Re: [PATCH 1/2] Add partition resize function to BLKPG ioctl

From: Phillip Susi
Date: Thu Dec 08 2011 - 10:25:30 EST


On 12/8/2011 10:16 AM, Karel Zak wrote:
Is it safe to alter the partition size in arbitrary way if the
partition is used by any process?

Vivek's BLKPG_EXTEND_PARTITIONV seems more safety, because it extends
a partition size only, so all offsets in all running stuff are still
valid.

Maybe you need to check bdevp->bd_openers and returns -EBUSY if you
want to alter the begin of the partition.

I disallowed altering the start of the partition ( that would just be crazy ), but altering the end has been supported on lvm for years now. Ext4 can not perform an online shrink, but btrfs can, and I was able to successfully have btrfs shrink the fs and then use BLKPG_RES_PARTITION to shrink the partition.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/