Greg KH wrote:
On Thu, Jan 16, 2003 at 11:43:23AM -0800, Matthew Dharm wrote:
Well, we only create the host when the device is first attached. After
that, if it goes away and comes back, we re-connect it to the old SCSI
host.
Ick, so when the device is gone, where does the SCSI host go? Is it
still represented in sysfs and in the SCSI core properly?
Just for the record ... I think usb-storage is the only USB driver
that tries to keep state about devices across disconnect/reconnect.
I agree with Greg that hotplugging (including unplug/replug) should
work well with SCSI. But given the problems of determining "identity"
of a disk (or volume or whatever) I'm sort of curious what working
well should really mean.
Have any of the SCSI people been looking much at SCSI hotplug on 2.5?
I attach "/etc/hotplug/scsi.agent" from one of my desktops; all it
does is make sure the right drivers are loaded, it doesn't have a
clue yet about whether/how/where to mount disks or do other stuff.
- Dave
#!/bin/bash
#
# SCSI hotplug agent for 2.5 kernels
#
# ACTION=add
# DEVPATH=devices/scsi0/0:0:0:0
#
cd /etc/hotplug
. hotplug.functions
case $ACTION in
add)
# 2.5.50 kernel bug: this happens sometimes
if [ ! -d /sys/$DEVPATH ]; then
mesg "bogus sysfs DEVPATH=$DEVPATH"
exit 1
fi
TYPE=$(cat /sys/$DEVPATH/type)
case "$TYPE" in
# 2.5.51 style attributes; <scsi/scsi.h> TYPE_* constants
0) TYPE=disk ; MODULE=sd_mod ;;
# FIXME some tapes use 'osst' not 'st'
1) TYPE=tape ; MODULE=st ;;
2) TYPE=printer ;;
3) TYPE=processor ;;
4) TYPE=worm ; MODULE=sr_mod ;;
5) TYPE=cdrom ; MODULE=sr_mod ;;
6) TYPE=scanner ;;
7) TYPE=mod ; MODULE=sd_mod ;;
8) TYPE=changer ;;
9) TYPE=comm ;;
14) TYPE=enclosure ;;
esac
if [ "$MODULE" != "" ]; then
mesg "$TYPE at $DEVPATH"
modprobe $MODULE
else
mesg "how to add device type=$TYPE at $DEVPATH ??"
fi
;;
*)
debug_mesg SCSI $ACTION event not supported
exit 1
;;
esac
