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=-18.8 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 A62E3C4338F for ; Wed, 11 Aug 2021 02:54:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C7FD60230 for ; Wed, 11 Aug 2021 02:54:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232169AbhHKCya (ORCPT ); Tue, 10 Aug 2021 22:54:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232411AbhHKCy3 (ORCPT ); Tue, 10 Aug 2021 22:54:29 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5638AC061765; Tue, 10 Aug 2021 19:54:06 -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=iwzzerqMwO0iARK6ivjyqoH0sPMbU6DdjS1W/L65Gw4=; b=dl4Idaw9os9wRyASw7lpS62HOc uKMrpUoq04IeDgqBDLyq7mdsf7JH8Vx/+ozDbo7kG6T3O2Lzl/w/cw40mvsC3f4PFlcRsUkMVX74M AEcDlY6tGRRRqZolxggI1XFJu2c7lY+nLzvvaP+3MAhQx7EVpDmJUFtObw1lwMeLKcPCgUtz01T7P CaSRY+bnjrUxaZfXOWAHSDBszlChtAWPrlYzqfqz3B6pgY/rhDn/5/Qbfwd97JFjDtHi+icgZ6YOF joPXDLfwdob5DByPLCPhWGSkPfQb2nugWT8agM7A5JMAQrmrLL8cAJy5y6Hrq+dAcd4tJAGem6X0n ibjDPxYw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDeMH-00CsUv-Bk; Wed, 11 Aug 2021 02:53:05 +0000 From: "Matthew Wilcox (Oracle)" To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" Subject: [PATCH 8/8] iomap: Add writethrough for O_SYNC Date: Wed, 11 Aug 2021 03:46:47 +0100 Message-Id: <20210811024647.3067739-9-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210811024647.3067739-1-willy@infradead.org> References: <20210811024647.3067739-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org For O_SYNC writes, if the filesystem has already allocated blocks for the range, we can avoid marking the page as dirty and skip straight to marking the page as writeback. Signed-off-by: Matthew Wilcox (Oracle) --- fs/iomap/buffered-io.c | 78 +++++++++++++++++++++++++++++++++++------- 1 file changed, 66 insertions(+), 12 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index eb068e21d3bb..93b889338172 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -657,8 +657,45 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, return status; } -static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, - size_t copied, struct page *page) +/* Rearrange file so we don't need this forward declaration */ +static struct iomap_ioend *iomap_add_to_ioend(struct inode *inode, + loff_t pos, size_t len, struct page *page, + struct iomap_page *iop, struct iomap *iomap, + struct iomap_ioend *ioend, struct writeback_control *wbc, + struct list_head *iolist); + +/* Returns true if we can skip dirtying the page */ +static bool iomap_write_through(struct iomap_write_ctx *iwc, + struct iomap *iomap, struct inode *inode, struct page *page, + loff_t pos, size_t len) +{ + unsigned int blksize = i_blocksize(inode); + + if (!iwc || !iwc->write_through) + return false; + if (PageDirty(page)) + return true; + if (PageWriteback(page)) + return false; + + /* Can't allocate blocks here because we don't have ->prepare_ioend */ + if (iomap->type != IOMAP_MAPPED || iomap->type != IOMAP_UNWRITTEN || + iomap->flags & IOMAP_F_SHARED) + return false; + + len = round_up(pos + len - 1, blksize); + pos = round_down(pos, blksize); + len -= pos; + iwc->ioend = iomap_add_to_ioend(inode, pos, len, page, + iomap_page_create(inode, page), iomap, iwc->ioend, NULL, + &iwc->iolist); + set_page_writeback(page); + return true; +} + +static size_t __iomap_write_end(struct iomap_write_ctx *iwc, + struct iomap *iomap, struct inode *inode, loff_t pos, + size_t len, size_t copied, struct page *page) { flush_dcache_page(page); @@ -676,7 +713,8 @@ static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, if (unlikely(copied < len && !PageUptodate(page))) return 0; iomap_set_range_uptodate(page, offset_in_page(pos), len); - __set_page_dirty_nobuffers(page); + if (!iomap_write_through(iwc, iomap, inode, page, pos, len)) + __set_page_dirty_nobuffers(page); return copied; } @@ -698,9 +736,9 @@ static size_t iomap_write_end_inline(struct inode *inode, struct page *page, } /* Returns the number of bytes copied. May be 0. Cannot be an errno. */ -static size_t iomap_write_end(struct inode *inode, loff_t pos, size_t len, - size_t copied, struct page *page, struct iomap *iomap, - struct iomap *srcmap) +static size_t iomap_write_end(struct iomap_write_ctx *iwc, struct inode *inode, + loff_t pos, size_t len, size_t copied, struct page *page, + struct iomap *iomap, struct iomap *srcmap) { const struct iomap_page_ops *page_ops = iomap->page_ops; loff_t old_size = inode->i_size; @@ -712,7 +750,8 @@ static size_t iomap_write_end(struct inode *inode, loff_t pos, size_t len, ret = block_write_end(NULL, inode->i_mapping, pos, len, copied, page, NULL); } else { - ret = __iomap_write_end(inode, pos, len, copied, page); + ret = __iomap_write_end(iwc, iomap, inode, pos, len, copied, + page); } /* @@ -780,8 +819,8 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, copied = copy_page_from_iter_atomic(page, offset, bytes, i); - status = iomap_write_end(inode, pos, bytes, copied, page, iomap, - srcmap); + status = iomap_write_end(iwc, inode, pos, bytes, copied, page, + iomap, srcmap); if (unlikely(copied != status)) iov_iter_revert(i, copied - status); @@ -808,6 +847,10 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, return written ? written : status; } +/* Also rearrange */ +static int iomap_submit_ioend(struct iomap_writepage_ctx *wpc, + struct iomap_ioend *ioend, int error); + ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops) @@ -817,6 +860,7 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter, .iolist = LIST_HEAD_INIT(iwc.iolist), .write_through = iocb->ki_flags & IOCB_SYNC, }; + struct iomap_ioend *ioend, *next; struct inode *inode = iocb->ki_filp->f_mapping->host; loff_t pos = iocb->ki_pos, ret = 0, written = 0; @@ -829,6 +873,15 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *iter, written += ret; } + if (ret > 0) + ret = 0; + + list_for_each_entry_safe(ioend, next, &iwc.iolist, io_list) { + list_del_init(&ioend->io_list); + ret = iomap_submit_ioend(NULL, ioend, ret); + } + if (iwc.ioend) + ret = iomap_submit_ioend(NULL, iwc.ioend, ret); return written ? written : ret; } EXPORT_SYMBOL_GPL(iomap_file_buffered_write); @@ -857,8 +910,8 @@ iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, if (unlikely(status)) return status; - status = iomap_write_end(inode, pos, bytes, bytes, page, iomap, - srcmap); + status = iomap_write_end(NULL, inode, pos, bytes, bytes, page, + iomap, srcmap); if (WARN_ON_ONCE(status == 0)) return -EIO; @@ -908,7 +961,8 @@ static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length, zero_user(page, offset, bytes); mark_page_accessed(page); - return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); + return iomap_write_end(NULL, inode, pos, bytes, bytes, page, iomap, + srcmap); } static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos, -- 2.30.2