[PATCH v2] xen-blkfront: Use the bitmap API when applicable

[Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>]

Use 'bitmap_zalloc()' to simplify code, improve the semantic and avoid some
open-coded arithmetic in allocator arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.

Use 'bitmap_copy()' to avoid an explicit 'memcpy()'

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
v1 --> v2: change another kfree into bitmap_free
---
 drivers/block/xen-blkfront.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 700c765a759a..69cf13608ce0 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -442,22 +442,20 @@ static int xlbd_reserve_minors(unsigned int minor, 
unsigned int nr)
        if (end > nr_minors) {
                unsigned long *bitmap, *old;
 
-               bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
-                                GFP_KERNEL);
+               bitmap = bitmap_zalloc(end, GFP_KERNEL);
                if (bitmap == NULL)
                        return -ENOMEM;
 
                spin_lock(&minor_lock);
                if (end > nr_minors) {
                        old = minors;
-                       memcpy(bitmap, minors,
-                              BITS_TO_LONGS(nr_minors) * sizeof(*bitmap));
+                       bitmap_copy(bitmap, minors, nr_minors);
                        minors = bitmap;
                        nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG;
                } else
                        old = bitmap;
                spin_unlock(&minor_lock);
-               kfree(old);
+               bitmap_free(old);
        }
 
        spin_lock(&minor_lock);
@@ -2610,7 +2608,7 @@ static void __exit xlblk_exit(void)
 
        xenbus_unregister_driver(&blkfront_driver);
        unregister_blkdev(XENVBD_MAJOR, DEV_NAME);
-       kfree(minors);
+       bitmap_free(minors);
 }
 module_exit(xlblk_exit);
 
-- 
2.30.2