sd: Fix rw_max for devices that report an optimal xfer size

backported from upstream kernel

diff --git a/Makefile b/Makefile
index e281e7acadbd6c113556c252d0a69c7a911afbac..8c724fee5c5b9c9be44e7aeccfa355b052d18c50 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -266,6 +266,8 @@ ${KERNEL_SRC}/README ${KERNEL_CFG_ORG}: ${KERNELSRCTAR}
        cd ${KERNEL_SRC}; patch -p1 < ../watchdog_implement-mei-iamt-driver.patch
        cd ${KERNEL_SRC}; patch -p1 < ../mei_drop-watchdog-code.patch
        cd ${KERNEL_SRC}; patch -p1 < ../mei_bus-whitelist-watchdog-client.patch
        cd ${KERNEL_SRC}; patch -p1 < ../watchdog_implement-mei-iamt-driver.patch
        cd ${KERNEL_SRC}; patch -p1 < ../mei_drop-watchdog-code.patch
        cd ${KERNEL_SRC}; patch -p1 < ../mei_bus-whitelist-watchdog-client.patch

+       #sd: Fix rw_max for devices that report an optimal xfer size
+       cd ${KERNEL_SRC}; patch -p1 < ../sd-fix-rw_max.patch

        sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
        touch $@
 
        sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
        touch $@
 

diff --git a/sd-fix-rw_max.patch b/sd-fix-rw_max.patch
new file mode 100644 (file)
index 0000000..e0752ee
--- /dev/null
+++ b/sd-fix-rw_max.patch
@@ -0,0 +1,60 @@
+From 6b7e9cde49691e04314342b7dce90c67ad567fcc Mon Sep 17 00:00:00 2001
+From: "Martin K. Petersen" <martin.petersen@oracle.com>
+Date: Thu, 12 May 2016 22:17:34 -0400
+Subject: sd: Fix rw_max for devices that report an optimal xfer size
+
+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>
+Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
+Reviewed-by: Christoph Hellwig <hch@lst.de>
+Tested-by: Andrew Patterson <andrew.patterson@hpe.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 f459dff..60bff78 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_CACHE_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 654630b..765a6f1 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:
+-- 
+cgit v0.12
+