On Thu, Dec 29, 2011 at 11:51:45AM +0800, Wanlong Gao wrote: > Hi all: > > This is first reported to *libguestfs*: https://bugzilla.redhat.com/show_bug.cgi?id=624335 > > Then, I looked into upstream util-linux and it seems nothing wrong. I'm not convinced that it's a kernel bug. > > produce: > > --- > # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6 > 4096 > # ./util-linux/disk-utils/blockdev --setbsz 2048 /dev/sda6 > # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6 > 4096 > # ./util-linux/disk-utils/blockdev --setbsz 512 /dev/sda6 > # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6 > 4096 I think each blockdev invocation is working on a *new* bdev object. You'll get consistent results if somehow keep it referenced, for example, run a background copy task: # cp /dev/sda6 /dev/null & # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6 # ./util-linux/disk-utils/blockdev --setbsz 512 /dev/sda6 # ./util-linux/disk-utils/blockdev --getbsz /dev/sda6 Thanks, Fengguang -- 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
