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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 123FFC7C86A for ; Mon, 27 Apr 2020 08:48:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDE9C2080C for ; Mon, 27 Apr 2020 08:48:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726948AbgD0Is5 (ORCPT ); Mon, 27 Apr 2020 04:48:57 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:3144 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726904AbgD0Isv (ORCPT ); Mon, 27 Apr 2020 04:48:51 -0400 X-IronPort-AV: E=Sophos;i="5.73,323,1583164800"; d="scan'208";a="90547665" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 27 Apr 2020 16:48:38 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id 6332250A996F; Mon, 27 Apr 2020 16:37:53 +0800 (CST) Received: from G08CNEXCHPEKD05.g08.fujitsu.local (10.167.33.203) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 27 Apr 2020 16:48:35 +0800 Received: from localhost.localdomain (10.167.225.141) by G08CNEXCHPEKD05.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 27 Apr 2020 16:48:35 +0800 From: Shiyang Ruan To: , , CC: , , , , , , , , Subject: [RFC PATCH 4/8] fs/dax: copy data before write Date: Mon, 27 Apr 2020 16:47:46 +0800 Message-ID: <20200427084750.136031-5-ruansy.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200427084750.136031-1-ruansy.fnst@cn.fujitsu.com> References: <20200427084750.136031-1-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-yoursite-MailScanner-ID: 6332250A996F.AB3ED X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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, 32 insertions(+), 5 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 8107ed10c851..13a6a1d3c3b3 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1276,9 +1276,6 @@ 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)) - return -EIO; - /* * Write can allocate block for an area which has a hole page mapped * into page tables. We have to tear down these mappings so that data @@ -1315,6 +1312,12 @@ 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; @@ -1426,6 +1429,7 @@ 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); /* @@ -1507,19 +1511,27 @@ 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, &pfn, - NULL); + &kaddr); 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. @@ -1543,6 +1555,9 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto finish_iomap; case IOMAP_UNWRITTEN: + if (srcmap.type != IOMAP_HOLE) + goto cow; + /*FALLTHRU*/ case IOMAP_HOLE: if (!write) { ret = dax_load_hole(&xas, mapping, &entry, vmf); @@ -1650,6 +1665,7 @@ 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 @@ -1731,14 +1747,22 @@ 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, &pfn, - NULL); + &kaddr); 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. @@ -1757,6 +1781,9 @@ 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 (srcmap.type != IOMAP_HOLE) + goto cow; + /*FALLTHRU*/ case IOMAP_HOLE: if (WARN_ON_ONCE(write)) break; -- 2.26.2