Re: [PATCH] tracefs: Simplify get_dname() with kmemdup_nul()

[Steven Rostedt]

On Fri, 27 Feb 2026 20:18:24 +0000
Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:

> On Fri, Feb 27, 2026 at 02:44:53PM -0500, AnishMulay wrote:
> > index d9d8932a7b9c9..86ba8dc25aaef 100644
> > --- a/fs/tracefs/inode.c
> > +++ b/fs/tracefs/inode.c
> > @@ -96,17 +96,7 @@ static struct tracefs_dir_ops {
> >  
> >  static char *get_dname(struct dentry *dentry)
> >  {
> > -	const char *dname;
> > -	char *name;
> > -	int len = dentry->d_name.len;
> > -
> > -	dname = dentry->d_name.name;
> > -	name = kmalloc(len + 1, GFP_KERNEL);
> > -	if (!name)
> > -		return NULL;
> > -	memcpy(name, dname, len);
> > -	name[len] = 0;
> > -	return name;
> > +	return kmemdup_nul(dentry->d_name.name, dentry->d_name.len, GFP_KERNEL);
> >  }  
> 
> Why not have the callers use {take,release}_dentry_name_snapshot()
> instead of doing any allocations at all?
> 
> I mean,
> static struct dentry *tracefs_syscall_mkdir(struct mnt_idmap *idmap,
>                                             struct inode *inode, struct dentry *dentry,
>                                             umode_t mode)
> {
>         struct tracefs_inode *ti;
>         struct name_snapshot s;
>         int ret;
>  
>         take_dentry_name_snapshot(&s, dentry);
> 	...
>         ret = tracefs_ops.mkdir(s.name.name);
> 	release_dentry_name_snapshot(&s);
> 	...
> }
> 
> and similar on the rmdir side.  Then remove get_dname()...

That sounds good to me.

-- Steve