Subject: lstape, lsluns: handle non-zfcp; lin_tape multiple paths From: Steffen Maier Description: lstape, lsluns: handle non-zfcp; lin_tape multiple paths Symptom: lstape shows unexpected additional Device suffix numbers in excess output columns for each additional path of the same tape/changer driven by the IBM lin_tape device driver (independent of actual path failover enablement in lin_tape). It also shows a wrong number of found devices in the header (without --scsi-only). lstape prints error about "Unexpected extra argument:" and the usage for "sg_inq" along with wrong tabular output. lsluns prints ENOENT error text for "cat" on SCSI device sysfs attributes hba_id, wwpn, and fcp_lun. lstape with --verbose option prints ENOENT error text for "cat" on SCSI device sysfs attributes hba_id and wwpn. lstape man page: Description of --type and filter for channel tapes is incomplete. SCSI output description is incomplete. lstape shows "N/A" instead of the HBA device bus-ID with virtio-scsi-ccw. Problem: s390-tools-1.8.0 before the first upstream commit b627b8d8e1ab ("Initial s390-tools-2.0.0 import") introduced SCSI tape/changer output for lstape. It used the SCSI device serial number as lookup key to find a match in IBM lin_tape device driver proc-fs output for a given SCSI device name. Multiple paths to the same tape/changer have the same serial number. Multiple matches cause excess arguments to printf. Explaining the resulting output, the bash man page says: "The format is reused as necessary to consume all of the arguments." This also causes a wrong number of found devices. The default bash settings have nullglob disabled so if $SCSI_DEV/scsi_generic* aka /sys/bus/scsi/devices/*:*:*:*/scsi_generic* does not match anything, it leaves the glob pattern unmodified and SG_DEV=$(basename $SG_DEV/*) results in the literal "*". If $SG_INQ exists, it invoked sg_inq with more than the one allowed positional argument for a SCSI generic device node "sg_inq /dev/*". Causing error messages and the usage of sg_inq to land in $TAPE_SERIAL. lsluns iterates SCSI generic devices and unconditionally reads zfcp-specific SCSI device sysfs attributes hba_id, wwpn, and fcp_lun. lstape --verbose unconditionally reads zfcp-specific SCSI device sysfs attributes hba_id and wwpn. filter missing from synopsis. example at wrong place with filter. filter option description is a duplicate of filter option description. SCSI output description misses fields. Lstape only used the zfcp-specific sysfs attribute hba_id. Solution: Prefer sysfs to find lin_tape device name for SCSI device. Fallback: The lin_tape proc-fs output format has changed over the years. The HBA device driver string can contain whitespace (e.g. "Virtio SCSI HBA") and breaks the field numbers with tokenized parsing. Grep for the SCSI device name as word (to skip names with same substring, such as 0:0:1:1 also matching 0:0:1:10) and cut the first field 'Number' (lin_tape device name suffix). If there is no SCSI column at all [lin_tape before v2.2.0] (and no SCSI LLDD or other column with a name accidentally matching an existing SCSI device name), we get no match and better bail out with the initialized "N/A" for the lstape column "Device". To not have to rely on the nullglob setting, explicitly check for the existence of $SCSI_DEV/scsi_generic before evaluating SG_DEV=$(basename $SG_DEV/*). Also handle availability of sg_inq but absence of scsi_generic individually to provide the user with a hint if only sg is missing. Simply skip non-zfcp SCSI devices, such as iSCSI or virtio-scsi-ccw, to not erroneously access absent attributes. Assume "N/A" for HBA and WWPN of non-zfcp SCSI devices, such as iSCSI or virtio-scsi-ccw, to not erroneously access absent zfcp-specific sysfs attributes. Add filter to synopsis. Move example to option. Replace filter option description. Move existing SCSI output description to a new subsection and add description of missing fields. Also search sysfs for an ancestor with subsystem ccw. Reproduction: Attach more than one path to the same SCSI tape or changer and load the IBM lin_tape device driver. Unload sg kernel module. Attach non-zfcp SCSI devices such as iSCSI or virtio-scsi-ccw. Attach non-zfcp SCSI devices such as iSCSI or virtio-scsi-ccw. man lstape Attach SCSI tape or changer with virtio-scsi-ccw to a KVM guest and run "lstape --verbose". Upstream-ID: - Problem-ID: 170633 Signed-off-by: Steffen Maier --- zconf/lstape | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/zconf/lstape +++ b/zconf/lstape @@ -291,6 +291,23 @@ function SysfsCreateListSCSI() if [ "$CHG_IDX" != "" ]; then TAPE_DEV=$CHG_IDX fi + elif [ "$(echo "$SCSI_LIST"|grep lin_tape)" != "" ]; then + # bash glob sorts so IBMtape0 comes before IBMtape0n + local IBM_PATH=$( + ls -1d $SCSI_DEV/lin_tape/$DEV_NAME[0-9]* | + head -n 1) + if [ -d "$IBM_PATH" ]; then + IBM_IDX=${IBM_PATH##*/} + else + # deprecated sysfs layout + IBM_IDX=$( + echo "$SCSI_LIST" | + awk -F: '/lin_tape\:'"$DEV_NAME"'[0-9]+$/{print $NF}' + ) + fi + if [ "$IBM_IDX" != "" ]; then + TAPE_DEV=$IBM_IDX + fi elif [ -r /proc/scsi/$DEV_NAME ]; then IBM_IDX=$( grep -wF "$SCSI_ID" /proc/scsi/$DEV_NAME |