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: 11371239 X-Patchwork-Delegate: snitzer@redhat.com 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 E9D6F14E3 for ; Fri, 7 Feb 2020 20:27:16 +0000 (UTC) Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A73C921775 for ; Fri, 7 Feb 2020 20:27:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WIFOjbR+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A73C921775 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=dm-devel-bounces@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581107235; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=U5lt9I3L5dTzewuT3x++YUndEc3ZdlIBwMbamM4D1v4=; b=WIFOjbR+YqkbVaPi/mkB4IJGovdhA8oyYfB39kAl3/9GL/cIuL5yKxxJvdcFGQDzVli8R2 F0WtzwVtJBz7/AQMyytJAk1+Kmx3Ayci8cEqNuscqLTnQOq+H6hvot4FQxeMIH/FE4/HrY Jg6M9ewcLVsuloQxhX4+oljx5x+SN5s= 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-408-kAv_hQ0BPqi9hvPSWOV-Lw-1; Fri, 07 Feb 2020 15:27:12 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 81913101FC61; Fri, 7 Feb 2020 20:27:08 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5DEEB19C7F; Fri, 7 Feb 2020 20:27:08 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id BFB288B2A0; Fri, 7 Feb 2020 20:27:07 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 017KR5Wg019034 for ; Fri, 7 Feb 2020 15:27:05 -0500 Received: by smtp.corp.redhat.com (Postfix) id D115B60C05; Fri, 7 Feb 2020 20:27:05 +0000 (UTC) Delivered-To: dm-devel@redhat.com 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 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 X-loop: dm-devel@redhat.com Cc: vishal.l.verma@intel.com, dm-devel@redhat.com, vgoyal@redhat.com Subject: [dm-devel] [PATCH v3 3/7] dax, pmem: Add a dax operation zero_page_range X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: kAv_hQ0BPqi9hvPSWOV-Lw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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,