The connector driver never modifies any cb_id passed to it, so add a const
qualifier to those arguments so callers can declare their struct cb_id as a
constant object.
Fixes build warnings like these when passing a constant struct cb_id:
warning: passing argument 1 of ‘cn_add_callback’ discards ‘const’ qualifier from pointer target
Signed-off-by: Geoff Levand <geoff@infradead.org>
Link: https://lore.kernel.org/r/a9e49c9e-67fa-16e7-0a6b-72f6bd30c58a@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As it has some function definitions, move them to connector.h.
The remaining conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)
Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.
The variable cn_callback_entry.refcnt is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This increases the amount of bundling to reduce the number of packets
sent. For the one wire use there can be multiple struct
w1_netlink_cmd in a struct w1_netlink_msg and multiple of those in
struct cn_msg, and with this change multiple of those in a struct
nlmsghdr, and at each level the len identifies there being multiple of
the next.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows replying only to the requestor portid while still
supporting broadcasting. Pass 0 to portid for the previous behavior.
Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current KVP code carries some private connector related defines.
Update connector.h to have all the KVP defines. As part of this patch
get rid of some unused defines.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The CN_NETLINK_USERS must be set to the highest valid index +1.
Thanks to Evgeniy for pointing this out.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: stable <stable@kernel.org> [.39]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commits 01a16b21 (netlink: kill eff_cap from struct netlink_skb_parms)
and c53fa1ed (netlink: kill loginuid/sessionid/sid members from struct
netlink_skb_parms) removed some members from struct netlink_skb_parms
that depend on the current context, all netlink users are now required
to do synchronous message processing.
connector however queues received messages and processes them in a work
queue, which is not valid anymore. This patch converts connector to do
synchronous message processing by invoking the registered callback handler
directly from the netlink receive function.
In order to avoid invoking the callback with connector locks held, a
reference count is added to struct cn_callback_entry, the reference
is taken when finding a matching callback entry on the device's queue_list
and released after the callback handler has been invoked.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Added a connector index to support key value/pair (KVP) functionality
for Linux guests hosted on a HyperV platform.
Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 1a5645bc (connector: create connector workqueue only while
needed once) implements lazy workqueue creation for connector
workqueue. With cmwq now in place, lazy workqueue creation doesn't
make much sense while adding a lot of complexity. Remove it and
allocate an ordered workqueue during initialization.
This also removes a call to flush_scheduled_work() which is deprecated
and scheduled to be removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Tue, Feb 02, 2010 at 02:57:14PM -0800, Greg KH (gregkh@suse.de) wrote:
> > There are at least two ways to fix it: using a big cannon and a small
> > one. The former way is to disable notification registration, since it is
> > not used by anyone at all. Second way is to check whether calling
> > process is root and its destination group is -1 (kind of priveledged
> > one) before command is dispatched to workqueue.
>
> Well if no one is using it, removing it makes the most sense, right?
>
> No objection from me, care to make up a patch either way for this?
Getting it is not used, let's drop support for notifications about
(un)registered events from connector.
Another option was to check credentials on receiving, but we can always
restore it without bugs if needed, but genetlink has a wider code base
and none complained, that userspace can not get notification when some
other clients were (un)registered.
Kudos for Sebastian Krahmer <krahmer@suse.de>, who found a bug in the
code.
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The connector documentation states that the argument to the callback
function is always a pointer to a struct cn_msg, but rather than encode it
in the API itself, it uses a void pointer everywhere. This doesn't make
much sense to encode the pointer in documentation as it prevents proper C
type checking from occurring and can easily allow people to use the wrong
pointer type. So convert the argument type to an explicit struct cn_msg
pointer.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains a device-mapper mirror log module that forwards
requests to userspace for processing.
The structures used for communication between kernel and userspace are
located in include/linux/dm-log-userspace.h. Due to the frequency,
diversity, and 2-way communication nature of the exchanges between
kernel and userspace, 'connector' was chosen as the interface for
communication.
The first log implementations written in userspace - "clustered-disk"
and "clustered-core" - support clustered shared storage. A userspace
daemon (in the LVM2 source code repository) uses openAIS/corosync to
process requests in an ordered fashion with the rest of the nodes in the
cluster so as to prevent log state corruption. Other implementations
with no association to LVM or openAIS/corosync, are certainly possible.
(Imagine if two machines are writing to the same region of a mirror.
They would both mark the region dirty, but you need a cluster-aware
entity that can handle properly marking the region clean when they are
done. Otherwise, you might clear the region when the first machine is
done, not the second.)
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch contains DST core files, which introduce
block layer, connector and sysfs registration glue and main headers.
Connector is used for the configuration of the node (its type, address,
device name and so on). Sysfs provides bits of information about running
devices in the following format:
+/*
+ * DST sysfs tree for device called 'storage':
+ *
+ * /sys/bus/dst/devices/storage/
+ * /sys/bus/dst/devices/storage/type : 192.168.4.80:1025
+ * /sys/bus/dst/devices/storage/size : 800
+ * /sys/bus/dst/devices/storage/name : storage
+ */
DST header contains structure definitions and protocol command description.
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
