From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/filemap: split filemap_readahead out of filemap_get_pages This simplifies the error handling. Link: https://lkml.kernel.org/r/20210122160140.223228-15-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/filemap.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) --- a/mm/filemap.c~mm-filemap-split-filemap_readahead-out-of-filemap_get_pages +++ a/mm/filemap.c @@ -2330,6 +2330,17 @@ error: return error; } +static int filemap_readahead(struct kiocb *iocb, struct file *file, + struct address_space *mapping, struct page *page, + pgoff_t last_index) +{ + if (iocb->ki_flags & IOCB_NOIO) + return -EAGAIN; + page_cache_async_readahead(mapping, &file->f_ra, file, page, + page->index, last_index - page->index); + return 0; +} + static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter, struct pagevec *pvec) { @@ -2367,17 +2378,15 @@ find_page: got_pages: { struct page *page = pvec->pages[pvec->nr - 1]; - pgoff_t pg_index = page->index; if (PageReadahead(page)) { - if (iocb->ki_flags & IOCB_NOIO) { + err = filemap_readahead(iocb, filp, mapping, page, + last_index); + if (err) { put_page(page); pvec->nr--; - err = -EAGAIN; goto err; } - page_cache_async_readahead(mapping, ra, filp, page, - pg_index, last_index - pg_index); } if (!PageUptodate(page)) { _
