On Wed, Jul 17, 2013 at 11:38:50PM +0200, Jan Kara wrote: > On Wed 17-07-13 10:52:18, Dave Jones wrote: > > On Wed, Jul 17, 2013 at 02:53:22PM +0200, Jan Kara wrote: > > > On Tue 16-07-13 16:25:33, Dave Jones wrote: > > > > I've seen this happen a few times this week.. > > > Thanks for report! Was this when fuzzing or just normal desktop load? > > > What is inode with inode number 12 on your filesystem sdb1? What IO happens > > > to it? Apparently some delalloc accounting went wrong somewhere and it's > > > searching for a needle in a haystack unless we have more details... > > > > It was running this.. https://github.com/kernelslacker/io-tests/blob/master/setup.sh > > in a loop. After about 6 hours, that fell out. It made it all the way through > > every test a few times, which is odd, as the test should be fairly deterministic. > > Ah, I wasn't capturing the fsx seed. I'll do that on the next run. > So inode 12 was likely the file used by fsx. OK. Looking at the script > link, fsx is run as: > /usr/local/bin/fsx -N 250000 -S0 foo & > so the seed is always 0. So it is a deterministic test and there must be > some race with writeback or something that is rarely triggered. Drat. > > Umm, looking at the filesystems this tests, ext4 with 1 KB blocksize is > likely the config which hits this (the accounting is more complex there) so > it might be interesting to concentrace on this one. I just retried these tests, and hit this again. I can confirm it happens on the 1k block filesystem. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
