[LU-4953] /proc/fs/lustre/lmv/*/target_obds missing on second mounts

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.6.0
• Affects Version/s: Lustre 2.6.0
• Labels: lmv lprocfs mq313 patch
• Severity: 3
• Assignee: Bob Glossman (Inactive)
• Reporter: John Hammond

Description

If I double mount a client (for example with MOUNT_2=y llmount.sh) then the second mount point will have a missing /proc/fs/lustre/lmv/*/target_obds directory.

u:~# umount /mnt/lustre
u:~# umount /mnt/lustre2
#### 
u:~# mount -o user_xattr,flock u@tcp:/lustre /mnt/lustre -t lustre
u:~# ls /proc/fs/lustre/lmv/
lustre-clilmv-ffff8801f6d64e60
u:~# ls /proc/fs/lustre/lmv/lustre-clilmv-ffff8801f6d64e60/
activeobd  desc_uuid  md_stats  numobd  placement  target_obd  target_obds  uuid
u:~# ls -l /proc/fs/lustre/lmv/lustre-clilmv-ffff8801f6d64e60/target_obds/
total 0
lrwxrwxrwx 1 root root 48 Apr 24 12:49 lustre-MDT0000-mdc-ffff8801f6d64e60 -> ../../../mdc/lustre-MDT0000-mdc-ffff8801f6d64e60
u:~# 
u:~# mount -o user_xattr,flock u@tcp:/lustre /mnt/lustre2 -t lustre
u:~# ls /proc/fs/lustre/lmv/
lustre-clilmv-ffff8801f487f778  lustre-clilmv-ffff8801f6d64e60
u:~# ls /proc/fs/lustre/lmv/lustre-clilmv-ffff8801f487f778
activeobd  desc_uuid  md_stats  numobd  placement  target_obd  uuid
u:~# 

I see this when I unmount the second client mount:

[  263.149071] LustreError: 3790:0:(lmv_obd.c:761:lmv_disconnect()) /proc/fs/lustre/lmv/lustre-clilmv-ffff8802169bc688/target_obds missing