linux-toradex.git/drivers/nvdimm/btt.h, branch v5.16

nvdimm-btt: convert to blk_alloc_disk/blk_cleanup_disk

2021-06-01T13:42:23+00:00

Convert the nvdimm-btt driver to use the blk_alloc_disk and
blk_cleanup_disk helpers to simplify gendisk and request_queue
allocation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Ulf Hansson 
Link: https://lore.kernel.org/r/20210521055116.1053587-17-hch@lst.de
Signed-off-by: Jens Axboe

libnvdimm: Cleanup include of badblocks.h

2020-12-16T05:47:45+00:00

* drivers/nvdimm/core.c doesn't use anything from badblocks.h on its own,
  thus including it isn't needed. There's indeed indirect use, via funcs
  in nd.h, but this one already includes badblocks.h.

* drivers/nvdimm/claim.c calls stuff from badblocks.h and therefore should
  include it on its own (instead of relying any other header doing that)

* drivers/nvdimm/btt.h doesn't really need anything from badblocks.h and
  can easily live with a forward declaration of struct badblocks (just
  having pointers to it, but not dereferencing it anywhere)

Signed-off-by: Enrico Weigelt 
Link: https://lore.kernel.org/r/20201215163531.21446-1-info@metux.net
Signed-off-by: Dan Williams

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288

2019-06-05T15:36:37+00:00

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: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Alexios Zavras 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman

libnvdimm/btt: Fix LBA masking during 'free list' population

2019-02-28T17:57:39+00:00

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

libnvdimm, btt: Fix an incompatibility in the log layout

2017-12-21T22:59:27+00:00

Due to a spec misinterpretation, the Linux implementation of the BTT log
area had different padding scheme from other implementations, such as
UEFI and NVML.

This fixes the padding scheme, and defaults to it for new BTT layouts.
We attempt to detect the padding scheme in use when probing for an
existing BTT. If we detect the older/incompatible scheme, we continue
using it.

Reported-by: Juston Li 
Cc: Dan Williams 
Cc: 
Fixes: 5212e11fde4d ("nd_btt: atomic sector updates")
Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, btt: add a couple of missing kernel-doc lines

2017-12-21T22:59:27+00:00

Recent updates to btt.h neglected to add corresponding kernel-doc lines
for new structure members. Add them.

Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, btt: rework error clearing

2017-08-31T22:05:10+00:00

Clearing errors or badblocks during a BTT write requires sending an ACPI
DSM, which means potentially sleeping. Since a BTT IO happens in atomic
context (preemption disabled, spinlocks may be held), we cannot perform
error clearing in the course of an IO. Due to this error clearing for
BTT IOs has hitherto been disabled.

In this patch we move error clearing out of the atomic section, and thus
re-enable error clearing with BTTs. When we are about to add a block to
the free list, we check if it was previously marked as an error, and if
it was, we add it to the freelist, but also set a flag that says error
clearing will be required. We then drop the lane (ending the atomic
context), and send a zero buffer so that the error can be cleared. The
error flag in the free list is protected by the nd 'lane', and is set
only be a thread while it holds that lane. When the error is cleared,
the flag is cleared, but while holding a mutex for that freelist index.

When writing, we check for two things -
1/ If the freelist mutex is held or if the error flag is set. If so,
this is an error block that is being (or about to be) cleared.
2/ If the block is a known badblock based on nsio->bb

The second check is required because the BTT map error flag for a map
entry only gets set when an error LBA is read. If we write to a new
location that may not have the map error flag set, but still might be in
the region's badblock list, we can trigger an EIO on the write, which is
undesirable and completely avoidable.

Cc: Jeff Moyer 
Cc: Toshi Kani 
Cc: Dan Williams 
Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, btt: cache sector_size in arena_info

2017-08-31T22:05:10+00:00

In preparation for the error clearing rework, add sector_size in the
arena_info struct.

Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, btt: refactor map entry operations with macros

2017-08-31T22:05:10+00:00

Add helpers for converting a raw map entry to just the block number, or
either of the 'e' or 'z' flags in preparation for actually using the
error flag to mark blocks with media errors.

Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, btt: BTT updates for UEFI 2.7 format

2017-06-29T20:50:38+00:00

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