[LU-16469] Add parent FID to CL_LAYOUT changelog records

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.15.2
• Severity: 3
• Assignee: Nikitas Angelinas
• Reporter: Nikitas Angelinas

Description

The parent FID on some CL_LAYOUT changelog records is either incorrect or missing:

# git rev-parse --abbrev-ref HEAD
master
# git describe
v2_15_53-54-g3dd73b5c5d
# lctl set_param mdd.*.changelog_mask=ALL
mdd.testfs-MDT0000.changelog_mask=ALL
mdd.testfs-MDT0001.changelog_mask=ALL
# lfs mirror create -N2 -S 2M -c -1 /mnt/lustre/testdir0/testfile3
# lfs mirror split --mirror-id 1 /mnt/lustre/testdir0/testfile3 -f /mnt/lustre/testdir0/testfile3_old_mirror
# lfs changelog testfs-MDT0000 | grep LYOUT
10080 12LYOUT 10:58:28.679831842 2023.01.13 0x0 t=[0x20000a812:0x1:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a042:0x1:0x0]
10085 12LYOUT 10:59:10.186307098 2023.01.13 0x0 t=[0x20000a812:0x3:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a812:0x2:0x0]
10099 12LYOUT 11:05:54.839659504 2023.01.13 0x0 t=[0x20000a812:0x4:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a812:0x2:0x0]
10109 12LYOUT 11:06:16.777327819 2023.01.13 0x0 t=[0x20000a812:0x4:0x0] ef=0xf u=0:0 nid=0@lo p=[0x200000007:0x1:0x0]
10110 12LYOUT 11:06:16.777334740 2023.01.13 0x0 t=[0x20000a812:0x5:0x0] ef=0xf u=0:0 nid=0@lo p=[0x200000007:0x1:0x0]
# lfs fid2path /mnt/lustre 0x20000a812:0x4:0x0
/mnt/lustre/testdir0/testfile3
# lfs fid2path /mnt/lustre 0x20000a812:0x2:0x0
/mnt/lustre/testdir0
# lfs fid2path /mnt/lustre 0x200000007:0x1:0x0
/mnt/lustre// <- incorrect
# lfs fid2path /mnt/lustre 0x20000a812:0x5:0x0
/mnt/lustre/testdir0/testfile3_old_mirror
# lfs mirror create -N2 -S 2M -c -1 /mnt/lustre/testdir0/testdir1/testfile3
# lfs mirror split --mirror-id 1 /mnt/lustre/testdir0/testdir1/testfile3 -f /mnt/lustre/testdir0/testdir1/testfile3_old_mirror
# lfs changelog testfs-MDT0001 | grep LYOUT
# lfs changelog testfs-MDT0000 | grep LYOUT
10080 12LYOUT 10:58:28.679831842 2023.01.13 0x0 t=[0x20000a812:0x1:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a042:0x1:0x0]
10085 12LYOUT 10:59:10.186307098 2023.01.13 0x0 t=[0x20000a812:0x3:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a812:0x2:0x0]
10099 12LYOUT 11:05:54.839659504 2023.01.13 0x0 t=[0x20000a812:0x4:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a812:0x2:0x0]
10109 12LYOUT 11:06:16.777327819 2023.01.13 0x0 t=[0x20000a812:0x4:0x0] ef=0xf u=0:0 nid=0@lo p=[0x200000007:0x1:0x0]
10110 12LYOUT 11:06:16.777334740 2023.01.13 0x0 t=[0x20000a812:0x5:0x0] ef=0xf u=0:0 nid=0@lo p=[0x200000007:0x1:0x0]
10120 12LYOUT 11:14:56.897017703 2023.01.13 0x0 t=[0x20000a812:0x7:0x0] ef=0xf u=0:0 nid=0@lo p=[0x20000a812:0x6:0x0]
10128 12LYOUT 11:15:57.363209534 2023.01.13 0x0 t=[0x20000a812:0x7:0x0] ef=0xf u=0:0 nid=0@lo <- missing
10129 12LYOUT 11:15:57.363218365 2023.01.13 0x0 t=[0x20000a812:0x8:0x0] ef=0xf u=0:0 nid=0@lo <- missing

CL_LAYOUT changelog records can be useful for tools that read changelogs in determining HSM or mirror operations that have taken place in the filesystem; such tools can potentially use the parent FID in changelog entries to make some aspects of their operation more efficient, e.g. using fewer OBC_IOC_FID2PATH ioctls for determining which filesystem directories need to be rescanned, and/or reducing the number of updates to any databases they might be using, as per LU-13151.

Issue Links

• is related to: LU-13151 Add parent FID to MTIME changelogs