From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.7 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=unavailable 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 2871BC48BE5 for ; Tue, 22 Jun 2021 12:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11AE56113E for ; Tue, 22 Jun 2021 12:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231875AbhFVM7E (ORCPT ); Tue, 22 Jun 2021 08:59:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231236AbhFVM7B (ORCPT ); Tue, 22 Jun 2021 08:59:01 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29C60C061574; Tue, 22 Jun 2021 05:56:45 -0700 (PDT) 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=JJaZiPnSuuNOzB/6aENHsDzMj9Vk4E7kgG+v4Zoamzw=; b=o4n6mIEWIQnNZfqNoT/SsusYKd eManugI5okW797cSLpEWU++lTs8+1h3v+/VyHZrvgwOZnmMseDlf+9hdCnH8WyQRoA1ODkb3ABIWy cZMXdCONsOfShhGYzSDWbeQvN2l4ks4XkxvTyTOcoS4QfB5JYUkKSfZyB/qYTBLlgvnS9wo8Sr5Vx WM8Fe9IGuMIVeXAEV41F7EVtzdFp6AKoBTs9ZgvK7OnuysxDoo+oHS1jJbL0AvE9ftUzy8y0k+ftF pu4vx9K8yc5ObfZhm1X2PKmZC5fV2m4Ul/PvF3RmFrRtuN01lUSypMHY5qx0dweJ2+ob2xGqJQkVj bVPbLZSA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lvfwP-00EJAM-D6; Tue, 22 Jun 2021 12:56:00 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 46/46] mm/filemap: Add FGP_STABLE Date: Tue, 22 Jun 2021 13:15:51 +0100 Message-Id: <20210622121551.3398730-47-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210622121551.3398730-1-willy@infradead.org> References: <20210622121551.3398730-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Allow filemap_get_folio() to wait for writeback to complete (if the filesystem wants that behaviour). This is the folio equivalent of grab_cache_page_write_begin(), which is moved into the folio-compat file as a reminder to migrate all the code using it. This paves the way for getting rid of AOP_FLAG_NOFS once grab_cache_page_write_begin() is removed. Kernel grows by 11 bytes. filemap_get_folio() grows by 33 bytes but grab_cache_page_write_begin() shrinks by 22 bytes to make up for it. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 1 + mm/filemap.c | 25 +++---------------------- mm/folio-compat.c | 13 +++++++++++++ 3 files changed, 17 insertions(+), 22 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 669bdebe2861..865b7784e99b 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -301,6 +301,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, #define FGP_FOR_MMAP 0x00000040 #define FGP_HEAD 0x00000080 #define FGP_ENTRY 0x00000100 +#define FGP_STABLE 0x00000200 struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, int fgp_flags, gfp_t gfp); diff --git a/mm/filemap.c b/mm/filemap.c index e431461279c3..4951fe8787d8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1817,6 +1817,7 @@ static struct folio *mapping_get_entry(struct address_space *mapping, * * %FGP_WRITE - The page will be written to by the caller. * * %FGP_NOFS - __GFP_FS will get cleared in gfp. * * %FGP_NOWAIT - Don't get blocked by page lock. + * * %FGP_STABLE - Wait for the folio to be stable (finished writeback) * * If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even * if the %GFP flags specified for %FGP_CREAT are atomic. @@ -1867,6 +1868,8 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, folio_clear_idle_flag(folio); } + if (fgp_flags & FGP_STABLE) + folio_wait_stable(folio); no_page: if (!folio && (fgp_flags & FGP_CREAT)) { int err; @@ -3590,28 +3593,6 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from) } EXPORT_SYMBOL(generic_file_direct_write); -/* - * Find or create a page at the given pagecache position. Return the locked - * page. This function is specifically for buffered writes. - */ -struct page *grab_cache_page_write_begin(struct address_space *mapping, - pgoff_t index, unsigned flags) -{ - struct page *page; - int fgp_flags = FGP_LOCK|FGP_WRITE|FGP_CREAT; - - if (flags & AOP_FLAG_NOFS) - fgp_flags |= FGP_NOFS; - - page = pagecache_get_page(mapping, index, fgp_flags, - mapping_gfp_mask(mapping)); - if (page) - wait_for_stable_page(page); - - return page; -} -EXPORT_SYMBOL(grab_cache_page_write_begin); - ssize_t generic_perform_write(struct file *file, struct iov_iter *i, loff_t pos) { diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 78365eaee7d3..206bedd621d0 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -115,6 +115,7 @@ void lru_cache_add(struct page *page) } EXPORT_SYMBOL(lru_cache_add); +noinline struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, int fgp_flags, gfp_t gfp) { @@ -126,3 +127,15 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, return folio_file_page(folio, index); } EXPORT_SYMBOL(pagecache_get_page); + +struct page *grab_cache_page_write_begin(struct address_space *mapping, + pgoff_t index, unsigned flags) +{ + unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE; + + if (flags & AOP_FLAG_NOFS) + fgp_flags |= FGP_NOFS; + return pagecache_get_page(mapping, index, fgp_flags, + mapping_gfp_mask(mapping)); +} +EXPORT_SYMBOL(grab_cache_page_write_begin); -- 2.30.2