[LU-3240] The link count is not updated after the mkdir

• Type: Bug
• Resolution: Fixed
• Priority: Blocker
• Fix Version/s: Lustre 2.5.0, Lustre 2.4.2
• Affects Version/s: Lustre 2.2.0, Lustre 2.3.0, Lustre 2.1.5
• Labels: mn1 patch
• Environment: RHEL6.3
• Severity: 3
• Assignee: Nathaniel Clark
• Reporter: Shuichi Ihara (Inactive)

Description

We sometimes saw incorrect link counts after the mkdir or remove directories.
The link counts seem not to be updated after create/remove directory.

We created a simple reproducer for this problem below.

#!/bin/sh -x 

TESTDIR=/lustre/linkcount_test
[ -d "$TESTDIR" ] && rm -rf $TESTDIR

mkdir $TESTDIR
cd $TESTDIR
ls
mkdir a b
ls
ls -adl $TESTDIR
rmdir b
ls -ald

# ./test.sh
+ TESTDIR=/lustre/linkcount_test
+ '[' -d /lustre/linkcount_test ']'
+ rm -rf /lustre/linkcount_test
+ mkdir /lustre/linkcount_test
+ cd /lustre/linkcount_test
+ ls
+ mkdir a b
+ ls
a  b
+ ls -adl /lustre/linkcount_test
drwxr-xr-x 2 root root 4096 Apr 30 02:52 /lustre/linkcount_test
          ^^^
          This should be 4 after two directories created.
+ rmdir b
+ ls -ald
drwxr-xr-x 3 root root 4096 Apr 30 02:52 .
          ^^^
          Updated after an directory is removed.

This problem happens on b2_1, b2_2 and b2_3, but not happens if both server and clients are running with current master.
However, master (server) - b2_1(client), we see same problem.

Issue Links

• is related to: LU-4405 stat degradation (interoperability bug after landing a LU-3240)
• is related to: LU-4095 Eliminate extra rpc when revalidating remote objects
• is related to: LU-3849 Client cache directory information is not updated
• is related to: LU-3385 missing permission lock check in ll_have_md_lock.
• is related to: LU-4050 NFS reexport issue

Comments

[Alexey Lyashkov]

please reopen a ticket due introducing an regressions with open with last Oleg changes
and removing one huge and important part from original patch.

ps. it's strange - but i don't able to reopen ticket.

[Jian Yu]

The patch was cherry-picked to Lustre b2_4 branch.

[Bob Glossman (Inactive)]

backport to b2_4
http://review.whamcloud.com/8317

[Patrick Farrell (Inactive)]

Sebastien,

As I understand it, that second patch is not required. Oleg commented (I can't find where right now) that it was unnecessary to send the parent FID when doing that operation, as the child FID is sufficient. I don't believe it fixes any specific problem, it's just cleanup/improvement.

To summarize:
http://review.whamcloud.com/6460 is, by itself, the full fix for LU-3240. 7910 is as you said - a bonus patch that came out of the work for 6460.

[Sebastien Buisson (Inactive)]

I am sorry, but in addition to patch http://review.whamcloud.com/6460 that was landed on master, I can also see patch http://review.whamcloud.com/7910 merged at the same time.
Where this patch is coming from? Is this a mandatory part of the solution to this bug? Or is this just a bonus patch?

TIA,
Sebastien.

[Jodi Levi (Inactive)]

Eliminating the extra roc when revalidating remote objects is being handled in LU-4095.

[Peter Jones]

Cory yes that would be more clear

[Cory Spitz]

Should 'Fix Version/s' == 2.5.0?

[Dmitry Eremin (Inactive)]

I tested Patch Set 5 of http://review.whamcloud.com/6460 with master, it partially solve the LU-4050.

[Patrick Valentin (Inactive)]

I tested set 4 of patch http://review.whamcloud.com/6460 on a lustre 2.4.0 client, and it also fixes the issue described in LU-3849.