[Libguestfs] [PATCH] daemon: inspect_fs_windows: Handle parted errors

[Sam Eiderman]

Yea, I noticed that commit, but since it was used in gpt too
regardless of that commit, I decided not to mention this regression.

I also noticed that list_filesystems() still works, this is probably
due to filtering of devices (daemon/listfs.ml):

"let devices = List.filter is_not_partitioned_device devices in"

What do you have in mind here?

On Tue, Jun 30, 2020 at 12:33 PM Pino Toscano <ptoscano at redhat.com> wrote:
>
> On Tuesday, 30 June 2020 10:33:40 CEST Sam Eiderman wrote:
> > By creating an empty disk and using it as the first disk of the vm (i.e.
> > /dev/sda, /dev/sdb{1,2} contains the windows fses) we change the
> > iteration order of the disks.
> > This causes inspect_os() to fail since Parted returns a Unix_error if
> > the device does not contain any partitions - fix this by handling this
> > Unix_error.
> >
> > Signed-off-by: Sam Eiderman <sameid at google.com>
> > ---
> >  daemon/inspect_fs_windows.ml | 11 ++++++++---
> >  1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/daemon/inspect_fs_windows.ml b/daemon/inspect_fs_windows.ml
> > index c4a05bc38..bc6b98b60 100644
> > --- a/daemon/inspect_fs_windows.ml
> > +++ b/daemon/inspect_fs_windows.ml
> > @@ -365,8 +365,10 @@ and map_registry_disk_blob_mbr devices blob =
> >      let device =
> >        List.find (
> >          fun dev ->
> > -          Parted.part_get_parttype dev = "msdos" &&
> > -            pread dev 4 0x01b8 = diskid
> > +          try
> > +            Parted.part_get_parttype dev = "msdos" &&
> > +              pread dev 4 0x01b8 = diskid
> > +          with Unix.Unix_error (Unix.EINVAL, _, _) -> false
>
> The old C inspection code did not check for the partition type:
> https://github.com/libguestfs/libguestfs/blob/stable-1.36/lib/inspect-fs-windows.c#L591
> The partition type check was added recently:
> https://github.com/libguestfs/libguestfs/commit/7b4d13626ff878b124d01ec452a4fd0052934133
>
> TBH I'd rather prefer that we check for the situation explicitly
> before, rather than catching a generic EINVAL error. Or, even better,
> try to avoid altogether the situation that 7b4d13626ff878 checks,
> handling this issue as well.
>
> > @@ -402,7 +404,10 @@ and map_registry_disk_blob_gpt partitions blob =
> >          fun part ->
> >            let partnum = Devsparts.part_to_partnum part in
> >            let device = Devsparts.part_to_dev part in
> > -          let typ = Parted.part_get_parttype device in
> > +          let typ =
> > +            try
> > +              Parted.part_get_parttype device
> > +            with Unix.Unix_error (Unix.EINVAL, _, _) -> "unknown" in
> >            if typ <> "gpt" then false
> >            else (
>
> Ditto.
>
> --
> Pino Toscano_______________________________________________
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