On Mon, Oct 07, 2024 at 04:19:21PM +0200, Amir Goldstein wrote:
> +static int ovl_real_fdget_path(const struct file *file, struct fd *real,
> + struct path *realpath)
> - if (allow_meta) {
> - ovl_path_real(dentry, &realpath);
> - } else {
> - /* lazy lookup and verify of lowerdata */
> - err = ovl_verify_lowerdata(dentry);
This check went
> - if (err)
> - return err;
> -
> - ovl_path_realdata(dentry, &realpath);
> - }
> @@ -138,7 +129,33 @@ static int ovl_real_fdget(const struct file *file, struct fd *real)
> return 0;
> }
>
> - return ovl_real_fdget_meta(file, real, false);
> + /* lazy lookup and verify of lowerdata */
> + err = ovl_verify_lowerdata(dentry);
... here
> + if (err)
> + return err;
> +
> + ovl_path_realdata(dentry, &realpath);
> +static int ovl_upper_fdget(const struct file *file, struct fd *real, bool data)
> +{
> + struct dentry *dentry = file_dentry(file);
> + struct path realpath;
> + enum ovl_path_type type;
> +
> + if (data)
> + type = ovl_path_realdata(dentry, &realpath);
... but not here.
I can see the point of not doing that in ->fsync() after we'd already
done ovl_verify_lowerdata() at open time, but what's different about
->read_iter() and friends that also come only after ->open()?
IOW, why is fdatasync() different from other data-access cases?
