double close strikes panic if md attaching a corrupt file

[Robert Watson]

On Sat, 26 Nov 2005, Csaba Henk wrote:

> On Fri, Nov 25, 2005 at 09:56:20PM -0500, Kris Kennaway wrote:
>>> I attach two patches, they realize the above ideas, respectively.
>>> Note that I didn't test either.
>>
>> You probably should do so ;-) This isn't the easiest thing for someone
>> to test without such corrupted media.
>
> Umm... I was hoping that someone in the list will suggest a way for 
> easily creating corrupt files. As I don't have a corrupt media, either 
> :)
>
> I picked this when Fuse was panicking upon md attaching from a Fuse 
> based filesystem, cf.
>
> http://lists.freebsd.org/pipermail/freebsd-ports/2005-November/027724.html

Well, a very easy way to test would be to add a local modification to UFS 
to create a file flag that causes VOP_READ to return EIO :-).  That way 
you can easily mark files to return EIO.

Robert N M Watson