Re: 5.0.0-rc8-next-20190301+: kernel bug at fs/inode.c:513

[Theodore Y. Ts'o]

(Adding linux-mm and moving linux-ext4 and linux-kernel to the bcc
list...)

On Mon, Mar 04, 2019 at 05:02:55PM +0100, Pavel Machek wrote:
> 
> This happened on trying to sync filesystems with unison:
> 
> Any ideas?
> 
> Should I be forcing fsck soon?
> 								Pavel
> 
> [12717.827444] ------------[ cut here ]------------
> [12717.827465] kernel BUG at fs/inode.c:513!

It seems unlikely that fsck is going to help.  The BUG_ON in question
appears to be:

	BUG_ON(inode->i_data.nrexceptional);

This is an in-memory accounting variable which seems to be related to
tracking DAX and shadow page entries --- and it seems very unlikely to
be the sort of thing triggered by an on-disk corruption.

Do you have a reliable repro for this?  If so, the next step would be
to bisect...

					- Ted