file-posix: Handle EINVAL fallocate return value

The `detect-zeroes=unmap` option may issue unaligned
`FALLOC_FL_PUNCH_HOLE` requests, raw block devices can (and will) return
`EINVAL`, qemu should then write the zeroes to the blockdev instead of
issuing an `IO_ERROR`.

The problem can be reprodced like this:

$ qemu-io -c 'write -P 0 42 1234' --image-opts driver=host_device,filename=/dev/loop0,detect-zeroes=unmap
write failed: Invalid argument

Signed-off-by: Antoine Damhet <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>

Author: xdbob

block/file-posix.c

@@ -1698,7 +1698,11 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
 #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
     int ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
                            aiocb->aio_offset, aiocb->aio_nbytes);
-    if (ret != -ENOTSUP) {
+    switch (ret) {
+    case -ENOTSUP:
+    case -EINVAL:
+        break;
+    default:
         return ret;
     }
 #endif