linux-ext4 - Re: [f2fs-dev] [PATCH v6 0/9] Support negative dentries on case-insensitive ext4 and f2fs

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: <20231122210414.GI38156@ZenIV>
Date: Wed, 22 Nov 2023 21:04:14 +0000
From: Al Viro <viro@...iv.linux.org.uk>
To: Theodore Ts'o <tytso@....edu>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
	Christian Brauner <brauner@...nel.org>,
	Gabriel Krisman Bertazi <krisman@...e.de>,
	linux-f2fs-devel@...ts.sourceforge.net, ebiggers@...nel.org,
	linux-fsdevel@...r.kernel.org, jaegeuk@...nel.org,
	linux-ext4@...r.kernel.org
Subject: Re: [f2fs-dev] [PATCH v6 0/9] Support negative dentries on
 case-insensitive ext4 and f2fs

On Tue, Nov 21, 2023 at 12:12:15AM -0500, Theodore Ts'o wrote:
> Yeah, agreed, that would be a nice optimization.  However, in the
> unfortunate case where (a) it's non-ASCII, and (b) the input string is
> non-normalized and/or differs in case, we end up scanning some portion
> of the two strings twice; once doing the strcmp, and once doing the
> Unicode slow path.

The first pass is cheap and the second one will be running entirely
from the cache, so I doubt that scanning them twice will be a loss...