From patchwork Fri Feb 7 20:26:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11371213 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 65F7314E3 for ; Fri, 7 Feb 2020 20:27:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44E5F21775 for ; Fri, 7 Feb 2020 20:27:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GwuIn7ez" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbgBGU1J (ORCPT ); Fri, 7 Feb 2020 15:27:09 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:28737 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726969AbgBGU1J (ORCPT ); Fri, 7 Feb 2020 15:27:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581107228; 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=PB+gWFvG77GLEzOFbhdQg0iy3vsZ/QZsUnjkaWFwfK0=; b=GwuIn7ezDt9nZiunBhxqaiHfItC/n+KUdjUiMzmC/gmGfxsWhmb3qI3acjUYDIScNP74fm K1z+TykiTiodt8ga5fxf9EcXP4C3EQhpY2kF/E62opuuhXE6x8q5RMwLmufczOnh5fqv21 iqYRLIkfL9m0u+5B6R4KutW64k11ZH8= 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-372-6Spsn_9VOW2BnY8Cgm3YQg-1; Fri, 07 Feb 2020 15:27:07 -0500 X-MC-Unique: 6Spsn_9VOW2BnY8Cgm3YQg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D472214E0; Fri, 7 Feb 2020 20:27:05 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0885D60BF7; Fri, 7 Feb 2020 20:27:03 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 9664B2257D5; Fri, 7 Feb 2020 15:27:02 -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: dm-devel@redhat.com, vishal.l.verma@intel.com, vgoyal@redhat.com Subject: [PATCH v3 3/7] dax, pmem: Add a dax operation zero_page_range Date: Fri, 7 Feb 2020 15:26:48 -0500 Message-Id: <20200207202652.1439-4-vgoyal@redhat.com> In-Reply-To: <20200207202652.1439-1-vgoyal@redhat.com> References: <20200207202652.1439-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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 range of memory. This will also clear any poison in the range being zeroed. As of now, zeroing of up to 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 --- drivers/dax/super.c | 19 +++++++++++++++++++ drivers/nvdimm/pmem.c | 15 +++++++++++++++ include/linux/dax.h | 3 +++ 3 files changed, 37 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 26a654dbc69a..31ee0b47b4ed 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -344,6 +344,25 @@ 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, u64 offset, size_t len) +{ + if (!dax_alive(dax_dev)) + return -ENXIO; + + if (!dax_dev->ops->zero_page_range) + return -EOPNOTSUPP; + /* + * There are no callers that want to zero across a page boundary 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 (offset_in_page(offset) + len > PAGE_SIZE) + return -EIO; + + return dax_dev->ops->zero_page_range(dax_dev, offset, len); +} +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 281fe04d25fd..0def7dc8e487 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -299,6 +299,20 @@ 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, u64 offset, + size_t len) +{ + int rc; + struct pmem_device *pmem = dax_get_private(dax_dev); + struct page *page = ZERO_PAGE(0); + + rc = pmem_do_write(pmem, page, 0, offset, len); + if (rc > 0) + return -EIO; + + return 0; +} + static long pmem_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) { @@ -330,6 +344,7 @@ 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 9bd8528bd305..a555f0aeb7bd 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 range with-in a page */ + int (*zero_page_range)(struct dax_device *, u64, size_t); }; extern struct attribute_group dax_attribute_group; @@ -209,6 +211,7 @@ 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, u64 offset, size_t len); 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,