Re: kern/42455: tstile hang with nfs

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

The following reply was made to PR kern/42455; it has been noted by GNATS.

From: yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)
To: Christoph_Egger%gmx.de@localhost
Cc: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost, 
gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/42455: tstile hang with nfs
Date: Thu, 11 Nov 2010 05:52:21 +0000 (UTC)

 hi,
 
 the debug code (nfs_vnops.c rev.1.285) seems racy at best.
 i don't understand what the check is trying to detect.
 the mbuf chain is handed off to the underlying layers at that point and
 it's completely legal for eg. network drivers clears mb->m_next while
 keeping the next mbuf in the mbuf chain.
 can you please fix?
 
 YAMAMOTO Takashi