What were you trying to do that didn't work?

A customer having a 4KB sector size disk on a PPC64LE system was unable to execute grub2-install <PREPPART> command, because the /boot partition was not detected as XFS, despite being valid.

We were able to make the command work again after reformatting /boot with a new XFS file system.

We copied the beginning of the disk, including the /boot partition and with this I was able to reproduce the issue on a QEMU/KVM in PPC64LE emulation mode while loading the disk as a second disk and making sure the sector size was set to 4KB.

The issue doesn't reproduce on RHEL9 nor RHEL10. RHEL9.0 initial grub2-tools-2.06-27.el9_0.ppc64le works already.
This tends to indicate a change in either XFS or disk reading between grub2-2.02 (RHEL8 codebase) and grub2-2.06 (RHEL9 codebase).

What is the impact of this issue to you?

System breaks.

Please provide the package NVR for which the bug is seen:

grub2-tools-2.02-169.el8_10.ppc64le

How reproducible is this bug?

Always with customer's disk (available on demand)

Steps to reproduce

1. Setup a QEMU/KVM PPC64LE system (I used the KVM image in Customer Portal Download area) and attach the disk image as second disk, making sure 4KB sector size is set

   <disk type="file" device="disk">
     <driver name="qemu" type="raw"/>
     <source file="/home/rmetrich/newdump8.img" index="2"/>
     <backingStore/>
     <blockio logical_block_size="4096" physical_block_size="4096" discard_granularity="4096"/>
     <target dev="vdb" bus="virtio"/>
     <alias name="virtio-disk1"/>
     <address type="pci" domain="0x0000" bus="0x00" slot="0x08" function="0x0"/>
   </disk>

2. Boot the VM on the DVD
3. Mount /dev/vdb2 as /mnt/sysroot/boot

   # mount /dev/vdb2 /mnt/sysroot/boot

4. Enter the chroot and execute {{grub2-install}

   # chroot /mnt/sysroot
   # grub2-install -vvvvv /dev/vdb1

   Expected results

   Installation finished. No error reported.

   Actual results

   1768811375.837s + 0.000s grub-core/kern/fs.c:56: Detecting xfs...
   1768811375.837s + 0.000s grub-core/fs/xfs.c:1045: Reading sb
   1768811375.837s + 0.000s grub-core/fs/xfs.c:288: Validating superblock
   1768811375.837s + 0.000s grub-core/fs/xfs.c:300: XFS v5 superblock detected
   1768811375.837s + 0.000s grub-core/fs/xfs.c:1078: Reading root ino 96
   1768811375.838s + 0.001s grub-core/fs/xfs.c:536: Reading inode (96) - 96, 0
   1768811375.839s + 0.001s grub-core/osdep/hostdisk.c:395: reusing open device `/dev/vdb2'
   1768811375.840s + 0.001s grub-core/fs/xfs.c:536: Reading inode (11529670523055300623) - 11529670523055300616, 3584
   1768811375.840s + 0.000s grub-core/kern/disk.c:431: Read out of range: sector 0xa0019e410000e00f (../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition).
   error: ../grub-core/kern/disk_common.c:27:attempt to read or write outside of partition.
   [...]
   1768811375.844s + 0.000s grub-core/kern/fs.c:78: xfs detection failed.
   [...]
   grub2-install: error: ../grub-core/kern/fs.c:120:unknown filesystem.