Re: [libvirt] [PATCH 2/6] qemu: Add a hash table for the shared disks

On 01/03/2013 08:35 PM, Osier Yang wrote: >> ...when you could just use a single int value comprising the combination >> of major and minor as the hash key, if only you had used > > Sounds good, how about something like "805516", where "8" is major, and > "16" is the minor? It should be small enough to be not overflowing. In fact, we already know of a single integer value large enough to contain both major and minor at the same time: the original st_rdev (of type dev_t) from stat(). We could simply add 'verify(sizeof(dev_t)<= sizeof(void*))', then reconstruct the st_rdev value by undoing the decomposition done by the major() and minor() macros. Or, you could even tweak patch 1/6 to return st_rdev as a single value instead of major/minor as two separate values.