udev-rules: make tape devices also accessable by ENV{ID_SCSI_SERIAL}

Tape and tape changer devices from Amazon Webservice Storage Gateway VTLs
and maybe other iSCSI VTLs all have the same ENV{ID_SERIAL}.
The results is, that only the last device is available in
/dev/tape/by-id/, as the former devices have been overwritten.
However, the devices can be distinguished by ENV{ID_SCSI_SERIAL}.

ENV{ID_SCSI_SERIAL} is not set on directly connected SCSI devices.

This rule additional creates links based on the ENV{ID_SCSI_SERIAL}, if
it is set.

In my case, it creates (ID_SCSI_SERIAL)
/dev/tape/by-id/scsi-AMZN_SGW-6BF81D02_MC_00001
/dev/tape/by-id/scsi-AMZN_SGW-6BF81D02_TD_00001
/dev/tape/by-id/scsi-AMZN_SGW-6BF81D02_TD_00002
...

instead of only (ID_SERIAL)
scsi-2414d5a4e5f5347572d364246

diff --git a/rules/60-persistent-storage-tape.rules b/rules/60-persistent-storage-tape.rules
index 0575f308df5c343e356ff69b3cdeb58133335900..0136140a46697c69bc2206b44c41c5e25a700668 100644 (file)
--- a/rules/60-persistent-storage-tape.rules
+++ b/rules/60-persistent-storage-tape.rules
@@ -9,6 +9,11 @@ ENV{UDEV_DISABLE_PERSISTENT_STORAGE_RULES_FLAG}=="1", GOTO="persistent_storage_t
 SUBSYSTEM=="scsi_generic", SUBSYSTEMS=="scsi", ATTRS{type}=="8", IMPORT{program}="scsi_id --sg-version=3 --export --whitelisted -d $devnode", \
   SYMLINK+="tape/by-id/scsi-$env{ID_SERIAL}"
 
+# iSCSI devices from the same host have all the same ID_SERIAL,
+# but additionally a property named ID_SCSI_SERIAL.
+SUBSYSTEM=="scsi_generic", SUBSYSTEMS=="scsi", ATTRS{type}=="8", ENV{ID_SCSI_SERIAL}=="?*", \
+  SYMLINK+="tape/by-id/scsi-$env{ID_SCSI_SERIAL}"
+
 SUBSYSTEM=="scsi_generic", SUBSYSTEMS=="scsi", ATTRS{type}=="8", IMPORT{builtin}="path_id", \
   SYMLINK+="tape/by-path/$env{ID_PATH}-changer"
 
@@ -18,8 +23,10 @@ KERNEL=="st*[0-9]|nst*[0-9]", ATTRS{ieee1394_id}=="?*", ENV{ID_SERIAL}="$attr{ie
 KERNEL=="st*[0-9]|nst*[0-9]", ENV{ID_SERIAL}!="?*", SUBSYSTEMS=="usb", IMPORT{builtin}="usb_id"
 KERNEL=="st*[0-9]|nst*[0-9]", ENV{ID_SERIAL}!="?*", SUBSYSTEMS=="scsi", KERNELS=="[0-9]*:*[0-9]", ENV{.BSG_DEV}="$root/bsg/$id"
 KERNEL=="st*[0-9]|nst*[0-9]", ENV{ID_SERIAL}!="?*", IMPORT{program}="scsi_id --whitelisted --export --device=$env{.BSG_DEV}", ENV{ID_BUS}="scsi"
-KERNEL=="st*[0-9]",  ENV{ID_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SERIAL}"
-KERNEL=="nst*[0-9]", ENV{ID_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SERIAL}-nst"
+KERNEL=="st*[0-9]",  ENV{ID_SERIAL}=="?*",      SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SERIAL}"
+KERNEL=="st*[0-9]",  ENV{ID_SCSI_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SCSI_SERIAL}"
+KERNEL=="nst*[0-9]", ENV{ID_SERIAL}=="?*",      SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SERIAL}-nst"
+KERNEL=="nst*[0-9]", ENV{ID_SCSI_SERIAL}=="?*", SYMLINK+="tape/by-id/$env{ID_BUS}-$env{ID_SCSI_SERIAL}-nst"
 
 # by-path (parent device path)
 KERNEL=="st*[0-9]|nst*[0-9]", IMPORT{builtin}="path_id"