From owner-freebsd-current@FreeBSD.ORG  Thu Nov 16 21:24:21 2006
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: freebsd-current@FreeBSD.org
Delivered-To: freebsd-current@FreeBSD.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 8A6DF16A415;
	Thu, 16 Nov 2006 21:24:21 +0000 (UTC)
	(envelope-from jkim@FreeBSD.org)
Received: from anuket.mj.niksun.com (gwnew.niksun.com [65.115.46.162])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 0BD1343D7D;
	Thu, 16 Nov 2006 21:24:12 +0000 (GMT)
	(envelope-from jkim@FreeBSD.org)
Received: from niksun.com (anuket [10.70.0.5])
	by anuket.mj.niksun.com (8.13.1/8.13.1) with ESMTP id kAGLNajb058333;
	Thu, 16 Nov 2006 16:23:46 -0500 (EST)
	(envelope-from jkim@FreeBSD.org)
From: Jung-uk Kim <jkim@FreeBSD.org>
To: freebsd-current@FreeBSD.org
Date: Thu, 16 Nov 2006 16:23:07 -0500
User-Agent: KMail/1.6.2
References: <200611162005.kAGK58cB084521@ambrisko.com>
In-Reply-To: <200611162005.kAGK58cB084521@ambrisko.com>
MIME-Version: 1.0
Content-Disposition: inline
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-Id: <200611161623.10758.jkim@FreeBSD.org>
X-Virus-Scanned: ClamAV 0.88.6/2200/Thu Nov 16 09:10:16 2006 on
	anuket.mj.niksun.com
X-Virus-Status: Clean
Cc: freebsd-fs@FreeBSD.org, Pawel Jakub Dawidek <pjd@FreeBSD.org>
Subject: Re: ZFS patches for FreeBSD.
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 16 Nov 2006 21:24:21 -0000

On Thursday 16 November 2006 03:05 pm, Doug Ambrisko wrote:
> This is on i386:
>   one% grep memset zfs_20061117.patch
>   +       (void) memset(p, 0, n);
>   +       (void) memset(wp, 0, sizeof (*wp));
>   +       (void) memset(wp, 0, sizeof (*wp));
>   +zap_memset(void *a, int c, size_t n)
>   +       zap_memset(&l->l_phys->l_hdr, 0, sizeof (struct
> zap_leaf_header)); +       zap_memset(l->l_phys->l_hash, CHAIN_END,
> 2*ZAP_LEAF_HASH_NUMENTRIES(l)); +      
> zap_memset(l->l_phys->l_hash, CHAIN_END,
> 2*ZAP_LEAF_HASH_NUMENTRIES(l)); one%
>
>   In contrib/opensolaris/lib/libuutil/common/uu_alloc.c
>   +void *
>   +uu_zalloc(size_t n)
>   +{
>   +       void *p = malloc(n);
>   +
>   +       if (p == NULL) {
>   +               uu_set_error(UU_ERROR_SYSTEM);
>   +               return (NULL);
>   +       }
>   +
>   +       (void) memset(p, 0, n);
>   +
>   +       return (p);
>   +}
>   +
>
>   %nm dmu_objset.o | grep memset
>            U memset
>   %
>
> If I run it compile -E I see
>   static __inline void *
>   memset(void *b, int c, size_t len)
>   {
>    char *bb;
>
>    if (c == 0)
>     bzero(b, len);
>    else
>     for (bb = (char *)b; len--; )
>      *bb++ = c;
>    return (b);
>   }
>
> and nothing calling it unless it is what Max. is talking about.
> I don't see other stuff breaking.

It seems the memset() is not used in the kernel part.  However, there 
are at least three places, which does 'struct foo bar = { 0 }':

%grep '{ 0 }' zfs_20061117_sys.patch 
+       struct oscarg oa = { 0 };
+       struct snaparg sn = { 0 };
+       zfs_create_data_t cbdata = { 0 };

(Note: zfs_20061117_sys.patch is extracted from the original patch.)

The first two are from dmu_objset_create() and dmu_objset_snapshot() 
in sys/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c and that is 
what you saw.  The third one is from zfs_ioc_create() in 
sys/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c.

FYI...

Jung-uk Kim