This function returns the number of bytes in a THP.  It is like
page_size(), but compiles to just PAGE_SIZE if CONFIG_TRANSPARENT_HUGEPAGE
is disabled.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/20200629151959.15779-5-willy@infradead.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The make_request_fn is a little weird in that it sits directly in
struct request_queue instead of an operation vector.  Replace it with
a block_device_operations method called submit_bio (which describes much
better what it does).  Also remove the request_queue argument to it, as
the queue can be derived pretty trivially from the bio.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This seems to lead to some crazy include loops when using
asm-generic/cacheflush.h on more architectures, so leave it to the arch
header for now.

[hch@lst.de: fix warning]
  Link: http://lkml.kernel.org/r/20200520173520.GA11199@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Will Deacon <will@kernel.org>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/20200515143646.3857579-7-hch@lst.deSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch dm to use the nicer bio accounting helpers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In preparation for removing queuedata as an argument to
make_request_fn() drop the dependency ->queuedata.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200508161517.252308-16-hch@lst.deSigned-off-by: NDan Williams <dan.j.williams@intel.com>

zero_page_range() dax operation is mandatory for dax devices. Right now
that check happens in dax_zero_page_range() function. Dan thinks that's
too late and its better to do the check earlier in alloc_dax().

I also modified alloc_dax() to return pointer with error code in it in
case of failure. Right now it returns NULL and caller assumes failure
happened due to -ENOMEM. But with this ->zero_page_range() check, I
need to return -EINVAL instead.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/r/20200401161125.GB9398@redhat.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

Add a dax operation zero_page_range, to zero a page. This will also clear any
known poison in the page being zeroed.

As of now, zeroing of 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: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Reviewed-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: https://lore.kernel.org/r/20200228163456.1587-3-vgoyal@redhat.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

This splits pmem_do_bvec() into pmem_do_read() and pmem_do_write().
pmem_do_write() will be used by pmem zero_page_range() as well. Hence
sharing the same code.
Suggested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: https://lore.kernel.org/r/20200228163456.1587-2-vgoyal@redhat.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper.  Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter.  A lower-level __blk_alloc_queue is kept for the blk-mq case.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

After the removal of the device-public infrastructure there are only 2
->page_free() call backs in the kernel.  One of those is a
device-private callback in the nouveau driver, the other is a generic
wakeup needed in the DAX case.  In the hopes that all ->page_free()
callbacks can be migrated to common core kernel functionality, move the
device-private specific actions in __put_devmap_managed_page() under the
is_device_private_page() conditional, including the ->page_free()
callback.  For the other page types just open-code the generic wakeup.

Yes, the wakeup is only needed in the MEMORY_DEVICE_FSDAX case, but it
does no harm in the MEMORY_DEVICE_DEVDAX and MEMORY_DEVICE_PCI_P2PDMA
case.

Link: http://lkml.kernel.org/r/20200107224558.2362728-4-jhubbard@nvidia.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The entire point of nd-core.h is to hide functionality that no leaf
driver should touch. In fact, the commit that added it had no need to
include it.

Fixes: 06e8ccda ("acpi: nfit: Add support for detect platform...")
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The nvdimm core currently maps the full namespace to an ioremap range
while probing the namespace mode. This can result in probe failures on
architectures that have limited ioremap space.

For example, with a large btt namespace that consumes most of I/O remap
range, depending on the sequence of namespace initialization, the user
can find a pfn namespace initialization failure due to unavailable I/O
remap space which nvdimm core uses for temporary mapping.

nvdimm core can avoid this failure by only mapping the reserved info
block area to check for pfn superblock type and map the full namespace
resource only before using the namespace.

Given that personalities like BTT can be layered on top of any namespace
type create a generic form of devm_nsio_enable (devm_namespace_enable)
and use it inside the per-personality attach routines. Now
devm_namespace_enable() is always paired with disable unless the mapping
is going to be used for long term runtime access.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20191017073308.32645-1-aneesh.kumar@linux.ibm.com
[djbw: reworks to move devm_namespace_{en,dis}able into *attach helpers]
Reported-by: Nkbuild test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20191031105741.102793-2-aneesh.kumar@linux.ibm.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

In order to support marking namespaces with unsupported feature/versions
disabled, nvdimm core should advance the namespace seed on these
probe failures. Otherwise, these failed namespaces will be considered a
seed namespace and will be wrongly used while creating new namespaces.

Add -EOPNOTSUPP as return from pmem probe callback to indicate a namespace
initialization failures due to pfn superblock feature/version mismatch.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190905154603.10349-3-aneesh.kumar@linux.ibm.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

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: NDan Williams <dan.j.williams@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com

This patch adds 'DAXDEV_SYNC' flag which is set
for nd_region doing synchronous flush. This later
is used to disable MAP_SYNC functionality for
ext4 & xfs filesystem for devices don't support
synchronous flush.
Signed-off-by: NPankaj Gupta <pagupta@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This patch adds functionality to perform flush from guest
to host over VIRTIO. We are registering a callback based
on 'nd_region' type. virtio_pmem driver requires this special
flush function. For rest of the region types we are registering
existing flush function. Report error returned by host fsync
failure to userspace.
Signed-off-by: NPankaj Gupta <pagupta@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

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: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

struct dev_pagemap is always embedded into a containing structure, so
there is no need to an additional private data field.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Just check if there is a ->page_free operation set and take care of the
static key enable, as well as the put using device managed resources.
Also check that a ->page_free is provided for the pgmaps types that
require it, and check for a valid type as well while we are at it.

Note that this also fixes the fact that hmm never called
dev_pagemap_put_ops and thus would leave the slow path enabled forever,
even after a device driver unload or disable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Passing the actual typed structure leads to more understandable code
vs just passing the ref member.
Reported-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

The dev_pagemap is a growing too many callbacks.  Move them into a
separate ops structure so that they are not duplicated for multiple
instances, and an attacker can't easily overwrite them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Logan noticed that devm_memremap_pages_release() kills the percpu_ref
drops all the page references that were acquired at init and then
immediately proceeds to unplug, arch_remove_memory(), the backing pages
for the pagemap.  If for some reason device shutdown actually collides
with a busy / elevated-ref-count page then arch_remove_memory() should
be deferred until after that reference is dropped.

As it stands the "wait for last page ref drop" happens *after*
devm_memremap_pages_release() returns, which is obviously too late and
can lead to crashes.

Fix this situation by assigning the responsibility to wait for the
percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup()
callback.  Implement the new cleanup callback for all
devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma.

Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 41e94a85 ("add devm_memremap_pages")
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reported-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope 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 263 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NAlexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Jeff discovered that performance improves from ~375K iops to ~519K iops
on a simple psync-write fio workload when moving the location of 'struct
page' from the default PMEM location to DRAM. This result is surprising
because the expectation is that 'struct page' for dax is only needed for
third party references to dax mappings. For example, a dax-mapped buffer
passed to another system call for direct-I/O requires 'struct page' for
sending the request down the driver stack and pinning the page. There is
no usage of 'struct page' for first party access to a file via
read(2)/write(2) and friends.

However, this "no page needed" expectation is violated by
CONFIG_HARDENED_USERCOPY and the check_copy_size() performed in
copy_from_iter_full_nocache() and copy_to_iter_mcsafe(). The
check_heap_object() helper routine assumes the buffer is backed by a
slab allocator (DRAM) page and applies some checks.  Those checks are
invalid, dax pages do not originate from the slab, and redundant,
dax_iomap_actor() has already validated that the I/O is within bounds.
Specifically that routine validates that the logical file offset is
within bounds of the file, then it does a sector-to-pfn translation
which validates that the physical mapping is within bounds of the block
device.

Bypass additional hardened usercopy overhead and call the 'no check'
versions of the copy_{to,from}_iter operations directly.

Fixes: 0aed55af ("x86, uaccess: introduce copy_from_iter_flushcache...")
Cc: <stable@vger.kernel.org>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Reported-and-tested-by: NJeff Smits <jeff.smits@intel.com>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Pankaj reports that starting with commit ad428cdb "dax: Check the
end of the block-device capacity with dax_direct_access()" device-mapper
no longer allows dax operation. This results from the stricter checks in
__bdev_dax_supported() that validate that the start and end of a
block-device map to the same 'pagemap' instance.

Teach the dax-core and device-mapper to validate the 'pagemap' on a
per-target basis. This is accomplished by refactoring the
bdev_dax_supported() internals into generic_fsdax_supported() which
takes a sector range to validate. Consequently generic_fsdax_supported()
is suitable to be used in a device-mapper ->iterate_devices() callback.
A new ->dax_supported() operation is added to allow composite devices to
split and route upper-level bdev_dax_supported() requests.

Fixes: ad428cdb ("dax: Check the end of the block-device...")
Cc: <stable@vger.kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reported-by: NPankaj Gupta <pagupta@redhat.com>
Reviewed-by: NPankaj Gupta <pagupta@redhat.com>
Tested-by: NPankaj Gupta <pagupta@redhat.com>
Tested-by: NVaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

If offset is not zero and length is bigger than PAGE_SIZE,
this will cause to out of boundary access to a page memory

Fixes: 98cc093c ("block, THP: make block_device_operations.rw_page support THP")
Co-developed-by: NLiang ZhiCheng <liangzhicheng@baidu.com>
Signed-off-by: NLiang ZhiCheng <liangzhicheng@baidu.com>
Signed-off-by: NLi RongQing <lirongqing@baidu.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The last step before devm_memremap_pages() returns success is to allocate
a release action, devm_memremap_pages_release(), to tear the entire setup
down.  However, the result from devm_add_action() is not checked.

Checking the error from devm_add_action() is not enough.  The api
currently relies on the fact that the percpu_ref it is using is killed by
the time the devm_memremap_pages_release() is run.  Rather than continue
this awkward situation, offload the responsibility of killing the
percpu_ref to devm_memremap_pages_release() directly.  This allows
devm_memremap_pages() to do the right thing relative to init failures and
shutdown.

Without this change we could fail to register the teardown of
devm_memremap_pages().  The likelihood of hitting this failure is tiny as
small memory allocations almost always succeed.  However, the impact of
the failure is large given any future reconfiguration, or disable/enable,
of an nvdimm namespace will fail forever as subsequent calls to
devm_memremap_pages() will fail to setup the pgmap_radix since there will
be stale entries for the physical address range.

An argument could be made to require that the ->kill() operation be set in
the @pgmap arg rather than passed in separately.  However, it helps code
readability, tracking the lifetime of a given instance, to be able to grep
the kill routine directly at the devm_memremap_pages() call site.

Link: http://lkml.kernel.org/r/154275558526.76910.7535251937849268605.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>
Fixes: e8d51348 ("memremap: change devm_memremap_pages interface...")
Reviewed-by: N"Jérôme Glisse" <jglisse@redhat.com>
Reported-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the legacy request path gone there is no real need to override the
queue_lock.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The driver is only initializing bb_res in the devm_memremap_pages()
paths, but the raw namespace case is passing an uninitialized bb_res to
nvdimm_badblocks_populate().

Fixes: e8d51348 ("memremap: change devm_memremap_pages interface...")
Cc: <stable@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Reported-by: NJacek Zloch <jacek.zloch@intel.com>
Reported-by: NKrzysztof Rusocki <krzysztof.rusocki@intel.com>
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Update device_add_disk() to take an 'groups' argument so that
individual drivers can register a device with additional sysfs
attributes.
This avoids race condition the driver would otherwise have if these
groups were to be created with sysfs_add_groups().
Signed-off-by: NMartin Wilck <martin.wilck@suse.com>
Signed-off-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use clear_mce_nospec() to restore WB mode for the kernel linear mapping
of a pmem page that was marked 'HWPoison'. A page with 'HWPoison' set
has also been marked UC in PAT (page attribute table) via
set_mce_nospec() to prevent speculative retrievals of poison.

The 'HWPoison' flag is only cleared when overwriting an entire page.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>

pmem_direct_access() needs to check the validity of pointers kaddr
and pfn for NULL assignment. If anyone equals to NULL, it doesn't need
to calculate the value.

If pointer equals to NULL, that is to say callers may have no need for
kaddr or pfn, so this patch is prepared for allowing them to pass in
NULL instead of having to pass in a pointer or local variable that
they then just throw away.
Signed-off-by: NHuaisheng Ye <yehs1@lenovo.com>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>

c11f0c0b ("block/mm: make bdev_ops->rw_page() take a bool for
read/write") replaced @OP with boolean @is_write, which limited the
amount of information going into ->rw_page() and more importantly
page_endio(), which removed the need to expose block internals to mm.

Unfortunately, we want to track discards separately and @is_write
isn't enough information.  This patch updates bdev_ops->rw_page() to
take REQ_OP instead but leaves page_endio() to take bool @is_write.
This allows the block part of operations to have enough information
while not leaking it to mm.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

QUEUE_FLAG_DAX is an indication that a given block device supports
filesystem DAX and should not be set for PMEM namespaces which are in "raw"
mode.  These namespaces lack struct page and are prevented from
participating in filesystem DAX as of commit 569d0365 ("dax: require
'struct page' by default for filesystem dax").
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: NMike Snitzer <snitzer@redhat.com>
Fixes: 569d0365 ("dax: require 'struct page' by default for filesystem dax")
Cc: stable@vger.kernel.org
Acked-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NToshi Kani <toshi.kani@hpe.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Prior to this commit we would only do a "deep flush" (have nvdimm_flush()
write to each of the flush hints for a region) in response to an
msync/fsync/sync call if the nvdimm_has_cache() returned true at the time
we were setting up the request queue.  This happens due to the write cache
value passed in to blk_queue_write_cache(), which then causes the block
layer to send down BIOs with REQ_FUA and REQ_PREFLUSH set.  We do have a
"write_cache" sysfs entry for namespaces, i.e.:

  /sys/bus/nd/devices/pfn0.1/block/pmem0/dax/write_cache

which can be used to control whether or not the kernel thinks a given
namespace has a write cache, but this didn't modify the deep flush behavior
that we set up when the driver was initialized.  Instead, it only modified
whether or not DAX would flush CPU caches via dax_flush() in response to
*sync calls.

Simplify this by making the *sync deep flush always happen, regardless of
the write cache setting of a namespace.  The DAX CPU cache flushing will
still be controlled the write_cache setting of the namespace.

Cc: <stable@vger.kernel.org>
Fixes: 5fdf8e5b ("libnvdimm: re-enable deep flush for pmem devices via fsync()")
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Complete the move from REQ_FLUSH to REQ_PREFLUSH that apparently started
way back in v4.8.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Use the machine check safe version of copy_to_iter() for the
->copy_to_iter() operation published by the pmem driver.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Similar to the ->copy_from_iter() operation, a platform may want to
deploy an architecture or device specific routine for handling reads
from a dax_device like /dev/pmemX. On x86 this routine will point to a
machine check safe version of copy_to_iter(). For now, add the plumbing
to device-mapper and the dax core.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

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: Nkbuild test robot <lkp@intel.com>
Reported-by: NThomas Meyer <thomas@m3y3r.de>
Reported-by: NDave Jiang <dave.jiang@intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Machine check safe memory copies are currently deployed in the pmem
driver whenever reading from persistent memory media, so that -EIO is
returned rather than triggering a kernel panic. While this protects most
pmem accesses, it is not complete in the filesystem-dax case. When
filesystem-dax is enabled reads may bypass the block layer and the
driver via dax_iomap_actor() and its usage of copy_to_iter().

In preparation for creating a copy_to_iter() variant that can handle
machine checks, teach memcpy_mcsafe() to return the number of bytes
remaining rather than -EFAULT when an exception occurs.
Co-developed-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: hch@lst.de
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/152539238119.31796.14318473522414462886.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>