* [PATCH] sd: Fix rw_max for devices that report an optimal xfer size
@ 2016-05-20 3:16 Martin K. Petersen
2016-05-23 15:58 ` Bart Van Assche
2016-06-01 7:52 ` Christoph Hellwig
0 siblings, 2 replies; 5+ messages in thread
From: Martin K. Petersen @ 2016-05-20 3:16 UTC (permalink / raw)
To: linux-scsi; +Cc: Martin K. Petersen, stable
For historic reasons, io_opt is in bytes and max_sectors in block layer
sectors. This interface inconsistency is error prone and should be
fixed. But for 4.4--4.7 let's make the unit difference explicit via a
wrapper function.
Fixes: d0eb20a863ba ("sd: Optimal I/O size is in bytes, not sectors")
Cc: stable@vger.kernel.org # 4.4+
Reported-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/sd.c | 8 ++++----
drivers/scsi/sd.h | 5 +++++
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f459dff30512..60bff78e9ead 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2867,10 +2867,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
if (sdkp->opt_xfer_blocks &&
sdkp->opt_xfer_blocks <= dev_max &&
sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
- sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_SIZE)
- rw_max = q->limits.io_opt =
- sdkp->opt_xfer_blocks * sdp->sector_size;
- else
+ logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) {
+ q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
+ rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
+ } else
rw_max = BLK_DEF_MAX_SECTORS;
/* Combine with controller limits */
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 654630bb7d0e..765a6f1ac1b7 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -151,6 +151,11 @@ static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blo
return blocks << (ilog2(sdev->sector_size) - 9);
}
+static inline unsigned int logical_to_bytes(struct scsi_device *sdev, sector_t blocks)
+{
+ return blocks * sdev->sector_size;
+}
+
/*
* A DIF-capable target device can be formatted with different
* protection schemes. Currently 0 through 3 are defined:
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] sd: Fix rw_max for devices that report an optimal xfer size
2016-05-20 3:16 [PATCH] sd: Fix rw_max for devices that report an optimal xfer size Martin K. Petersen
@ 2016-05-23 15:58 ` Bart Van Assche
2016-06-01 7:52 ` Christoph Hellwig
1 sibling, 0 replies; 5+ messages in thread
From: Bart Van Assche @ 2016-05-23 15:58 UTC (permalink / raw)
To: Martin K. Petersen; +Cc: linux-scsi
On 05/19/2016 08:16 PM, Martin K. Petersen wrote:
> For historic reasons, io_opt is in bytes and max_sectors in block layer
> sectors. This interface inconsistency is error prone and should be
> fixed. But for 4.4--4.7 let's make the unit difference explicit via a
> wrapper function.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] sd: Fix rw_max for devices that report an optimal xfer size
2016-05-20 3:16 [PATCH] sd: Fix rw_max for devices that report an optimal xfer size Martin K. Petersen
2016-05-23 15:58 ` Bart Van Assche
@ 2016-06-01 7:52 ` Christoph Hellwig
2016-06-01 21:57 ` Andrew Patterson
1 sibling, 1 reply; 5+ messages in thread
From: Christoph Hellwig @ 2016-06-01 7:52 UTC (permalink / raw)
To: Martin K. Petersen; +Cc: linux-scsi, stable
Looks fine,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] sd: Fix rw_max for devices that report an optimal xfer size
2016-06-01 7:52 ` Christoph Hellwig
@ 2016-06-01 21:57 ` Andrew Patterson
2016-06-04 1:11 ` Long Li
0 siblings, 1 reply; 5+ messages in thread
From: Andrew Patterson @ 2016-06-01 21:57 UTC (permalink / raw)
To: Christoph Hellwig, Martin K. Petersen; +Cc: linux-scsi, stable
On 06/01/2016 01:52 AM, Christoph Hellwig wrote:
> Looks fine,
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
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>
I tested this patch on a 3Par array (32K optimal transfer length) that has
issues without this patch. After applying this patch on a linux-stable
kernel, optimal_io_size is correctly reported as 32K.
Tested-by: Andrew Patterson <andrew.patterson@hpe.com>
--
Andrew Patterson
Hewlett-Packard Enterprise
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [PATCH] sd: Fix rw_max for devices that report an optimal xfer size
2016-06-01 21:57 ` Andrew Patterson
@ 2016-06-04 1:11 ` Long Li
0 siblings, 0 replies; 5+ messages in thread
From: Long Li @ 2016-06-04 1:11 UTC (permalink / raw)
To: Andrew Patterson, Christoph Hellwig, Martin K. Petersen
Cc: linux-scsi, stable
It tested well with hyper-v virtual disk.
Tested-by: Long Li <longli@microsoft.com>
> -----Original Message-----
> From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-
> owner@vger.kernel.org] On Behalf Of Andrew Patterson
> Sent: Wednesday, June 1, 2016 2:57 PM
> To: Christoph Hellwig <hch@infradead.org>; Martin K. Petersen
> <martin.petersen@oracle.com>
> Cc: linux-scsi@vger.kernel.org; stable@vger.kernel.org
> Subject: Re: [PATCH] sd: Fix rw_max for devices that report an optimal xfer
> size
>
> On 06/01/2016 01:52 AM, Christoph Hellwig wrote:
> > Looks fine,
> >
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> > in the body of a message to majordomo@vger.kernel.org More
> majordomo
> > info at
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> 47%
> > 7c1&sdata=cojfwxQ8%2bZLpkiT5mFlsclG6DDLBWPk8qNAg3crPtIc%3d
> >
>
> I tested this patch on a 3Par array (32K optimal transfer length) that has
> issues without this patch. After applying this patch on a linux-stable kernel,
> optimal_io_size is correctly reported as 32K.
>
> Tested-by: Andrew Patterson <andrew.patterson@hpe.com>
>
> --
> Andrew Patterson
> Hewlett-Packard Enterprise
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-06-04 1:11 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-20 3:16 [PATCH] sd: Fix rw_max for devices that report an optimal xfer size Martin K. Petersen
2016-05-23 15:58 ` Bart Van Assche
2016-06-01 7:52 ` Christoph Hellwig
2016-06-01 21:57 ` Andrew Patterson
2016-06-04 1:11 ` Long Li
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