18 Nov, 2019
1 commit
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Statically initialize the attribute groups for each libnvdimm
device_type. This is a preparation step for removing unnecessary exports
of attributes that can be included in the device_type by default.Also take the opportunity to mark 'struct device_type' instances const.
Cc: Ira Weiny
Cc: Vishal Verma
Signed-off-by: Dan Williams
Reviewed-by: Aneesh Kumar K.V
Link: https://lore.kernel.org/r/157309900111.1582359.2445687530383470348.stgit@dwillia2-desk3.amr.corp.intel.com
19 Jul, 2019
1 commit
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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
Cc: Ira Weiny
Cc: Will Deacon
Cc: Dave Jiang
Cc: Keith Busch
Cc: Peter Zijlstra
Cc: Vishal Verma
Cc: "Rafael J. Wysocki"
Cc: Greg Kroah-Hartman
Signed-off-by: Dan Williams
Acked-by: Greg Kroah-Hartman
Reviewed-by: Ira Weiny
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
05 Jun, 2019
1 commit
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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 detailsextracted 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
Reviewed-by: Alexios Zavras
Reviewed-by: Allison Randal
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman
28 Mar, 2019
1 commit
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In case kmemdup fails, the fix releases resources and returns to
avoid the NULL pointer dereference.Signed-off-by: Aditya Pakki
Signed-off-by: Dan Williams
01 Mar, 2019
1 commit
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The Linux BTT implementation assumes that log entries will never have
the 'zero' flag set, and indeed it never sets that flag for log entries
itself.However, the UEFI spec is ambiguous on the exact format of the LBA field
of a log entry, specifically as to whether it should include the
additional flag bits or not. While a zero bit doesn't make sense in the
context of a log entry, other BTT implementations might still have it set.If an implementation does happen to have it set, we would happily read
it in as the next block to write to for writes. Since a high bit is set,
it pushes the block number out of the range of an 'arena', and we fail
such a write with an EIO.Follow the robustness principle, and tolerate such implementations by
stripping out the zero flag when populating the free list during
initialization. Additionally, use the same stripped out entries for
detection of incomplete writes and map restoration that happens at this
stage.Add a sysfs file 'log_zero_flags' that indicates the ability to accept
such a layout to userspace applications. This enables 'ndctl
check-namespace' to recognize whether the kernel is able to handle zero
flags, or whether it should attempt a fix-up under the --repair option.Cc: Dan Williams
Reported-by: Dexuan Cui
Reported-by: Pedro d'Aquino Filocre F S Barbuda
Tested-by: Dexuan Cui
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
07 Mar, 2018
1 commit
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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
Reported-by: Ross Zwisler
Signed-off-by: Dan Williams
12 Aug, 2017
1 commit
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Prepare for other another consumer of this size selection scheme that is
not a 'sector size'.Cc: Oliver O'Halloran
Signed-off-by: Dan Williams
30 Jun, 2017
1 commit
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The UEFI 2.7 specification defines an updated BTT metadata format,
bumping the revision to 2.0. Add support for the new format, while
retaining compatibility for the old 1.1 format.Cc: Toshi Kani
Cc: Linda Knippers
Cc: Dan Williams
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
16 Jun, 2017
1 commit
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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
Signed-off-by: Dan Williams
05 Jun, 2017
1 commit
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Hoist the libnvdimm helper as an inline helper to linux/uuid.h
using an auxiliary const variable uuid_null in lib/uuid.c.[hch: also add the guid variant. Both do the same but I'd like
to keep casts to a minimum]The common helper uses the new abstract type uuid_t * instead of
u8 *.Suggested-by: Christoph Hellwig
Signed-off-by: Amir Goldstein
[hch: added guid_is_null]
Signed-off-by: Christoph Hellwig
Acked-by: Dan Williams
Reviewed-by: Andy Shevchenko
11 May, 2017
1 commit
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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
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
01 May, 2017
1 commit
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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: [] nd_attach_ndns+0x178/0x1b0 [libnvdimm]but task is already holding lock:
(&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [] 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:
Fixes: 8c2f7e8658df ("libnvdimm: infrastructure for btt devices")
Reported-by: Yi Zhang
Signed-off-by: Dan Williams
09 Aug, 2016
1 commit
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To be consistent with other namespaces, expose a 'size' attribute for
BTT devices also.Cc: Dan Williams
Reported-by: Linda Knippers
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
24 Jul, 2016
1 commit
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The __nd_device_register() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring
Signed-off-by: Dan Williams
23 Apr, 2016
2 commits
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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
Signed-off-by: Dan Williams -
Pass the device performing the probe so we can use a devm allocation for
the btt superblock.Cc: Vishal Verma
Reviewed-by: Johannes Thumshirn
Signed-off-by: Dan Williams
17 Sep, 2015
1 commit
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Always take device_lock() before nvdimm_bus_lock() to prevent deadlock.
Cc:
Signed-off-by: Axel Lin
Signed-off-by: Dan Williams
29 Aug, 2015
1 commit
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Implement the base infrastructure for libnvdimm PFN devices. Similar to
BTT devices they take a namespace as a backing device and layer
functionality on top. In this case the functionality is reserving space
for an array of 'struct page' entries to be handed out through
pfn_to_page(). For now this is just the basic libnvdimm-device-model for
configuring the base PFN device.As the namespace claiming mechanism for PFN devices is mostly identical
to BTT devices drivers/nvdimm/claim.c is created to house the common
bits.Cc: Ross Zwisler
Signed-off-by: Dan Williams
15 Aug, 2015
2 commits
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When a BTT is instantiated on a namespace it must validate the namespace
uuid matches the 'parent_uuid' stored in the btt superblock. This
property enforces that changing the namespace UUID invalidates all
former BTT instances on that storage. For "IO namespaces" that don't
have a label or UUID, the parent_uuid is set to zero, and this
validation is skipped. For such cases, old BTTs have to be invalidated
by forcing the namespace to raw mode, and overwriting the BTT info
blocks.Based on a patch by Dan Williams
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams -
Use arena_is_valid as a common routine for checking the validity of an
info block from both discover_arenas, and nd_btt_probe.As a result, don't check for validity of the BTT's UUID, and lbasize.
The checksum in the BTT info block guarantees self-consistency, and when
we're called from nd_btt_probe, we don't have a valid uuid or lbasize
available to check against.Also cleanup to return a bool instead of an int.
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
26 Jun, 2015
3 commits
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Add support of sysfs 'numa_node' to I/O-related NVDIMM devices
under /sys/bus/nd/devices, regionN, namespaceN.0, and bttN.x.An example of numa_node values on a 2-socket system with a single
NVDIMM range on each socket is shown below.
/sys/bus/nd/devices
|-- btt0.0/numa_node:0
|-- btt1.0/numa_node:1
|-- btt1.1/numa_node:1
|-- namespace0.0/numa_node:0
|-- namespace1.0/numa_node:1
|-- region0/numa_node:0
|-- region1/numa_node:1These numa_node files are then linked under the block class of
their device names.
/sys/class/block/pmem0/device/numa_node:0
/sys/class/block/pmem1s/device/numa_node:1This enables numactl(8) to accept 'block:' and 'file:' paths of
pmem and btt devices as shown in the examples below.
numactl --preferred block:pmem0 --show
numactl --preferred file:/dev/pmem1s --showSigned-off-by: Toshi Kani
Signed-off-by: Dan Williams -
Support multiple block sizes (sector + metadata) using the blk integrity
framework. This registers a new integrity template that defines the
protection information tuple size based on the configured metadata size,
and simply acts as a passthrough for protection information generated by
another layer. The metadata is written to the storage as-is, and read back
with each sector.Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams -
BTT stands for Block Translation Table, and is a way to provide power
fail sector atomicity semantics for block devices that have the ability
to perform byte granularity IO. It relies on the capability of libnvdimm
namespace devices to do byte aligned IO.The BTT works as a stacked blocked device, and reserves a chunk of space
from the backing device for its accounting metadata. It is a bio-based
driver because all IO is done synchronously, and there is no queuing or
asynchronous completions at either the device or the driver level.The BTT uses 'lanes' to index into various 'on-disk' data structures,
and lanes also act as a synchronization mechanism in case there are more
CPUs than available lanes. We did a comparison between two lane lock
strategies - first where we kept an atomic counter around that tracked
which was the last lane that was used, and 'our' lane was determined by
atomically incrementing that. That way, for the nr_cpus > nr_lanes case,
theoretically, no CPU would be blocked waiting for a lane. The other
strategy was to use the cpu number we're scheduled on to and hash it to
a lane number. Theoretically, this could block an IO that could've
otherwise run using a different, free lane. But some fio workloads
showed that the direct cpu -> lane hash performed faster than tracking
'last lane' - my reasoning is the cache thrash caused by moving the
atomic variable made that approach slower than simply waiting out the
in-progress IO. This supports the conclusion that the driver can be a
very simple bio-based one that does synchronous IOs instead of queuing.Cc: Andy Lutomirski
Cc: Boaz Harrosh
Cc: H. Peter Anvin
Cc: Jens Axboe
Cc: Ingo Molnar
Cc: Christoph Hellwig
Cc: Neil Brown
Cc: Jeff Moyer
Cc: Dave Chinner
Cc: Greg KH
[jmoyer: fix nmi watchdog timeout in btt_map_init]
[jmoyer: move btt initialization to module load path]
[jmoyer: fix memory leak in the btt initialization path]
[jmoyer: Don't overwrite corrupted arenas]
Signed-off-by: Vishal Verma
Signed-off-by: Dan Williams
25 Jun, 2015
1 commit
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NVDIMM namespaces, in addition to accepting "struct bio" based requests,
also have the capability to perform byte-aligned accesses. By default
only the bio/block interface is used. However, if another driver can
make effective use of the byte-aligned capability it can claim namespace
interface and use the byte-aligned ->rw_bytes() interface.The BTT driver is the initial first consumer of this mechanism to allow
adding atomic sector update semantics to a pmem or blk namespace. This
patch is the sysfs infrastructure to allow configuring a BTT instance
for a namespace. Enabling that BTT and performing i/o is in a
subsequent patch.Cc: Greg KH
Cc: Neil Brown
Signed-off-by: Dan Williams