[LU-14012] new layout incompletely initialized in lod_layout_convert()

Thu, 29 Oct 2020 12:30:06 +0000

In lod_layout_convert() the composite layout generated as a result of conversion is only partially initialized. Some member of lcm and lcme (including lcme_id) are filled with left-over garbage from previous uses of lti_ea_store.

# rm -f /mnt/lustre/f0
# echo XXX > /mnt/lustre/f0
# lfs mirror extend -N /mnt/lustre/f0
# lfs getstripe /mnt/lustre/f0 | grep lcme_mirror_id
    lcme_mirror_id:      1
    lcme_mirror_id:      2


# lctl pool_new lustre.garbage
Pool lustre.garbage created
# lctl pool_add lustre.garbage lustre-OST0000
OST lustre-OST0000_UUID added to pool lustre.garbage
# lfs setstripe -p garbage /mnt/lustre
# rm -f /mnt/lustre/f0
# echo XXX > /mnt/lustre/f0
# lfs mirror extend -N /mnt/lustre/f0
 lfs getstripe /mnt/lustre/f0 | grep lcme_mirror_id
    lcme_mirror_id:      25202
    lcme_mirror_id:      25203
# lfs getstripe /mnt/lustre/f0 | grep lcme_id
    lcme_id:             1651663207
    lcme_id:             1651703809
# printf '%x\n' 1651663207
62726167
# echo -n garbage | hexdump
0000000    6167    6272    6761    0065                                
0000007

As seen above, one result of this is that mirror ids may not start at 1.

Whamcloud Community JIRA

[LU-14012] new layout incompletely initialized in lod_layout_convert()