On Mon, Dec 14, 2020 at 10:21:59AM -0700, Jens Axboe wrote:
 
 > >>>> [   87.290698] attempt to access beyond end of device
 > >>>>                md0: rw=4096, want=13996467328, limit=6261202944
 > >>>> [   87.293371] attempt to access beyond end of device
 > >>>>                md0: rw=4096, want=13998564480, limit=6261202944
 > >>>> [   87.296045] BTRFS warning (device md0): couldn't read tree root
 > >>>> [   87.300056] BTRFS error (device md0): open_ctree failed
 > >>>>
 > >>>> Reverting it goes back to the -rc7 behaviour where it mounts fine.
 > >>>
 > >>> If the developer/maintainer(s) agree, I can revert this and push out a
 > >>> 5.10.1, just let me know.
 > >>
 > >> Yes, these should be reverted from 5.10 via 5.10.1:
 > >>
 > >> e0910c8e4f87 dm raid: fix discard limits for raid1 and raid10
 > >> f075cfb1dc59 md: change mddev 'chunk_sectors' from int to unsigned
 > > 
 > > Sorry, f075cfb1dc59 was my local commit id, the corresponding upstream
 > > commit as staged by Jens is:
 > > 
 > > 6ffeb1c3f82 md: change mddev 'chunk_sectors' from int to unsigned
 > > 
 > > So please revert:
 > > 6ffeb1c3f822 md: change mddev 'chunk_sectors' from int to unsigned
 > > and then revert:
 > > e0910c8e4f87 dm raid: fix discard limits for raid1 and raid10
 > 
 > Working with Song on understanding the failure case here. raid6 was
 > tested prior to this being shipped. We'll be back with more soon...

FYI, mixup in my original mail, it was raid5  (I forgot I converted it from
raid6->raid5 a few months back).  But I wouldn't be surprised if they
were both equally affected given what that header touched.

	Dave