On 05/17/22 13:18, Richard W.M. Jones wrote: > On Tue, May 17, 2022 at 01:10:32PM +0200, Laszlo Ersek wrote: >> On 05/17/22 12:59, Richard W.M. Jones wrote: >>> These devices can be left around by grub2 when it runs the osprober >>> tool after we run “/sbin/grub2-mkconfig -o /boot/grub2/grub.cfg”. >>> They are read-only mirrors of existing filesystems. These confuse >>> later steps in conversion, specifically fstrim. >>> >>> Reported-by: Ming Xie >>> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2003503 >>> --- >>> convert/linux_bootloaders.ml | 9 ++++++++- >>> 1 file changed, 8 insertions(+), 1 deletion(-) >>> >>> diff --git a/convert/linux_bootloaders.ml b/convert/linux_bootloaders.ml >>> index a70b65a41c..7c5fb0be3f 100644 >>> --- a/convert/linux_bootloaders.ml >>> +++ b/convert/linux_bootloaders.ml >>> @@ -345,7 +345,14 @@ object (self) >>> method remove_console = self#grub2_update_console ~remove:true >>> >>> method update () = >>> - ignore (g#command [| grub2_mkconfig_cmd; "-o"; grub_config |]) >>> + ignore (g#command [| grub2_mkconfig_cmd; "-o"; grub_config |]); >>> + >>> + (* Grub2 runs osprober which sometimes leaves around read-only >>> + * device-mapper maps covering existing filesystems. These >>> + * confuse later steps (especially fstrim). So just delete >>> + * any if found. (RHBZ#2003503). >>> + *) >>> + ignore (g#command [| "bash"; "-c"; "rm -f /dev/mapper/osprober-*" |]) >>> >>> method get_config_file () = >>> grub_config >>> >> >> Hmm... I'm not sure why this is better than "dmsetup remove", but it >> does not really matter. We need these nodes to disappear only for the >> remainder of the conversion -- so command that effects that suffices! >> >> Reviewed-by: Laszlo Ersek <ler...@redhat.com> > > Yeah, I'm not really sure what I was thinking there. I certainly > *meant* to use dmsetup remove, but maybe ... it's accidentally better? > > The problem with running dmsetup is that we have to run the guest > command, which might not exist. > > Fun fact I found when investigating this. Upstream os-prober dropped > the whole device mapper / dmsetup / osprober-linux-* stuff back in > 2017.
Wow, indeed! ... Earlier I had trouble finding the upstream repository for os-prober, but now I've found it: https://salsa.debian.org/installer-team/os-prober.git and the commit you mean is most likely b760c18ffec7 ("Remove code using device mapper.", 2017-04-30) It names three debian bug reports, and sure enough, the last one of those is what we're hitting: "Leaves stale device-mapper entry" https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=853163 (The bug report also refers to "dmsetup remove".) Similar Fedora bug reports ("CLOSED EOL"): os-prober gives device-mapper errors https://bugzilla.redhat.com/show_bug.cgi?id=1600778 grub2-mkconfig does not work correctly with os-prober https://bugzilla.redhat.com/show_bug.cgi?id=1744693 Then upstream fixed the bug by ripping out the device mapper code. :/ As replacement, the upstream commit recommends "grub-mount" -- which I guess is not available in RHEL8? That's right, in dist-git, on the rhel-8.7.0 branch at least, the "grub.macros" file passes "--disable-grub-mount" to the BIOS and EFI builds both. :/ This option seems to go back to historical dist-git commit 31004e676e8c ("Rebase to upstream snapshot.", 2013-06-07), which was even part of rhel-7.0! In other words, the dmsetup leak was never per se fixed (despite the many reports), and upstream's recommended alternative has never been enabled in RHEL. Stellar! > The current code doesn't mention osprober-linux-* at all. > So I guess the version in this RHEL 8 guest is quite old. > > Since I'm still testing the (above) version of this patch, let's see > if "rm" actually works before doing any further work on this. OK! Laszlo _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs
