William Harrington wrote: > > On Mar 7, 2014, at 7:00 PM, William Harrington wrote:
> I talked to Armin and looked up the Changes between Util linux 2.20 > and 2.21 and found that findmnt and lsblk include udev support. Not > sure what more info would be presented with udev support, but I now > see the reason more clearly. > > https://www.kernel.org/pub/linux/utils/util-linux/v2.21/v2.21-ReleaseNotes FYI. From Karel Zak 1/8/14 -- Bruce > Let me add that util-linux builds very nicely when building up the > different packages in Linux From Scratch. In our sequence when > util-linux is built, we have not yet built udev (we extract only the > udev portion out of the systemd tarball, but do that later). At that > point we have: > $ ldd /bin/findmnt > linux-vdso.so.1 (0x00007fffdebff000) > libmount.so.1 => /lib/libmount.so.1 (0x00007fe5c4563000) > libblkid.so.1 => /lib/libblkid.so.1 (0x00007fe5c432a000) > libuuid.so.1 => /lib/libuuid.so.1 (0x00007fe5c4126000) > libc.so.6 => /lib/libc.so.6 (0x00007fe5c3d7c000) > /lib64/ld-linux-x86-64.so.2 (0x00007fe5c479f000) > > Looking at the code, it's not clear to me what extra functionality > get_tag_from_udev() provides. That's simple -- you don't need root permissions to read from udev, but you need root permissions to parse filesystem/PT on the device by libblkid. udev has also more information collected from more sources, see for example lsblk.c where non-udev part does not provide WWN and serial number. It's also better if all system use information from one place (udev), so libblkid is fallback solution here (in findmnt, lsblk). -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
