From patchwork Mon Feb 3 20:00:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11363353 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 6FA70921 for ; Mon, 3 Feb 2020 20:00:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 449EC20721 for ; Mon, 3 Feb 2020 20:00:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="a76lDm3N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726853AbgBCUA4 (ORCPT ); Mon, 3 Feb 2020 15:00:56 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:51841 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726331AbgBCUA4 (ORCPT ); Mon, 3 Feb 2020 15:00:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580760054; 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=S67a5FmWny8OUQz/Os/tqeEXDXljoowi80eZq1WINIk=; b=a76lDm3NbugbXGRMP5oSXdNL6BJGOzyQ68uF4TG77vJcQpR3MCg9ybk659lRZa/zEf36/q HW/OwBtyn0L+lGTnH+16kSxCASI+EK+AhCNECCez3dM4OH8FIUNrKAePf6nVf3I31I5EJY wG8DLMfHLVoL43VmkDXpIc1tMsBaed4= 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-370-vX3gM4q9MPa3fPvuVXeDbQ-1; Mon, 03 Feb 2020 15:00:50 -0500 X-MC-Unique: vX3gM4q9MPa3fPvuVXeDbQ-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 514FF800D55; Mon, 3 Feb 2020 20:00:49 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7528B60BE0; Mon, 3 Feb 2020 20:00:46 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 092842246AE; Mon, 3 Feb 2020 15:00:46 -0500 (EST) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, dan.j.williams@intel.com, hch@infradead.org Cc: vgoyal@redhat.com, vishal.l.verma@intel.com, dm-devel@redhat.com Subject: [PATCH 1/5] dax, pmem: Add a dax operation zero_page_range Date: Mon, 3 Feb 2020 15:00:25 -0500 Message-Id: <20200203200029.4592-2-vgoyal@redhat.com> In-Reply-To: <20200203200029.4592-1-vgoyal@redhat.com> References: <20200203200029.4592-1-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 | 20 +++++++++++++++++ drivers/nvdimm/pmem.c | 50 +++++++++++++++++++++++++++++++++++++++++++ fs/dax.c | 15 +++++++++++++ include/linux/dax.h | 6 ++++++ 4 files changed, 91 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 26a654dbc69a..371744256fe5 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, + unsigned offset, size_t len) +{ + if (!dax_alive(dax_dev)) + return -ENXIO; + + if (!dax_dev->ops->zero_page_range) + return -EOPNOTSUPP; + + /* + * There are no users as of now. Once users are there, fix dm code + * to be able to split a long range across targets. + */ + if (offset + len > PAGE_SIZE) + return -EIO; + + return dax_dev->ops->zero_page_range(dax_dev, pgoff, 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 ad8e4df1282b..8739244a72a4 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -268,6 +268,55 @@ 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, + unsigned int offset, size_t len) +{ + int rc = 0; + phys_addr_t phys_pos = pgoff * PAGE_SIZE + offset; + struct pmem_device *pmem = dax_get_private(dax_dev); + struct page *page = ZERO_PAGE(0); + unsigned bytes, nr_sectors = 0; + sector_t sector_start, sector_end; + bool bad_pmem = false; + phys_addr_t pmem_off = phys_pos + pmem->data_offset; + void *pmem_addr = pmem->virt_addr + pmem_off; + + bytes = min_t(size_t, PAGE_SIZE - offset_in_page(phys_pos), + len); + /* + * As of now zeroing only with-in a page is supported. This can be + * changed once there are users of zeroing across multiple pages + */ + if (WARN_ON(len > bytes)) + return -EIO; + + sector_start = ALIGN(phys_pos, 512)/512; + sector_end = ALIGN_DOWN(phys_pos + bytes, 512)/512; + if (sector_end > sector_start) + nr_sectors = sector_end - sector_start; + + if (nr_sectors && + unlikely(is_bad_pmem(&pmem->bb, sector_start, + nr_sectors * 512))) + bad_pmem = true; + + write_pmem(pmem_addr, page, 0, bytes); + if (unlikely(bad_pmem)) { + /* + * Pass block aligned offset and length. That seems + * to work as of now. Other finer grained alignment + * cases can be addressed later if need be. + */ + rc = pmem_clear_poison(pmem, ALIGN(pmem_off, 512), + nr_sectors * 512); + write_pmem(pmem_addr, page, 0, bytes); + } + 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) { @@ -299,6 +348,7 @@ 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/fs/dax.c b/fs/dax.c index 1f1f0201cad1..35631a4d0295 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1057,6 +1057,21 @@ static bool dax_range_is_aligned(struct block_device *bdev, return true; } +int generic_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + unsigned int offset, size_t len) +{ + long rc; + void *kaddr; + + rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL); + if (rc < 0) + return rc; + memset(kaddr + offset, 0, len); + dax_flush(dax_dev, kaddr + offset, len); + return 0; +} +EXPORT_SYMBOL_GPL(generic_dax_zero_page_range); + int __dax_zero_page_range(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, unsigned int offset, unsigned int size) diff --git a/include/linux/dax.h b/include/linux/dax.h index 9bd8528bd305..3356b874c55d 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 for fs-dax direct-i/o */ + int (*zero_page_range)(struct dax_device *, pgoff_t, unsigned, size_t); }; extern struct attribute_group dax_attribute_group; @@ -209,6 +211,10 @@ 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, + unsigned offset, size_t len); +int generic_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, + unsigned int 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,