Re: [libvirt] [PATCH 1/2] resize: add virStorageVolResize() API

On 01/30/2012 07:28 AM, Daniel P. Berrange wrote: >>>> Why has this changed from 'unsigned long long' to just 'long long'. >>> >>> Because of VIR_STORAGE_VOL_RESIZE_DELTA and >>> VIR_STORAGE_VOL_RESIZE_SHRINK. That is, >>> >>> virStorageVolResize(vol, -10 * 1024 * 1024, DELTA|SHRINK) >>> >>> is a valid call to shave off 10 MiB of data. >> >> Isn't that rather redundant. Either you need a negative size, or you >> need a SHRINK flag. If you have a shrink flag, then we don't need a >> signed int. > > In fact since our existing virDomainBlockResize API is already > using unsigned long long, I'd say we should do shrinkage solely > based off the SHRINK flag, and *not* require a negative size > as well Here's what I was envisioning: set my size to an absolute of 10M, regardless of whether it was previously 5M or 15M: virStorageVolResize(vol, 10*1024*1024, SHRINK) set my size to an absolute of 10M, but only if it does not shrink: virStorageVolResize(vol, 10*1024*1024, 0) set my size to a relative of 10M larger virStorageVolResize(vol, 10*1024*1024, DELTA) set my size to a relative of 10M smaller, provided it was at least 10M to begin with: virStorageVolResize(vol, -10*1024*1024, DELTA|SHRINK) You are proposing that the negative sign should be implied by the combination of DELTA|SHRINK; I guess I can live with that, since the other three use cases still work as-is, and DELTA|SHRINK is the only point where a negative value makes sense (and therefore where implying the negative is okay). Shall I go ahead and write the patch?