From: Michael A Cassaniti <michael@cassaniti.id.au>
Date: Fri, 7 Oct 2022 06:14:39 +0000 (+1100)
Subject: Chunk partition insert using sendfile because sendfile has a maximum transfer size
X-Git-Tag: v14~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=022bbd35e0f40482478fd5ad2748c86aab699bb1;p=thirdparty%2Fmkosi.git

Chunk partition insert using sendfile because sendfile has a maximum transfer size
---

diff --git a/mkosi/__init__.py b/mkosi/__init__.py
index 1b468f398..9418aad17 100644
--- a/mkosi/__init__.py
+++ b/mkosi/__init__.py
@@ -3661,7 +3661,15 @@ def insert_partition(
 
             # Without this the entire blob will be read into memory which could exceed system memory
             with open(path, mode='wb') as path_fp:
-                os.sendfile(path_fp.fileno(), blob.fileno(), offset=0, count=blob_size)
+                # Chunk size for 32/64-bit systems
+                # Chunking required because sendfile under Linux has a maximum copy size
+                chunksize = 2 ** 30 if sys.maxsize < 2 ** 32 else 0x7ffff000
+                offset = 0
+                while True:
+                    sent = os.sendfile(path_fp.fileno(), blob.fileno(), offset=offset, count=chunksize)
+                    if not sent:
+                        break
+                    offset += sent
 
     return part