fs: dlm: allow different allocation context per _create_message

This patch allows to give the use control about the allocation context
based on a per message basis. Currently all messages forced to be
created under GFP_NOFS context.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs: dlm: use a non-static queue for callbacks

This patch will introducde a queue implementation for callbacks by using
the Linux lists. The current callback queue handling is implemented by a
static limit of 6 entries, see DLM_CALLBACKS_SIZE. The sequence number
inside the callback structure was used to see if the entries inside the
static entry is valid or not. We don't need any sequence numbers anymore
with a dynamic datastructure with grows and shrinks during runtime to
offer such functionality.

We assume that every callback will be delivered to the DLM user if once
queued. Therefore the callback flag DLM_CB_SKIP was dropped and the
check for skipping bast was moved before worker handling and not skip
while the callback worker executes. This will reduce unnecessary queues
of the callback worker.

All last callback saves are pointers now and don't need to copied over.
There is a reference counter for callback structures which will care
about to free the callback structures at the right time if they are not
referenced anymore.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs: dlm: memory cache for lowcomms hotpath

This patch introduces a kmem cache for dlm_msg handles which are used
always if dlm sends a message out. Even if their are covered by midcomms
layer or not.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs: dlm: memory cache for writequeue_entry

This patch introduces a kmem cache for writequeue entry. A writequeue
entry get quite a lot allocated if dlm transmit messages.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs: dlm: memory cache for midcomms hotpath

This patch will introduce a kmem cache for allocating message handles
which are needed for midcomms layer to take track of lowcomms messages.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193

Based on 1 normalized pattern(s):

this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license v 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 45 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170027.342746075@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dlm: improve rsb searches

By pre-allocating rsb structs before searching the hash
table, they can be inserted immediately. This avoids
always having to repeat the search when adding the struct
to hash list.

This also adds space to the rsb struct for a max resource
name, so an rsb allocation can be used by any request.
The constant size also allows us to finally use a slab
for the rsb structs.

Signed-off-by: David Teigland <teigland@redhat.com>

dlm: use dlm prefix on alloc and free functions

The dlm functions in memory.c should use the dlm_ prefix. Also, use
kzalloc/kfree directly for dlm_direntry's, removing the wrapper functions.

Signed-off-by: David Teigland <teigland@redhat.com>

[DLM] Remove range locks from the DLM

This patch removes support for range locking from the DLM

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[DLM] The core of the DLM for GFS2/CLVM

This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>