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=-9.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 E286DC433E1 for ; Wed, 10 Jun 2020 20:16:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C31072074B for ; Wed, 10 Jun 2020 20:16:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OiAighL9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728494AbgFJUQE (ORCPT ); Wed, 10 Jun 2020 16:16:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730555AbgFJUNu (ORCPT ); Wed, 10 Jun 2020 16:13:50 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81565C08C5C2; Wed, 10 Jun 2020 13:13:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=C9KNZLFkt8Tle4VaX/QjFZQwjCdLqmDjaJSbY4g1BBc=; b=OiAighL9mBrPMhnrkS/gqGty1F u+yNVja/T7n3ktY+YB0D0qaJCPfbXCZl+5ippi9ekL75UScg7fDbqZKZZfN8RISA5FApVLRtZbdg5 p0jd/PBsujMOChVBoe5Yno51GObGHDl00288vESYdf5iSJKEiH7iyWk5zCgBFto9+w9teXyQzL6hs eRHuA3fYJSvvczre/GDjn6fTWi0+rF5f1F0zwZFOTJtDR1b3TqOi3Glh1clzvypR6h2AZWUBEmf6J VqYU60h2wqrw0yz/hoFGCNB2yzIv9RcVmZBNol0fiYqT6bP6Vi7e0weWLFJWRUPFOBzhXVQ0OCLel hdP4QG6w==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jj76a-0003Vv-BK; Wed, 10 Jun 2020 20:13:48 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 28/51] iomap: Change iomap_write_begin calling convention Date: Wed, 10 Jun 2020 13:13:22 -0700 Message-Id: <20200610201345.13273-29-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200610201345.13273-1-willy@infradead.org> References: <20200610201345.13273-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: "Matthew Wilcox (Oracle)" Pass (up to) the remaining length of the extent to iomap_write_begin() and have it return the number of bytes that will fit in the page. That lets us copy more bytes per call to iomap_write_begin() if the page cache has already allocated a THP (and will in future allow us to pass a hint to the page cache that it should try to allocate a larger page if there are none in the cache). Signed-off-by: Matthew Wilcox (Oracle) --- fs/iomap/buffered-io.c | 63 +++++++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 29 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8d690ad68657..e445ee5f0521 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -571,14 +571,14 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, return submit_bio_wait(&bio); } -static int -__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, - struct page *page, struct iomap *srcmap) +static ssize_t __iomap_write_begin(struct inode *inode, loff_t pos, + size_t len, int flags, struct page *page, struct iomap *srcmap) { loff_t block_size = i_blocksize(inode); loff_t block_start = pos & ~(block_size - 1); loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1); - unsigned from = offset_in_page(pos), to = from + len; + size_t from = offset_in_thp(page, pos); + size_t to = from + len; size_t poff, plen; int status; @@ -614,12 +614,13 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, return 0; } -static int -iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, - struct page **pagep, struct iomap *iomap, struct iomap *srcmap) +static ssize_t iomap_write_begin(struct inode *inode, loff_t pos, loff_t len, + unsigned flags, struct page **pagep, struct iomap *iomap, + struct iomap *srcmap) { const struct iomap_page_ops *page_ops = iomap->page_ops; struct page *page; + size_t offset; int status = 0; BUG_ON(pos + len > iomap->offset + iomap->length); @@ -630,6 +631,8 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, return -EINTR; if (page_ops && page_ops->page_prepare) { + if (len > UINT_MAX) + len = UINT_MAX; status = page_ops->page_prepare(inode, pos, len, iomap); if (status) return status; @@ -641,6 +644,10 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, status = -ENOMEM; goto out_no_page; } + page = thp_head(page); + offset = offset_in_thp(page, pos); + if (len > thp_size(page) - offset) + len = thp_size(page) - offset; if (srcmap->type == IOMAP_INLINE) iomap_read_inline_data(inode, page, srcmap); @@ -650,11 +657,11 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, status = __iomap_write_begin(inode, pos, len, flags, page, srcmap); - if (unlikely(status)) + if (status < 0) goto out_unlock; *pagep = page; - return 0; + return len; out_unlock: unlock_page(page); @@ -809,8 +816,10 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap); - if (unlikely(status)) + if (status < 0) break; + /* We may be partway through a THP */ + offset = offset_in_thp(page, pos); if (mapping_writably_mapped(inode->i_mapping)) flush_dcache_page(page); @@ -872,8 +881,7 @@ static loff_t iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iomap *iomap, struct iomap *srcmap) { - long status = 0; - ssize_t written = 0; + loff_t written = 0; /* don't bother with blocks that are not shared to start with */ if (!(iomap->flags & IOMAP_F_SHARED)) @@ -883,25 +891,24 @@ iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data, return length; do { - unsigned long offset = offset_in_page(pos); - unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length); struct page *page; + ssize_t bytes; - status = iomap_write_begin(inode, pos, bytes, + bytes = iomap_write_begin(inode, pos, length, IOMAP_WRITE_F_UNSHARE, &page, iomap, srcmap); - if (unlikely(status)) - return status; + if (bytes < 0) + return bytes; - status = iomap_write_end(inode, pos, bytes, bytes, page, iomap, + bytes = iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); - if (WARN_ON_ONCE(status == 0)) + if (WARN_ON_ONCE(bytes == 0)) return -EIO; cond_resched(); - pos += status; - written += status; - length -= status; + pos += bytes; + written += bytes; + length -= bytes; balance_dirty_pages_ratelimited(inode->i_mapping); } while (length); @@ -932,15 +939,13 @@ static ssize_t iomap_zero(struct inode *inode, loff_t pos, loff_t length, struct iomap *iomap, struct iomap *srcmap) { struct page *page; - int status; - unsigned offset = offset_in_page(pos); - unsigned bytes = min_t(loff_t, PAGE_SIZE - offset, length); + ssize_t bytes; - status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap); - if (status) - return status; + bytes = iomap_write_begin(inode, pos, length, 0, &page, iomap, srcmap); + if (bytes < 0) + return bytes; - zero_user(page, offset, bytes); + zero_user(page, offset_in_thp(page, pos), bytes); mark_page_accessed(page); return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); -- 2.26.2