diff --git a/fs/vfs/fs_ioctl.c b/fs/vfs/fs_ioctl.c
index dfd2b038011af..97e098132f292 100644
--- a/fs/vfs/fs_ioctl.c
+++ b/fs/vfs/fs_ioctl.c
@@ -139,6 +139,22 @@ static int file_vioctl(FAR struct file *filep, int req, va_list ap)
                 *(FAR blksize_t *)(uintptr_t)arg = geo.geo_sectorsize;
               }
           }
+        break;
+
+      case BIOC_BLKGETSIZE:
+        if (ret == -ENOTTY && inode->u.i_ops != NULL &&
+            inode->u.i_ops->ioctl != NULL)
+          {
+            struct geometry geo;
+            ret = inode->u.i_ops->ioctl(filep, BIOC_GEOMETRY,
+                                        (unsigned long)(uintptr_t)&geo);
+            if (ret >= 0)
+              {
+                *(FAR blksize_t *)(uintptr_t)arg = geo.geo_nsectors;
+              }
+          }
+        break;
+
 #endif
     }
 
diff --git a/include/nuttx/fs/ioctl.h b/include/nuttx/fs/ioctl.h
index 1ccf37cf232bf..dd70cc634bf43 100644
--- a/include/nuttx/fs/ioctl.h
+++ b/include/nuttx/fs/ioctl.h
@@ -305,6 +305,12 @@
                                            *      to return sector size.
                                            * OUT: Data return in user-provided
                                            *      buffer. */
+#define BIOC_BLKGETSIZE _BIOC(0x0010)     /* Get block device sector numbers.
+                                           * IN:  Pointer to writable instance
+                                           *      of sector numbers in which
+                                           *      to return sector numbers.
+                                           * OUT: Data return in user-provided
+                                           *      buffer. */
 
 /* NuttX MTD driver ioctl definitions ***************************************/
 
diff --git a/include/sys/mount.h b/include/sys/mount.h
index c23e9246f6e53..7796dc3e7ac0e 100644
--- a/include/sys/mount.h
+++ b/include/sys/mount.h
@@ -32,7 +32,8 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#define BLKSSZGET BIOC_BLKSSZGET
+#define BLKSSZGET  BIOC_BLKSSZGET
+#define BLKGETSIZE BIOC_BLKGETSIZE
 
 /* Mount flags */