[Pkg-xen-devel] Bug#1106420: xen-utils-common: block-iscsi script doesn't work when iqn is a prefix of an existing iqn

[Tim Woodall]

Package: xen-utils-common
Version: 4.17.5+23-ga4e5191dc0-1+deb12u1
Severity: normal

two issues with block-iscsi

1. If the iqn that is being used as a disk device is a prefix of an 
existing in use iqn then xl create will fail with
libxl: error: libxl_device.c:1337:device_hotplug_child_death_cb: script: Device already opened

My fix is to match a space before and after the iqn.

iscsiadm -m session | grep ' iqn.xen17:trixie17 '
tcp: [32] [fd01:8b0:bfcd:100:230:18ff:fe08:5ad6]:3260,1 iqn.xen17:trixie17 (non-flash)

Without the trailing space:
iscsiadm -m session | grep 'iqn.xen17:trixie17'
tcp: [30] [fd01:8b0:bfcd:100:230:18ff:fe08:5ad6]:3260,1 iqn.xen17:trixie17-build (non-flash)
tcp: [32] [fd01:8b0:bfcd:100:230:18ff:fe08:5ad6]:3260,1 iqn.xen17:trixie17 (non-flash)

2. There's no way to specify the LUN, it seems to always want lun-0. All 
of my LUNS are 1, so I've changed the default to 1 rather than 0 but it 
needs an extra lun=<> parameter.

diff -u scripts/block-iscsi.distrib scripts/block-iscsi
--- scripts/block-iscsi.distrib 2022-12-29 23:12:25.000000000 +0000
+++ scripts/block-iscsi 2025-05-24 16:24:53.000000000 +0000
@@ -26,6 +26,8 @@
 dir=$(dirname "$0")
 . "$dir/block-common.sh"
 
+LUN=1
+
 remove_label()
 {
     echo $1 | sed "s/^\("$2"\)//"
@@ -59,6 +61,9 @@
         multipath=*)
             multipath=$(remove_label $param "multipath=")
             ;;
+        lun=*)
+            LUN=$(remove_label $param "lun=")
+            ;;
         esac
     done
     if [ -z "$iqn" ] || [ -z "$portal" ]; then
@@ -73,7 +78,7 @@
 find_device()
 {
     count=0
-    while [ ! -e /dev/disk/by-path/*"$iqn"-lun-0 ]; do
+    while [ ! -e /dev/disk/by-path/*"$iqn"-lun-"${LUN}" ]; do
         sleep 1
         count=`expr $count + 1`
         if [ count = 100 ]; then
@@ -81,7 +86,7 @@
             fatal "timeout waiting for iSCSI disk to settle"
         fi
     done
-    sddev=$(readlink -f /dev/disk/by-path/*"$iqn"-lun-0 || true)
+    sddev=$(readlink -f /dev/disk/by-path/*"$iqn"-lun-"${LUN}" || true)
     if [ ! -b "$sddev" ]; then
         fatal "Unable to find attached device path"
     fi
@@ -109,9 +114,9 @@
 prepare()
 {
     # Check if target is already opened
-    iscsiadm -m session 2>&1 | grep -q "$iqn" && fatal "Device already opened"
+    iscsiadm -m session 2>&1 | grep -q " $iqn " && fatal "Device already opened"
     # Discover portal targets
-    iscsiadm -m discovery -t st -p $portal 2>&1 | grep -q "$iqn" || \
+    iscsiadm -m discovery -t st -p $portal 2>&1 | grep -q " $iqn\$" || \
         fatal "No matching target iqn found"
 }
 

-- System Information:
Debian Release: 12.11
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-35-amd64 (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages xen-utils-common depends on:
ii  libc6                      2.36-9+deb12u10
ii  libxenhypfs1               4.17.5+23-ga4e5191dc0-1+deb12u1
ii  libxenstore4               4.17.5+23-ga4e5191dc0-1+deb12u1
ii  lsb-base                   11.6
ii  python3                    3.11.2-1+b1
ii  sysvinit-utils [lsb-base]  3.06-4
ii  ucf                        3.0043+nmu1+deb12u1
ii  udev                       252.36-1~deb12u1
ii  xenstore-utils             4.17.5+23-ga4e5191dc0-1+deb12u1

xen-utils-common recommends no packages.

Versions of packages xen-utils-common suggests:
pn  xen-doc  <none>

-- Configuration Files:
/etc/xen/scripts/block-iscsi changed:
<snip - diff above>

-- no debconf information