From patchwork Fri Feb 28 16:34:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11412765 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 1C23E138D for ; Fri, 28 Feb 2020 16:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0291246BA for ; Fri, 28 Feb 2020 16:35:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="O+VhbNEL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726642AbgB1QfW (ORCPT ); Fri, 28 Feb 2020 11:35:22 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:29904 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726046AbgB1QfW (ORCPT ); Fri, 28 Feb 2020 11:35:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582907721; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LzvhLPASDAYE9tGXnm3XfqZQuF+iiZo5UZjI/h6SXbQ=; b=O+VhbNELhxfXtPVO1wkJFzAU0lPB5MMA+9QA7bR8ls+bFeQHFFrrjhdFzB7YgJhU6NQ/5r 2J1nL8+xenl2NPOKJNuKVRMNGF95NiGEP+IUJ1ASWxzW0V9p0eyj0jPB6UuxaWNy4jjOhf 0cX/PnYXKcg6/o3Sm5AaI3+K8kJqMfk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-401-Ri0bvLgjOeOqTxU7c8Ql1g-1; Fri, 28 Feb 2020 11:35:15 -0500 X-MC-Unique: Ri0bvLgjOeOqTxU7c8Ql1g-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1C0791005514; Fri, 28 Feb 2020 16:35:14 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 52DC89184F; Fri, 28 Feb 2020 16:35:11 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id C5A012257D4; Fri, 28 Feb 2020 11:35:10 -0500 (EST) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, hch@infradead.org, dan.j.williams@intel.com Cc: vgoyal@redhat.com, david@fromorbit.com, jmoyer@redhat.com, dm-devel@redhat.com Subject: [PATCH v6 2/6] dax, pmem: Add a dax operation zero_page_range Date: Fri, 28 Feb 2020 11:34:52 -0500 Message-Id: <20200228163456.1587-3-vgoyal@redhat.com> In-Reply-To: <20200228163456.1587-1-vgoyal@redhat.com> References: <20200228163456.1587-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add a dax operation zero_page_range, to zero a page. This will also clear any known poison in the page being zeroed. As of now, zeroing of one page is allowed in a single call. There are no callers which are trying to zero more than a page in a single call. Once we grow the callers which zero more than a page in single call, we can add that support. Primary reason for not doing that yet is that this will add little complexity in dm implementation where a range might be spanning multiple underlying targets and one will have to split the range into multiple sub ranges and call zero_page_range() on individual targets. Suggested-by: Christoph Hellwig Signed-off-by: Vivek Goyal Reviewed-by: Pankaj Gupta --- drivers/dax/super.c | 20 ++++++++++++++++++++ drivers/nvdimm/pmem.c | 11 +++++++++++ include/linux/dax.h | 4 ++++ 3 files changed, 35 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0aa4b6bc5101..e498daf3c0d7 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -344,6 +344,26 @@ size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, } EXPORT_SYMBOL_GPL(dax_copy_to_iter); +int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages) +{ + if (!dax_alive(dax_dev)) + return -ENXIO; + + if (!dax_dev->ops->zero_page_range) + return -EOPNOTSUPP; + /* + * There are no callers that want to zero more than one page as of now. + * Once users are there, this check can be removed after the + * device mapper code has been updated to split ranges across targets. + */ + if (nr_pages != 1) + return -EIO; + + return dax_dev->ops->zero_page_range(dax_dev, pgoff, nr_pages); +} +EXPORT_SYMBOL_GPL(dax_zero_page_range); + #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_wb_cache_pmem(void *addr, size_t size); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 075b11682192..5b774ddd0efb 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -282,6 +282,16 @@ static const struct block_device_operations pmem_fops = { .revalidate_disk = nvdimm_revalidate_disk, }; +static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages) +{ + struct pmem_device *pmem = dax_get_private(dax_dev); + + return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0, + PFN_PHYS(pgoff) >> SECTOR_SHIFT, + PAGE_SIZE)); +} + static long pmem_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -313,6 +323,7 @@ static const struct dax_operations pmem_dax_ops = { .dax_supported = generic_fsdax_supported, .copy_from_iter = pmem_copy_from_iter, .copy_to_iter = pmem_copy_to_iter, + .zero_page_range = pmem_dax_zero_page_range, }; static const struct attribute_group *pmem_attribute_groups[] = { diff --git a/include/linux/dax.h b/include/linux/dax.h index 328c2dbb4409..71735c430c05 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -34,6 +34,8 @@ struct dax_operations { /* copy_to_iter: required operation for fs-dax direct-i/o */ size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t, struct iov_iter *); + /* zero_page_range: required operation. Zero page range */ + int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; extern struct attribute_group dax_attribute_group; @@ -199,6 +201,8 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); +int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + size_t nr_pages); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,