[PATCH 4.6 046/203] sd: Fix rw_max for devices that report an optimal xfer size
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-07-25 22:19:49
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4.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin K. Petersen <martin.petersen@oracle.com>
commit 6b7e9cde49691e04314342b7dce90c67ad567fcc upstream.
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")
Reported-by: Fam Zheng <redacted>
Reviewed-by: Bart Van Assche <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Andrew Patterson <redacted>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/sd.c | 8 ++++----
drivers/scsi/sd.h | 5 +++++
2 files changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c@@ -2862,10 +2862,10 @@ static int sd_revalidate_disk(struct gen 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 */ --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h
@@ -151,6 +151,11 @@ static inline sector_t logical_to_sector 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: