include: move qemu_msync() to osdep

The implementation depends on the OS. (and longer-term goal is to move
cutils to a common subproject)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-21-marcandre.lureau@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 14b6b65a5f..bf4f75dcde 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -642,6 +642,19 @@ static inline void qemu_reset_optind(void)
 }
 
 /**
+ * Sync changes made to the memory mapped file back to the backing
+ * storage. For POSIX compliant systems this will fallback
+ * to regular msync call. Otherwise it will trigger whole file sync
+ * (including the metadata case there is no support to skip that otherwise)
+ *
+ * @addr   - start of the memory area to be synced
+ * @length - length of the are to be synced
+ * @fd     - file descriptor for the file to be synced
+ *           (mandatory only for POSIX non-compliant systems)
+ */
+int qemu_msync(void *addr, size_t length, int fd);
+
+/**
  * qemu_get_host_name:
  * @errp: Error object
  *