On Tue, Dec 17, 2019 at 07:39:43AM -0700, Jens Axboe wrote:
> +static void buffered_put_page(struct page *page, bool clear_mapping)
> +{
> + if (clear_mapping)
> + page->mapping = NULL;
> + put_page(page);
> +}
I'm not a huge fan of the variable name 'clear_mapping'. It describes
what it does rather than why it does it. So maybe 'drop_immediate'?
Or 'uncached'?
> if (!page) {
> if (iocb->ki_flags & IOCB_NOWAIT)
> goto would_block;
> + /* UNCACHED implies no read-ahead */
> + if (iocb->ki_flags & IOCB_UNCACHED) {
> + did_dio_begin = true;
> + /* block truncate for UNCACHED reads */
> + inode_dio_begin(inode);
I think this needs to be:
if (!did_dio_begin)
inode_dio_begin(inode);
did_dio_begin = true;
otherwise inode->i_dio_count is going to be increased once per uncached
page. Do you have a test in your test-suite that does I/O to more than
one page at a time?
