>Number: 182181
>Category: kern
>Synopsis: UFS: Leakage of vnode references (race condition?)
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Tue Sep 17 07:30:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator: Alexey Markov
>Release: 8.4-RELEASE-p3
>Organization:
JSC Complitex
>Environment:
FreeBSD ku-old.memo.ru 8.4-RELEASE-p3 FreeBSD 8.4-RELEASE-p3 #0: Fri Aug 23
13:32:07 MSK 2013 supp...@ku-new.memo.ru:/arc/obj/arc/src/sys/KU-OLD amd64
>Description:
While running pgbench PostgreSQL benchmark I suddenly found a vnode leakage
which leads in particular to an inability to unmount partition.
>How-To-Repeat:
Install a releng/8.4 branch, PostgreSQL 9.1 from ports, set "wal_level =
hot_standby" and "wal_keep_segments = 32" in the postgresql.conf, make a
dedicated partition for testing and run a following script:
#!/bin/sh -e
i=0
while (true); do
i=$(($i+1))
echo Iteration: ${i}
# Format and mount a pristine filesystem
newfs -n /dev/da0s1f > /dev/null
mount /test
# Prepare an empty instance
tar xjf /root/pgsql.tbz -C /test
# Start the PostgreSQL
/usr/local/etc/rc.d/postgresql start
# Run a pgbench
date
su - pgsql -c "pgbench -i -s 1000 pgbench 2> /dev/null"
date
df -i /test
du -xs /test
# Stop the PostgreSQL
/usr/local/etc/rc.d/postgresql stop
# Try to unmount the filesystem
umount /test
done
Result is:
ku-old:home/support# /root/2.sh
Iteration: 1
вторник, 17
сентября 2013 г. 09:33:54
(MSK)
вторник, 17
сентября 2013 г. 10:44:34
(MSK)
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused Mounted
on
/dev/da0s1f 56616608 15951754 36135526 31% 1053 7323617 0% /test
15951742 /test
umount: unmount of /test failed: Device busy
ku-old:home/support# rm -rf /test/*
ku-old:home/support# df -i /test; du -xs /test
Filesystem 1K-blocks Used Avail Capacity iused ifree %iused Mounted on
/dev/da0s1f 56616608 14 52087266 0% 2 7324668 0% /test
2 /test
As you can see, df shows 12 KiB (6 fragments) more than du. After force unmount
and remount both shows 2 KiB as expected.
>Fix:
It seems a very similar bug was recently fixed in the HEAD and 9-STABLE:
http://svnweb.freebsd.org/changeset/base/253998
I will try to apply that fix to my 8-RELEASE server and run a testing script
again, but it will take a time.
>Release-Note:
>Audit-Trail:
>Unformatted:
_______________________________________________
freebsd-bugs@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"
