[src/trunk]: src/sys/miscfs/specfs Add a diagnostic test for buffers written ...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c221f22f796c
branches:  trunk
changeset: 822102:c221f22f796c
user:      hannken <hannken%NetBSD.org@localhost>
date:      Wed Mar 01 10:46:05 2017 +0000

description:
Add a diagnostic test for buffers written to a block device holding
a read-only mounted file system.

This will become a KASSERT in the near future.

diffstat:

 sys/miscfs/specfs/spec_vnops.c |  14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diffs (35 lines):

diff -r 507fe690949d -r c221f22f796c sys/miscfs/specfs/spec_vnops.c
--- a/sys/miscfs/specfs/spec_vnops.c    Wed Mar 01 10:45:24 2017 +0000
+++ b/sys/miscfs/specfs/spec_vnops.c    Wed Mar 01 10:46:05 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: spec_vnops.c,v 1.168 2017/01/02 10:33:28 hannken Exp $ */
+/*     $NetBSD: spec_vnops.c,v 1.169 2017/03/01 10:46:05 hannken Exp $ */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -58,7 +58,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.168 2017/01/02 10:33:28 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.169 2017/03/01 10:46:05 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/proc.h>
@@ -1053,6 +1053,16 @@
        bp->b_dev = dev;
 
        if (!(bp->b_flags & B_READ)) {
+#ifdef DIAGNOSTIC
+               if (bp->b_vp && bp->b_vp->v_type == VBLK) {
+                       struct mount *mp = spec_node_getmountedfs(bp->b_vp);
+
+                       if (mp && (mp->mnt_flag & MNT_RDONLY)) {
+                               printf("%s blk %"PRId64" written while ro!\n",
+                                   mp->mnt_stat.f_mntonname, bp->b_blkno);
+                       }
+               }
+#endif /* DIAGNOSTIC */
                error = fscow_run(bp, false);
                if (error)
                        goto out;