Date: Tue, 15 Oct 1996 18:19:15 +0200 (MET DST) From: Tor Egge <Tor.Egge@idt.ntnu.no> To: FreeBSD-gnats-submit@freebsd.org Subject: kern/1812: vnodes are left in a locked state Message-ID: <199610151619.SAA25686@ikke.idt.unit.no> Resent-Message-ID: <199610151620.JAA17033@freefall.freebsd.org>
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>Number: 1812
>Category: kern
>Synopsis: vnodes are left in a locked state
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Tue Oct 15 09:20:01 PDT 1996
>Last-Modified:
>Originator: Tor Egge
>Organization:
Norwegian University of Science and Technology, Trondheim, Norway
>Release: FreeBSD 2.2-CURRENT i386
>Environment:
FreeBSD ikke.idt.unit.no 2.2-CURRENT FreeBSD 2.2-CURRENT #3: Mon Oct 14 02:10:57 MET DST 1996 root@ikke.idt.unit.no:/usr/src/sys/compile/TEGGE i386
>Description:
Writing to memory regions corresponding to a few hundred mmapped files
and using msync() to flush the file system may cause the process
to hang.
The process is unkillable, in diskwait.
ps xl outout shows
UID PID PPID CPU PRI NI VSZ RSS WCHAN STAT TT TIME COMMAND
26850 24861 24860 45 -18 19 612 38132 vmiorl DN ?? 2:02.79 bin/domainhelp
One of the vnodes for the mmapped files is left in a locked state,
i.e. lstat() hangs :-(
UID PID PPID CPU PRI NI VSZ RSS WCHAN STAT TT TIME COMMAND
26850 25492 25098 145 -14 0 204 592 uihget D+ p9 0:00.03 ls -F -ld h.de (ls@386freebsd)
As a side effect of this, the vnode for the directory in which
the file resides
(/export/akg2/ftpsearch/datasets/datasets/dataset2/domain)
becomes locked. :-(
>How-To-Repeat:
open and mmap 250 files, each 1.2 MB in size.
Write to the first 32 KB on each of the 250 mmapped memory regions,
then use msync() with the MS_ASYNC flag and fsync() for each of the 250
mmapped memory regions.
Continue with the next 32 KB, until all of the mmapped regions have
been written to disk.
>Fix:
Temporary workaround: reboot the system whenever this occurs.
>Audit-Trail:
>Unformatted:
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