Commit Graph

56 Commits

Author SHA1 Message Date
Linus Torvalds
523634db14 libnvdimm fixes v5.3-rc2
- Fix duplicate device_unregister() calls (multiple threads competing to
   do unregister work when scheduling device removal from a sysfs attribute
   of the self-same device).
 
 - Fix badblocks registration order bug. Ensure region badblocks are
   initialized in advance of namespace registration.
 
 - Fix a deadlock between the bus lock and probe operations.
 
 - Export device-core infrastructure to coordinate async operations via
   the device ->dead state.
 
 - Add device-core infrastructure to validate device_lock() usage with
   lockdep.
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Merge tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "A collection of locking and async operations fixes for v5.3-rc2. These
  had been soaking in a branch targeting the merge window, but missed
  due to a regression hunt. This fixed up version has otherwise been in
  -next this past week with no reported issues.

  In order to gain confidence in the locking changes the pull also
  includes a debug / instrumentation patch to enable lockdep coverage
  for libnvdimm subsystem operations that depend on the device_lock for
  exclusion. As mentioned in the changelog it is a hack, but it works
  and documents the locking expectations of the sub-system in a way that
  others can use lockdep to verify. The driver core touches got an ack
  from Greg.

  Summary:

   - Fix duplicate device_unregister() calls (multiple threads competing
     to do unregister work when scheduling device removal from a sysfs
     attribute of the self-same device).

   - Fix badblocks registration order bug. Ensure region badblocks are
     initialized in advance of namespace registration.

   - Fix a deadlock between the bus lock and probe operations.

   - Export device-core infrastructure to coordinate async operations
     via the device ->dead state.

   - Add device-core infrastructure to validate device_lock() usage with
     lockdep"

* tag 'libnvdimm-fixes-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  driver-core, libnvdimm: Let device subsystems add local lockdep coverage
  libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock
  libnvdimm/bus: Stop holding nvdimm_bus_list_mutex over __nd_ioctl()
  libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant
  libnvdimm/region: Register badblocks before namespaces
  libnvdimm/bus: Prevent duplicate device_unregister() calls
  drivers/base: Introduce kill_device()
2019-07-27 08:25:51 -07:00
Dan Williams
a3619190d6 libnvdimm/pfn: stop padding pmem namespaces to section alignment
Now that the mm core supports section-unaligned hotplug of ZONE_DEVICE
memory, we no longer need to add padding at pfn/dax device creation
time.  The kernel will still honor padding established by older kernels.

Link: http://lkml.kernel.org/r/156092356588.979959.6793371748950931916.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
Dan Williams
7e3e888dfc libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
At namespace creation time there is the potential for the "expected to
be zero" fields of a 'pfn' info-block to be filled with indeterminate
data.  While the kernel buffer is zeroed on allocation it is immediately
overwritten by nd_pfn_validate() filling it with the current contents of
the on-media info-block location.  For fields like, 'flags' and the
'padding' it potentially means that future implementations can not rely on
those fields being zero.

In preparation to stop using the 'start_pad' and 'end_trunc' fields for
section alignment, arrange for fields that are not explicitly
initialized to be guaranteed zero.  Bump the minor version to indicate
it is safe to assume the 'padding' and 'flags' are zero.  Otherwise,
this corruption is expected to benign since all other critical fields
are explicitly initialized.

Note The cc: stable is about spreading this new policy to as many
kernels as possible not fixing an issue in those kernels.  It is not
until the change titled "libnvdimm/pfn: Stop padding pmem namespaces to
section alignment" where this improper initialization becomes a problem.
So if someone decides to backport "libnvdimm/pfn: Stop padding pmem
namespaces to section alignment" (which is not tagged for stable), make
sure this pre-requisite is flagged.

Link: http://lkml.kernel.org/r/156092356065.979959.6681003754765958296.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 32ab0a3f51 ("libnvdimm, pmem: 'struct page' for pmem")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
Cc: <stable@vger.kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
Dan Williams
87a30e1f05 driver-core, libnvdimm: Let device subsystems add local lockdep coverage
For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.

A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.

Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:

    "Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
     using it as much as anything else, so user beware :)

     I don't object to it if it makes things easier for you to debug."

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
2019-07-18 16:23:27 -07:00
Christoph Hellwig
514caf23a7 memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
Add a flags field to struct dev_pagemap to replace the altmap_valid
boolean to be a little more extensible.  Also add a pgmap_altmap() helper
to find the optional altmap and clean up the code using the altmap using
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-02 14:32:44 -03:00
Thomas Gleixner
5b497af42f treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of version 2 of the gnu general public license as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 64 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:38 +02:00
Christoph Hellwig
72deb455b5 block: remove CONFIG_LBDAF
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures.  These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time.  Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.

Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06 10:48:35 -06:00
Dan Williams
4960461f5d libnvdimm/pfn: Remove dax_label_reserve
The reserve was for an abandoned effort to add label (partitioning
support) to device-dax instances. Remove it.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-02-22 11:52:32 -08:00
Dan Williams
11a358109e libnvdimm/pfn: Account for PAGE_SIZE > info-block-size in nd_pfn_init()
Similar to "libnvdimm: Fix altmap reservation size calculation" provide
for a reservation of a full page worth of info block space at info-block
establishment time.  Typically there is already slack in the padding
from honoring the default 2MB alignment, but provide for a reservation
for corner case configurations that would otherwise fit.

Cc: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-02-12 10:37:16 -08:00
Oliver O'Halloran
07464e8836 libnvdimm: Fix altmap reservation size calculation
Libnvdimm reserves the first 8K of pfn and devicedax namespaces to
store a superblock describing the namespace. This 8K reservation
is contained within the altmap area which the kernel uses for the
vmemmap backing for the pages within the namespace. The altmap
allows for some pages at the start of the altmap area to be reserved
and that mechanism is used to protect the superblock from being
re-used as vmemmap backing.

The number of PFNs to reserve is calculated using:

	PHYS_PFN(SZ_8K)

Which is implemented as:

 #define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))

So on systems where PAGE_SIZE is greater than 8K the reservation
size is truncated to zero and the superblock area is re-used as
vmemmap backing. As a result all the namespace information stored
in the superblock (i.e. if it's a PFN or DAX namespace) is lost
and the namespace needs to be re-created to get access to the
contents.

This patch fixes this by using PFN_UP() rather than PHYS_PFN() to ensure
that at least one page is reserved. On systems with a 4K pages size this
patch should have no effect.

Cc: stable@vger.kernel.org
Cc: Dan Williams <dan.j.williams@intel.com>
Fixes: ac515c084b ("libnvdimm, pmem, pfn: move pfn setup to the core")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-02-12 10:36:34 -08:00
Wei Yang
f101ada7da libnvdimm, pfn: Fix over-trim in trim_pfn_device()
When trying to see whether current nd_region intersects with others,
trim_pfn_device() has already calculated the *size* to be expanded to
SECTION size.

Do not double append 'adjust' to 'size' when calculating whether the end
of a region collides with the next pmem region.

Fixes: ae86cbfef3 "libnvdimm, pfn: Pad pfn namespaces relative to other regions"
Cc: <stable@vger.kernel.org>
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-02-12 10:18:44 -08:00
Dan Williams
ae86cbfef3 libnvdimm, pfn: Pad pfn namespaces relative to other regions
Commit cfe30b8720 "libnvdimm, pmem: adjust for section collisions with
'System RAM'" enabled Linux to workaround occasions where platform
firmware arranges for "System RAM" and "Persistent Memory" to collide
within a single section boundary. Unfortunately, as reported in this
issue [1], platform firmware can inflict the same collision between
persistent memory regions.

The approach of interrogating iomem_resource does not work in this
case because platform firmware may merge multiple regions into a single
iomem_resource range. Instead provide a method to interrogate regions
that share the same parent bus.

This is a stop-gap until the core-MM can grow support for hotplug on
sub-section boundaries.

[1]: https://github.com/pmem/ndctl/issues/76

Fixes: cfe30b8720 ("libnvdimm, pmem: adjust for section collisions with...")
Cc: <stable@vger.kernel.org>
Reported-by: Patrick Geary <patrickg@supermicro.com>
Tested-by: Patrick Geary <patrickg@supermicro.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-12-05 14:16:12 -08:00
Vishal Verma
48af2f7e52 libnvdimm, pfn: during init, clear errors in the metadata area
If there are badblocks present in the 'struct page' area for pfn
namespaces, until now, the only way to clear them has been to force the
namespace into raw mode, clear the errors, and re-enable the fsdax mode.
This is clunky, given that it should be easy enough for the pfn driver
to do the same.

Add a new helper that uses the most recently available badblocks list to
check whether there are any badblocks that lie in the volatile struct
page area. If so, before initializing the struct pages, send down
targeted writes via nvdimm_write_bytes to write zeroes to the affected
blocks, and thus clear errors.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-09-28 11:06:56 -07:00
Dan Williams
e763848843 mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
In preparation for fixing dax-dma-vs-unmap issues, filesystems need to
be able to rely on the fact that they will get wakeups on dev_pagemap
page-idle events. Introduce MEMORY_DEVICE_FS_DAX and
generic_dax_page_free() as common indicator / infrastructure for dax
filesytems to require. With this change there are no users of the
MEMORY_DEVICE_HOST designation, so remove it.

The HMM sub-system extended dev_pagemap to arrange a callback when a
dev_pagemap managed page is freed. Since a dev_pagemap page is free /
idle when its reference count is 1 it requires an additional branch to
check the page-type at put_page() time. Given put_page() is a hot-path
we do not want to incur that check if HMM is not in use, so a static
branch is used to avoid that overhead when not necessary.

Now, the FS_DAX implementation wants to reuse this mechanism for
receiving dev_pagemap ->page_free() callbacks. Rework the HMM-specific
static-key into a generic mechanism that either HMM or FS_DAX code paths
can enable.

For ARCH=um builds, and any other arch that lacks ZONE_DEVICE support,
care must be taken to compile out the DEV_PAGEMAP_OPS infrastructure.
However, we still need to support FS_DAX in the FS_DAX_LIMITED case
implemented by the s390/dcssblk driver.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Reported-by: Dave Jiang <dave.jiang@intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-22 06:59:39 -07:00
Dan Williams
1ed41b5696 Merge branch 'for-4.17/libnvdimm' into libnvdimm-for-next 2018-04-09 10:50:08 -07:00
Colin Ian King
0cbfeef230 libnvdimm: remove redundant assignment to pointer 'dev'
Pointer dev is being assigned a value that is never read, it is being
re-assigned the same value later on, hence the initialization is redundant
and can be removed.

Cleans up clang warning:
drivers/nvdimm/pfn_devs.c:307:17: warning: Value stored to 'dev' during
its initialization is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-13 21:35:50 -07:00
Dan Williams
426824d63b libnvdimm: remove redundant __func__ in dev_dbg
Dynamic debug can be instructed to add the function name to the debug
output using the +f switch, so there is no need for the libnvdimm
modules to do it again. If a user decides to add the +f switch for
libnvdimm's dynamic debug this results in double prints of the function
name.

Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-06 08:44:17 -08:00
Christoph Hellwig
e8d5134833 memremap: change devm_memremap_pages interface to use struct dev_pagemap
This new interface is similar to how struct device (and many others)
work. The caller initializes a 'struct dev_pagemap' as required
and calls 'devm_memremap_pages'. This allows the pagemap structure to
be embedded in another structure and thus container_of can be used. In
this way application specific members can be stored in a containing
struct.

This will be used by the P2P infrastructure and HMM could probably
be cleaned up to use it as well (instead of having it's own, similar
'hmm_devmem_pages_create' function).

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-01-08 11:46:23 -08:00
Dan Williams
41fce90f26 libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment
The following namespace configuration attempt:

    # ndctl create-namespace -e namespace0.0 -m devdax -a 1G -f
    libndctl: ndctl_dax_enable: dax0.1: failed to enable
      Error: namespace0.0: failed to enable

    failed to reconfigure namespace: No such device or address

...fails when the backing memory range is not physically aligned to 1G:

    # cat /proc/iomem | grep Persistent
    210000000-30fffffff : Persistent Memory (legacy)

In the above example the 4G persistent memory range starts and ends on a
256MB boundary.

We handle this case correctly when needing to handle cases that violate
section alignment (128MB) collisions against "System RAM", and we simply
need to extend that padding/truncation for the 1GB alignment use case.

Cc: <stable@vger.kernel.org>
Fixes: 315c562536 ("libnvdimm, pfn: add 'align' attribute...")
Reported-and-tested-by: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-12-19 15:37:34 -08:00
Dan Williams
19deaa217b libnvdimm, pfn: fix start_pad handling for aligned namespaces
The alignment checks at pfn driver startup fail to properly account for
the 'start_pad' in the case where the namespace is misaligned relative
to its internal alignment. This is typically triggered in 1G aligned
namespace, but could theoretically trigger with small namespace
alignments. When this triggers the kernel reports messages of the form:

    dax2.1: bad offset: 0x3c000000 dax disabled align: 0x40000000

Cc: <stable@vger.kernel.org>
Fixes: 1ee6667cd8 ("libnvdimm, pfn, dax: fix initialization vs autodetect...")
Reported-by: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-12-19 15:10:06 -08:00
Dan Williams
26417ae4fc libnvdimm, pfn: make 'resource' attribute only readable by root
For the same reason that /proc/iomem returns 0's for non-root readers
and acpi tables are root-only, make the 'resource' attribute for pfn
devices only readable by root. Otherwise we disclose physical address
information.

Fixes: f6ed58c70d ("libnvdimm, pfn: 'resource'-address and 'size'...")
Cc: <stable@vger.kernel.org>
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-09-28 09:13:06 -07:00
Dan Williams
f13d2b61e5 libnvdimm, pfn, dax: limit namespace alignments to the supported set
Now that we properly advertise the supported pte, pmd, and pud sizes,
restrict the supported alignments that can be set on a namespace. This
assumes that userspace was not previously relying on the ability to set
odd alignments. At least ndctl only ever supported setting the namespace
alignment to 4K, 2M, or 1G.

Cc: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-08-15 09:32:12 -07:00
Oliver O'Halloran
1fdadbebc4 libnvdimm, pfn, dax: show supported dax/pfn region alignments in sysfs
The alignment of a DAX and PFN regions dictates the page sizes that can
be used to map the region. Even if the hardware page sizes are known the
actual range of supported page sizes that can be used with DAX depends
on the kernel configuration. As a result it's best that the kernel
advertises the alignments that should be used with these region types.

This patch adds the 'supported_alignments' region attribute to expose
this information to userspace.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[djbw: integrate with nd_size_select_show() rename and other fixups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-08-11 18:06:16 -07:00
Oliver O'Halloran
0dd6964306 libnvdimm: Stop using HPAGE_SIZE
Currently libnvdimm uses HPAGE_SIZE as the default alignment for DAX and
PFN devices. HPAGE_SIZE is the default hugetlbfs page size and when
hugetlbfs is disabled it defaults to PAGE_SIZE. Given DAX has more
in common with THP than hugetlbfs we should proably be using
HPAGE_PMD_SIZE, but this is undefined when THP is disabled so lets just
give it a new name.

The other usage of HPAGE_SIZE in libnvdimm is when determining how large
the altmap should be. For the reasons mentioned above it doesn't really
make sense to use HPAGE_SIZE here either. PMD_SIZE seems to be safe to
use in generic code and it happens to match the vmemmap allocation block
on x86 and Power. It's still a hack, but it's a slightly nicer hack.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-07-25 16:30:51 -07:00
Dan Williams
9d92573fff Merge branch 'for-4.13/dax' into libnvdimm-for-next 2017-07-03 16:54:58 -07:00
Dan Williams
c9e582aa68 libnvdimm, nfit: enable support for volatile ranges
Allow volatile nfit ranges to participate in all the same infrastructure
provided for persistent memory regions. A resulting resulting namespace
device will still be called "pmem", but the parent region type will be
"nd_volatile". This is in preparation for disabling the dax ->flush()
operation in the pmem driver when it is hosted on a volatile range.

Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-27 16:44:13 -07:00
Dan Williams
b3fde74ea1 libnvdimm, label: add address abstraction identifiers
Starting with v1.2 labels, 'address abstractions' can be hinted via an
address abstraction id that implies an info-block format. The standard
address abstraction in the specification is the v2 format of the
Block-Translation-Table (BTT). Support for that is saved for a later
patch, for now we add support for the Linux supported address
abstractions BTT (v1), PFN, and DAX.

The new 'holder_class' attribute for namespace devices is added for
tooling to specify the 'abstraction_guid' to store in the namespace label.
For v1.1 labels this field is undefined and any setting of
'holder_class' away from the default 'none' value will only have effect
until the driver is unloaded. Setting 'holder_class' requires that
whatever device tries to claim the namespace must be of the specified
class.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15 14:31:40 -07:00
Vishal Verma
3ae3d67ba7 libnvdimm: add an atomic vs process context flag to rw_bytes
nsio_rw_bytes can clear media errors, but this cannot be done while we
are in an atomic context due to locking within ACPI. From the BTT,
->rw_bytes may be called either from atomic or process context depending
on whether the calls happen during initialization or during IO.

During init, we want to ensure error clearing happens, and the flag
marking process context allows nsio_rw_bytes to do that. When called
during IO, we're in atomic context, and error clearing can be skipped.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-10 21:46:22 -07:00
Dan Williams
d5483feda8 libnvdimm, pfn: fix 'npfns' vs section alignment
Fix failures to create namespaces due to the vmem_altmap not advertising
enough free space to store the memmap.

 WARNING: CPU: 15 PID: 8022 at arch/x86/mm/init_64.c:656 arch_add_memory+0xde/0xf0
 [..]
 Call Trace:
  dump_stack+0x63/0x83
  __warn+0xcb/0xf0
  warn_slowpath_null+0x1d/0x20
  arch_add_memory+0xde/0xf0
  devm_memremap_pages+0x244/0x440
  pmem_attach_disk+0x37e/0x490 [nd_pmem]
  nd_pmem_probe+0x7e/0xa0 [nd_pmem]
  nvdimm_bus_probe+0x71/0x120 [libnvdimm]
  driver_probe_device+0x2bb/0x460
  bind_store+0x114/0x160
  drv_attr_store+0x25/0x30

In commit 658922e57b "libnvdimm, pfn: fix memmap reservation sizing"
we arranged for the capacity to be allocated, but failed to also update
the 'npfns' parameter. This leads to cases where there is enough
capacity reserved to hold all the allocated sections, but
vmemmap_populate_hugepages() still encounters -ENOMEM from
altmap_alloc_block_buf().

This fix is a stop-gap until we can teach the core memory hotplug
implementation to permit sub-section hotplug.

Cc: <stable@vger.kernel.org>
Fixes: 658922e57b ("libnvdimm, pfn: fix memmap reservation sizing")
Reported-by: Anisha Allada <anisha.allada@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-04 19:54:42 -07:00
Dan Williams
452bae0aed libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering
A debug patch to turn the standard device_lock() into something that
lockdep can analyze yielded the following:

 ======================================================
 [ INFO: possible circular locking dependency detected ]
 4.11.0-rc4+ #106 Tainted: G           O
 -------------------------------------------------------
 lt-libndctl/1898 is trying to acquire lock:
  (&dev->nvdimm_mutex/3){+.+.+.}, at: [<ffffffffc023c948>] nd_attach_ndns+0x178/0x1b0 [libnvdimm]

 but task is already holding lock:
  (&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffc022e0b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm]

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&nvdimm_bus->reconfig_mutex){+.+.+.}:
        lock_acquire+0xf6/0x1f0
        __mutex_lock+0x88/0x980
        mutex_lock_nested+0x1b/0x20
        nvdimm_bus_lock+0x21/0x30 [libnvdimm]
        nvdimm_namespace_capacity+0x1b/0x40 [libnvdimm]
        nvdimm_namespace_common_probe+0x230/0x510 [libnvdimm]
        nd_pmem_probe+0x14/0x180 [nd_pmem]
        nvdimm_bus_probe+0xa9/0x260 [libnvdimm]

 -> #0 (&dev->nvdimm_mutex/3){+.+.+.}:
        __lock_acquire+0x1107/0x1280
        lock_acquire+0xf6/0x1f0
        __mutex_lock+0x88/0x980
        mutex_lock_nested+0x1b/0x20
        nd_attach_ndns+0x178/0x1b0 [libnvdimm]
        nd_namespace_store+0x308/0x3c0 [libnvdimm]
        namespace_store+0x87/0x220 [libnvdimm]

In this case '&dev->nvdimm_mutex/3' mirrors '&dev->mutex'.

Fix this by replacing the use of device_lock() with nvdimm_bus_lock() to protect
nd_{attach,detach}_ndns() operations.

Cc: <stable@vger.kernel.org>
Fixes: 8c2f7e8658 ("libnvdimm: infrastructure for btt devices")
Reported-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-01 08:29:37 -07:00
Dan Williams
bfb34527a3 libnvdimm, pfn: fix memmap reservation size versus 4K alignment
When vmemmap_populate() allocates space for the memmap it does so in 2MB
sized chunks. The libnvdimm-pfn driver incorrectly accounts for this
when the alignment of the device is set to 4K. When this happens we
trigger memory allocation failures in altmap_alloc_block_buf() and
trigger warnings of the form:

 WARNING: CPU: 0 PID: 3376 at arch/x86/mm/init_64.c:656 arch_add_memory+0xe4/0xf0
 [..]
 Call Trace:
  dump_stack+0x86/0xc3
  __warn+0xcb/0xf0
  warn_slowpath_null+0x1d/0x20
  arch_add_memory+0xe4/0xf0
  devm_memremap_pages+0x29b/0x4e0

Fixes: 315c562536 ("libnvdimm, pfn: add 'align' attribute, default to HPAGE_SIZE")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-02-04 14:47:31 -08:00
Dan Williams
af7d9f0c57 libnvdimm, pfn: fix align attribute
Fix the format specifier so that the attribute can be parsed correctly.
Currently it returns decimal 1000 for a 4096-byte alignment.

Cc: <stable@vger.kernel.org>
Reported-by: Dave Jiang <dave.jiang@intel.com>
Fixes: 315c562536 ("libnvdimm, pfn: add 'align' attribute, default to HPAGE_SIZE")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-12-10 08:12:05 -08:00
Dan Williams
1ee6667cd8 libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment
The updated ndctl unit tests discovered that if a pfn configuration with
a 4K alignment is read from the namespace, that alignment will be
ignored in favor of the default 2M alignment.  The result is that the
configuration will fail initialization with a message like:

    dax6.1: bad offset: 0x22000 dax disabled align: 0x200000

Fix this by allowing the alignment read from the info block to override
the default which is 2M not 0 in the autodetect path.  This also fixes a
similar problem with the mode and alignment settings silently being
overwritten by the kernel when userspace has changed it.  We now will
either overwrite the info block if userspace changes the uuid or fail
and warn if a live setting disagrees with the info block.

Cc: <stable@vger.kernel.org>
Cc: Micah Parrish <micah.parrish@hpe.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-23 17:50:39 -07:00
Dan Williams
36092ee8ba Merge branch 'for-4.7/dax' into libnvdimm-for-next 2016-05-21 12:33:04 -07:00
Dan Williams
03dca343af libnvdimm, dax: fix deletion
The ndctl unit tests discovered that the dax enabling omitted updates to
nd_detach_and_reset().  This routine clears device the configuration
when the namespace is detached.  Without this clearing userspace may
assume that the device is in the process of being configured by another
agent in the system.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-21 12:22:41 -07:00
Dan Williams
5e24c9fd36 libnvdimm, dax: fix alignment validation
Testing the dax-device autodetect support revealed a probe failure with
the following result:

    dax0.1: bad offset: 0x8200000 dax disabled

The original pfn-device implementation inferred the alignment from
ilog2(offset), now that the alignment is explicit the is_power_of_2()
needs replacing with a real sanity check against the recorded alignment.
Otherwise the alignment check is useless in the implicit case and only
the minimum size of the offset matters.

This self-consistency check is further validated by the probe path that
will re-check that the offset is large enough to contain all the
metadata required to enable the device.

Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-21 11:01:41 -07:00
Dan Williams
c5ed926864 libnvdimm, dax: autodetect support
For autodetecting a previously established dax configuration we need the
info block to indicate block-device vs device-dax mode, and we need to
have the default namespace probe hand-off the configuration to the
dax_pmem driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-20 22:02:57 -07:00
Dan Williams
594d6d96ea Merge branch 'for-4.7/dax' into libnvdimm-for-next 2016-05-18 09:59:34 -07:00
Dan Williams
45a0dac045 libnvdimm, dax: record the specified alignment of a dax-device instance
We want to use the alignment as the allocation and mapping unit.
Previously this information was only useful for establishing the data
offset, but now it is important to remember the granularity for the
later use.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-09 15:35:42 -07:00
Dan Williams
52ac23b25e libnvdimm, dax: reserve space to store labels for device-dax
We may want to subdivide a device-dax range into multiple devices so
that each can have separate permissions or naming.  Reserve 128K of
label space by default so we have the capability of making allocation
decisions persistent.  This reservation is not something we can add
later since it would result in the default size of a device-dax range
changing between kernel versions.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-09 15:35:42 -07:00
Dan Williams
cd03412a51 libnvdimm, dax: introduce device-dax infrastructure
Device DAX is the device-centric analogue of Filesystem DAX
(CONFIG_FS_DAX).  It allows persistent memory ranges to be allocated and
mapped without need of an intervening file system.  This initial
infrastructure arranges for a libnvdimm pfn-device to be represented as
a different device-type so that it can be attached to a driver other
than the pmem driver.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-09 15:35:42 -07:00
Dan Williams
ac515c084b libnvdimm, pmem, pfn: move pfn setup to the core
Now that pmem internals have been disentangled from pfn setup, that code
can move to the core.  This is in preparation for adding another user of
the pfn-device capabilities.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-22 12:26:23 -07:00
Dan Williams
200c79da82 libnvdimm, pmem, pfn: make pmem_rw_bytes generic and refactor pfn setup
In preparation for providing an alternative (to block device) access
mechanism to persistent memory, convert pmem_rw_bytes() to
nsio_rw_bytes().  This allows ->rw_bytes() functionality without
requiring a 'struct pmem_device' to be instantiated.

In other words, when ->rw_bytes() is in use i/o is driven through
'struct nd_namespace_io', otherwise it is driven through 'struct
pmem_device' and the block layer.  This consolidates the disjoint calls
to devm_exit_badblocks() and devm_memunmap() into a common
devm_nsio_disable() and cleans up the init path to use a unified
pmem_attach_disk() implementation.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-22 12:26:23 -07:00
Dan Williams
bd032943b5 libnvdimm, pfn, convert nd_pfn_probe() to devm
Pass the device performing the probe so we can use a devm allocation for
the pfn superblock.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-22 10:59:54 -07:00
Dan Williams
e5670563f5 libnvdimm, pfn: fix uuid validation
If we detect a namespace has a stale info block in the init path, we
should overwrite with the latest configuration.  In fact, we already
return -ENODEV when the parent uuid is invalid, the same should be done
for the 'self' uuid.  Otherwise we can get into a condition where
userspace is unable to reconfigure the pfn-device without directly /
manually invalidating the info block.

Cc: <stable@vger.kernel.org>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-04-07 19:59:27 -07:00
Dan Williams
f6ed58c70d libnvdimm, pfn: 'resource'-address and 'size' attributes for pfn devices
Currenty with a raw mode pmem namespace the physical memory address range for
the device can be obtained via /sys/block/pmemX/device/{resource|size}.  Add
similar attributes for pfn instances that takes the struct page memmap and
section padding into account.

Reported-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-05 12:25:45 -08:00
Dan Williams
cfe30b8720 libnvdimm, pmem: adjust for section collisions with 'System RAM'
On a platform where 'Persistent Memory' and 'System RAM' are mixed
within a given sparsemem section, trim the namespace and notify about the
sub-optimal alignment.

Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-03-05 12:25:45 -08:00
Dan Williams
45eb570a0d libnvdimm, pfn: fix restoring memmap location
This path was missed when turning on the memmap in pmem support.  Permit
'pmem' as a valid location for the map.

Reported-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-29 17:43:16 -08:00
Dan Williams
d2c0f041e1 libnvdimm, pfn, pmem: allocate memmap array in persistent memory
Use the new vmem_altmap capability to enable the pmem driver to arrange
for a struct page memmap to be established in persistent memory.

[linux@roeck-us.net: mn10300: declare __pfn_to_phys() to fix build error]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Dan Williams
a34d5e8a6a libnvdimm, pfn: add parent uuid validation
Track and check the uuid of the namespace hosting a pfn instance.  This
forces the pfn info block to be invalidated if the namespace is
re-configured with a different uuid.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-12-13 11:40:20 -08:00