RE: [PATCH v2 2/2] f2fs: Advertise encrypted casefolding in sysfs

From: David Laight <David.Laight@ACULAB.COM>
To: 'Jaegeuk Kim' <jaegeuk@kernel.org>, Eric Biggers <ebiggers@kernel.org>
Cc: Daniel Rosenberg <drosen@google.com>, Chao Yu <chao@kernel.org>,
	"linux-f2fs-devel@lists.sourceforge.net" 
	<linux-f2fs-devel@lists.sourceforge.net>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	"kernel-team@android.com" <kernel-team@android.com>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: RE: [PATCH v2 2/2] f2fs: Advertise encrypted casefolding in sysfs
Date: Fri, 4 Jun 2021 08:27:32 +0000	[thread overview]
Message-ID: <4f56f2781fac4b8bac1a78b0fecc318d@AcuMS.aculab.com> (raw)
In-Reply-To: <YLmv5Ykb3QUzDOlL@google.com>

From: Jaegeuk Kim
> Sent: 04 June 2021 05:45
...
> > > @@ -161,6 +161,9 @@ static ssize_t features_show(struct f2fs_attr *a,
> > >  	if (f2fs_sb_has_compression(sbi))
> > >  		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > >  				len ? ", " : "", "compression");
> > > +	if (f2fs_sb_has_casefold(sbi) && f2fs_sb_has_encrypt(sbi))
> > > +		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > > +				len ? ", " : "", "encrypted_casefold");
> > >  	len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > >  				len ? ", " : "", "pin_file");
> > >  	len += scnprintf(buf + len, PAGE_SIZE - len, "\n");

Looking at that pattern, why don't you just append "tag, "
each time and then replace the final ", " with "\n" at the end.

Although if I wanted to quickly parse that in (say) a shell
script I wouldn't really want the ",".
OTOH it is too late to change that.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)