On Thu, 4 Jan 2024 01:48:37 +0000 Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > On Wed, Jan 03, 2024 at 08:32:46PM -0500, Steven Rostedt wrote: > > > + /* Get the tracefs root from the parent */ > > + inode = d_inode(dentry->d_parent); > > + inode = d_inode(inode->i_sb->s_root); > > That makes no sense. First of all, for any positive dentry we have > dentry->d_sb == dentry->d_inode->i_sb. And it's the same for all > dentries on given superblock. So what's the point of that dance? > If you want the root inode, just go for d_inode(dentry->d_sb->s_root) > and be done with that... That was more of thinking that the dentry and dentry->d_parent are different. As dentry is part of eventfs and dentry->d_parent is part of tracefs. Currently they both have the same superblock so yeah, I could just write it that way too and it would work. But in my head, I was thinking that they behave differently and maybe one day eventfs would get its own superblock which would not work. To explain this better: /sys/kernel/tracing/ is the parent of /sys/kernel/tracing/events But everything but "events" in /sys/kernel/tracing/* is part of tracefs. Everything in /sys/kernel/tracing/events is part of eventfs. That was my thought process. But as both tracefs and eventfs still use tracefs_get_inode(), it would work as you state. I'll update that, as I don't foresee that eventfs will become its own file system. Thanks, -- Steve
