Hi, CC-ing Vladimir...
On Wed, Dec 18, 2019 at 07:24:45PM +0100, Thomas Schmitt wrote: > Hi, > > during tests about the changes in blkid which are still discussed in > https://github.com/karelzak/util-linux/pull/913 > i noted that a grub-mkrescue ISO for x86 BIOS and EFI shows the same > filesystem label with its ISO 9660 and HFS+ filesystem superblocks. > > # lsblk -o NAME,FSTYPE,LABEL /dev/sdd > NAME FSTYPE LABEL > sdd iso9660 ISOIMAGE > ├─sdd1 > ├─sdd2 vfat > ├─sdd3 hfsplus ISOIMAGE > └─sdd4 > > On Linux this causes a name collision when udev creates /dev/disk/by-label > links. Usually HFS+ wins. But that's not guaranteed. > > The label identity is currently hardcoded in libisofs. The code stems from > Vladimir Serbinenko. I am in charge of maintaining it, though. > See > https://sources.debian.org/src/libisofs/1.5.2-1/libisofs/hfsplus.c/#L1632 > > ret = set_hfsplus_name (target, target->image->volume_id, > &target->hfsp_leafs[target->hfsp_curleaf]); > > It looks like the Volume Id from the libisofs ISO 9660 model is set as > name of HFS+ node target->hfsp_leafs[0]. I guess this is the root node. > > Whatever, it is the only occurence of volume_id in Vladimir's code. > Thus this line must be the gateway of "LABEL" between libisofs settings > and HFS+ metadata production. ("ISOIMAGE" is the default Volume Id of > xorriso.) > > -------------------------------------------------------------------------- > > So what to do ? > > [ ] Leave both labels identical and continue to confuse users via udev. It does not seem like reasonable idea. > [ ] Change HFS+ LABEL automatically by adding "_HFSPLUS" to the upto 32 > characters of Volume Id. Where this automatic change should happen? grub-mkrescue or libisofs? > [ ] Have independent setting and default of HFS+ LABEL in libisofs. > This is most flexible but also creates new duties for the users of > grub-mkrescue, if both LABELs have to be unique in comparison to other > filesystems on other devices. What kind of duties do you think about? > I would vote for the middle alternative, if i had any experience with HFS+ > beyond hosting Vladimir's code in libisofs. > > Vladimir ? Anybody else with HFS+ experience ? > > -------------------------------------------------------------------------- > > Further: > > Should grub-mkrescue give the EFI FAT filesystem a LABEL, too ? > > man mformat says about option -v > v Specifies the volume label. A volume label identifies the disk > and can be a maximum of 11 characters. If you omit the -v > switch, mformat will assign no label to the disk. > > "GRUBMKR_EFI" ? > > On the other hand, no LABEL means no label problems. I do not see any reason to have labels for EFI FAT filesystem. Do you? Daniel _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
