On Mon, Jul 27, 2015 at 05:41:57AM -0400, Ming Lei wrote: > > Why the hardcoded value? I suspect this should be more like: > > > > if (dio && inode->i_sb->s_bdev && > > (lo->lo_offset & (bdev_io_min(inode->i_sb->s_bdev) - 1)) != 0) > > dio = false; > > The above can't work if the backing device has a bigger sector size > (such as 4K), that is why loop's direct-io requires 512 min_io_size of > backing device.
Why doesn't it work? If the backing device sector size is 4k and lo_offset is 0 or a multiple of 4k it should allow direct I/O, and my code sniplet will allow that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
