Re: [PATCH 3/6] tracefs: dentry lookup crapectomy

[Al Viro <viro@zeniv.linux.org.uk>]

On Tue, Jan 30, 2024 at 06:55:36PM -0500, Steven Rostedt wrote:

> Actually it's the tracefs_start_creating() locks the inode, the
> eventfs_start_creating() doesn't.

Right.

> > 
> > >  	if (unlikely(!inode))
> > >  		return eventfs_failed_creating(dentry);  
> > 
> > ... and that still unlocks it.

This is still bogus, though - both the stray dput() and
dropping a reference to internal mount.

struct dentry *eventfs_failed_creating(struct dentry *dentry)
{
        dput(dentry);
	simple_release_fs(&tracefs_mount, &tracefs_mount_count);
	return NULL;
}