| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <874jl88ed1.fsf@mail.parknet.co.jp>
Date: Wed, 09 Aug 2023 23:44:26 +0900
From: OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
To: Jeff Layton <jlayton@...nel.org>
Cc: Alexander Viro <viro@...iv.linux.org.uk>,
Christian Brauner <brauner@...nel.org>,
Eric Van Hensbergen <ericvh@...nel.org>,
Latchesar Ionkov <lucho@...kov.net>,
Dominique Martinet <asmadeus@...ewreck.org>,
Christian Schoenebeck <linux_oss@...debyte.com>,
David Howells <dhowells@...hat.com>,
Marc Dionne <marc.dionne@...istor.com>,
Chris Mason <clm@...com>, Josef Bacik <josef@...icpanda.com>,
David Sterba <dsterba@...e.com>, Xiubo Li <xiubli@...hat.com>,
Ilya Dryomov <idryomov@...il.com>,
Jan Harkes <jaharkes@...cmu.edu>, coda@...cmu.edu,
Tyler Hicks <code@...icks.com>, Gao Xiang <xiang@...nel.org>,
Chao Yu <chao@...nel.org>,
Yue Hu <huyue2@...jj8bn.sched.sma.tdnsstic1.cn>,
Jeffle Xu <jefflexu@...ux.alibaba.com>,
Namjae Jeon <linkinjeon@...nel.org>,
Sungjong Seo <sj1557.seo@...sung.com>,
Jan Kara <jack@...e.com>, "Theodore Ts'o" <tytso@....edu>,
Andreas Dilger <adilger.kernel@...ger.ca>,
Jaegeuk Kim <jaegeuk@...nel.org>,
Miklos Szeredi <miklos@...redi.hu>,
Bob Peterson <rpeterso@...hat.com>,
Andreas Gruenbacher <agruenba@...hat.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Tejun Heo <tj@...nel.org>,
Trond Myklebust <trond.myklebust@...merspace.com>,
Anna Schumaker <anna@...nel.org>,
Konstantin Komarov <almaz.alexandrovich@...agon-software.com>,
Mark Fasheh <mark@...heh.com>,
Joel Becker <jlbec@...lplan.org>,
Joseph Qi <joseph.qi@...ux.alibaba.com>,
Mike Marshall <hubcap@...ibond.com>,
Martin Brandenburg <martin@...ibond.com>,
Luis Chamberlain <mcgrof@...nel.org>,
Kees Cook <keescook@...omium.org>,
Iurii Zaikin <yzaikin@...gle.com>,
Steve French <sfrench@...ba.org>,
Paulo Alcantara <pc@...guebit.com>,
Ronnie Sahlberg <ronniesahlberg@...il.com>,
Shyam Prasad N <sprasad@...rosoft.com>,
Tom Talpey <tom@...pey.com>,
Sergey Senozhatsky <senozhatsky@...omium.org>,
Richard Weinberger <richard@....at>,
Hans de Goede <hdegoede@...hat.com>,
Hugh Dickins <hughd@...gle.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Amir Goldstein <amir73il@...il.com>,
"Darrick J. Wong" <djwong@...nel.org>,
Benjamin Coddington <bcodding@...hat.com>,
linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
v9fs@...ts.linux.dev, linux-afs@...ts.infradead.org,
linux-btrfs@...r.kernel.org, ceph-devel@...r.kernel.org,
codalist@...emann.coda.cs.cmu.edu, ecryptfs@...r.kernel.org,
linux-erofs@...ts.ozlabs.org, linux-ext4@...r.kernel.org,
linux-f2fs-devel@...ts.sourceforge.net, cluster-devel@...hat.com,
linux-nfs@...r.kernel.org, ntfs3@...ts.linux.dev,
ocfs2-devel@...ts.linux.dev, devel@...ts.orangefs.org,
linux-cifs@...r.kernel.org, samba-technical@...ts.samba.org,
linux-mtd@...ts.infradead.org, linux-mm@...ck.org,
linux-unionfs@...r.kernel.org, linux-xfs@...r.kernel.org
Subject: Re: [PATCH v7 05/13] fat: make fat_update_time get its own timestamp
Jeff Layton <jlayton@...nel.org> writes:
> I'm a little confused too. Why do you believe this will break
> -o relatime handling? This patch changes two things:
>
> 1/ it has fat_update_time fetch its own timestamp (and ignore the "now"
> parameter). This is in line with the changes in patch #3 of this series,
> which explains the rationale for this in more detail.
>
> 2/ it changes fat_update_time to also update the i_version if any of
> S_CTIME|S_MTIME|S_VERSION are set. relatime is all about the S_ATIME,
> and it is specifically excluded from that set.
>
> The rationale for the second change is is also in patch #3, but
> basically, we can't guarantee that current_time hasn't changed since we
> last checked for inode_needs_update_time, so if any of
> S_CTIME/S_MTIME/S_VERSION have changed, then we need to assume that any
> of them may need to be changed and attempt to update all 3.
>
> That said, I think the logic in fat_update_time isn't quite right. I
> think want something like this on top of this patch to ensure that the
> S_CTIME and S_MTIME get updated, even if the flags only have S_VERSION
> set.
>
> Thoughts?
I'm not talking about "relatime" at all, I'm always talking about
"lazytime".
I_DIRTY_TIME delays to update on disk inode only if changed
timestamp. But you changed it to I_DIRTY_SYNC, i.e. always update on
disk inode by timestamp.
Thanks.
> ---------------------8<-----------------------
>
> diff --git a/fs/fat/misc.c b/fs/fat/misc.c
> index 080a5035483f..313eef02f45c 100644
> --- a/fs/fat/misc.c
> +++ b/fs/fat/misc.c
> @@ -346,15 +346,21 @@ int fat_update_time(struct inode *inode, int flags)
> if (inode->i_ino == MSDOS_ROOT_INO)
> return 0;
>
> - if (flags & (S_ATIME | S_CTIME | S_MTIME)) {
> - fat_truncate_time(inode, NULL, flags);
> - if (inode->i_sb->s_flags & SB_LAZYTIME)
> - dirty_flags |= I_DIRTY_TIME;
> - else
> - dirty_flags |= I_DIRTY_SYNC;
> - }
> + /*
> + * If any of the flags indicate an expicit change to the file, then we
> + * need to ensure that we attempt to update all of 3. We do not do
> + * this in the case of an S_ATIME-only update.
> + */
> + if (flags & (S_CTIME | S_MTIME | S_VERSION))
> + flags |= S_CTIME | S_MTIME | S_VERSION;
> +
> + fat_truncate_time(inode, NULL, flags);
> + if (inode->i_sb->s_flags & SB_LAZYTIME)
> + dirty_flags |= I_DIRTY_TIME;
> + else
> + dirty_flags |= I_DIRTY_SYNC;
>
> - if ((flags & (S_VERSION|S_CTIME|S_MTIME)) && inode_maybe_inc_iversion(inode, false))
> + if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false))
> dirty_flags |= I_DIRTY_SYNC;
>
--
OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
Powered by blists - more mailing lists