Date: Thu, 3 Apr 1997 22:10:40 -0500 (EST) From: Thomas David Rivers <ponds!rivers@dg-rtp.dg.com> To: ponds!freefall.cdrom.com!freebsd-hackers, ponds!dg.com!root, ponds!idi.ntnu.no!Tor.Egge Subject: Re: kern/3184: vnodes are used after they are freed. (dup alloc?) Message-ID: <199704040310.WAA09093@lakes.water.net>
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Wow!
I was _very_ excited by this report; especially since it seemed
to match the 'dup alloc' panic I've reported, and it was a timing
issue, and this is certainly the area where I get "dup alloc"s and
"free vnode isn't" panics...
So, I applied the following diff to a 2.1.7 tree, which basically
moves the call to VOP_INACTIVE() until after the vnode has been
added to the free list (as Tor had described) [Tor - does this seem
to be what you intended? The source in 2.1.7, of course, doesn't
have the SMP locking, etc....]:
*** vfs_subr.c.ori Thu Aug 15 13:08:20 1996
--- vfs_subr.c Thu Apr 3 20:07:46 1997
***************
*** 835,840 ****
--- 835,843 ----
panic("vrele: ref cnt");
}
#endif
+
+ VOP_INACTIVE(vp);
+
if (vp->v_flag & VAGE) {
TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
vp->v_flag &= ~VAGE;
***************
*** 843,849 ****
}
freevnodes++;
- VOP_INACTIVE(vp);
}
/*
--- 846,851 ----
Unfortunately, I am still able to demonstrate my particular problem :-(
So, I'm beginning to wonder... is there a way a vnode can get
onto the freelist; but still be "busy" somehow... Of hand,
is there a way to check for this condition I could add to the code
to see if that's what's going on?
- Thanks -
- Dave Rivers -
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