Re: [PATCH] SCSI IOCTL: Check for device deletion [was Re:__elv_add_request OOPS]

From: Parag Warudkar
Date: Wed May 25 2011 - 19:00:23 EST


On Wed, May 25, 2011 at 4:52 PM, James Bottomley
<James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 2011-05-25 at 16:42 -0400, Parag Warudkar wrote:
>> Yeah - that makes sense. By that logic, looks like we can only disallow
>> for SDEV_DEL (if we decide to do that check here).
>
> I don't think this is the root cause.  I think q is non-NULL but has
> already been released, so we're just getting a NULL deref on the actual
> list head.
>
> Does this fix it?  It adds the refcounting at approximately the correct
> places.  Of course, we'll now be trying elevator operations on an extant
> queue but one whose elevator functions have been destroyed, so there are
> probably additional state guards to place.

[ Resend with URL - I got a bounce back from vger for attaching the OOPS JPEG ]

It doesn't seem to help. Machine locked up and I was dropped to text
console. I could only capture the oops by a camera.

OOPS available at below URLs [*]

Parag

[*] https://picasaweb.google.com/lh/photo/yccmqaz3xwumwjvecb-b0pTdDOYIfFRksMrZBIo-Inw?feat=directlink

[*] https://picasaweb.google.com/lh/photo/Lim6d3b8p7Lj4D3nHmkbFJTdDOYIfFRksMrZBIo-Inw?feat=directlink
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