[LU-14268] mirror split does not increase layout generation properly

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: Zhenyu Xu
• Reporter: Zhenyu Xu

Description

To reproduce the hang try:

lfs setstripe -c1 -i0 /mnt/lustre/f0
umount /mnt/lustre-mds1
mount /dev/mapper/mds1_flakey /mnt/lustre-mds1 -t lustre
lfs mirror extend -N -c1 -i1 /mnt/lustre/f0
umount /mnt/lustre-mds1
mount /dev/mapper/mds1_flakey /mnt/lustre-mds1 -t lustre
lfs mirror split -d --mirror-id=1 /mnt/lustre/f0
dd if=/dev/zero of=/mnt/lustre/f0 bs=1M count=1

The layout generation does not increase in mirror split, and not set the flr state properly, so client does not get the updated layout and setattr loops sending write intent RPC while cannot get the latest layout.