Re: [REGRESSION] commit b520c4eef83d ("block: split bio_alloc_bioset more clearly into a fast and slowpath") causes fsync to fail with pmem

Sven-Hendrik Haase <[email protected]> Fri, 10 Jul 2026 20:26:46 +0200

Newsgroups	dev.linux.lists.regressions,org.kernel.vger.linux-block
Message-ID	<[email protected]>


On 10.07.26 20:17, Keith Busch wrote:
> On Fri, Jul 10, 2026 at 08:07:32PM +0200, Sven-Hendrik Haase wrote:
>> I noticed that starting with Linux 7.1, my pmem volumes inside of QEMU
>> stopped working. My use case is this:
>>
>> qemu-system-x86_64 ... tons of QEMU flags ...
>> -object memory-backend-file,id=pmem0,share=on,merge=on,discard-data=on,mem-path=/path/pmem0.pmem,size=100G
>> -device virtio-pmem-pci,memdev=pmem0,id=nv0
>>
>> This used to work but inside the VM I'd get this when running mkfs.ext4
>> /dev/pmem0 with guest kernel 7.1.3:
> 
> This pending fix (which is the same as what you proposed here) should
> take care of it:
> 
> https://lore.kernel.org/linux-block/[email protected]/

Oh, indeed. That's the very same patch. Well, looks like it's in the 
queue, then.

Sorry for the noise. :)

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