On Wed, Sep 15, 2021 at 06:00:09PM +0200, Daniel Kiper wrote: > On Thu, Sep 09, 2021 at 09:02:29PM +0800, Michael Chang via Grub-devel wrote: > > Currently the grub_diskfilter_memberlist function returns all physical > > volumes added to a volume group to which a logical volume (LV) belongs. > > However this is suboptimal as it doesn't fit the intended behavior of > > returning underlying devices that make up the LV. To give a clear > > picture, the result should be identical to running commands below to > > display the logical volumes with underlying physical volumes in use. > > > > localhost:~ # lvs -o lv_name,vg_name,devices /dev/system/root > > LV VG Devices > > root system /dev/vda2(512) > > > > localhost:~ # lvdisplay --maps /dev/system/root > > --- Logical volume --- > > ... > > --- Segments --- > > Logical extents 0 to 4604: > > Type linear > > Physical volume /dev/vda2 > > Physical extents 512 to 5116 > > > > As shown above, we can know system-root lv uses only /dev/vda2 to > > allocate it's extents, or we can say that /dev/vda2 is the member device > > comprising the system-root lv. > > > > It is important to be precise on the member devices, because that helps > > to avoid pulling in excessive dependency. Let's use an example to > > demonstrate why it is needed. > > > > localhost:~ # findmnt / > > TARGET SOURCE FSTYPE OPTIONS > > / /dev/mapper/system-root ext4 rw,relatime > > > > localhost:~ # pvs > > PV VG Fmt Attr PSize PFree > > /dev/mapper/data system lvm2 a-- 1020.00m 0 > > /dev/vda2 system lvm2 a-- 19.99g 0 > > > > localhost:~ # cryptsetup status /dev/mapper/data > > /dev/mapper/data is active and is in use. > > type: LUKS1 > > cipher: aes-xts-plain64 > > keysize: 512 bits > > key location: dm-crypt > > device: /dev/vdb > > sector size: 512 > > offset: 4096 sectors > > size: 2093056 sectors > > mode: read/write > > > > localhost:~ # vgs > > VG #PV #LV #SN Attr VSize VFree > > system 2 3 0 wz--n- 20.98g 0 > > > > localhost:~ # lvs -o lv_name,vg_name,devices > > LV VG Devices > > data system /dev/mapper/data(0) > > root system /dev/vda2(512) > > swap system /dev/vda2(0) > > > > We can learn from above that /dev/mapper/data is an encrypted volume and > > also gets assigned to volume group 'system' as one of it's physical > > volumes. And also it is not used by root device, > > /dev/mapper/system-root, for allocating extents, so it shouldn't be > > taking part in the process of setting up grub to access root device. > > > > However running grub-install reports error as volume group 'system' > > contains encrypted volume. > > > > error: attempt to install to encrypted disk without cryptodisk > > enabled. Set `GRUB_ENABLE_CRYPTODISK=y' in file `/etc/default/grub'. > > > > Certainly we can enable GRUB_ENABLE_CRYPTODISK=y and move on, but that > > is not always acceptable since the server may need to be booted > > unattended. Additionally, typing passphase for every system startup can > > be a big hassle of which most users would like to avoid. > > > > This patch solves the problem by returning exact physical volume, > > /dev/vda2, rightly used by system-root from the example above, thus > > grub-install will not error out because the excessive encrypted device > > to boot the root device is not configured. > > > > Signed-off-by: Michael Chang <mch...@suse.com> > > Tested-by: Olav Reinert <seroto...@gmail.com> > > --- > > grub-core/disk/diskfilter.c | 60 ++++++++++++++++++++++++++----------- > > 1 file changed, 43 insertions(+), 17 deletions(-) > > > > diff --git a/grub-core/disk/diskfilter.c b/grub-core/disk/diskfilter.c > > index 6eb2349a6..3d02d56ec 100644 > > --- a/grub-core/disk/diskfilter.c > > +++ b/grub-core/disk/diskfilter.c > > @@ -300,6 +300,8 @@ grub_diskfilter_memberlist (grub_disk_t disk) > > grub_disk_dev_t p; > > struct grub_diskfilter_vg *vg; > > struct grub_diskfilter_lv *lv2 = NULL; > > + struct grub_diskfilter_segment *seg; > > + unsigned int i, j; > > > > if (!lv->vg->pvs) > > return NULL; > > @@ -331,27 +333,51 @@ grub_diskfilter_memberlist (grub_disk_t disk) > > } > > } > > > > - for (pv = lv->vg->pvs; pv; pv = pv->next) > > - { > > - if (!pv->disk) > > + for (i = 0, seg = lv->segments; i < lv->segment_count; i++, seg++) > > + for (j = 0; j < seg->node_count; ++j) > > + if (seg->nodes[j].pv != NULL) > > { > > - /* TRANSLATORS: This message kicks in during the detection of > > - which modules needs to be included in core image. This happens > > - in the case of degraded RAID and means that autodetection may > > - fail to include some of modules. It's an installation time > > - message, not runtime message. */ > > - grub_util_warn (_("Couldn't find physical volume `%s'." > > - " Some modules may be missing from core image."), > > - pv->name); > > - continue; > > + pv = seg->nodes[j].pv; > > + > > + if (!pv->disk) > > + { > > + /* TRANSLATORS: This message kicks in during the detection of > > + which modules needs to be included in core image. This happens > > + in the case of degraded RAID and means that autodetection may > > + fail to include some of modules. It's an installation time > > + message, not runtime message. */ > > Again, please fix formatting of this comment if you are moving it [1].
Sorry, I should have double checked grub-dev document before sending the patch. I'll fix this in next version. > > > + grub_util_warn (_("Couldn't find physical volume `%s'." > > + " Some modules may be missing from core > > image."), > > + pv->name); > > + continue; > > + } > > + > > + for (tmp = list; tmp != NULL; tmp = tmp->next) > > + if (!grub_strcmp (tmp->disk->name, pv->disk->name)) > > + break; > > + if (tmp != NULL) > > + continue; > > + > > + tmp = grub_malloc (sizeof (*tmp)); > > + if (!tmp) > > + goto fail; > > Please call grub_error() here. Hm. I think it is not necessary because grub_error() has been called by grub_malloc() when it fails, so we should just return NULL and don't try to override the error number and message already set. Even we can preserve grub_malloc's error via grub_error_push (), still it makes little sense to me to duplicate the effort here ... Would you please shed more light on this ? > > > + tmp->disk = pv->disk; > > + tmp->next = list; > > + list = tmp; > > } > > - tmp = grub_malloc (sizeof (*tmp)); > > - tmp->disk = pv->disk; > > - tmp->next = list; > > - list = tmp; > > - } > > > > return list; > > + > > +fail: > > Please add a space before label. OK. > > > + > > Please drop this empty line. OK. > > > + while (list != NULL) > > + { > > + tmp = list; > > + list = list->next; > > + grub_free (tmp); > > + } > > + > > + return NULL; > > } Thanks a lot for review. Michael > > Daniel > > [1] https://www.gnu.org/software/grub/manual/grub-dev/grub-dev.html#Comments _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel