From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Fri, 29 Nov 2024 13:37:29 +0000 (+0100)
Subject: sandbox: Bind mount on top of symlink if possible
X-Git-Tag: v25~132
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51704dd86fa170317d6b2aa78907b5d30516ab33;p=thirdparty%2Fmkosi.git

sandbox: Bind mount on top of symlink if possible

Instead of mounting on top of the resolved symlink, let's just mount
directly on top of the symlink if we can.

Fixes #3247
---

diff --git a/mkosi/sandbox.py b/mkosi/sandbox.py
index 20fca27aa..be1a0370f 100755
--- a/mkosi/sandbox.py
+++ b/mkosi/sandbox.py
@@ -459,11 +459,17 @@ class BindOperation(FSOperation):
 
     def execute(self, oldroot: str, newroot: str) -> None:
         src = chase(oldroot, self.src)
-        dst = chase(newroot, self.dst)
 
         if not os.path.exists(src) and not self.required:
             return
 
+        # If we're mounting a file on top of a symlink, mount directly on top of the symlink instead of
+        # resolving it.
+        dst = joinpath(newroot, self.dst)
+        if not os.path.isdir(src) and os.path.islink(dst):
+            return mount_rbind(src, dst, attrs=MOUNT_ATTR_RDONLY if self.readonly else 0)
+
+        dst = chase(newroot, self.dst)
         if not os.path.exists(dst):
             isfile = os.path.isfile(src)