Description of problem: Multiple kernel messages when loading ses.ko: kobject_add failed for ArrayDevice03 with -EEXIST, don't try to register things with the same name in the same directory. Call Trace: [<ffffffff80155274>] kobject_add+0x166/0x191 [<ffffffff801cd822>] class_device_add+0xa6/0x422 [<ffffffff80057a83>] kobject_get+0x12/0x17 [<ffffffff88775727>] :enclosure:enclosure_component_register+0xa6/0xdb [<ffffffff88781a9b>] :ses:ses_intf_add+0x49f/0x680 [<ffffffff801ce005>] class_interface_register+0x76/0xb5 [<ffffffff8822100d>] :ses:ses_init+0xd/0x35 [<ffffffff800a93a7>] sys_init_module+0xbd/0x206 [<ffffffff8005d28d>] tracesys+0xd5/0xe0 It is highly likely (though not verified yet) that pulling a disk in the backplane will cause a kernel panic. Version-Release number of selected component (if applicable): 2.6.18-266.el5 How reproducible: always Steps to Reproduce: 1. install on PRIMERGY TX300S6 with SAS expander (enclosure) backplane Actual results: see above Expected results: no error messages, no panic Additional info: See bug #619422 for the same problem on RHEL6. Under RHEL5.6 the problem didn't exist because ses support was lacking. A possible workaround is to disable the ses module.
Created attachment 504903 [details] log file with some information about the enclosure. The interesting part is sg_ses -p 7 /dev/sg0: Element descriptor In diagnostic page: generation code: 0x0 Element type: Array device, subenclosure id: 0 Overall descriptor: ArrayDevicesInSubEnclsr0 Element 1 descriptor: ArrayDevice00 Element 2 descriptor: ArrayDevice01 Element 3 descriptor: ArrayDevice02 Element 4 descriptor: ArrayDevice03 Element 5 descriptor: ArrayDevice03 Element 6 descriptor: ArrayDevice03 Element 7 descriptor: ArrayDevice03 Element 8 descriptor: ArrayDevice03 Element 9 descriptor: ArrayDevice03 Element 10 descriptor: ArrayDevice03 Element 11 descriptor: ArrayDevice03 Element 12 descriptor: ArrayDevice03 The firmware uses the same name for all Elements 4...12. This could be a FW bug, but the kernel should be able to handle it gracefully.
From: https://bugzilla.redhat.com/show_bug.cgi?id=619422#c39 "It's the fact that ses.ko can't handle non-unique element names." Considering the short time remaining, we may need to consider a way to disable ses by default in 5.7. Or remove it and ship it as a DUP, some other alternative...
(In reply to comment #2) > From: > > https://bugzilla.redhat.com/show_bug.cgi?id=619422#c39 > > "It's the fact that ses.ko can't handle non-unique element names." Could someone please enable IBM access to bz619422 so we can read the entire thread? Thanks in advance.
Could this problem is smiliar to, https://bugzilla.redhat.com/show_bug.cgi?id=703084
The panic situation when a disk is pulled from the expander has *not* been reproduced on RHEL5.7. Thus, as there is a workaround available (disable ses), and apparently no panic, we can accept this as a limitation.
Okay, so as I understand it, no code change for 5.7 is needed, but we will need a Technical Note to warn about the problem. Martin, would you be willing to draft that? James, if this is correct, then you can set the technical_note flag, and close this BZ.
(In reply to comment #6) > Okay, so as I understand it, no code change for 5.7 is needed, but we will need > a Technical Note to warn about the problem. Martin, would you be willing to > draft that? > > James, if this is correct, then you can set the technical_note flag, and close > this BZ. I added a tech note, and am closing per Tom's and peterm's recommendation.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: On Fujitsu PRIMERGY TX300S6 servers with SAS expander, firmware may incorrectly report duplicate element names which result in the following warnings being logged: kobject_add failed for ArrayDevice03 with -EEXIST, don't try to register things with the same name in the same directory. Please see your firmware vendor for a fix for this issue. Otherwise, you may blacklist the 'ses' module to prevent it from loading.
The problem is not limited to PRIMERGY TX300S6. It will occur on all PRIMERGYs with SAS expander. Actually, it will occur on all SAS expanders with a certain LSI firmware, there may be expanders from other vendors than Fujitsu. I'd appreciate a modified release note like this: On some servers with SAS expanders (enclosures), firmware may incorrectly report duplicate element names which result in the following warnings being logged: kobject_add failed for ArrayDevice03 with -EEXIST, don't try to register things with the same name in the same directory. This happens e.g. on Fujitsu PRIMERGY TX300S6. Please see your firmware vendor for a fix for this issue. Otherwise, you may blacklist the 'ses' module to prevent it from loading.
Tweaking tech note per Martin's comment #9.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1,3 +1,3 @@ -On Fujitsu PRIMERGY TX300S6 servers with SAS expander, firmware may incorrectly report duplicate element names which result in the following warnings being logged: +On servers with SAS expanders/enclosures (e.g., Fujitsu PRIMERGY TX300S6), firmware may incorrectly report duplicate element names which results in the following warnings being logged: kobject_add failed for ArrayDevice03 with -EEXIST, don't try to register things with the same name in the same directory. Please see your firmware vendor for a fix for this issue. Otherwise, you may blacklist the 'ses' module to prevent it from loading.