From patchwork Tue Apr 16 16:41:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 10903479 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E3CD413B5 for ; Tue, 16 Apr 2019 16:42:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CD3FF289AB for ; Tue, 16 Apr 2019 16:42:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CB35328A03; Tue, 16 Apr 2019 16:42:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 76B04289AB for ; Tue, 16 Apr 2019 16:42:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730044AbfDPQmZ (ORCPT ); Tue, 16 Apr 2019 12:42:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:36282 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729237AbfDPQmY (ORCPT ); Tue, 16 Apr 2019 12:42:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 23E6EB0BE; Tue, 16 Apr 2019 16:42:23 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, jack@suse.cz, david@fromorbit.com, willy@infradead.org, hch@lst.de, darrick.wong@oracle.com, kilobyte@angband.pl, dsterba@suse.cz, nborisov@suse.com, linux-nvdimm@lists.01.org, Goldwyn Rodrigues Subject: [PATCH 08/18] dax: memcpy page in case of IOMAP_DAX_COW for mmap faults Date: Tue, 16 Apr 2019 11:41:44 -0500 Message-Id: <20190416164154.30390-9-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190416164154.30390-1-rgoldwyn@suse.de> References: <20190416164154.30390-1-rgoldwyn@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Goldwyn Rodrigues Change dax_iomap_pfn to return the address as well in order to use it for performing a memcpy in case the type is IOMAP_DAX_COW. Question: The sequence of bdev_dax_pgoff() and dax_direct_access() is used multiple times to calculate address and pfn's. Would it make sense to call it while calculating address as well to reduce code? Signed-off-by: Goldwyn Rodrigues --- fs/dax.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 4b4ac51fbd16..45fc2e18969a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -983,7 +983,7 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) } static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, - pfn_t *pfnp) + pfn_t *pfnp, void **addr) { const sector_t sector = dax_iomap_sector(iomap, pos); pgoff_t pgoff; @@ -995,7 +995,7 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size, return rc; id = dax_read_lock(); length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size), - NULL, pfnp); + addr, pfnp); if (length < 0) { rc = length; goto out; @@ -1280,6 +1280,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, XA_STATE(xas, &mapping->i_pages, vmf->pgoff); struct inode *inode = mapping->host; unsigned long vaddr = vmf->address; + void *addr; loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; struct iomap iomap = { 0 }; unsigned flags = IOMAP_FAULT; @@ -1369,16 +1370,23 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, sync = dax_fault_is_synchronous(flags, vma, &iomap); switch (iomap.type) { + case IOMAP_DAX_COW: case IOMAP_MAPPED: 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_pfn(&iomap, pos, PAGE_SIZE, &pfn); + error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn, &addr); if (error < 0) goto error_finish_iomap; + if (iomap.type == IOMAP_DAX_COW) { + if (iomap.inline_data) + memcpy(addr, iomap.inline_data, PAGE_SIZE); + else + memset(addr, 0, PAGE_SIZE); + } entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn, 0, write && !sync); @@ -1577,7 +1585,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, switch (iomap.type) { case IOMAP_MAPPED: - error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn); + error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn, NULL); if (error < 0) goto finish_iomap;