From nobody Thu Dec 25 12:13:48 2025 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 03CDD20334 for ; Wed, 17 Jan 2024 14:36:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705502214; cv=none; b=FCnPZXKvLa1KoPAoXkBtdcYlScU5QXRZVMoXJxf85jg9OOM5u34Vdsvkhua1cG/+R0AtIuhV0CrIPZjGDheVBUAmBbB6oZVvUqFV+lOVgfdgg4hs4v7K2RNbQIbUE9tBK7obXKaegC0v+EHUWG4EbyVNc7d7L8svzEfo/YspCoE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705502214; c=relaxed/simple; bh=+l/2J1wuNvwwox8H/9diOMBy2Vp1lI/iE/4NnUV0Ybw=; h=Received:Received:Message-ID:User-Agent:Date:From:To:Cc:Subject: References:MIME-Version:Content-Type; b=FZNMTsUO2lvJrMLYd/9JDY4wuxXJ9/MB8Yfkb217f+wgowVEs/9Q4YMgoA4HKRXR3PnXU8g+/Bg5+m53nx4R3WC1/LgK3LoDJ71FZM/5A3id7/czR6lf+WgRrSWNxjeidDqWxT3yMsy0lCpOip8KsPlVNsxyXQzb89usGYjlxk0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9275BC43399; Wed, 17 Jan 2024 14:36:53 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rQ73S-00000001XY4-2pb8; Wed, 17 Jan 2024 09:38:10 -0500 Message-ID: <20240117143810.531966508@goodmis.org> User-Agent: quilt/0.67 Date: Wed, 17 Jan 2024 09:35:49 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Christian Brauner , Al Viro , Ajay Kaher , Linus Torvalds Subject: [for-linus][PATCH 1/3] eventfs: Have the inodes all for files and directories all be the same References: <20240117143548.595884070@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" The dentries and inodes are created in the readdir for the sole purpose of getting a consistent inode number. Linus stated that is unnecessary, and that all inodes can have the same inode number. For a virtual file system they are pretty meaningless. Instead use a single unique inode number for all files and one for all directories. Link: https://lore.kernel.org/all/20240116133753.2808d45e@gandalf.local.hom= e/ Link: https://lore.kernel.org/linux-trace-kernel/20240116211353.412180363@g= oodmis.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Christian Brauner Cc: Al Viro Cc: Ajay Kaher Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (Google) Reviewed-by: Kees Cook --- fs/tracefs/event_inode.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index fdff53d5a1f8..5edf0b96758b 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -32,6 +32,10 @@ */ static DEFINE_MUTEX(eventfs_mutex); =20 +/* Choose something "unique" ;-) */ +#define EVENTFS_FILE_INODE_INO 0x12c4e37 +#define EVENTFS_DIR_INODE_INO 0x134b2f5 + /* * The eventfs_inode (ei) itself is protected by SRCU. It is released from * its parent's list and will have is_freed set (under eventfs_mutex). @@ -352,6 +356,9 @@ static struct dentry *create_file(const char *name, umo= de_t mode, inode->i_fop =3D fop; inode->i_private =3D data; =20 + /* All files will have the same inode number */ + inode->i_ino =3D EVENTFS_FILE_INODE_INO; + ti =3D get_tracefs(inode); ti->flags |=3D TRACEFS_EVENT_INODE; d_instantiate(dentry, inode); @@ -388,6 +395,9 @@ static struct dentry *create_dir(struct eventfs_inode *= ei, struct dentry *parent inode->i_op =3D &eventfs_root_dir_inode_operations; inode->i_fop =3D &eventfs_file_operations; =20 + /* All directories will have the same inode number */ + inode->i_ino =3D EVENTFS_DIR_INODE_INO; + ti =3D get_tracefs(inode); ti->flags |=3D TRACEFS_EVENT_INODE; =20 --=20 2.43.0