From patchwork Thu Jan 21 04:16:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12034467 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A351C433DB for ; Thu, 21 Jan 2021 04:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3F9E2368A for ; Thu, 21 Jan 2021 04:26:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726017AbhAUE0M (ORCPT ); Wed, 20 Jan 2021 23:26:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729318AbhAUEYp (ORCPT ); Wed, 20 Jan 2021 23:24:45 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB204C0613CF for ; Wed, 20 Jan 2021 20:24:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=PzKvXsMsWUhjneoIxI+kPg+VyvK2S1wuuVi6Tr6zSHo=; b=oqyn7XisgT5u7uHTjGmiZQTRde W45d9eBXJO1AJzAQ/p+lX037NqONFGeB7lnFC8l89N20fayVVhEqvY+2gB7MbTzwkg/DGAXPj47Xc FgRc6LnmYtfLLaFhx84wrOt8Nlh/aQxzbxa/OgA40fBCpo4ppG2zQUgn+XBDfk/j+BEJHWVOlLqg8 L+aT66ya6Ujs3SlCf/JpVTYh/LsYp9+ei2GT7BJtug83wdnIuwFm8fhkLO2KMPx3xW2l3npTIWQeS cHFJCnBNOdqtRYiutiSEDvNj/5LANwj/geDE4Xt664mZ/vvzjVHpDxMEchf3WV2jH4bDm7GBnJDuD vYDgNdqw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l2RUW-00GbQM-GA; Thu, 21 Jan 2021 04:22:47 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , hch@lst.de, kent.overstreet@gmail.com Subject: [PATCH v4 09/18] mm/filemap: Change filemap_read_page calling conventions Date: Thu, 21 Jan 2021 04:16:07 +0000 Message-Id: <20210121041616.3955703-10-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210121041616.3955703-1-willy@infradead.org> References: <20210121041616.3955703-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Make this function more generic by passing the file instead of the iocb. Check in the callers whether we should call readpage or not. Also make it return an errno / 0 / AOP_TRUNCATED_PAGE, and make calling put_page() the caller's responsibility. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Kent Overstreet Reviewed-by: Christoph Hellwig --- mm/filemap.c | 89 +++++++++++++++++++++++++--------------------------- 1 file changed, 42 insertions(+), 47 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index e904e53ae90d9..ff5c217057d4e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2189,56 +2189,38 @@ static void filemap_get_read_batch(struct address_space *mapping, rcu_read_unlock(); } -static struct page *filemap_read_page(struct kiocb *iocb, struct file *filp, - struct address_space *mapping, struct page *page) +static int filemap_read_page(struct file *file, struct address_space *mapping, + struct page *page) { - struct file_ra_state *ra = &filp->f_ra; int error; - if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) { - unlock_page(page); - put_page(page); - return ERR_PTR(-EAGAIN); - } - /* - * A previous I/O error may have been due to temporary - * failures, eg. multipath errors. - * PG_error will be set again if readpage fails. + * A previous I/O error may have been due to temporary failures, + * eg. multipath errors. PG_error will be set again if readpage + * fails. */ ClearPageError(page); /* Start the actual read. The read will unlock the page. */ - error = mapping->a_ops->readpage(filp, page); - - if (unlikely(error)) { - put_page(page); - return error != AOP_TRUNCATED_PAGE ? ERR_PTR(error) : NULL; - } + error = mapping->a_ops->readpage(file, page); + if (error) + return error; + if (PageUptodate(page)) + return 0; + error = lock_page_killable(page); + if (error) + return error; if (!PageUptodate(page)) { - error = lock_page_killable(page); - if (unlikely(error)) { - put_page(page); - return ERR_PTR(error); - } - if (!PageUptodate(page)) { - if (page->mapping == NULL) { - /* - * invalidate_mapping_pages got it - */ - unlock_page(page); - put_page(page); - return NULL; - } - unlock_page(page); - shrink_readahead_size_eio(ra); - put_page(page); - return ERR_PTR(-EIO); + if (page->mapping == NULL) { + /* page truncated */ + error = AOP_TRUNCATED_PAGE; + } else { + shrink_readahead_size_eio(&file->f_ra); + error = -EIO; } - unlock_page(page); } - - return page; + unlock_page(page); + return error; } static struct page *filemap_update_page(struct kiocb *iocb, struct file *filp, @@ -2280,7 +2262,18 @@ static struct page *filemap_update_page(struct kiocb *iocb, struct file *filp, return page; readpage: - return filemap_read_page(iocb, filp, mapping, page); + if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) { + unlock_page(page); + put_page(page); + return ERR_PTR(-EAGAIN); + } + error = filemap_read_page(iocb->ki_filp, mapping, page); + if (!error) + return page; + put_page(page); + if (error == AOP_TRUNCATED_PAGE) + return NULL; + return ERR_PTR(error); truncated: unlock_page(page); put_page(page); @@ -2296,7 +2289,7 @@ static struct page *filemap_create_page(struct kiocb *iocb, struct page *page; int error; - if (iocb->ki_flags & IOCB_NOIO) + if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) return ERR_PTR(-EAGAIN); page = page_cache_alloc(mapping); @@ -2305,12 +2298,14 @@ static struct page *filemap_create_page(struct kiocb *iocb, error = add_to_page_cache_lru(page, mapping, index, mapping_gfp_constraint(mapping, GFP_KERNEL)); - if (error) { - put_page(page); - return error != -EEXIST ? ERR_PTR(error) : NULL; - } - - return filemap_read_page(iocb, filp, mapping, page); + if (!error) + error = filemap_read_page(iocb->ki_filp, mapping, page); + if (!error) + return page; + put_page(page); + if (error == -EEXIST || error == AOP_TRUNCATED_PAGE) + return NULL; + return ERR_PTR(error); } static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,