fs: dlm: constify receive buffer

The dlm receive buffer should be never manipulated as DLM is the last
instance of parsing layer. This patch constify the whole receive buffer
so we are sure it never gets manipulated when it's being parsed.

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

fs: dlm: drop rxbuf manipulation in dlm_copy_master_names

This patch removes the manipulation of the receive buffer in case of an
error and be sure the buffer is null terminated before an error
messagea is printed out. Instead of manipulate the receive buffer we
tell inside the format string the maximum length the string buffer is
being read.

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

fs: dlm: get recovery sequence number as parameter

This patch removes a read of the ls->ls_recover_seq uint64_t number in
_create_rcom(). If the ls->ls_recover_seq is readed the ls_recover_lock
need to held. However this number was always readed before when any rcom
message is received and it's not necessary to read it again from a per
lockspace variable to use it for the replying message. This patch will
pass the sequence number as parameter so another read of ls->ls_recover_seq
and holding the ls->ls_recover_lock is not required.

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

dlm: use __le types for dlm header

This patch changes to use __le types directly in the dlm header
structure which is casted at the right dlm message buffer positions.

The main goal what is reached here is to remove sparse warnings
regarding to host to little byte order conversion or vice versa. Leaving
those sparse issues ignored and always do it in out/in functionality
tends to leave it unknown in which byte order the variable is being
handled.

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

fs: dlm: use dlm_recovery_stopped in condition

This patch will change to evaluate the dlm_recovery_stopped() in the
condition of the if branch instead fetch it before evaluating the
condition. As this is an atomic test-set operation it should be
evaluated in the condition itself.

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

fs: dlm: fix return -EINTR on recovery stopped

This patch will return -EINTR instead of 1 if recovery is stopped. In
case of ping_members() the return value will be checked if the error is
-EINTR for signaling another recovery was triggered and the whole
recovery process will come to a clean end to process the next one.
Returning 1 will abort the recovery process and can leave the recovery
in a broken state.

It was reported with the following kernel log message attached and a gfs2
mount stopped working:

"dlm: bobvirt1: dlm_recover_members error 1"

whereas 1 was returned because of a conversion of "dlm_recovery_stopped()"
to an errno was missing which this patch will introduce. While on it all
other possible missing errno conversions at other places were added as
they are done as in other places.

It might be worth to check the error case at this recovery level,
because some of the functionality also returns -ENOBUFS and check why
recovery ends in a broken state. However this will fix the issue if
another recovery was triggered at some points of recovery handling.

Reported-by: Bob Peterson <rpeterso@redhat.com>
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: use INFO for recovery messages

The log messages relating to the progress of recovery
are minimal and very often useful. Change these to
the KERN_INFO level so they are always available.

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

dlm: use rsbtbl as resource directory

Remove the dir hash table (dirtbl), and use
the rsb hash table (rsbtbl) as the resource
directory. It has always been an unnecessary
duplication of information.

This improves efficiency by using a single rsbtbl
lookup in many cases where both rsbtbl and dirtbl
lookups were needed previously.

This eliminates the need to handle cases of rsbtbl
and dirtbl being out of sync.

In many cases there will be memory savings because
the dir hash table no longer exists.

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

dlm: fix slow rsb search in dir recovery

The function used to find an rsb during directory
recovery was searching the single linear list of
rsb's. This wasted a lot of time compared to
using the standard hash table to find the rsb.

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

dlm: move recovery barrier calls

Put all the calls to recovery barriers in the same function
to clarify where they each happen. Should not change any behavior.
Also modify some recovery debug lines to make them consistent.

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

dlm: always use GFP_NOFS

Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
ls_allocation would be GFP_KERNEL for userland lockspaces
and GFP_NOFS for file system lockspaces.

It was discovered that any lockspaces on the system can
affect all others by triggering memory reclaim in the
file system which could in turn call back into the dlm
to acquire locks, deadlocking dlm threads that were
shared by all lockspaces, like dlm_recv.

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

dlm: use more NOFS allocation

Change some GFP_KERNEL allocations to use either GFP_NOFS or
ls_allocation (when available) which the fs sets to GFP_NOFS.
The point is to prevent allocations from going back into the
cluster fs in places where that might lead to deadlock.

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

dlm: Change rwlock which is only used in write mode to a spinlock

The ls_dirtbl[].lock was an rwlock, but since it was only used in write
mode a spinlock will suffice.

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

dlm: trivial annotation of be16 value

fs/dlm/dir.c:419:14: warning: incorrect type in assignment (different base types)
fs/dlm/dir.c:419:14: expected unsigned short [unsigned] [addressable] [assigned] [usertype] be_namelen
fs/dlm/dir.c:419:14: got restricted __be16 [usertype] <noident>

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>

dlm: fix dlm_dir_lookup() handling of too long names

... those can happen and BUG() from DLM_ASSERT() in allocate_direntry() is
not a good way to handle them.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Teigland <teigland@redhat.com>

dlm: validate data in dlm_recover_directory()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Teigland <teigland@redhat.com>

dlm: use proper type for ->ls_recover_buf

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Teigland <teigland@redhat.com>

dlm: keep cached master rsbs during recovery

To prevent the master of an rsb from changing rapidly, an unused rsb is kept
on the "toss list" for a period of time to be reused. The toss list was
being cleared completely for each recovery, which is unnecessary. Much of
the benefit of the toss list can be maintained if nodes keep rsb's in their
toss list that they are the master of. These rsb's need to be included
when the resource directory is rebuilt during recovery.

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] Update DLM to the latest patch level

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