block: Add a wrapper for setting minimum request size without a queue

Introduce blk_limits_io_min() and make blk_queue_io_min() call it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 25 insertions, 7 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 8e86e2d2b147..1f7197434166 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -384,6 +384,29 @@ void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
 EXPORT_SYMBOL(blk_queue_alignment_offset);
 
 /**
+ * blk_limits_io_min - set minimum request size for a device
+ * @limits: the queue limits
+ * @min:  smallest I/O size in bytes
+ *
+ * Description:
+ *   Some devices have an internal block size bigger than the reported
+ *   hardware sector size.  This function can be used to signal the
+ *   smallest I/O the device can perform without incurring a performance
+ *   penalty.
+ */
+void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
+{
+        limits->io_min = min;
+
+        if (limits->io_min < limits->logical_block_size)
+                limits->io_min = limits->logical_block_size;
+
+        if (limits->io_min < limits->physical_block_size)
+                limits->io_min = limits->physical_block_size;
+}
+EXPORT_SYMBOL(blk_limits_io_min);
+
+/**
  * blk_queue_io_min - set minimum request size for the queue
  * @q:  the request queue for the device
  * @min:  smallest I/O size in bytes
@@ -396,13 +419,7 @@ EXPORT_SYMBOL(blk_queue_alignment_offset);
  */
 void blk_queue_io_min(struct request_queue *q, unsigned int min)
 {
-        q->limits.io_min = min;
-
-        if (q->limits.io_min < q->limits.logical_block_size)
-                q->limits.io_min = q->limits.logical_block_size;
-
-        if (q->limits.io_min < q->limits.physical_block_size)
-                q->limits.io_min = q->limits.physical_block_size;
+        blk_limits_io_min(&q->limits, min);
 }
 EXPORT_SYMBOL(blk_queue_io_min);
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e7cb5dbf6c26..69103e053c92 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -913,6 +913,7 @@ extern void blk_queue_logical_block_size(struct request_queue *, unsigned short)
 extern void blk_queue_physical_block_size(struct request_queue *, unsigned short);
 extern void blk_queue_alignment_offset(struct request_queue *q,
                                        unsigned int alignment);
+extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
 extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
 extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
 extern void blk_set_default_limits(struct queue_limits *lim);