote on Mon, 12 Jul > 2021 16:29:16 +0800: > >> On 12/7/21 1:27 pm, Christoph Hellwig wrote: >>> On Sat, Jul 10, 2021 at 09:16:38PM +0800, Hillf Danton wrote: >>>> To break the lock chain, un/register blkdev without mtd_table_mutex held. >>> >>> Yes, Desmond Cheong Zhi Xi sent pretty much the same patch on June 18th >>> (mtd: break circular locks in register_mtd_blktrans), but it did not get >>> picked up. >>> >> >> I believe Miquèl was waiting for -rc1 to apply it. > > Indeed, I already applied it but did not advertise yet. >
Thanks Miquèl!
>> >> But taking a closer look, although the fix for the register path is the same, Hillf Danton's proposed patch additionally avoids inverting the lock hierarchy on the unregister path. So I believe this new patch should be more robust. > > We can definitely do this in two steps if you want. >
Sounds good, I'll prepare a patch with Hillf's suggestion for the unregister path.
> Thanks, > Miquèl >
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