diff -r 00055dc47347 sys/dev/fss.c
--- sys/dev/fss.c	Wed Mar 22 15:20:34 2023 +0100
+++ sys/dev/fss.c	Wed Mar 22 15:26:36 2023 +0100
@@ -1285,7 +1285,7 @@ fss_bs_thread(void *arg)
 
 			/* Not on backing store, read from device. */
 			nbp = getiobuf(NULL, true);
-			nbp->b_flags = B_READ;
+			nbp->b_flags = B_READ | (bp->b_flags & B_PHYS);
 			nbp->b_resid = nbp->b_bcount = bp->b_bcount;
 			nbp->b_bufsize = bp->b_bcount;
 			nbp->b_data = bp->b_data;