From: Dan Williams <dan.j.williams@intel.com>
To: linux-nvdimm <linux-nvdimm@lists.01.org>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
stable <stable@vger.kernel.org>, Jan Kara <jack@suse.cz>,
"Oliver O'Halloran" <oohall@gmail.com>,
Jeff Moyer <jmoyer@redhat.com>,
Johannes Thumshirn <jthumshirn@suse.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Vishal L Verma <vishal.l.verma@intel.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 0/7] libnvdimm/pfn: Fix section-alignment padding
Date: Wed, 20 Feb 2019 09:11:04 -0800 [thread overview]
Message-ID: <CAPcyv4j9uEn9j=Y0Vo3oQJaXo-d-Xf=2-=0ucufhcXWeYOb0Yg@mail.gmail.com> (raw)
In-Reply-To: <155000668075.348031.9371497273408112600.stgit@dwillia2-desk3.amr.corp.intel.com>
On Tue, Feb 12, 2019 at 1:37 PM Dan Williams <dan.j.williams@intel.com> wrote:
>
> Lately Linux has encountered platforms that collide Persistent Memory
> regions between each other, specifically cases where ->start_pad needed
> to be non-zero. This lead to commit ae86cbfef381 "libnvdimm, pfn: Pad
> pfn namespaces relative to other regions". That commit allowed
> namespaces to be mapped with devm_memremap_pages(). However dax
> operations on those configurations currently fail if attempted within the
> ->start_pad range because pmem_device->data_offset was still relative to
> raw resource base not relative to the section aligned resource range
> mapped by devm_memremap_pages().
>
> Luckily __bdev_dax_supported() caught these failures and simply disabled
> dax. However, to fix this situation a non-backwards compatible change
> needs to be made to the interpretation of the nd_pfn info-block.
> ->start_pad needs to be accounted in ->map.map_offset (formerly
> ->data_offset), and ->map.map_base (formerly ->phys_addr) needs to be
> adjusted to the section aligned resource base used to establish
> ->map.map formerly (formerly ->virt_addr).
>
> See patch 7 "libnvdimm/pfn: Fix 'start_pad' implementation" for more
> details, and the ndctl patch series "Improve support + testing for
> labels + info-blocks" for the corresponding regression test.
Hello valued reviewers, can I plead for a sanity check of at least
"libnvdimm/pfn: Introduce super-block minimum version requirements"
and "libnvdimm/pfn: Fix 'start_pad' implementation"? In particular
Jeff / Johannes this has end user / distro impact in that users may
lose access to namespaces that are upgraded to v1.3 info-blocks and
then boot an old kernel. I did not see a way around that sharp edge.
> ---
>
> Dan Williams (7):
> libnvdimm/pfn: Account for PAGE_SIZE > info-block-size in nd_pfn_init()
> libnvdimm/pmem: Honor force_raw for legacy pmem regions
> dax: Check the end of the block-device capacity with dax_direct_access()
> libnvdimm/pfn: Introduce super-block minimum version requirements
> libnvdimm/pfn: Remove dax_label_reserve
> libnvdimm/pfn: Introduce 'struct pfn_map_info'
> libnvdimm/pfn: Fix 'start_pad' implementation
>
>
> drivers/dax/pmem.c | 9 +-
> drivers/dax/super.c | 39 ++++++--
> drivers/nvdimm/namespace_devs.c | 4 +
> drivers/nvdimm/nd.h | 15 +++
> drivers/nvdimm/pfn.h | 4 +
> drivers/nvdimm/pfn_devs.c | 181 ++++++++++++++++++++++++++++-----------
> drivers/nvdimm/pmem.c | 111 +++++++++++-------------
> drivers/nvdimm/pmem.h | 12 ---
> tools/testing/nvdimm/pmem-dax.c | 15 ++-
> 9 files changed, 244 insertions(+), 146 deletions(-)
next prev parent reply other threads:[~2019-02-20 17:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 21:24 [PATCH 0/7] libnvdimm/pfn: Fix section-alignment padding Dan Williams
2019-02-12 21:24 ` [PATCH 1/7] libnvdimm/pfn: Account for PAGE_SIZE > info-block-size in nd_pfn_init() Dan Williams
2019-02-12 21:24 ` [PATCH 2/7] libnvdimm/pmem: Honor force_raw for legacy pmem regions Dan Williams
2019-02-12 21:24 ` [PATCH 3/7] dax: Check the end of the block-device capacity with dax_direct_access() Dan Williams
2019-02-13 10:22 ` Jan Kara
2019-02-13 16:49 ` Dan Williams
2019-02-21 5:15 ` [PATCH v2] " Dan Williams
2019-02-12 21:25 ` [PATCH 4/7] libnvdimm/pfn: Introduce super-block minimum version requirements Dan Williams
2019-02-12 21:25 ` [PATCH 5/7] libnvdimm/pfn: Remove dax_label_reserve Dan Williams
2019-02-12 21:25 ` [PATCH 6/7] libnvdimm/pfn: Introduce 'struct pfn_map_info' Dan Williams
2019-02-12 21:25 ` [PATCH 7/7] libnvdimm/pfn: Fix 'start_pad' implementation Dan Williams
2019-02-21 23:47 ` Jeff Moyer
2019-02-22 3:58 ` Dan Williams
2019-02-22 15:42 ` Jeff Moyer
2019-02-22 17:12 ` Dan Williams
2019-02-22 17:21 ` Jeff Moyer
2019-02-20 17:11 ` Dan Williams [this message]
2019-02-20 17:19 ` [PATCH 0/7] libnvdimm/pfn: Fix section-alignment padding Johannes Thumshirn
2019-02-20 17:45 ` Jeff Moyer
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