Re: [PATCH RESEND^2] sd: fix infinite kernel/udev loop onnon-removable Medium Not Present

From: Greg KH
Date: Fri Apr 26 2013 - 13:10:42 EST

On Fri, Apr 26, 2013 at 11:39:33AM -0500, Steven J. Magnani wrote:
> Commit eface65c336eff420d70beb0fb6787a732e05ffb (2.6.38) altered
> set_media_not_present() in a way that prevents the sd driver from
> remembering that a non-removable device has reported "Medium Not Present".
> This condition can occur on hotplug of a (i.e.) USB Mass Storage device
> whose medium is offline due to an unrecoverable controller error,
> but which is otherwise capable of SCSI communication (to download new
> microcode, etc.).
> Under these conditions, the changed code results in an infinite loop
> between the kernel and udevd. When udevd attempts to open the device
> in response to a change notification, a SCSI "Medium Not Present" error
> occurs which causes the kernel to signal another change. The cycle
> repeats until the device is unplugged, resulting in udevd consuming ever-
> increasing amounts of CPU and virtual memory.
> Resolve this by remembering "media not present" whether the device has
> declared itself "removable" or not.
> Signed-off-by: Steven J. Magnani <steve@xxxxxxxxxxxxxxx>
> ---


This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

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