Re: [libvirt] [PATCH] storage: Round up capacity for LVM volume creation

On Sat, Jan 22, 2011 at 07:18:00PM +0800, Osier Yang wrote: > If vol->capacity is odd, the capacity will be rounded down > by devision, this patch is to round it up instead of rounding > down, to be safer in case of one writes to the volume with the > size he used to create. > > * src/storage/storage_backend_logical.c > --- > src/storage/storage_backend_logical.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c > index 203fe5d..2057692 100644 > --- a/src/storage/storage_backend_logical.c > +++ b/src/storage/storage_backend_logical.c > @@ -604,7 +604,10 @@ virStorageBackendLogicalCreateVol(virConnectPtr conn, > cmdargv = cmdargvsnap; > } > > - snprintf(size, sizeof(size)-1, "%lluK", vol->capacity/1024); > + unsigned long long int capacity; > + capacity = vol->capacity/1024 + (vol->capacity%1024> 0 ? 1 : 0); > + > + snprintf(size, sizeof(size)-1, "%lluK", capacity); > size[sizeof(size)-1] = '\0'; > > vol->type = VIR_STORAGE_VOL_BLOCK; To fix such rounding issues I would usually do capacity = (vol->capacity + 1023) /1024; instead, it's really easier to read :-)

But the principle of the patch looks right to me ! Daniel