block: add zoned BlockDriver check to block layer

Putting zoned/non-zoned BlockDrivers on top of each other is not
allowed.

Signed-off-by: Sam Li <faithilikerun@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20230508045533.175575-6-faithilikerun@gmail.com
Message-id: 20230324090605.28361-6-faithilikerun@gmail.com
[Adjust commit message prefix as suggested by Philippe Mathieu-Daudé
<philmd@linaro.org> and clarify that the check is about zoned
BlockDrivers.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

block/file-posix.c

@@ -776,6 +776,18 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
             goto fail;
         }
     }
+#ifdef CONFIG_BLKZONED
+    /*
+     * The kernel page cache does not reliably work for writes to SWR zones
+     * of zoned block device because it can not guarantee the order of writes.
+     */
+    if ((bs->bl.zoned != BLK_Z_NONE) &&
+        (!(s->open_flags & O_DIRECT))) {
+        error_setg(errp, "The driver supports zoned devices, and it requires "
+                         "cache.direct=on, which was not specified.");
+        return -EINVAL; /* No host kernel page cache */
+    }
+#endif
 
     if (S_ISBLK(st.st_mode)) {
 #ifdef __linux__