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authorMartin K. Petersen <martin.petersen@oracle.com>2015-06-23 12:13:59 -0400
committerJames Bottomley <JBottomley@Odin.com>2015-08-12 11:54:37 -0700
commit4f258a46346c03fa0bbb6199ffaf4e1f9f599660 (patch)
tree87f6203edaaa3e9156c5f1710427a1915195e98e
parent8f2777f53e3d5ad8ef2a176a4463a5c8e1a16431 (diff)
downloadlinux-4f258a46346c03fa0bbb6199ffaf4e1f9f599660.tar.bz2
sd: Fix maximum I/O size for BLOCK_PC requests
Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK LIMITS VPD. This had the unfortunate effect of also limiting the maximum size of non-filesystem requests sent to the device through sg/bsg. Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue limit directly. Also update the comment in blk_limits_max_hw_sectors() to clarify that max_hw_sectors defines the limit for the I/O controller only. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Brian King <brking@linux.vnet.ibm.com> Tested-by: Brian King <brking@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: James Bottomley <JBottomley@Odin.com>
-rw-r--r--block/blk-settings.c4
-rw-r--r--drivers/scsi/sd.c6
2 files changed, 5 insertions, 5 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 12600bfffca9..e0057d035200 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -241,8 +241,8 @@ EXPORT_SYMBOL(blk_queue_bounce_limit);
* Description:
* Enables a low level driver to set a hard upper limit,
* max_hw_sectors, on the size of requests. max_hw_sectors is set by
- * the device driver based upon the combined capabilities of I/O
- * controller and storage device.
+ * the device driver based upon the capabilities of the I/O
+ * controller.
*
* max_sectors is a soft limit imposed by the block layer for
* filesystem type requests. This value can be overridden on a
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3b2fcb4fada0..a20da8c25b4f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2770,9 +2770,9 @@ static int sd_revalidate_disk(struct gendisk *disk)
max_xfer = sdkp->max_xfer_blocks;
max_xfer <<= ilog2(sdp->sector_size) - 9;
- max_xfer = min_not_zero(queue_max_hw_sectors(sdkp->disk->queue),
- max_xfer);
- blk_queue_max_hw_sectors(sdkp->disk->queue, max_xfer);
+ sdkp->disk->queue->limits.max_sectors =
+ min_not_zero(queue_max_hw_sectors(sdkp->disk->queue), max_xfer);
+
set_capacity(disk, sdkp->capacity);
sd_config_write_same(sdkp);
kfree(buffer);