Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 05 Oct 2002 11:46:45 -0400
From:      Brian Fundakowski Feldman <green@FreeBSD.org>
To:        current@FreeBSD.org
Subject:   vnode locking screwed up in src/sys/ufs/ffs/ffs_snapshot.c:ffs_snapshot()
Message-ID:  <200210051546.g95FkkX1008580@green.bikeshed.org>

next in thread | raw e-mail | index | archive | help
I got a crash today because "xvp" did not have an interlock when the
call was made to vn_lock(LK_INTERLOCK):
407                     if (snapdebug)
408                             vprint("ffs_snapshot: busy vnode", xvp);
409                     if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK, td) != 0)
410                             goto loop;
411                     xp = VTOI(xvp);
412

I don't in fact see any reason why "xvp" would have been locked already
and that this could possibly be valid in the face of a mountpoint which
had any vnodes at all open.  This occurred on fscking my "/tmp"
filesystem because of crashes (due to an SSE utilization bug in the
kernel, it seems), which I'm sure was a filesystem in heavy use already.

Does anyone have any insight on what the correct fix to this is?  I
don't have any idea exactly how to correct the locking in this function.
Thanks for insight!

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200210051546.g95FkkX1008580>