On Thu, Nov 29, 2012 at 12:26:06PM -0700, Linus Torvalds wrote: > On Thu, Nov 29, 2012 at 11:15 AM, Chris Mason <chris.mason@xxxxxxxxxxxx> wrote: > > > > The fs/buffer.c part makes sense during a quick read. But > > fs/direct-io.c plays with i_blkbits too. The semaphore was fixing real > > bugs there. > > Ugh. I _hate_ direct-IO. What a mess. And yeah, it seems to be > incestuously playing games that should be in fs/buffer.c. I thought it > was doing the sane thing with the page cache. > > (I now realize that Mikulas was talking about this mess, while I > thought he was talking about the AIO code which is largely sane). It was all a trick to get you to say the AIO code was sane. It looks like we could use the private copy of i_blkbits that DIO is already recording. blkdev_get_blocks (called during DIO) is also checking i_blkbits, but I really don't get why that isn't byte based instead. DIO is already doing the shift & mask game. I think only clean_blockdev_aliases is intentionally using the inode's i_blkbits, but again that shouldn't be changing for filesystems so it seems safe to use the DIO copy. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
