Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
For bugs related to Red Hat Enterprise Linux 5 product line. The current stable release is 5.10. For Red Hat Enterprise Linux 6 and above, please visit Red Hat JIRA https://issues.redhat.com/secure/CreateIssue!default.jspa?pid=12332745 to report new issues.

Bug 450862

Summary: scsi_add_host() returns success even if the work_q was not created
Product: Red Hat Enterprise Linux 5 Reporter: carl.lajeunesse
Component: kernelAssignee: Mike Christie <mchristi>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: medium Docs Contact:
Priority: low    
Version: 5.2CC: coughlan, cward, mchristi
Target Milestone: rc   
Target Release: ---   
Hardware: ppc64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-09-02 09:00:04 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description carl.lajeunesse 2008-06-11 14:15:43 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 1.1.4322)

Description of problem:
User sees a new host was added and later a dump stack on the console will be displayed during a scsi scan.

error is zero at this point.
        if (shost->transportt->create_work_queue) {
                snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d",
                        shost->host_no);
                shost->work_q = create_singlethread_workqueue(
                                        shost->work_q_name);
                if (!shost->work_q)
                        goto out_free_shost_data;
        }
So the goto out_free_shost_data will return success.
Change:
if (!shost->work_q)
    goto out_free_shost_data;

To:
if (!shost->work_q) {
    error = -ENOMEM;
    goto out_free_shost_data;
}


Version-Release number of selected component (if applicable):
kernel-2.6.18-92.el5

How reproducible:
Sometimes


Steps to Reproduce:
1. Install an NPIV capable Fibre Channel adapter.
2. Create and delete 1000s of vports.
3. Need a system low on kernel memory so that the work_q cannot be allocated.

Actual Results:
lpfc 0007:01:00.0: 2:(1):1825 Vport Created.
ERROR: FC host 'lpfc' attempted to flush work, when no workqueue created.
Call Trace:
[C0000000220E76A0] [C000000000010378] .show_stack+0x68/0x1b0 (unreliable)
[C0000000220E7740] [D00000000025051C] .fc_flush_work+0x44/0x68 [scsi_transport_f
c]
[C0000000220E77C0] [D000000000253334] .fc_remote_port_add+0x40/0x3f8 [scsi_trans
port_fc]
[C0000000220E7870] [D0000000003DB908] .lpfc_nlp_state_cleanup+0x25c/0x3f4 [lpfc]
[C0000000220E7940] [D0000000003DAF48] .lpfc_nlp_set_state+0x1f0/0x22c [lpfc]
[C0000000220E7A30] [D0000000003EA3B8] .lpfc_cmpl_prli_prli_issue+0x1c4/0x1e8 [lp
fc]
[C0000000220E7AC0] [D0000000003E71F4] .lpfc_disc_state_machine+0x104/0x228 [lpfc
]
[C0000000220E7B80] [D0000000003D7374] .lpfc_cmpl_els_prli+0x1a8/0x1e4 [lpfc]
[C0000000220E7C40] [D0000000003C9D04] .lpfc_sli_handle_slow_ring_event+0x4b0/0x9
1c [lpfc]
[C0000000220E7DF0] [D0000000003DDFD8] .lpfc_do_work+0x94c/0xe34 [lpfc]
[C0000000220E7EE0] [C000000000086DC4] .kthread+0x128/0x178
[C0000000220E7F90] [C000000000026FFC] .kernel_thread+0x4c/0x68
Unable to handle kernel paging request for data at address 0x00000010
Faulting instruction address: 0xc000000000152dac
cpu 0x0: Vector: 300 (Data Access) at [c0000000220e72c0]
    pc: c000000000152dac: .create_dir+0x38/0x2a8
    lr: c0000000001535c4: .sysfs_create_dir+0x78/0xa0
    sp: c0000000220e7540
   msr: 8000000000009032
   dar: 10
dsisr: 40000000
  current = 0xc0000000250b2d80
  paca    = 0xc0000000004d4e80
    pid   = 3986, comm = lpfc_worker_2
enter ? for help
0:mon>



Expected Results:
-ENOMEM from scsi_add_host() if work_q not created.

Additional info:
The debug stack occurs much later and is the symptom of the problem. The problem is with scsi_add_host() failing to return an error to the LLD when the fiber channel port was being added. Can effect any scsi adapter that fails to create a work_q.

Comment 1 carl.lajeunesse 2008-06-13 18:46:30 UTC
It's fixed upstream.  Here's the git commit:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-
2.6.git;a=commitdiff;h=77cca462c69d827fabee0ef3fdab86109c2fe8d8



Comment 4 RHEL Program Management 2009-02-11 21:00:31 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 5 RHEL Program Management 2009-02-16 15:44:34 UTC
Updating PM score.

Comment 6 Don Zickus 2009-03-04 19:59:24 UTC
in kernel-2.6.18-133.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Please do NOT transition this bugzilla state to VERIFIED until our QE team
has sent specific instructions indicating when to do so.  However feel free
to provide a comment indicating that this fix has been verified.

Comment 8 Chris Ward 2009-07-03 18:03:37 UTC
~~ Attention - RHEL 5.4 Beta Released! ~~

RHEL 5.4 Beta has been released! There should be a fix present in the Beta release that addresses this particular request. Please test and report back results here, at your earliest convenience. RHEL 5.4 General Availability release is just around the corner!

If you encounter any issues while testing Beta, please describe the issues you have encountered and set the bug into NEED_INFO. If you encounter new issues, please clone this bug to open a new issue and request it be reviewed for inclusion in RHEL 5.4 or a later update, if it is not of urgent severity.

Please do not flip the bug status to VERIFIED. Only post your verification results, and if available, update Verified field with the appropriate value.

Questions can be posted to this bug or your customer or partner representative.

Comment 10 errata-xmlrpc 2009-09-02 09:00:04 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2009-1243.html