tcm_vhost: Use iov_num_pages to calculate sgl_count

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c
index defc28595656..62058d7a562f 100644
--- a/drivers/vhost/tcm_vhost.c
+++ b/drivers/vhost/tcm_vhost.c
@@ -479,11 +479,9 @@ static int vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *tv_cmd,
          * Find out how long sglist needs to be
          */
         sgl_count = 0;
-        for (i = 0; i < niov; i++) {
-                sgl_count += (((uintptr_t)iov[i].iov_base + iov[i].iov_len +
-                                PAGE_SIZE - 1) >> PAGE_SHIFT) -
-                                ((uintptr_t)iov[i].iov_base >> PAGE_SHIFT);
-        }
+        for (i = 0; i < niov; i++)
+                sgl_count += iov_num_pages(&iov[i]);
+
         /* TODO overflow checking */
 
         sg = kmalloc(sizeof(tv_cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);