Bug 983521
| Summary: | tgtadm: the read-only parameter does not work | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Xiaowei Li <xiaoli> |
| Component: | scsi-target-utils | Assignee: | Andy Grover <agrover> |
| Status: | CLOSED WONTFIX | QA Contact: | Bruno Goncalves <bgoncalv> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 6.4 | CC: | bgoncalv, mhoyer |
| Target Milestone: | rc | Keywords: | FutureFeature |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Enhancement | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-12-06 11:37:26 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
This request was not resolved in time for the current release. Red Hat invites you to ask your support representative to propose this request, if still desired, for consideration in the next release of Red Hat Enterprise Linux. The problem is still reproducible on scsi-target-utils-1.0.24-16.el6 Still reproducible with scsi-target-utils-1.0.24-17.el6 kernel-2.6.32-592.el6 There are two parts. What tgt "readonly=1" does now is set the WP (write protect) bit in the lun's MODE SENSE response (e.g. "sg_modes /dev/sdb" you will see "WP=1"). If the underlying media were incapable of writes outside of iscsi, this would be the way for the initiator to know that. But tgt doesn't itself stop writes if the device actually isn't readonly. There's another feature called Software Write Protect (SWP) which actually enforces that writes are not performed. This is not in tgt 1.0.24 but it is in a later version, it would need to be backported to make the test case in comment 0 succeed. Or, just ensuring that tgt only had read access via Unix permissions to the backing store would also achieve the same goal. Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available. The official life cycle policy can be reviewed here: http://redhat.com/rhel/lifecycle This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation. Red Hat Customer Support can be contacted via the Red Hat Customer Portal at the following URL: https://access.redhat.com/ |
Description of problem: I create a passthrough readonly device and export it via iscsi. On the initiator, I still can write to the device. Version-Release number of selected component (if applicable): scsi-target-utils-1.0.24-2.el6.x86_64 How reproducible: 100% Steps to Reproduce: 1. # tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.tgt:disk:target1 # tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL # tgtadm --lld iscsi --op new --mode logicalunit --tid 1 --lun 1 --bstype=sg --device-type=pt --backing-store=/dev/sg0 # tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 1 --params readonly=1 # tgtadm --lld iscsi --op show --mode target Target 1: iqn.tgt:disk:target1 System information: Driver: iscsi State: ready I_T nexus information: I_T nexus: 1 Initiator: iqn.1994-05.com.redhat:d7c1e0c5733 Connection: 0 IP Address: 127.0.0.1 I_T nexus: 2 Initiator: iqn.1994-05.com.redhat:92256b5b4c9a Connection: 0 IP Address: 10.66.12.156 LUN information: LUN: 0 Type: controller SCSI ID: IET 00010000 SCSI SN: beaf10 Size: 0 MB, Block size: 1 Online: Yes Removable media: No Prevent removal: No Readonly: No Backing store type: null Backing store path: None Backing store flags: LUN: 1 Type: passthrough SCSI ID: IET 00010001 SCSI SN: beaf11 Size: 0 MB, Block size: 1 Online: Yes Removable media: No Prevent removal: No Readonly: Yes Backing store type: sg Backing store path: /dev/sg0 Backing store flags: Account information: ACL information: ALL 2. 3. Actual results: on the initiator, I still can write to the device exported by the /dev/sg0 Expected results: Additional info: