fs: dlm: revert check required context while close

This patch reverts commit 2c3fa6ae4d52 ("dlm: check required context
while close"). The function dlm_midcomms_close(), which will call later
dlm_lowcomms_close(), is called when the cluster manager tells the node
got fenced which means on midcomms/lowcomms layer to disconnect the node
from the cluster communication. The node can rejoin the cluster later.
This patch was ensuring no new message were able to be triggered when we
are in the close() function context. This was done by checking if the
lockspace has been stopped. However there is a missing check that we
only need to check specific lockspaces where the fenced node is member
of. This is currently complicated because there is no way to easily
check if a node is part of a specific lockspace without stopping the
recovery. For now we just revert this commit as it is just a check to
finding possible leaks of stopping lockspaces before close() is called.

Cc: stable@vger.kernel.org
Fixes: 2c3fa6ae4d52 ("dlm: check required context while close")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs: dlm: remove DLM_LSFL_FS from uapi

The DLM_LSFL_FS flag is set in lockspaces created directly
for a kernel user, as opposed to those lockspaces created
for user space applications. The user space libdlm allowed
this flag to be set for lockspaces created from user space,
but then used by a kernel user. No kernel user has ever
used this method, so remove the ability to do it.

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

dlm: check required context while close

This patch adds a WARN_ON() check to validate the right context while
dlm_midcomms_close() is called. Even before commit 489d8e559c65
("fs: dlm: add reliable connection if reconnect") in this context
dlm_lowcomms_close() flushes all ongoing transmission triggered by dlm
application stack. If we do that, it's required that no new message will
be triggered by the dlm application stack. The function
dlm_midcomms_close() is not called often so we can check if all
lockspaces are in such context.

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: detect available userspace daemon

If dlm_controld (the userspace daemon that controls the setup and
recovery of the dlm) fails, the kernel should shut down the lockspaces
in the kernel rather than leaving them running. This is detected by
having dlm_controld hold a misc device open while running, and if
the kernel detects a close while the daemon is still needed, it stops
the lockspaces in the kernel.

Knowing that the userspace daemon isn't running also allows the
lockspace create/remove routines to avoid waiting on the daemon
for join/leave operations.

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

[DLM] dlm: user locks

This changes the way the dlm handles user locks. The core dlm is now
aware of user locks so they can be dealt with more efficiently. There is
no more dlm_device module which previously managed its own duplicate copy
of every user lock.

Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
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>