From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCH] UBIFS: fill f_fsid Date: Wed, 03 Sep 2008 12:44:33 +0300 Message-ID: <1220435073.4036.41.camel@sauron> References: <1220194366-12731-1-git-send-email-dedekind@infradead.org> <1220194366-12731-13-git-send-email-dedekind@infradead.org> <1220262187.2982.58.camel@pmac.infradead.org> Reply-To: dedekind@infradead.org Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Adrian Hunter To: David Woodhouse Return-path: Received: from smtp.nokia.com ([192.100.122.233]:35097 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751533AbYICJof (ORCPT ); Wed, 3 Sep 2008 05:44:35 -0400 In-Reply-To: <1220262187.2982.58.camel@pmac.infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, 2008-09-01 at 10:43 +0100, David Woodhouse wrote: > For btrfs I xor the first 64 bits with the second 64 bits, and put > _that_ into f_fsid. You're just putting the first 64 bits in and > ignoring the second 64 bits. Neither is really _better_ than the other; > you just alter the circumstances in which you get collisions. But I > suppose we might as well be consistent about how we do it? Like this? From: Artem Bityutskiy Date: Wed, 3 Sep 2008 14:16:42 +0300 Subject: [PATCH] UBIFS: amend f_fsid David Woodhouse suggested to be consistent with other FSes and xor the beginning and the end of the UUID. Signed-off-by: Artem Bityutskiy --- fs/ubifs/super.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index ab9b5cb..83fe0a5 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -370,6 +370,7 @@ static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct ubifs_info *c = dentry->d_sb->s_fs_info; unsigned long long free; + __le32 *uuid = (__le32 *)c->uuid; free = ubifs_get_free_space(c); dbg_gen("free space %lld bytes (%lld blocks)", @@ -386,8 +387,8 @@ static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_files = 0; buf->f_ffree = 0; buf->f_namelen = UBIFS_MAX_NLEN; - memcpy(&buf->f_fsid, c->uuid, sizeof(__kernel_fsid_t)); - + buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]); + buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]); return 0; } -- 1.5.4.1