linux-kernel - Re: [PATCH 1/6] sysfs: Basic support for multiple super blocks

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]

Date:	Wed, 31 Mar 2010 07:02:39 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	"Serge E. Hallyn" <serue@...ibm.com>
Cc:	Tejun Heo <tj@...nel.org>, Greg Kroah-Hartman <gregkh@...e.de>,
	Kay Sievers <kay.sievers@...y.org>,
	linux-kernel@...r.kernel.org,
	Cornelia Huck <cornelia.huck@...ibm.com>,
	linux-fsdevel@...r.kernel.org,
	Eric Dumazet <eric.dumazet@...il.com>,
	Benjamin LaHaise <bcrl@...et.ca>, netdev@...r.kernel.org
Subject: Re: [PATCH 1/6] sysfs: Basic support for multiple super blocks

"Serge E. Hallyn" <serue@...ibm.com> writes:

> Quoting Eric W. Biederman (ebiederm@...ssion.com):
>> Tejun Heo <tj@...nel.org> writes:
>> >> index 30f5a44..030a39d 100644
>> >> --- a/fs/sysfs/sysfs.h
>> >> +++ b/fs/sysfs/sysfs.h
>> >> @@ -114,6 +114,9 @@ struct sysfs_addrm_cxt {
>> >>  /*
>> >>   * mount.c
>> >>   */
>> >> +struct sysfs_super_info {
>> >> +};
>> >> +#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
>> >
>> > Another nit picking.  It would be better to wrap SB in the macro
>> > definition.  Also, wouldn't an inline function be better?
>> 
>> Good spotting.  That doesn't bite today but it will certainly bite
>> someday if it isn't fixed.
>> 
>> I wonder how that has slipped through the review all of this time.
>
> (let me demonstrate how: )
>
> WTH are you talking about?  Unless you mean doing (SB) inside
> the definition?
>
> I actually was going to suggest dropping the #define as it obscures
> the code, but I figured it would get more complicated later.

I believe the discuss change was to make the define:
#define sysfs_info(SB) ((struct sysfs_super_info *)((SB)->s_fs_info))

As for dropping the define and using s_fs_info raw.  I rather like
a light weight type safe wrapper.  Maybe I just think s_fs_info
is an ugly name.

In practice I never call sysfs_info() with any expression that has
a side effect, so it doesn't matter.

Eric



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/