From 11f5d5939699b910cf4286a55c994a1574123edf Mon Sep 17 00:00:00 2001
From: Dietmar Maurer <dietmar@proxmox.com>
Date: Sat, 27 Mar 2021 15:36:35 +0100
Subject: [PATCH] tape: page-align BlockHeader so that we can use it with SG_IO

---
 src/tape/file_formats/mod.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tape/file_formats/mod.rs b/src/tape/file_formats/mod.rs
index e94818b2..bf41b8a4 100644
--- a/src/tape/file_formats/mod.rs
+++ b/src/tape/file_formats/mod.rs
@@ -288,9 +288,12 @@ impl BlockHeader {
     pub fn new() -> Box<Self> {
         use std::alloc::{alloc_zeroed, Layout};
 
+        // align to PAGESIZE, so that we can use it with SG_IO
+        let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) } as usize;
+
         let mut buffer = unsafe {
             let ptr = alloc_zeroed(
-                Layout::from_size_align(Self::SIZE, std::mem::align_of::<u64>())
+                 Layout::from_size_align(Self::SIZE, page_size)
                     .unwrap(),
             );
             Box::from_raw(