Re: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
On Tue, Mar 28, 2017 at 04:14:09PM +, Stephen Hemminger wrote: > I decided not to send it to stable since problem was only observed on > 4.11 but it is probably endemic to all GEN2 VM's So, what does this mean? What should stable@ do? Nothing? Ok, now dropped this from my patch queue :) thanks, greg k-h
RE: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
I decided not to send it to stable since problem was only observed on 4.11 but it is probably endemic to all GEN2 VM's -Original Message- From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] Sent: Tuesday, March 28, 2017 7:29 AM To: Stephen Hemminger ; Long Li Cc: KY Srinivasan ; Martin K. Petersen ; Haiyang Zhang ; j...@linux.vnet.ibm.com; de...@linuxdriverproject.org; linux-scsi ; LKML ; sta...@vger.kernel.org; Greg KH Subject: Re: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors On 03/27/2017 06:14 PM, Stephen Hemminger wrote: > Are you sure the real problem is not the one fixed by this commit? > > commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f > Author: Stephen Hemminger > Date: Tue Mar 7 09:15:53 2017 -0800 > > scsi: storvsc: Workaround for virtual DVD SCSI version > > Hyper-V host emulation of SCSI for virtual DVD device reports SCSI > version 0 (UNKNOWN) but is still capable of supporting REPORTLUN. > > Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11 > successfully with virtual DVD ROM device. What happens is that the SCSI > scan process falls back to doing sequential probing by INQUIRY. But the > storvsc driver has a previous workaround that masks/blocks all errors > reports from INQUIRY (or MODE_SENSE) commands. This workaround causes > the scan to then populate a full set of bogus LUN's on the target and > then sends kernel spinning off into a death spiral doing block reads on > the non-existent LUNs. > > By setting the correct blacklist flags, the target with the DVD device > is scanned with REPORTLUN and that works correctly. > > Patch needs to go in current 4.11, it is safe but not necessary in older > kernels. > > Signed-off-by: Stephen Hemminger > Reviewed-by: K. Y. Srinivasan > Reviewed-by: Christoph Hellwig > Signed-off-by: Martin K. Petersen > > -Original Message- > From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] > Sent: Monday, March 27, 2017 1:22 PM > To: Long Li > Cc: KY Srinivasan ; Martin K. Petersen > ; Haiyang Zhang ; Stephen > Hemminger ; j...@linux.vnet.ibm.com; > de...@linuxdriverproject.org; linux-scsi ; LKML > ; sta...@vger.kernel.org; Greg KH > > Subject: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] > scsi: storvsc: properly set residual data length on errors > > Hi Long Li, > > A kernel bug report was opened against Ubuntu [0]. After a kernel > bisect, it was found that reverting the following commit resolved this bug: > > commit 40630f462824ee24bc00d692865c86c3828094e0 > Author: Long Li > Date: Wed Dec 14 18:46:03 2016 -0800 > > scsi: storvsc: properly set residual data length on errors > > > The regression was introduced in mainline as of v4.11-rc1. It was also > cc'd to stable and has landed in v3.12.y, v4.4.y, v4.9.y and v4.10.y. > > > This regression seems pretty severe since it's preventing virtual > machines from booting. It's affecting a couple of users so far. I was > hoping to get your feedback, since you are the patch author. Do you > think gathering any additional data will help diagnose this issue, or > would it be best to submit a revert request? > > > Thanks, > > Joe > > > [0] http://pad.lv/1674635 > > Hi Stephen, Thanks again for pointing out commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f. It does indeed fix the bug. I noticed the commit was not cc'd to stable. Would it be possible to do that? Thanks, Joe
Re: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
On 03/27/2017 06:14 PM, Stephen Hemminger wrote: > Are you sure the real problem is not the one fixed by this commit? > > commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f > Author: Stephen Hemminger > Date: Tue Mar 7 09:15:53 2017 -0800 > > scsi: storvsc: Workaround for virtual DVD SCSI version > > Hyper-V host emulation of SCSI for virtual DVD device reports SCSI > version 0 (UNKNOWN) but is still capable of supporting REPORTLUN. > > Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11 > successfully with virtual DVD ROM device. What happens is that the SCSI > scan process falls back to doing sequential probing by INQUIRY. But the > storvsc driver has a previous workaround that masks/blocks all errors > reports from INQUIRY (or MODE_SENSE) commands. This workaround causes > the scan to then populate a full set of bogus LUN's on the target and > then sends kernel spinning off into a death spiral doing block reads on > the non-existent LUNs. > > By setting the correct blacklist flags, the target with the DVD device > is scanned with REPORTLUN and that works correctly. > > Patch needs to go in current 4.11, it is safe but not necessary in older > kernels. > > Signed-off-by: Stephen Hemminger > Reviewed-by: K. Y. Srinivasan > Reviewed-by: Christoph Hellwig > Signed-off-by: Martin K. Petersen > > -Original Message- > From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] > Sent: Monday, March 27, 2017 1:22 PM > To: Long Li > Cc: KY Srinivasan ; Martin K. Petersen > ; Haiyang Zhang ; Stephen > Hemminger ; j...@linux.vnet.ibm.com; > de...@linuxdriverproject.org; linux-scsi ; LKML > ; sta...@vger.kernel.org; Greg KH > > Subject: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] > scsi: storvsc: properly set residual data length on errors > > Hi Long Li, > > A kernel bug report was opened against Ubuntu [0]. After a kernel > bisect, it was found that reverting the following commit resolved this bug: > > commit 40630f462824ee24bc00d692865c86c3828094e0 > Author: Long Li > Date: Wed Dec 14 18:46:03 2016 -0800 > > scsi: storvsc: properly set residual data length on errors > > > The regression was introduced in mainline as of v4.11-rc1. It was also > cc'd to stable and has landed in v3.12.y, v4.4.y, v4.9.y and v4.10.y. > > > This regression seems pretty severe since it's preventing virtual > machines from booting. It's affecting a couple of users so far. I was > hoping to get your feedback, since you are the patch author. Do you > think gathering any additional data will help diagnose this issue, or > would it be best to submit a revert request? > > > Thanks, > > Joe > > > [0] http://pad.lv/1674635 > > Hi Stephen, Thanks again for pointing out commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f. It does indeed fix the bug. I noticed the commit was not cc'd to stable. Would it be possible to do that? Thanks, Joe
Re: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
On 03/27/2017 06:14 PM, Stephen Hemminger wrote: > Are you sure the real problem is not the one fixed by this commit? > > commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f > Author: Stephen Hemminger > Date: Tue Mar 7 09:15:53 2017 -0800 > > scsi: storvsc: Workaround for virtual DVD SCSI version > > Hyper-V host emulation of SCSI for virtual DVD device reports SCSI > version 0 (UNKNOWN) but is still capable of supporting REPORTLUN. > > Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11 > successfully with virtual DVD ROM device. What happens is that the SCSI > scan process falls back to doing sequential probing by INQUIRY. But the > storvsc driver has a previous workaround that masks/blocks all errors > reports from INQUIRY (or MODE_SENSE) commands. This workaround causes > the scan to then populate a full set of bogus LUN's on the target and > then sends kernel spinning off into a death spiral doing block reads on > the non-existent LUNs. > > By setting the correct blacklist flags, the target with the DVD device > is scanned with REPORTLUN and that works correctly. > > Patch needs to go in current 4.11, it is safe but not necessary in older > kernels. > > Signed-off-by: Stephen Hemminger > Reviewed-by: K. Y. Srinivasan > Reviewed-by: Christoph Hellwig > Signed-off-by: Martin K. Petersen > > -Original Message- > From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] > Sent: Monday, March 27, 2017 1:22 PM > To: Long Li > Cc: KY Srinivasan ; Martin K. Petersen > ; Haiyang Zhang ; Stephen > Hemminger ; j...@linux.vnet.ibm.com; > de...@linuxdriverproject.org; linux-scsi ; LKML > ; sta...@vger.kernel.org; Greg KH > > Subject: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] > scsi: storvsc: properly set residual data length on errors > > Hi Long Li, > > A kernel bug report was opened against Ubuntu [0]. After a kernel > bisect, it was found that reverting the following commit resolved this bug: > > commit 40630f462824ee24bc00d692865c86c3828094e0 > Author: Long Li > Date: Wed Dec 14 18:46:03 2016 -0800 > > scsi: storvsc: properly set residual data length on errors > > > The regression was introduced in mainline as of v4.11-rc1. It was also > cc'd to stable and has landed in v3.12.y, v4.4.y, v4.9.y and v4.10.y. > > > This regression seems pretty severe since it's preventing virtual > machines from booting. It's affecting a couple of users so far. I was > hoping to get your feedback, since you are the patch author. Do you > think gathering any additional data will help diagnose this issue, or > would it be best to submit a revert request? > > > Thanks, > > Joe > > > [0] http://pad.lv/1674635 > > Thanks for the pointer, Stephen. I'll have this patch tested and respond with the results. Joe
RE: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
Are you sure the real problem is not the one fixed by this commit? commit f1c635b439a5c01776fe3a25b1e2dc546ea82e6f Author: Stephen Hemminger Date: Tue Mar 7 09:15:53 2017 -0800 scsi: storvsc: Workaround for virtual DVD SCSI version Hyper-V host emulation of SCSI for virtual DVD device reports SCSI version 0 (UNKNOWN) but is still capable of supporting REPORTLUN. Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11 successfully with virtual DVD ROM device. What happens is that the SCSI scan process falls back to doing sequential probing by INQUIRY. But the storvsc driver has a previous workaround that masks/blocks all errors reports from INQUIRY (or MODE_SENSE) commands. This workaround causes the scan to then populate a full set of bogus LUN's on the target and then sends kernel spinning off into a death spiral doing block reads on the non-existent LUNs. By setting the correct blacklist flags, the target with the DVD device is scanned with REPORTLUN and that works correctly. Patch needs to go in current 4.11, it is safe but not necessary in older kernels. Signed-off-by: Stephen Hemminger Reviewed-by: K. Y. Srinivasan Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen -Original Message- From: Joseph Salisbury [mailto:joseph.salisb...@canonical.com] Sent: Monday, March 27, 2017 1:22 PM To: Long Li Cc: KY Srinivasan ; Martin K. Petersen ; Haiyang Zhang ; Stephen Hemminger ; j...@linux.vnet.ibm.com; de...@linuxdriverproject.org; linux-scsi ; LKML ; sta...@vger.kernel.org; Greg KH Subject: [REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors Hi Long Li, A kernel bug report was opened against Ubuntu [0]. After a kernel bisect, it was found that reverting the following commit resolved this bug: commit 40630f462824ee24bc00d692865c86c3828094e0 Author: Long Li Date: Wed Dec 14 18:46:03 2016 -0800 scsi: storvsc: properly set residual data length on errors The regression was introduced in mainline as of v4.11-rc1. It was also cc'd to stable and has landed in v3.12.y, v4.4.y, v4.9.y and v4.10.y. This regression seems pretty severe since it's preventing virtual machines from booting. It's affecting a couple of users so far. I was hoping to get your feedback, since you are the patch author. Do you think gathering any additional data will help diagnose this issue, or would it be best to submit a revert request? Thanks, Joe [0] http://pad.lv/1674635
[REGRESSION][Stable][v3.12.y][v4.4.y][v4.9.y][v4.10.y][v4.11-rc1] scsi: storvsc: properly set residual data length on errors
Hi Long Li, A kernel bug report was opened against Ubuntu [0]. After a kernel bisect, it was found that reverting the following commit resolved this bug: commit 40630f462824ee24bc00d692865c86c3828094e0 Author: Long Li Date: Wed Dec 14 18:46:03 2016 -0800 scsi: storvsc: properly set residual data length on errors The regression was introduced in mainline as of v4.11-rc1. It was also cc'd to stable and has landed in v3.12.y, v4.4.y, v4.9.y and v4.10.y. This regression seems pretty severe since it's preventing virtual machines from booting. It's affecting a couple of users so far. I was hoping to get your feedback, since you are the patch author. Do you think gathering any additional data will help diagnose this issue, or would it be best to submit a revert request? Thanks, Joe [0] http://pad.lv/1674635