Re: Problem hotplugging USB flashdrive (race?)

[Greg KH <greg@kroah.com>]

On Sat, Dec 13, 2003 at 01:58:57PM +0100, Bertrik Sikken wrote:
> I think what happens when inserting the flash drive is this:
> hotplug sees the embedded hub and mass-storage device in the
> USB stick and loads usb-storage and SCSI modules. Then it
> seems that scsi.agent tries to extract a number from the file
> /sys/devices/<.....>/type
> which appears to be an empty string according to the log.

Yeah, I've seen this a lot too.  userspace is a lot faster than the
kernel in this instance :)

> When I try to cat this file manually, it exists and it
> results in the number 0, which correctly indicates a
> SCSI disk with associated module sd_mod.
> I can imagine that this is some kind of race condition,
> where the script looks too soon for the file or its contents.

Exactly.  Try putting a sleep before reading the file, or loop on the
file for a bit before reading it.

thanks,

greg k-h


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