linux-ext4 - Re: [PATCH] f2fs: improve the performance of 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: <aGZFtmIxHDLKL6mc@infradead.org>
Date: Thu, 3 Jul 2025 01:56:22 -0700
From: Christoph Hellwig <hch@...radead.org>
To: Yuwen Chen <ywen.chen@...mail.com>
Cc: tytso@....edu, adilger.kernel@...ger.ca, jaegeuk@...nel.org,
	chao@...nel.org, viro@...iv.linux.org.uk, brauner@...nel.org,
	linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] f2fs: improve the performance of f2fs_lookup

On Thu, Jul 03, 2025 at 04:21:30PM +0800, Yuwen Chen wrote:
> On the Android system, the file creation operation will call
> the f2fs_lookup function. When there are too many files in a
> directory, the generic_ci_match operation will be called
> repeatedly in large quantities. In extreme cases, the file
> creation speed will drop to three times per second.

This files to explain what you are changing in detail, and why
(except for the very highlevel problem statement here).

> 
> Signed-off-by: Yuwen Chen <ywen.chen@...mail.com>
> ---
>  fs/ext4/namei.c    |  2 +-
>  fs/f2fs/dir.c      | 24 +++++++++++++++++-------
>  fs/f2fs/f2fs.h     |  3 ++-
>  fs/f2fs/inline.c   |  3 ++-
>  fs/libfs.c         | 32 +++++++++++++++++++++++++++++---
>  include/linux/fs.h |  8 +++++++-

Also please split generic infrastructure changes from f2fs ones.