Date: Thu, 21 Jan 2010 16:37:12 GMT From: Nikos Vassiliadis <nvass9573@gmx.com> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/143058: [patch] make mdconfig -o reserve default for malloc-backed memory disks Message-ID: <201001211637.o0LGbCNU033412@www.freebsd.org> Resent-Message-ID: <201001211640.o0LGe7dg080955@freefall.freebsd.org>
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>Number: 143058
>Category: misc
>Synopsis: [patch] make mdconfig -o reserve default for malloc-backed memory disks
>Confidential: no
>Severity: critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Jan 21 16:40:06 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator: Nikos Vassiliadis
>Release: 9.0-CURRENT
>Organization:
>Environment:
FreeBSD lab.localdomain 9.0-CURRENT FreeBSD 9.0-CURRENT #1: Fri Jan 8 12:01:55 EET 2010 root@lab.localdomain:/usr/obj/usr/src/sys/LAB i386
>Description:
Creating and filling a big malloc-backed memory disk is a way to panic the system. This could be easily avoided if the reseve option became the default for malloc disks.
>How-To-Repeat:
mdconfig -at malloc -s 200m
dd if=/dev/zero of=/dev/md0
>Fix:
The attached patch adds reserve to the defaults for malloc disks
Patch attached with submission follows:
Index: src/sbin/mdconfig/mdconfig.8
===================================================================
RCS file: /home/ncvs/src/sbin/mdconfig/mdconfig.8,v
retrieving revision 1.44
diff -u -r1.44 mdconfig.8
--- src/sbin/mdconfig/mdconfig.8 10 Jan 2009 17:17:18 -0000 1.44
+++ src/sbin/mdconfig/mdconfig.8 21 Jan 2010 16:12:10 -0000
@@ -91,8 +91,8 @@
.Xr malloc 9 .
This limits the size to the malloc bucket limit in the kernel.
If the
-.Fl o Cm reserve
-option is not set, creating and filling a large
+.Fl o Cm noreserve
+option is set, creating and filling a large
malloc-backed memory disk is a very easy way to
panic a system.
.It Cm vnode
Index: src/sbin/mdconfig/mdconfig.c
===================================================================
RCS file: /home/ncvs/src/sbin/mdconfig/mdconfig.c,v
retrieving revision 1.57
diff -u -r1.57 mdconfig.c
--- src/sbin/mdconfig/mdconfig.c 10 Jan 2009 17:17:18 -0000 1.57
+++ src/sbin/mdconfig/mdconfig.c 21 Jan 2010 16:12:10 -0000
@@ -115,7 +115,7 @@
usage();
if (!strcmp(optarg, "malloc")) {
mdio.md_type = MD_MALLOC;
- mdio.md_options = MD_AUTOUNIT | MD_COMPRESS;
+ mdio.md_options = MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE;
} else if (!strcmp(optarg, "preload")) {
mdio.md_type = MD_PRELOAD;
mdio.md_options = 0;
>Release-Note:
>Audit-Trail:
>Unformatted:
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