block: access copy_on_read with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-2-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
diff --git a/block.c b/block.c
index fa1d06d..af6366b 100644
--- a/block.c
+++ b/block.c
@@ -1300,7 +1300,9 @@
goto fail_opts;
}
- assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
+ /* bdrv_new() and bdrv_close() make it so */
+ assert(atomic_read(&bs->copy_on_read) == 0);
+
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
if (!bs->read_only) {
bdrv_enable_copy_on_read(bs);
@@ -3063,7 +3065,7 @@
g_free(bs->opaque);
bs->opaque = NULL;
- bs->copy_on_read = 0;
+ atomic_set(&bs->copy_on_read, 0);
bs->backing_file[0] = '\0';
bs->backing_format[0] = '\0';
bs->total_sectors = 0;