On Mon, Aug 31, 2020 at 01:25:34PM -0400, Qian Cai wrote:
> + case IOMAP_DELALLOC:
> + /*
> + * DIO is not serialised against mmap() access at all, and so
> + * if the page_mkwrite occurs between the writeback and the
> + * iomap_apply() call in the DIO path, then it will see the
> + * DELALLOC block that the page-mkwrite allocated.
> + */
> + path = file_path(dio->iocb->ki_filp, pathname,
> + sizeof(pathname));
> + if (IS_ERR(path))
> + path = "(unknown)";
> +
> + pr_warn_ratelimited("Direct I/O collision with buffered writes!
> File: %s Comm: %.20s\n",
> + path, current->comm);
"File: %pD4"?
