Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org
[10.30.226.201])
(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
(No client certificate requested)
by smtp.subspace.kernel.org (Postfix) with ESMTPS id 598B74C65;
Thu, 4 Jan 2024 01:53:31 +0000 (UTC)
Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0647AC433C7;
Thu, 4 Jan 2024 01:53:31 +0000 (UTC)
Received: from rostedt by gandalf with local (Exim 4.97)
(envelope-from <rostedt@goodmis.org>)
id 1rLCwN-00000000qgq-23WX;
Wed, 03 Jan 2024 20:54:35 -0500
Message-ID: <20240104015247.075935881@goodmis.org>
User-Agent: quilt/0.67
Date: Wed, 03 Jan 2024 20:52:47 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ajay Kaher <akaher@vmware.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
Christian Brauner <brauner@kernel.org>,
linux-fsdevel@vger.kernel.org
Subject: [PATCH v2 0/2] eventfs: Don't use dcache_readdir() for getdents()
Precedence: bulk
X-Mailing-List: linux-trace-kernel@vger.kernel.org
List-Id: <linux-trace-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-trace-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-trace-kernel+unsubscribe@vger.kernel.org>
After having a "pleasant" conversation with Linus over on the security
mailing list, we came to the conclusion that eventfs should not be
using the dcache_readdir() routine for iterating the entries of a
directory (getdents()).
Instead, the .open and .release callbacks of the directory file
operations was removed and all the work is now done in the .iterate_shared.
The function dcache_readdir_wrapper() was renamed to eventfs_iterate().
As the files and directories of eventfs is all known within the meta
data, it can easily supply getdents() with the information it needs without
traversing the dentry.
Changes since v1: https://lore.kernel.org/linux-trace-kernel/20240103102553.17a19cea@gandalf.local.home/
- Broke up into two patches, one to fix the lookup parameter and the
other to do the meat of the change.
- Moved the ctx->pos count up to skip creating of dentries in those cases.
Steven Rostedt (Google) (2):
eventfs: Remove "lookup" parameter from create_dir/file_dentry()
eventfs: Stop using dcache_readdir() for getdents()
----
fs/tracefs/event_inode.c | 241 ++++++++++++++++-------------------------------
1 file changed, 80 insertions(+), 161 deletions(-)
After having a "pleasant" conversation with Linus over on the security mailing list, we came to the conclusion that eventfs should not be using the dcache_readdir() routine for iterating the entries of a directory (getdents()). Instead, the .open and .release callbacks of the directory file operations was removed and all the work is now done in the .iterate_shared. The function dcache_readdir_wrapper() was renamed to eventfs_iterate(). As the files and directories of eventfs is all known within the meta data, it can easily supply getdents() with the information it needs without traversing the dentry. Changes since v1: https://lore.kernel.org/linux-trace-kernel/20240103102553.17a19cea@gandalf.local.home/ - Broke up into two patches, one to fix the lookup parameter and the other to do the meat of the change. - Moved the ctx->pos count up to skip creating of dentries in those cases. Steven Rostedt (Google) (2): eventfs: Remove "lookup" parameter from create_dir/file_dentry() eventfs: Stop using dcache_readdir() for getdents() ---- fs/tracefs/event_inode.c | 241 ++++++++++++++++------------------------------- 1 file changed, 80 insertions(+), 161 deletions(-)