Re: [PATCH 0/2] fsdax,xfs: fix warning messages

[Darrick J. Wong]

On Thu, Nov 24, 2022 at 02:54:52PM +0000, Shiyang Ruan wrote:
> Many testcases failed in dax+reflink mode with warning message in dmesg.
> This also effects dax+noreflink mode if we run the test after a
> dax+reflink test.  So, the most urgent thing is solving the warning
> messages.
> 
> Patch 1 fixes some mistakes and adds handling of CoW cases not
> previously considered (srcmap is HOLE or UNWRITTEN).
> Patch 2 adds the implementation of unshare for fsdax.
> 
> With these fixes, most warning messages in dax_associate_entry() are
> gone.  But honestly, generic/388 will randomly failed with the warning.
> The case shutdown the xfs when fsstress is running, and do it for many
> times.  I think the reason is that dax pages in use are not able to be
> invalidated in time when fs is shutdown.  The next time dax page to be
> associated, it still remains the mapping value set last time.  I'll keep
> on solving it.
> 
> The warning message in dax_writeback_one() can also be fixed because of
> the dax unshare.

This cuts down the amount of test failures quite a bit, but I think
you're still missing a piece or two -- namely the part that refuses to
enable S_DAX mode on a reflinked file when the inode is being loaded
from disk.  However, thank you for fixing dax.c, because that was the
part I couldn't figure out at all. :)

--D

> 
> Shiyang Ruan (2):
>   fsdax,xfs: fix warning messages at dax_[dis]associate_entry()
>   fsdax,xfs: port unshare to fsdax
> 
>  fs/dax.c             | 166 ++++++++++++++++++++++++++++++-------------
>  fs/xfs/xfs_iomap.c   |   6 +-
>  fs/xfs/xfs_reflink.c |   8 ++-
>  include/linux/dax.h  |   2 +
>  4 files changed, 129 insertions(+), 53 deletions(-)
> 
> -- 
> 2.38.1
>