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

[Vivek Goyal]

On Tue, Dec 20, 2011 at 08:53:52PM -0500, Phillip Susi wrote:
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> On 12/19/2011 03:25 PM, Vivek Goyal wrote:
> > Are there any restrictions on order of partition bdev and disk bdev
> > locking.
> 
> Good point, yes, it seems you need to take the partition first.  Now that I think about it though, I don't think we need the disk mutex at all.  I thought you needed to hold it in order to iterate over the partitions, but it looks like you don't since that uses an RCU, right?
> 

I guess taking disk mutex will help us providing mutual exclusion between
multiple ioctls or multiple instances of same ioctl. Like, while you are
extending a partition and checking for overlap, you don't want another call
making progress on next partition which might overlap with this partition.

Thanks
Vivek
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