Theodore Tso wrote: > On Fri, May 15, 2009 at 06:32:45AM +0930, Kevin Shanahan wrote: >> Okay, so now I've booted into 2.6.29.3 + check_block_validity patch + >> short circuit i_cached_extent patch, mounted the fs without >> nodelalloc. I was able to run the full exchange backup without >> triggering the check_block_validity error. > > Great! > > So here's the final fix (it replaces the short circuit i_cached_extent > patch) which I plan to push to Linus. It should be much less of a > performance hit than simply short-circuiting i_cached_extent... > > Thanks so much for helping to find track this down!!! If ever someone > deserved an "Ext4 Baker Street Irregulars" T-shirt, it would be > you.... > > - Ted So here's a fio job I thought would try to hit this ... [global] ioengine=libaio iodepth=1 filesize=4g bs=1m norandommap direct=1 loops=500 size=16g [setup] filename=file rw=randwrite loops=1 [thread1] stonewall filename=file rw=randwrite [thread2] filename=file rw=randread it should lay out a 4g file in random 1m direct IOs to fragment it and get a lot of extents, then launch 2 threads, one each doing random reads and random writes of that same file. I can't make this trip it, though ... -Eric -- 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
