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From:   Amir Goldstein <amir73il@gmail.com>
Date:   Sat, 31 Aug 2019 09:34:44 +0300
Message-ID: <CAOQ4uxichLUsPyg5Fqg-pSL85oqoDFcQHZbzdrkXX_-kK=CjDQ@mail.gmail.com>
Subject: Re: [PATCH v6 03/24] erofs: add super block operations
To:     Gao Xiang <gaoxiang25@huawei.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        "Theodore Ts'o" <tytso@mit.edu>, Pavel Machek <pavel@denx.de>,
        David Sterba <dsterba@suse.cz>,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        Dave Chinner <david@fromorbit.com>,
        Jaegeuk Kim <jaegeuk@kernel.org>, Jan Kara <jack@suse.cz>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        devel@driverdev.osuosl.org, LKML <linux-kernel@vger.kernel.org>,
        linux-erofs@lists.ozlabs.org, Chao Yu <yuchao0@huawei.com>,
        Miao Xie <miaoxie@huawei.com>,
        Li Guifu <bluce.liguifu@huawei.com>,
        Fang Wei <fangwei1@huawei.com>
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On Fri, Aug 30, 2019 at 8:16 PM Gao Xiang <gaoxiang25@huawei.com> wrote:
>
> Hi Christoph,
>
> On Fri, Aug 30, 2019 at 09:39:10AM -0700, Christoph Hellwig wrote:
> > On Thu, Aug 29, 2019 at 06:50:48PM +0800, Gao Xiang wrote:
> > > > Please use an erofs_ prefix for all your functions.
> > >
> > > It is already a static function, I have no idea what is wrong here.
> >
> > Which part of all wasn't clear?  Have you looked at the prefixes for
> > most functions in the various other big filesystems?
>
> I will add erofs prefix to free_inode as you said.
>
> At least, all non-prefix functions in erofs are all static functions,
> it won't pollute namespace... I will add "erofs_" to other meaningful
> callbacks...And as you can see...
>
> cifs/cifsfs.c
> 1303:cifs_init_inodecache(void)
> 1509:   rc = cifs_init_inodecache();
>
> hpfs/super.c
> 254:static int init_inodecache(void)
> 771:    int err = init_inodecache();
>
> minix/inode.c
> 84:static int __init init_inodecache(void)
> 665:    int err = init_inodecache();
>

Hi Gao,

"They did it first" is never a good reply for code review comments.
Nobody cares if you copy&paste code with init_inodecache().
I understand why you thought static function names do not pollute
the (linker) namespace, but they do pollute the global namespace.

free_inode() as a local function name is one of the worst examples
for VFS namespace pollution.

VFS code uses function names like those a lot in the global namespace, e.g.:
clear_inode(),new_inode().

For example from recent history of namespace collision caused by your line
of thinking, see:
e6fd2093a85d md: namespace private helper names

Besides, you really have nothing to loose from prefixing everything
with erofs_, do you? It's better for review, for debugging...

Thanks,
Amir.