On Thu, Jan 12, 2023 at 04:43:45PM +0100, Philipp Rudo wrote:
On Tue, 27 Dec 2022 09:26:23 +0800
Coiby Xu <coxu(a)redhat.com> wrote:
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2140721
> Currently, if users specify dumping to nfsv4 target via
> dracut_args --mount "<NFS-server-ip>:/var/crash /mnt nfs defaults"
> it fails with the following errors,
> [ 5.159760] mount: mount.nfs: Protocol not supported
> [ 5.164502] systemd: mnt.mount: Mount process exited, code=exited,
> [ 5.167616] systemd: mnt.mount: Failed with result 'exit-code'.
> [FAILED] Failed to mount /mnt.
> This is because nfsv4-releted drivers are not installed to kdump initrd.
> mkdumprd calls dracut with "--hostonly-mode strict". If nfsv4-related
> drivers aren't loaded before calling dracut, they won't be installed.
> When users specify nfs dumping via dracut_args, kexec-tools won't mount
> the nfs fs beforehand hence nfsv4-related drivers won't be installed.
> Note dracut only installs the nfs driver i.e. nfsv3 driver for "--mount
> ... nfs". So also install nfsv4-related drivers when users specify nfs
> dumping via dracut_args. Since nfs_layout_nfsv41_files depends on nfsv4,
> the nfsv4 driver will be installed automatically.
> As for the reason why we support nfs dumping via dracut_args instead of
> asking user to use the nfs directive, please refer to commit 74c6f464
> ("Support special mount information via 'dracut_args'").
I don't understand why this was designed the way it is. Personally I
would have treated the dracut_args and nfs directive identical and
would simply have added a "--no-mount" option...
Anyway that's nothing we can change right now. So your patch looks like
a valid workaround to me.
Thanks for reviewing the patch! Could I have you Reviewed-by or Acked-by
if it looks good to you.
Btw, out of curiosity, I managed to find bz1183555 which the commit
74c6f464 tried to resolve. But after going through all the comments
unfortunately I still don't know if they have considered about
introducing a "--no-mount" option or neither can I find the rationale
for using dracut_args to skip mounting nfs fs. But for the sake of not
surprising users, I think it's better to stick with the old design.
> Fixes: 4eedcae5 ("dracut-module-setup.sh: don't include
> Reported-by: rcheerla(a)redhat.com
> Signed-off-by: Coiby Xu <coxu(a)redhat.com>
> mkdumprd | 9 +++++++++
> 1 file changed, 9 insertions(+)
> diff --git a/mkdumprd b/mkdumprd
> index 3e250e02..51ca4f01 100644
> --- a/mkdumprd
> +++ b/mkdumprd
> @@ -420,6 +420,15 @@ while read -r config_opt config_val; do
> verify_core_collector "$config_val"
> + # When users specify nfs dumping via dracut_args, kexec-tools won't
> + # mount nfs fs beforehand thus nfsv4-related drivers won't be installed
> + # because we call dracut with --hostonly-mode strict. So manually install
> + # nfsv4-related drivers.
> + if [[ $(get_dracut_args_fstype "$config_val") == nfs* ]]; then
> + add_dracut_arg "--add-drivers" nfs_layout_nfsv41_files
> + fi
> while read -r dracut_arg; do
> add_dracut_arg "$dracut_arg"
> done <<< "$(echo "$config_val" | xargs -n 1 echo)"