DragonFly bugs List (threaded) for 2005-01
Re: Tentitive UFS patch to narrow down dup alloc panics
On Thu, 13 Jan 2005 13:22:34 -0800 (PST), Matthew Dillon
> I would appreciate it if everyone who regularly gets 'dup alloc' inode
> panics would apply this patch, install a new kernel, reboot into single
> user, and fsck (to get a 'clean slate'), then reboot normally and see if
> the dup alloc panic still occurs.
> I am trying to narrow down the possible sources of the bug. The
> dup alloc (inode) panic also occurs in FreeBSD 5.3 and FreeBSD 4.x,
> and I think they are all related. But finding the problem is proving
> to be difficult due to its delayed-action nature.
> This patch prevents the UFS filesystem from reallocating an inode
> that has not yet been completely disposed of by the system. There
> is a possible race in the vnode disposal code where the inode hash
> table is inconsistent with the vnode state. If an inode is reallocated
> at that point it is entirely possible that the on-disk inode structure
> could become inconsistent with the actual state of the system.
> If you get any 'conflict with vnode ...' messages on the console/dmesg
> using this patch, please report them immediately along with what you
> were doing at the time.
I have been running this patch on a few machines which are regularly
under heavy I/O load the past 4 days and haven't had any problems. I
would feel comfortable if you wanted to go ahead and commit this into
the tree for further testing.
Steven David Rhodus