linux-stable.git/drivers/firewire/sbp2.c, branch linux-5.4.y

firewire: remove check of list iterator against head past the loop body

2022-05-12T10:23:41+00:00

commit 9423973869bd4632ffe669f950510c49296656e0 upstream.

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Cc: 
Signed-off-by: Jakob Koschel 
Signed-off-by: Takashi Sakamoto 
Link: https://lore.kernel.org/r/20220409041243.603210-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+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 as published by
  the free software foundation either version 2 of the license or at
  your option any later version 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 if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

scsi: communicate max segment size to the DMA mapping code

2019-01-23T01:40:59+00:00

When a host driver sets a maximum segment size we should not only propagate
that setting to the block layer, which can merge segments, but also to the
DMA mapping layer which can merge segments as well.

Fixes: 50c2e9107f ("scsi: introduce a max_segment_size host_template parameters")
Signed-off-by: Christoph Hellwig 
Signed-off-by: Martin K. Petersen

scsi: flip the default on use_clustering

2018-12-19T04:13:12+00:00

Most SCSI drivers want to enable "clustering", that is merging of
segments so that they might span more than a single page.  Remove the
ENABLE_CLUSTERING define, and require drivers to explicitly set
DISABLE_CLUSTERING to disable this feature.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Martin K. Petersen

scsi: Do not set cmd_per_lun to 1 in the host template

2015-06-01T01:06:28+00:00

'0' is now used as the default cmd_per_lun value,
so there's no need to explicitly set it to '1' in the
host template.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Signed-off-by: James Bottomley

firewire: sbp2: remove redundant check for bidi command

2015-01-31T14:27:40+00:00

[Bart van Asche:]  SCSI core never sets cmd->sc_data_direction to
DMA_BIDIRECTIONAL; scsi_bidi_cmnd(cmd) should be used instead to
test for a bidirectional command.

[Christoph Hellwig:]  Bidirectional commands won't ever be queued
anyway, unless a LLD or transport driver sets QUEUE_FLAG_BIDI.

So, simply remove the respective queuecommand check in the SBP-2
transport driver.

Signed-off-by: Stefan Richter

firewire: sbp2: replace card lock by target lock

2014-12-10T19:53:21+00:00

firewire-core uses fw_card.lock to protect topology data and transaction
data.  firewire-sbp2 uses fw_card.lock for entirely unrelated purposes.

Introduce a sbp2_target.lock to firewire-sbp2 and replace all
fw_card.lock uses in the driver.  fw_card.lock is now entirely private
to firewire-core.  This has no immediate advantage apart from making it
clear in the code that firewire-sbp2 does not interact with the core
via the core lock.

Signed-off-by: Stefan Richter

firewire: sbp2: replace some spin_lock_irqsave by spin_lock_irq

2014-12-10T19:53:20+00:00

Users of card->lock        Calling context
------------------------------------------------------------------------
sbp2_status_write          AR-req handler, tasklet
complete_transaction       AR-resp or AT-req handler, tasklet
sbp2_send_orb              among else scsi host .queuecommand, which may
                           be called in some sort of atomic context
sbp2_cancel_orbs           sbp2_send_management_orb/
                               sbp2_{login,reconnect,remove},
                               worklet or process
                           sbp2_scsi_abort, scsi eh thread
sbp2_allow_block           sbp2_login, worklet
sbp2_conditionally_block   among else complete_command_orb, tasklet
sbp2_conditionally_unblock sbp2_{login,reconnect}, worklet
sbp2_unblock               sbp2_{login,remove}, worklet or process

Drop the IRQ flags saving from sbp2_cancel_orbs,
sbp2_conditionally_unblock, and sbp2_unblock.
It was already omitted in sbp2_allow_block.

Signed-off-by: Stefan Richter

firewire: sbp2: protect a reference counter properly

2014-12-10T19:53:20+00:00

The assertion in the comment in sbp2_allow_block() is no longer true.
Or maybe it never was true.  At least now, the sole caller of
sbp2_allow_block(), sbp2_login, can run concurrently to one of
sbp2_unblock()'s callers, sbp2_remove.

sbp2_login is performed by sbp2_logical_unit.work.
sbp2_remove is performed by fw_device.work.
sbp2_remove cancels sbp2_logical_unit.work, but only after it called
sbp2_unblock.

Signed-off-by: Stefan Richter

firewire: don't use PREPARE_DELAYED_WORK

2014-03-07T15:19:57+00:00

PREPARE_[DELAYED_]WORK() are being phased out.  They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

firewire core-device and sbp2 have been been multiplexing work items
with multiple work functions.  Introduce fw_device_workfn() and
sbp2_lu_workfn() which invoke fw_device->workfn and
sbp2_logical_unit->workfn respectively and always use the two
functions as the work functions and update the users to set the
->workfn fields instead of overriding work functions using
PREPARE_DELAYED_WORK().

This fixes a variety of possible regressions since a2c1c57be8d9
"workqueue: consider work function when searching for busy work items"
due to which fw_workqueue lost its required non-reentrancy property.

Signed-off-by: Tejun Heo 
Acked-by: Stefan Richter 
Cc: linux1394-devel@lists.sourceforge.net
Cc: stable@vger.kernel.org # v3.9+
Cc: stable@vger.kernel.org # v3.8.2+
Cc: stable@vger.kernel.org # v3.4.60+
Cc: stable@vger.kernel.org # v3.2.40+