Re: [PATCH v3 1/3] ovl: Let helper ovl_i_path_real() return the realinode

[Amir Goldstein]

On Tue, May 16, 2023 at 5:19 PM Zhihao Cheng <chengzhihao1@xxxxxxxxxx> wrote:
>
> Let helper ovl_i_path_real() return the realinode to prepare for
> checking non-null realinode in rcu walking path.
>
> Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>

Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>

> ---
>  fs/overlayfs/overlayfs.h | 2 +-
>  fs/overlayfs/util.c      | 7 ++++---
>  2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index 4d0b278f5630..7398de332527 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -382,7 +382,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry);
>  void ovl_path_upper(struct dentry *dentry, struct path *path);
>  void ovl_path_lower(struct dentry *dentry, struct path *path);
>  void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
> -void ovl_i_path_real(struct inode *inode, struct path *path);
> +struct inode *ovl_i_path_real(struct inode *inode, struct path *path);
>  enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
>  enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
>  struct dentry *ovl_dentry_upper(struct dentry *dentry);
> diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
> index 923d66d131c1..00d31e38b57d 100644
> --- a/fs/overlayfs/util.c
> +++ b/fs/overlayfs/util.c
> @@ -250,7 +250,7 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode)
>         return ovl_upperdentry_dereference(OVL_I(inode));
>  }
>
> -void ovl_i_path_real(struct inode *inode, struct path *path)
> +struct inode *ovl_i_path_real(struct inode *inode, struct path *path)
>  {
>         path->dentry = ovl_i_dentry_upper(inode);
>         if (!path->dentry) {
> @@ -259,6 +259,8 @@ void ovl_i_path_real(struct inode *inode, struct path *path)
>         } else {
>                 path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb));
>         }
> +
> +       return path->dentry ? d_inode(path->dentry) : NULL;
>  }
>
>  struct inode *ovl_inode_upper(struct inode *inode)
> @@ -1105,8 +1107,7 @@ void ovl_copyattr(struct inode *inode)
>         vfsuid_t vfsuid;
>         vfsgid_t vfsgid;
>
> -       ovl_i_path_real(inode, &realpath);
> -       realinode = d_inode(realpath.dentry);
> +       realinode = ovl_i_path_real(inode, &realpath);
>         real_idmap = mnt_idmap(realpath.mnt);
>
>         vfsuid = i_uid_into_vfsuid(real_idmap, realinode);
> --
> 2.39.2
>