From patchwork Sun Feb 7 17:09:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ruan Shiyang X-Patchwork-Id: 12073199 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 7A479C4332D for ; Sun, 7 Feb 2021 17:11:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D92764DD4 for ; Sun, 7 Feb 2021 17:11:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbhBGRK2 (ORCPT ); Sun, 7 Feb 2021 12:10:28 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:49728 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S229445AbhBGRK0 (ORCPT ); Sun, 7 Feb 2021 12:10:26 -0500 X-IronPort-AV: E=Sophos;i="5.81,160,1610380800"; d="scan'208";a="104299366" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 08 Feb 2021 01:09:32 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id A5EAA4CE6F78; Mon, 8 Feb 2021 01:09:31 +0800 (CST) Received: from G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.200) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 8 Feb 2021 01:09:32 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD04.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 8 Feb 2021 01:09:33 +0800 From: Shiyang Ruan To: , , , CC: , , , , , , , , , Subject: [PATCH 3/7] fsdax: Copy data before write Date: Mon, 8 Feb 2021 01:09:20 +0800 Message-ID: <20210207170924.2933035-4-ruansy.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210207170924.2933035-1-ruansy.fnst@cn.fujitsu.com> References: <20210207170924.2933035-1-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: A5EAA4CE6F78.AEB4A X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@cn.fujitsu.com Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Add dax_copy_edges() into each dax actor functions to perform CoW. Signed-off-by: Shiyang Ruan --- fs/dax.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index ea4e8a434900..b2195cbdf2dc 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1161,7 +1161,8 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, return iov_iter_zero(min(length, end - pos), iter); } - if (WARN_ON_ONCE(iomap->type != IOMAP_MAPPED)) + if (WARN_ON_ONCE(iomap->type != IOMAP_MAPPED && + !(iomap->flags & IOMAP_F_SHARED))) return -EIO; /* @@ -1200,6 +1201,12 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, break; } + if (iomap != srcmap) { + ret = dax_copy_edges(pos, length, srcmap, kaddr, false); + if (ret) + break; + } + map_len = PFN_PHYS(map_len); kaddr += offset; map_len -= offset; @@ -1311,6 +1318,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, vm_fault_t ret = 0; void *entry; pfn_t pfn; + void *kaddr; trace_dax_pte_fault(inode, vmf, ret); /* @@ -1392,19 +1400,27 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, switch (iomap.type) { case IOMAP_MAPPED: +cow: if (iomap.flags & IOMAP_F_NEW) { count_vm_event(PGMAJFAULT); count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); major = VM_FAULT_MAJOR; } error = dax_iomap_direct_access(&iomap, pos, PAGE_SIZE, - NULL, &pfn); + &kaddr, &pfn); if (error < 0) goto error_finish_iomap; entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, write && !sync); + if (srcmap.type != IOMAP_HOLE) { + error = dax_copy_edges(pos, PAGE_SIZE, &srcmap, kaddr, + false); + if (error) + goto error_finish_iomap; + } + /* * If we are doing synchronous page fault and inode needs fsync, * we can insert PTE into page tables only after that happens. @@ -1428,6 +1444,9 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto finish_iomap; case IOMAP_UNWRITTEN: + if (write && iomap.flags & IOMAP_F_SHARED) + goto cow; + fallthrough; case IOMAP_HOLE: if (!write) { ret = dax_load_hole(&xas, mapping, &entry, vmf); @@ -1535,6 +1554,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, loff_t pos; int error; pfn_t pfn; + void *kaddr; /* * Check whether offset isn't beyond end of file now. Caller is @@ -1616,14 +1636,22 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, switch (iomap.type) { case IOMAP_MAPPED: +cow: error = dax_iomap_direct_access(&iomap, pos, PMD_SIZE, - NULL, &pfn); + &kaddr, &pfn); if (error < 0) goto finish_iomap; entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, DAX_PMD, write && !sync); + if (srcmap.type != IOMAP_HOLE) { + error = dax_copy_edges(pos, PMD_SIZE, &srcmap, kaddr, + true); + if (error) + goto unlock_entry; + } + /* * If we are doing synchronous page fault and inode needs fsync, * we can insert PMD into page tables only after that happens. @@ -1642,6 +1670,9 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, result = vmf_insert_pfn_pmd(vmf, pfn, write); break; case IOMAP_UNWRITTEN: + if (write && iomap.flags & IOMAP_F_SHARED) + goto cow; + fallthrough; case IOMAP_HOLE: if (WARN_ON_ONCE(write)) break;