From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BFDEC3A589 for ; Tue, 20 Aug 2019 16:29:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E484A22DD6 for ; Tue, 20 Aug 2019 16:29:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VNtmQN9j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729937AbfHTQ26 (ORCPT ); Tue, 20 Aug 2019 12:28:58 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58856 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726981AbfHTQ25 (ORCPT ); Tue, 20 Aug 2019 12:28:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=HsG/F7Ogp9T1fgqikVwPMPM6wzzJxLkwajIeWfgFhs0=; b=VNtmQN9j07SQ46nnjhC0A8lTn F69eYG3Lfxt+UvCsXGRS5wNwHK1zbLiDIo58EKAFtJg9XTEw2d2Oon69C4+FPws5ixhpBL1keqcn4 XyV1r7ihK3pxWJJNfvM2Uc40myT96KXuJZqVcVTbWJANBZQclRu+PNLfaj1Zcr4WL08c8VDrvMyWy mldKUQ4p76bvlW1yvw00YjEoE5TM6lNrcnrrKjRsfIg4lbpLv15caps8ZKTe5OQSUDCgjPQ9TK0Pa PNBULtASBuCu8mIiXPSKSrLAPx5e/xwKenYXimha8Rb/Lm1sdFtz4JHpf70c4HjmmWh4CWe5vWI6/ OHKASCizg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1i070C-0006uR-IM; Tue, 20 Aug 2019 16:28:56 +0000 Date: Tue, 20 Aug 2019 09:28:56 -0700 From: Matthew Wilcox To: Deepa Dinamani Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, y2038@lists.linaro.org, arnd@arndb.de Subject: Re: [PATCH v8 08/20] adfs: Fill in max and min timestamps in sb Message-ID: <20190820162856.GA21274@bombadil.infradead.org> References: <20190818165817.32634-1-deepa.kernel@gmail.com> <20190818165817.32634-9-deepa.kernel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190818165817.32634-9-deepa.kernel@gmail.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Aug 18, 2019 at 09:58:05AM -0700, Deepa Dinamani wrote: > Note that the min timestamp is assumed to be > 01 Jan 1970 00:00:00 (Unix epoch). This is consistent > with the way we convert timestamps in adfs_adfs2unix_time(). That's not actually correct. RISC OS timestamps are centiseconds since 1900 stored in 5 bytes. > Signed-off-by: Deepa Dinamani > --- > fs/adfs/adfs.h | 13 +++++++++++++ > fs/adfs/inode.c | 8 ++------ > fs/adfs/super.c | 2 ++ > 3 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/fs/adfs/adfs.h b/fs/adfs/adfs.h > index b7e844d2f321..dca8b23aa43f 100644 > --- a/fs/adfs/adfs.h > +++ b/fs/adfs/adfs.h > @@ -3,6 +3,19 @@ > #include > #include > > +/* > + * 01 Jan 1970 00:00:00 (Unix epoch) as seconds since > + * 01 Jan 1900 00:00:00 (RISC OS epoch) > + */ > +#define RISC_OS_EPOCH_DELTA 2208988800LL > + > +/* > + * Convert 40 bit centi seconds to seconds > + * since 01 Jan 1900 00:00:00 (RISC OS epoch) > + * The result is 2248-06-03 06:57:57 GMT > + */ > +#define ADFS_MAX_TIMESTAMP ((0xFFFFFFFFFFLL / 100) - RISC_OS_EPOCH_DELTA) > + > /* Internal data structures for ADFS */ > > #define ADFS_FREE_FRAG 0 > diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c > index 124de75413a5..41eca1c451dc 100644 > --- a/fs/adfs/inode.c > +++ b/fs/adfs/inode.c > @@ -167,11 +167,7 @@ static void > adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode) > { > unsigned int high, low; > - /* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since > - * 01 Jan 1900 00:00:00 (RISC OS epoch) > - */ > - static const s64 nsec_unix_epoch_diff_risc_os_epoch = > - 2208988800000000000LL; > + static const s64 nsec_unix_epoch_diff_risc_os_epoch = RISC_OS_EPOCH_DELTA * NSEC_PER_SEC; > s64 nsec; > > if (!adfs_inode_is_stamped(inode)) > @@ -216,7 +212,7 @@ adfs_unix2adfs_time(struct inode *inode, unsigned int secs) > if (adfs_inode_is_stamped(inode)) { > /* convert 32-bit seconds to 40-bit centi-seconds */ > low = (secs & 255) * 100; > - high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; > + high = (secs / 256) * 100 + (low >> 8) + (RISC_OS_EPOCH_DELTA*100/256); > > ADFS_I(inode)->loadaddr = (high >> 24) | > (ADFS_I(inode)->loadaddr & ~0xff); > diff --git a/fs/adfs/super.c b/fs/adfs/super.c > index 65b04ebb51c3..f074fe7d7158 100644 > --- a/fs/adfs/super.c > +++ b/fs/adfs/super.c > @@ -463,6 +463,8 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent) > asb->s_map_size = dr->nzones | (dr->nzones_high << 8); > asb->s_map2blk = dr->log2bpmb - dr->log2secsize; > asb->s_log2sharesize = dr->log2sharesize; > + sb->s_time_min = 0; > + sb->s_time_max = ADFS_MAX_TIMESTAMP; > > asb->s_map = adfs_read_map(sb, dr); > if (IS_ERR(asb->s_map)) { > -- > 2.17.1 >