Jens Axboe wrote: > On 2010-06-18 17:28, Eric Sandeen wrote: >> Jens Axboe wrote: >>> On 18/06/10 16.59, Eric Sandeen wrote: >>> >>>> Eric Sandeen wrote: >>>> >>>>> Jens Axboe wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I was writing a small fio job file to do writes and read verifies on a >>>>>> device. It forks 32 processes, each writing randomly to 4 files with a >>>>>> block size between 4k and 16k. When it has written 1024 of those blocks, >>>>>> it'll verify the oldest 512 of them. Each block is checksummed for every >>>>>> 512b. It uses libaio and O_DIRECT. >>>>>> >>>>>> It works on ext2 and btrfs. I haven't run it to completion yet, but they >>>>>> survive 15-20 minutes just fine. ext4 doesn't even go a full minutes >>>>>> before this triggers: >>>>>> >>>>> Jens, can you try XFS too? Since ext3 can't do direct IO to a hole, >>>>> (and I'm not sure about btrfs in that regard), ext4 may be most similar >>>>> to xfs's behavior on the test ... wondering how it fares. >>>>> >>>>> Thanks, >>>>> -Eric >>>>> >>>> Actually mingming had a patch for direct-io.c which may be related, I'll >>>> test that out. >>>> >>> OK, I'll try XFS tonight as well. >>> >>> >>> >> I haven't been able to reproduce it on ext4 here, yet. >> >> FWIW here's the patch from mingming: >> >> When unaligned DIO writes, skip zero out the block if the buffer is marked >> unwritten. That means there is an asynconous direct IO (append or fill the hole) >> still pending. >> >> Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx> >> --- >> fs/direct-io.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> Index: linux-git/fs/direct-io.c >> =================================================================== >> --- linux-git.orig/fs/direct-io.c 2010-05-07 15:42:22.855033403 -0700 >> +++ linux-git/fs/direct-io.c 2010-05-07 15:44:17.695007770 -0700 >> @@ -740,7 +740,8 @@ >> struct page *page; >> >> dio->start_zero_done = 1; >> - if (!dio->blkfactor || !buffer_new(&dio->map_bh)) >> + if (!dio->blkfactor || !buffer_new(&dio->map_bh) >> + || buffer_unwritten(&dio->map_bh)) >> return; >> >> dio_blocks_per_fs_block = 1 << dio->blkfactor; >> >> > > What is this patch against? > Applied to 2.6.32, seems to apply upstream as well. It hits dio_zero-block() -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
