[src/trunk]: src/sys/kern if DIAGNOSTIC, check the size of the transaction in...

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

details:   https://anonhg.NetBSD.org/src/rev/1e9f35b19e44
branches:  trunk
changeset: 762056:1e9f35b19e44
user:      bouyer <bouyer%NetBSD.org@localhost>
date:      Mon Feb 14 16:05:11 2011 +0000

description:
if DIAGNOSTIC, check the size of the transaction in wapbl_end().
Hopefully this will point us to the place which generaed the large
transaction, before an asynchronous panic() in wabl_end()

diffstat:

 sys/kern/vfs_wapbl.c |  16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diffs (37 lines):

diff -r ae379a0cd8d6 -r 1e9f35b19e44 sys/kern/vfs_wapbl.c
--- a/sys/kern/vfs_wapbl.c      Mon Feb 14 15:15:40 2011 +0000
+++ b/sys/kern/vfs_wapbl.c      Mon Feb 14 16:05:11 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_wapbl.c,v 1.39 2011/01/08 20:37:05 christos Exp $  */
+/*     $NetBSD: vfs_wapbl.c,v 1.40 2011/02/14 16:05:11 bouyer Exp $    */
 
 /*-
  * Copyright (c) 2003, 2008, 2009 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
 #define WAPBL_INTERNAL
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.39 2011/01/08 20:37:05 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_wapbl.c,v 1.40 2011/02/14 16:05:11 bouyer Exp $");
 
 #include <sys/param.h>
 #include <sys/bitops.h>
@@ -901,6 +901,18 @@
              wl->wl_bufbytes, wl->wl_bcount));
 #endif
 
+#ifdef DIAGNOSTIC
+       size_t flushsize = wapbl_transaction_len(wl);
+       if (flushsize > (wl->wl_circ_size - wl->wl_reserved_bytes)) {
+               /*
+                * XXX this could be handled more gracefully, perhaps place
+                * only a partial transaction in the log and allow the
+                * remaining to flush without the protection of the journal.
+                */
+               panic("wapbl_end: current transaction too big to flush\n");
+       }
+#endif
+
        mutex_enter(&wl->wl_mtx);
        KASSERT(wl->wl_lock_count > 0);
        wl->wl_lock_count--;