linux-kernel - Re: [PATCH 02/16] f2fs: add on-disk layout

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] [day] [month] [year] [list]

Message-ID: <1350128388.1917.1.camel@kjgkr>
Date:	Sat, 13 Oct 2012 20:39:48 +0900
From:	Jaegeuk Kim <jaegeuk.kim@...il.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	±èÀç±Ø <jaegeuk.kim@...sung.com>,
	viro@...iv.linux.org.uk, 'Theodore Ts'o' <tytso@....edu>,
	gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
	chur.lee@...sung.com, cm224.lee@...sung.com,
	jooyoung.hwang@...sung.com
Subject: Re: [PATCH 02/16] f2fs: add on-disk layout

2012-10-12 (ê¸ˆ), 21:05 +0000, Arnd Bergmann:
> On Friday 05 October 2012 20:56:44 ê¹€ìž¬ê·¹ wrote:
> > +struct f2fs_nat_entry {
> > +       __u8 version;
> > +       __le32 ino;
> > +       __le32 block_addr;
> > +} __packed;
> > +
> > +struct f2fs_nat_block {
> > +       struct f2fs_nat_entry entries[NAT_ENTRY_PER_BLOCK];
> > +} __packed;
> 
> Using "__packed" on structure is rather inefficient on CPU architectures
> that cannot do aligned accesses. I would suggest you remove this
> attribute everywhere you can. The f2fs_nat_entry is particularly
> suboptimal because it is 9 bytes long, and I'm not sure if this
> can be reasonably changed to a multiple of four.
> 
> In all other cases, you should try to lay out the structures
> so that each member is naturally aligned and you don't need any __packed
> attributes, in particular for those that are accessed a lot.
> 

Ok, I'll check all the in-memory data structures.
Thank you for comments.

> 	Arnd
> --
> 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/

-- 
Jaegeuk Kim
Samsung

--
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/