virtmgr: disable disk file locking in crosvm
crosvm calls `man 2 flock` on disk image files. It used to only call it
on the "root" image, but now it calls it on all the nested images, e.g.
the "component" files in a composite disk image.
That isn't necessarily a bad thing, but the SELinux policies don't allow
it. For example, some of the disk images used by Microdroid are labelled
with the very generic "system_file" context. We should consider changing
the policies, but, in meantime, disable locking isn't a big deal.
Generally the files are either read-only at the FS level (and so the
locking is mostly redundant) or are generated per VM images (and so no
conflict is likely).
Bug: 364645148, 330911976
Test: launch microdroid
Change-Id: I5d64ee343d56620df4389c57dbbb99a57e2c3c8c
diff --git a/android/virtmgr/src/crosvm.rs b/android/virtmgr/src/crosvm.rs
index 5886535..0f41932 100644
--- a/android/virtmgr/src/crosvm.rs
+++ b/android/virtmgr/src/crosvm.rs
@@ -1045,8 +1045,9 @@
}
for disk in config.disks {
+ // Disk file locking is disabled because of missing SELinux policies.
command.arg("--block").arg(format!(
- "path={},ro={}",
+ "path={},ro={},lock=false",
add_preserved_fd(&mut preserved_fds, disk.image),
!disk.writable,
));