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
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <42c5bbe-a7a4-3546-e898-3f33bd71b062@google.com>
Date:   Tue, 25 Jul 2023 18:39:25 -0700 (PDT)
From:   Hugh Dickins <hughd@...gle.com>
To:     Jeff Layton <jlayton@...nel.org>
cc:     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@...lpad.com>,
        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>,
        OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>,
        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>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Christian Brauner <brauner@...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 <lsahlber@...hat.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>,
        "Darrick J. Wong" <djwong@...nel.org>,
        Dave Chinner <david@...morbit.com>,
        Anthony Iliopoulos <ailiop@...e.com>, v9fs@...ts.linux.dev,
        linux-kernel@...r.kernel.org, linux-afs@...ts.infradead.org,
        linux-btrfs@...r.kernel.org, ceph-devel@...r.kernel.org,
        codalist@...a.cs.cmu.edu, ecryptfs@...r.kernel.org,
        linux-erofs@...ts.ozlabs.org, linux-fsdevel@...r.kernel.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-xfs@...r.kernel.org
Subject: Re: [PATCH v6 3/7] tmpfs: bump the mtime/ctime/iversion when page
 becomes writeable

On Tue, 25 Jul 2023, Jeff Layton wrote:

> Most filesystems that use the pagecache will update the mtime, ctime,
> and change attribute when a page becomes writeable. Add a page_mkwrite
> operation for tmpfs and just use it to bump the mtime, ctime and change
> attribute.
> 
> This fixes xfstest generic/080 on tmpfs.

Huh.  I didn't notice when this one crept into the multigrain series.

I'm inclined to NAK this patch: at the very least, it does not belong
in the series, but should be discussed separately.

Yes, tmpfs does not and never has used page_mkwrite, and gains some
performance advantage from that.  Nobody has ever asked for this
change before, or not that I recall.

Please drop it from the series: and if you feel strongly, or know
strong reasons why tmpfs suddenly needs to use page_mkwrite now,
please argue them separately.  To pass generic/080 is not enough.

Thanks,
Hugh

> 
> Signed-off-by: Jeff Layton <jlayton@...nel.org>
> ---
>  mm/shmem.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/mm/shmem.c b/mm/shmem.c
> index b154af49d2df..654d9a585820 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -2169,6 +2169,16 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
>  	return ret;
>  }
>  
> +static vm_fault_t shmem_page_mkwrite(struct vm_fault *vmf)
> +{
> +	struct vm_area_struct *vma = vmf->vma;
> +	struct inode *inode = file_inode(vma->vm_file);
> +
> +	file_update_time(vma->vm_file);
> +	inode_inc_iversion(inode);
> +	return 0;
> +}
> +
>  unsigned long shmem_get_unmapped_area(struct file *file,
>  				      unsigned long uaddr, unsigned long len,
>  				      unsigned long pgoff, unsigned long flags)
> @@ -4210,6 +4220,7 @@ static const struct super_operations shmem_ops = {
>  
>  static const struct vm_operations_struct shmem_vm_ops = {
>  	.fault		= shmem_fault,
> +	.page_mkwrite	= shmem_page_mkwrite,
>  	.map_pages	= filemap_map_pages,
>  #ifdef CONFIG_NUMA
>  	.set_policy     = shmem_set_policy,
> @@ -4219,6 +4230,7 @@ static const struct vm_operations_struct shmem_vm_ops = {
>  
>  static const struct vm_operations_struct shmem_anon_vm_ops = {
>  	.fault		= shmem_fault,
> +	.page_mkwrite	= shmem_page_mkwrite,
>  	.map_pages	= filemap_map_pages,
>  #ifdef CONFIG_NUMA
>  	.set_policy     = shmem_set_policy,
> 
> -- 
> 2.41.0

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ