HotPlug Race condition with udevsend

[Gregory G Carter]

Small Problem....

I attempted a update/upgrade from test2->test3.

I am now experiencing HotPlug issues...specifically, udevsend appears to 
spawning a large number of copies immediately after mounting the USB 
file system on boot. 

This results with a system that has a load average of about 45.

At this point the little fan in my Sager 5670 starts going into turbo 
mode and lifts the laptop 3 feet into the air.

It is now a hovercraft, which I use to hitch a ride to the break room 
for a Vanilla Pepsi....but I DIGRESS...

In any case, here is a process list:

root      9136  0.0  0.0  2060 1028 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug scsi_host
root      9145  0.0  0.0  2060  992 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend scsi_host
root      9147  0.0  0.0  2060 1024 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug scsi
root      9161  0.0  0.0  2056 1024 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug block
root      9170  0.0  0.0  2056  992 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend block
root      9172  0.0  0.0  2056 1024 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug block
root      9180  0.0  0.0  2056 1020 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug scsi_device
root      9189  0.0  0.0  2060  996 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend scsi_devic
root      9191  0.0  0.0  2060 1028 ?        S<   10:32   0:00 /bin/sh 
/sbin/hotplug scsi_generi
root      9200  0.0  0.0  2060  996 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend scsi_gener
root      9203  0.0  0.0  2060  996 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend block
root      9225  0.0  0.0  2056  992 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend scsi
root      9227  0.0  0.0  2056  992 ?        S<   10:32   0:00 /bin/sh 
/sbin/udevsend usb
...(ad nauseum it gets pretty large)

Dmesg output with this particular example uninserts/inserts a USB 2.0 
Hard Disk

usb 1-2: USB disconnect, address 2
usb 1-2: new high speed USB device using address 3
scsi2 : SCSI emulation for USB Mass Storage devices
  Vendor: SAMSUNG   Model: SV0602H           Rev: RH10
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sdb: 117304992 512-byte hdwr sectors (60060 MB)
sdb: assuming drive cache: write through
 sdb: sdb1
Attached scsi disk sdb at scsi2, channel 0, id 0, lun 0
Attached scsi generic sg0 at scsi2, channel 0, id 0, lun 0,  type 0
USB Mass Storage device found at 3

Woopsy.  Looks like I forgot to issue a umount before I did that...oh 
well....e2fsck -f /dev/sdb1 seems to be in order...so while it is doing 
that....

As you can see, after any USB device removal or adding a hotplug event 
triggers a udevsend race condition.

For those of you curious, udevsend is a simple script (/sbin/udevsend):

#!/bin/sh

if [ -f /etc/sysconfig/udev ]; then
        . /etc/sysconfig/udev
fi

sleep 5

[ "$USE_UDEV" != "yes" ] && exit 0

exec /sbin/udevsend "$@"

(I added the sleep 5 line so my system can boot and I can issue a 
killall udevsend)
which is called from what I can tell by the kernel when it issues a 
/sbin/hotplug command.  Why it CONTINUES to issue it after the device is 
loaded, and why it doesn't stop is my question.

It would seem that the thing is recursive...(i.e. It calls itself upon 
exit) so my guess is $USE_UDEV never becomes NO.  So at the moment I am 
looking for something that sets US_DEV to NO in the call train.

So if anyone can answer what sets USE_DEV to NO in the HotPlug call 
train when a USB device is inserted I would be most happy.

Thanks for your time...

-gc