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? -- Jens Axboe -- 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
