From patchwork Mon Aug 24 15:16:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matthew Wilcox (Oracle)" X-Patchwork-Id: 11733433 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3E724138A for ; Mon, 24 Aug 2020 15:18:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23FCC2074D for ; Mon, 24 Aug 2020 15:18:53 +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="wOwrwRJD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727877AbgHXPSY (ORCPT ); Mon, 24 Aug 2020 11:18:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727814AbgHXPRg (ORCPT ); Mon, 24 Aug 2020 11:17:36 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72AE8C061797; Mon, 24 Aug 2020 08:17:06 -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=iplF7f6E9rVkJGIqHTB4yelEOJviHWixj4QJSoLjmRs=; b=wOwrwRJDflHbn0w8l8oVd8i/gG tDkiDCAoTdInbSi1U4J8L8XJ+4FtpCYlW6KYoznapN7lbPYwaEXP+IgUuQ8k38eYQJNWoMOSpUe3F ZGAiJBT6q9NrHezDtdE9spayZleXvlrupTLI31qA5MUil5lsTDYQ1NY4SFvDhH6pGk4dKU2G0mOx8 mi8dnnU/mP4QZ/sDShPacSwywxJhHkL/oFsGpIzGuVdJg5c3yZVtkqL2Xp4kWRMkCDv0vEMueaG17 DpXJxnwR9FEgTiHv6DaZ8g+0qu3PjtAhbodG4Z8OEKtI7Xg8Ld2GScT9R1lfXOXEr4SLJh7JZuN7s zGaW7JtA==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kAEDY-0004DG-9x; Mon, 24 Aug 2020 15:17:04 +0000 From: "Matthew Wilcox (Oracle)" To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , "Darrick J . Wong" , linux-block@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 08/11] iomap: Change iomap_write_begin calling convention Date: Mon, 24 Aug 2020 16:16:57 +0100 Message-Id: <20200824151700.16097-9-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200824151700.16097-1-willy@infradead.org> References: <20200824151700.16097-1-willy@infradead.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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 | 61 +++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 28 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index d14de8886d5c..f43a15aaa381 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -566,14 +566,14 @@ 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; @@ -609,12 +609,13 @@ __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); @@ -625,6 +626,8 @@ 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; @@ -636,6 +639,10 @@ 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); @@ -645,11 +652,11 @@ 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); @@ -805,8 +812,10 @@ 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); @@ -866,7 +875,6 @@ 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; loff_t written = 0; /* don't bother with blocks that are not shared to start with */ @@ -877,25 +885,24 @@ 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); @@ -926,15 +933,13 @@ static loff_t iomap_zero(struct inode *inode, loff_t pos, u64 length, struct iomap *iomap, struct iomap *srcmap) { struct page *page; - int status; - unsigned offset = offset_in_page(pos); - unsigned bytes = min_t(u64, 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);