Re: [PATCH v2 03/15] pidfs: move setting flags into pidfs_alloc_file()

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2025-03-04 at 10:41 +0100, Christian Brauner wrote:
> Instead od adding it into __pidfd_prepare() place it where the actual
> file allocation happens and update the outdated comment.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>
> ---
>  fs/pidfs.c    | 4 ++++
>  kernel/fork.c | 5 -----
>  2 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/pidfs.c b/fs/pidfs.c
> index aa8c8bda8c8f..ecc0dd886714 100644
> --- a/fs/pidfs.c
> +++ b/fs/pidfs.c
> @@ -696,6 +696,10 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags)
>  		return ERR_PTR(ret);
>  
>  	pidfd_file = dentry_open(&path, flags, current_cred());
> +	/* Raise PIDFD_THREAD explicitly as do_dentry_open() strips it. */
> +	if (!IS_ERR(pidfd_file))
> +		pidfd_file->f_flags |= (flags & PIDFD_THREAD);
> +
>  	path_put(&path);
>  	return pidfd_file;
>  }
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 6230f5256bc5..8eac9cd3385b 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -2042,11 +2042,6 @@ static int __pidfd_prepare(struct pid *pid, unsigned int flags, struct file **re
>  	if (IS_ERR(pidfd_file))
>  		return PTR_ERR(pidfd_file);
>  
> -	/*
> -	 * anon_inode_getfile() ignores everything outside of the
> -	 * O_ACCMODE | O_NONBLOCK mask, set PIDFD_THREAD manually.
> -	 */
> -	pidfd_file->f_flags |= (flags & PIDFD_THREAD);
>  	*ret = pidfd_file;
>  	return take_fd(pidfd);
>  }
> 

Reviewed-by: Jeff Layton <jlayton@kernel.org>