On 2016-08-17 23:02, Johannes Stezenbach wrote:

On Fri, Aug 05, 2016 at 08:11:36PM +0200, Johannes Stezenbach wrote:

quoted

On Fri, Aug 05, 2016 at 10:02:28AM -0700, Darrick J. Wong wrote:

quoted

When you're back on 4.7, can you apply this patch[1] to see if it fixes
the problem?  I speculate that the new parallel dir lookup code enables
multiple threads to be verifying the same directory block buffer at the
same time.

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/fs/ext4/inode.c?id=b47820edd1634dc1208f9212b7ecfb4230610a23

I added the patch, rebuilt and rebooted.  It will take some time
before I'll report back since the issue is so hard to reproduce.

FWIW, so far the issue didn't appear again after I applied
the patch to 4.7.0, and I stressed it a bit with repo syncs,
AOSP builds, rsync backups etc.

Same here: I've been using 4.7.0+patch daily, and everything is working fine.

Best regards,
--Edwin