kern/94769: [ufs] Multiple file deletions on multi-snapshotted filesystems causes hang

[Doug Poland]

The following reply was made to PR kern/94769; it has been noted by GNATS.

From: Doug Poland <doug at polands.org>
To: bug-followup at FreeBSD.org, john at kozubik.com
Cc:  
Subject: Re: kern/94769: [ufs] Multiple file deletions on multi-snapshotted
	filesystems causes hang
Date: Mon, 4 May 2009 15:11:33 -0500

 I recently started experiencing similar behavior on a 7.1-RELEASE i386
 host.  In this case the deadlock occurs as soon as
 sysutils/freebsd-snapshots run it's weekly cron entry:
 
 0   *   *   *   *   root    periodic-snapshot hourly
 0   0   *   *   *   root    periodic-snapshot daily
 0   0   *   *   0   root    periodic-snapshot weekly
 
 I am running a GENERIC kernel without quotas.
 
 Here's the list of snapshots on the various filesystems:
 
 Filesystem          User   User%     Snap   Snap%  Snapshot
 /                  267MB   54.0%    704KB    0.1%  daily.0
 /                  267MB   54.0%    704KB    0.1%  daily.1
 /                  267MB   54.0%    704KB    0.1%  daily.2
 /                  267MB   54.0%    704KB    0.1%  daily.3
 /                  267MB   54.0%    704KB    0.1%  daily.4
 /                  267MB   54.0%    784KB    0.2%  daily.5
 /                  267MB   54.0%    784KB    0.2%  daily.6
 /                  267MB   54.0%    608KB    0.1%  hourly.0
 /                  267MB   54.0%    640KB    0.1%  hourly.1
 /                  267MB   54.0%    656KB    0.1%  hourly.2
 /                  267MB   54.0%    656KB    0.1%  hourly.3
 /                  267MB   54.0%    704KB    0.1%  weekly.0
 /                  267MB   54.0%    896KB    0.2%  weekly.1
 /                  267MB   54.0%    928KB    0.2%  weekly.2
 /                  267MB   54.0%      1MB    0.2%  weekly.3
 /var              1237MB   10.4%     16MB    0.1%  daily.0
 /var              1237MB   10.4%     17MB    0.1%  daily.1
 /var              1237MB   10.4%     30MB    0.3%  daily.2
 /var              1237MB   10.4%     32MB    0.3%  daily.3
 /var              1237MB   10.4%     32MB    0.3%  daily.4
 /var              1237MB   10.4%     33MB    0.3%  daily.5
 /var              1237MB   10.4%    141MB    1.2%  daily.6
 /var              1237MB   10.4%      7MB    0.1%  hourly.0
 /var              1237MB   10.4%      7MB    0.1%  hourly.1
 /var              1237MB   10.4%      7MB    0.1%  hourly.2
 /var              1237MB   10.4%      8MB    0.1%  hourly.3
 /var              1237MB   10.4%      8MB    0.1%  hourly.4
 /var              1237MB   10.4%      8MB    0.1%  hourly.5
 /var              1237MB   10.4%      8MB    0.1%  hourly.6
 /var              1237MB   10.4%      8MB    0.1%  hourly.7
 /var              1237MB   10.4%      8MB    0.1%  hourly.8
 /var              1237MB   10.4%      8MB    0.1%  hourly.9
 /var              1237MB   10.4%     25MB    0.2%  weekly.0
 /usr             87545MB   74.1%    138MB    0.1%  daily.0
 /usr             87545MB   74.1%    217MB    0.2%  daily.1
 /usr             87545MB   74.1%    234MB    0.2%  daily.2
 /usr             87545MB   74.1%    287MB    0.2%  daily.3
 /usr             87545MB   74.1%    292MB    0.2%  daily.4
 /usr             87545MB   74.1%    278MB    0.2%  daily.5
 /usr             87545MB   74.1%    349MB    0.3%  daily.6
 /usr             87545MB   74.1%     88MB    0.1%  hourly.0
 /usr             87545MB   74.1%    200MB    0.2%  hourly.1
 /usr             87545MB   74.1%    864MB    0.7%  weekly.0
 /usr             87545MB   74.1%    721MB    0.6%  weekly.1
 /usr             87545MB   74.1%    782MB    0.7%  weekly.2
 /usr             87545MB   74.1%   4772MB    4.0%  weekly.3
 
 I am eager and willing to assist in anyway to investigate and eliminate
 this issue.
 
 
 -- 
 Regards,
 Doug