Messages in this thread | | | Date | Wed, 28 Dec 2022 17:35:51 +0800 | Subject | Re: [PATCH 0/2] scsi:donot skip lun if inquiry returns PQ=1 for all hosts | From | Wenchao Hao <> |
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On 2022/12/23 23:54, Christoph Hellwig wrote: > On Fri, Dec 16, 2022 at 07:41:26PM +0800, Wenchao Hao wrote: >> For nothing, I want the iscsi_tcp transport do not skip PQ=1 default >> as what it did before commit 948e922fc4461 ("scsi: core: map PQ=1, >> PDT=other values to SCSI_SCAN_TARGET_PRESENT"). > > Well, that commit was very much intentional and is now three an a half > years old, so we've not just going to partially revert it on a > per-transport basis when it is in no way transport related. > > If you can come up with a good enough rationale we could do the > sysfs override, but so far the reason mostly seems to be "I want" > and not anctual explanation of why it is useful. > .
Sorry, I did not describe in detail.
Here is the reason of my patches.
1. The SPC did not tell PQ=1 means the addressed lun is invalid explicitly. 2. scsi_bus_match() would prevent luns with PQ=1 be handled by any scsi drivers, so the only influence if we do not skip luns with PQ=1 is we would add an scsi_device and an sg device.
The reason I force a specific behavior for iSCSI:
1. This issue is occurred with iSCSI, it means there are scenarios where targets would return PQ=1 for an valid LUN which should not be skipped. 2. The changes for iSCSI could be tested
I did not change other transports' behavior is because I do not know if PQ=1 would be returned, and I do not have the related environment. If other transports like adaptec raid also needs these changes, they can override the default value by other patches.
Thanks.
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