[PATCH] SCSI logical and physical names for udev

  Hi, Greg. Appended is scsi-devfs.sh, a script for udev to implement
devfs-style names for SCSI hard discs, CD-ROM's and generic devices.
This has been tested with both hard discs and CD-ROM's. The SCSI
generic support should be OK for when there is sysfs/udev support for
SCSI generic devices. SCSI tapes are not yet implemented because I
don't have one to test with.

In addition, this script supports physical names, based on PCI bus
location, both longhand (/udev/bus/pci/...) and shorthand
(/udev/sd/pci/*).

diff --git a/extras/scsi-devfs.sh b/extras/scsi-devfs.sh
new file mode 100644 (file)
index 0000000..30f4553
--- /dev/null
+++ b/extras/scsi-devfs.sh
@@ -0,0 +1,88 @@
+#! /bin/sh
+#
+#  scsi-devfs.sh: udev external PROGRAM script
+#
+#  Copyright 2004  Richard Gooch <rgooch@atnf.csiro.au>
+#  Copyright 2004  Fujitsu Ltd.
+#  Distributed under the GNU Copyleft version 2.0.
+#
+# return devfs-names for scsi-devices
+# Usage in udev.rules:
+# BUS="scsi", KERNEL="sd*", PROGRAM="/etc/udev/scsi-devfs.sh sd %b %n", NAME="%c{1}", SYMLINK="%c{2} %k %c{3} %c{4}"
+# BUS="scsi", KERNEL="sr*", PROGRAM="/etc/udev/scsi-devfs.sh sr %b %n", NAME="%c{1}", SYMLINK="%c{2} %k %c{3} %c{4}"
+# BUS="scsi", KERNEL="st*", PROGRAM="/etc/udev/scsi-devfs.sh st %b %n", NAME="%c{1}", SYMLINK="%c{2} %k %c{3} %c{4}"
+# BUS="scsi", KERNEL="sg*", PROGRAM="/etc/udev/scsi-devfs.sh sg %b %n", NAME="%c{1}", SYMLINK="%c{2} %k %c{3} %c{4}"
+
+# Find out where sysfs is mounted. Exit if not available
+sysfs=`fgrep sysfs /proc/mounts | awk '{print $2}'`
+if [ "$sysfs" = "" ]; then
+    echo "sysfs is required"
+    exit 1
+fi
+cd $sysfs/bus/scsi/devices
+
+case "$1" in
+  sd)
+    # Extract partition component
+    if [ "$3" = "" ]; then
+       lpart="disc"
+       spart=""
+    else
+       lpart="part$3"
+       spart="p$3"
+    fi
+    ;;
+  sr)
+    lpart="cdrom"
+    spart=""
+    ;;
+  st)
+    # Not supported yet
+    exit 1
+    ;;
+  sg)
+    lpart="generic"
+    spart=""
+    ;;
+  *)
+    exit 1
+    ;;
+esac
+
+# Extract SCSI logical address components
+scsi_host=`echo $2 | cut -f 1 -d:`
+scsi_bus=`echo $2 | cut -f 2 -d:`
+scsi_target=`echo $2 | cut -f 3 -d:`
+scsi_lun=`echo $2 | cut -f 4 -d:`
+
+# Generate long and short common name parts
+l_com="bus$scsi_bus/target$scsi_target/lun$scsi_lun/$lpart"
+s_com="b${scsi_bus}t${scsi_target}u${scsi_lun}$spart"
+
+# Generate long and short logical names
+l_log="scsi/host$scsi_host/$l_com"
+s_log="$1/c${scsi_host}${s_com}"
+
+readlink $2 | fgrep -q pci
+if [ "$?" != "0" ]; then
+    # Not a PCI controller, show logical locations only
+    echo $l_log $s_log
+    exit 0
+fi
+
+# Extract PCI address
+tmp=`readlink $2 | sed -e 's@/host.*/.*@@'`
+pci_addr=`basename "$tmp"`
+pci_domain=`echo $pci_addr | cut -f 1 -d:`
+pci_bus=`echo $pci_addr | cut -f 2 -d:`
+pci_slot=`echo $pci_addr | tr . : | cut -f 3 -d:`
+pci_function=`echo $pci_addr | cut -f 2 -d.`
+
+# Generate long and short physical names
+l_pci="domain$pci_domain/bus$pci_bus/slot$pci_slot/function$pci_function"
+l_phy="bus/pci/$l_pci/scsi/$l_com"
+s_phy="$1/pci/$pci_addr/$s_com"
+
+echo $l_phy $s_phy $l_log $s_log
+
+