(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