linux-toradex.git/drivers/lightnvm, branch v5.3-rc8

lightnvm: fix uninitialized pointer in nvm_remove_tgt()

2019-06-21T09:14:30+00:00

With gcc 4.1:

    drivers/lightnvm/core.c: In function ‘nvm_remove_tgt’:
    drivers/lightnvm/core.c:510: warning: ‘t’ is used uninitialized in this function

Indeed, if no NVM devices have been registered, t will be an
uninitialized pointer, and may be dereferenced later.  A call to
nvm_remove_tgt() can be triggered from userspace by issuing the
NVM_DEV_REMOVE ioctl on the lightnvm control device.

Fix this by preinitializing t to NULL.

Fixes: 843f2edbdde085b4 ("lightnvm: do not remove instance under global lock")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: pblk: fix freeing of merged pages

2019-06-21T09:14:29+00:00

bio_add_pc_page() may merge pages when a bio is padded due to a flush.
Fix iteration over the bio to free the correct pages in case of a merge.

Signed-off-by: Heiner Litz 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 410

2019-06-05T15:37:14+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 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 you should have received a copy of the gnu general
  public license along with this program see the file copying if not
  write to the free software foundation 675 mass ave cambridge ma
  02139 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 3 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190112.675111872@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

lightnvm: pblk: use nvm_rq_to_ppa_list()

2019-05-06T16:19:19+00:00

This patch replaces few remaining usages of rqd->ppa_list[] with
existing nvm_rq_to_ppa_list() helpers. This is needed for theoretical
devices with ws_min/ws_opt equal to 1.

Signed-off-by: Igor Konopko 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: pblk: simplify partial read path

2019-05-06T16:19:19+00:00

This patch changes the approach to handling partial read path.

In old approach merging of data from round buffer and drive was fully
made by drive. This had some disadvantages - code was complex and
relies on bio internals, so it was hard to maintain and was strongly
dependent on bio changes.

In new approach most of the handling is done mostly by block layer
functions such as bio_split(), bio_chain() and generic_make request()
and generally is less complex and easier to maintain. Below some more
details of the new approach.

When read bio arrives, it is cloned for pblk internal purposes. All
the L2P mapping, which includes copying data from round buffer to bio
and thus bio_advance() calls is done on the cloned bio, so the original
bio is untouched. If we found that we have partial read case, we
still have original bio untouched, so we can split it and continue to
process only first part of it in current context, when the rest will be
called as separate bio request which is passed to generic_make_request()
for further processing.

Signed-off-by: Igor Konopko 
Reviewed-by: Heiner Litz 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: do not remove instance under global lock

2019-05-06T16:19:19+00:00

Currently all the target instances are removed under global nvm_lock.
This was needed to ensure that nvm_dev struct will not be freed by
hot unplug event during target removal. However, current implementation
has some drawbacks, since the same lock is used when new nvme subsystem
is registered, so we can have a situation, that due to long process of
target removal on drive A, registration (and listing in OS) of the
drive B will take a lot of time, since it will wait for that lock.

Now when we have kref which ensures that nvm_dev will not be freed in
the meantime, we can easily get rid of this lock for a time when we are
removing nvm targets.

Signed-off-by: Igor Konopko 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: track inflight target creations

2019-05-06T16:19:19+00:00

When creation process is still in progress, target is not yet on
targets list. This causes a chance for removing whole lightnvm
subsystem by calling nvm_unregister() in the meantime and finally by
causing kernel panic inside target init function.

This patch changes the behaviour by adding kref variable which tracks
all the users of nvm_dev structure. When nvm_dev is allocated, kref
value is set to 1. Then before every target creation the value is
increased and decreased after target removal. The extra reference
is decreased when nvm subsystem is unregistered.

Signed-off-by: Igor Konopko 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: pblk: recover only written metadata

2019-05-06T16:19:19+00:00

This patch ensures that smeta was fully written before even
trying to read it based on chunk table state and write pointer.

Signed-off-by: Igor Konopko 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe

lightnvm: pblk: IO path reorganization

2019-05-06T16:19:19+00:00

This patch is made in order to prepare read path for new approach to
partial read handling, which is simpler in compare with previous one.

The most important change is to move the handling of completed and
failed bio from the pblk_make_rq() to particular read and write
functions. This is needed, since after partial read path changes,
sometimes completed/failed bio will be different from original one, so
we cannot do this any longer in pblk_make_rq().

Other changes are small read path refactor in order to reduce the size
of the following patch with partial read changes.

Generally the goal of this patch is not to change the functionality,
but just to prepare the code for the following changes.

Signed-off-by: Igor Konopko 
Reviewed-by: Javier González 
Signed-off-by: Matias Bjørling 
Signed-off-by: Jens Axboe