Re: [RFC PATCH 05/11] smb/server: keep notify watches on file handles

> @@ -182,6 +182,21 @@ static int ksmbd_notify_add(struct ksmbd_file *fp, u32 mask, u32 filter,
>         struct fsnotify_mark *mark;
>         int err = 0;
>
> +       mutex_lock(&fp->notify_lock);
> +       if (fp->notify) {
> +               spin_lock(&fp->notify->lock);
> +               fp->notify->filter |= filter;
> +               fp->notify->mask |= mask;
This changes the watch semantics for later CHANGE_NOTIFY requests by
unioning their filter into the existing watch. CHANGE_NOTIFY request
is queued per open, but it must not reconfigure the underlying
directory watch.

> +               spin_unlock(&fp->notify->lock);
> +               fsnotify_modify_mark_mask(fp->notify->mark, mask, 0);
> +               ksmbd_debug(NOTIFY,
> +                           "Updated fsnotify mark, inode %llu, mask 0x%x\n",
> +                           (unsigned long long)file_inode(fp->filp)->i_ino,
> +                           fp->notify->mark->mask);
> +               *notify_out = fp->notify;
> +               goto out;
> +       }
> +