>Number:         7373
>Category:       kern
>Synopsis:       adosfs locks against itself when pwd-ing.
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Apr 13 14:05:00 1999
>Last-Modified:
>Originator:     Ignatios Souvatzis
>Organization:
	Little Daemon Fan Club
>Release:        1999 April 9
>Environment:
	
System: NetBSD jocelyn 1.4_ALPHA NetBSD 1.4_ALPHA (ISDN7) #14: Tue Apr 13 22:16:18 MEST 1999 is@jocelyn:/build2/i4b/ISDN7 amiga


>Description:
	pwd in a mounted adosfs makes the kernel panic("lockmgr: locking
	against myself")

	stack traceback:

	_panic / _adosfs_lock / _vn_lock / _vget / _adosfs_ahashget /
	_adosfs_vget / _adosfs_readdir / _getcwd_scandir / _getcwd_common /
	_sys__getcwd / _syscall / _trap0
>How-To-Repeat:
	mount -t ados -r /dev/sd0h /mnt
	cd /mnt/S
	tcsh

>Fix:
	Bill Sommerfeld suggested this patch:


From sommerfeld@orchard.arlington.ma.us Tue Apr 13 21:57:48 1999
Message-Id: <199904131958.TAA03778@orchard.arlington.ma.us>
To: is@jocelyn.rhein.de
Subject: getcwd patch..
Date: Tue, 13 Apr 1999 15:58:06 -0400
From: Bill Sommerfeld <sommerfeld@orchard.arlington.ma.us>
Content-Length: 570
Lines: 24

Try this...

Index: vfs_getcwd.c
===================================================================
RCS file: /cvsroot/src/sys/kern/vfs_getcwd.c,v
retrieving revision 1.4
diff -u -r1.4 vfs_getcwd.c
--- vfs_getcwd.c	1999/04/05 03:33:31	1.4
+++ vfs_getcwd.c	1999/04/13 19:57:35
@@ -163,8 +163,14 @@
 
 		eofflag = 0;
 
+		/* XXX un-break adosfs */
+		VOP_UNLOCK(cvp, 0);
+
 		error = VOP_READDIR(pvp, &uio, p->p_ucred, &eofflag, 0, 0);
 
+		/* XXX not handling lock failures here.. */
+		(void) vn_lock(cvp, LK_EXCLUSIVE | LK_RETRY);
+		
 		off = uio.uio_offset;
 
 		/*

>Audit-Trail:
>Unformatted: