Re: 5.3-rc1 regression with XFS log recovery

["hch@lst.de" <hch@lst.de>]

On Fri, Aug 16, 2019 at 08:59:44PM +0000, Verma, Vishal L wrote:
> Hi all,
> 
> When running the 'ndctl' unit tests against 5.3-rc kernels, I noticed a
> frequent failure of the 'mmap.sh' test [1][2].
> 
> [1]: https://github.com/pmem/ndctl/blob/master/test/mmap.sh
> [2]: https://github.com/pmem/ndctl/blob/master/test/mmap.c
> 
> But in trying to pare down the test further, I found that I can simply
> reproduce the problem by:
> 
>   mkfs.xfs -f /dev/pmem0
>   mount /dev/pmem0 /mnt/mem
> 
> Where 'pmem0' is a legacy pmem namespace from reserved memory using the
> memmap= command line option. (Specifically, I have this:
> memmap=3G!6G,3G!9G )
> 
> The above mkfs/mount steps don't reproduce the problem a 100% of the
> time, but it does happen on my qemu based setup over 75% of the times.
> 
> The kernel log shows the following when the mount fails:

Is it always that same message?  I'll see if I can reproduce it,
but I won't have that much memory to spare to create fake pmem,
hope this also works with a single device and/or less memory..