From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: SCSI regression in 4.11
Date: Wed, 1 Mar 2017 10:48:00 -0800
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To: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>, Linus Torvalds <torvalds@linux-foundation.org>, "Martin K. Petersen" <martin.petersen@oracle.com>, "K. Y. Srinivasan" <kys@microsoft.com>, Dexuan Cui <decui@microsoft.com>, Long Li <longli@microsoft.com>, Josh Poulson <jopoulso@microsoft.com>, v-adsuho@microsoft.com, linux-scsi@vger.kernel.org, Haiyang Zhang <haiyangz@microsoft.com>

On Tue, 28 Feb 2017 22:20:58 -0800
James Bottomley <jejb@linux.vnet.ibm.com> wrote:

> On Tue, 2017-02-28 at 17:25 -0800, Stephen Hemminger wrote:
> > [    1.346023] hv_storvsc:  IO cmd 0x12 0x0 0x0 scsi status 0x0 srb
> > status 0x20 length 36
> > [    1.352913] inquiry data: 00000000: 00 aa be f1 5c 98 ff ff f0 64
> > 02 89 ff ff ff ff
> > [    1.356543] inquiry data: 00000010: 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00
> > [    1.359996] inquiry data: 00000020: 00 00 00 00
> > [    1.361835] scsi host1: scsi scan: INQUIRY result too short (5),
> > using 36
> > [    1.361888] hv_storvsc:  IO cmd 0xa0 0x0 0x0 scsi status 0x0 srb
> > status 0x1 length 16
> > [    1.362307] hv_storvsc:  IO cmd 0x12 0x0 0x0 scsi status 0x0 srb
> > status 0x1 length 36
> > [    1.362308] inquiry data: 00000000: 00 23 34 f1 5c 98 ff ff f0 64
> > 02 89 ff ff ff ff
> > [    1.362309] inquiry data: 00000010: 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00
> > [    1.362309] inquiry data: 00000020: 00 00 00 00
> > [    1.377423] scsi 1:0:0:1: Direct-Access                           
> >          PQ: 0 ANSI: 0  
> 
> Well, this pinpoints the fault to the block uncopy, I think.  The
> Inquiry data is clearly correct in the page frame, so it's not getting
> copied to the scsi_execute() buffer for some reason.
> 
> James
> 

Why do I see different sense data on good (4.10) versus bad (4.11)

Good 4.10 initial INQUIRY buffer
[    1.012413] data: 00000000: 00 2e 64 71 db 97 ff ff f0 94 62 96 ff ff ff ff
[    1.012413] data: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[    1.012414] data: 00000020: 00 00 00 00

Bad 4.11 initial INQUIRY buffer  
[    1.218159] data: 00000000: 00 00 05 02 1f 00 00 02 4d 73 66 74 20 20 20 20
[    1.225654] data: 00000010: 56 69 72 74 75 61 6c 20 44 69 73 6b 20 20 20 20
[    1.242930] data: 00000020: 31 2e 30 20

Is the kmap_atomic looking at the right place?