Craig Rodrigues wrote this message on Sun, Aug 24, 2014 at 15:37 -0700: > On Sun, Aug 24, 2014 at 12:05 PM, Marcel Moolenaar <mar...@xcllnt.net> wrote: > > > > On Aug 24, 2014, at 9:59 AM, Craig Rodrigues <rodr...@freebsd.org> wrote: > > > >> On Sun, Aug 24, 2014 at 2:11 AM, Andrey V. Elsukov <bu7c...@yandex.ru> > >> wrote: > >>> > >>> Yes, the problem is in the ptable_gptread() function. I'll commit the fix. > >> > > > >> Should mkimg be changed to create a partition table with 128 entries > >> by default, to match older versions of FreeBSD which do not have this fix? > > > > Maybe. 128 is the suggested default. It's not a hard lower > > limit. Technically speaking, it's perfectly fine to create > > just enough entries to fill a single sector. Then again, > > code makes all kinds of assumptions or has all kinds of > > bugs -- just like the logic in the loader apparently. > > > > By having mkimg create a large table, even if it's knows > > up front that it doesn't have to may prevent broken code > > from tripping over, bit it surely bloats the image for > > no reason. > > I see what you are saying. If you have a new device > and do "gpart create -s GPT", then this value in sys/geom/part/g_part_gpt.c: > > .gps_minent = 128, > > causes the logic in the g_part_ctl_create() function in sys/geom/part/g_part.c > to set the number of partitions to 128, and then it calls g_part_ctl_create() > which creates the partition table with 128 empty entries. > > "gpart create" doesn't know how many partitions you want, so it > needs to allocate some space up front for the partition table, > and then you can do "gpart add" to add the partitions later. > > With mkimg, you know exactly how many partitions you are creating > , so you don't need to specify 128 as the number of partitions.
Though, w/ people dd'ing images onto disks, and using growfs to grow as necessary, we might want to allocate a few more more than the minimum... I do agree that we want to keep sizes to a minimum... > Since only gpart was available for creating GPT partitions, the side-effect > of always having 128 partitions hid the bug in the loader. > > Hopefully Andrey's fix can be backported to at least stable/9, because > the loader bug seems to have been there since at least 2012. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not." _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"