When dlm_release_lockspace does active shutdown on connections to
other nodes, the active shutdown will wait for any exisitng passive
shutdowns to be resolved. But, the sequence of operations during
dlm_release_lockspace can prevent the normal resolution of passive
shutdowns (processed normally by way of lockspace recovery.)
This disruption of passive shutdown handling can cause the active
shutdown to wait for a full timeout period, delaying the completion
of dlm_release_lockspace.
To fix this, make dlm_release_lockspace resolve existing passive
shutdowns (by calling dlm_clear_members earlier), before it does
active shutdowns. The active shutdowns will not find any passive
shutdowns to wait for, and will not be delayed.
Reported-by: Chris Mackowski <cmackows@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will use READ_ONCE to signal the compiler to read this
variable only one time. If we don't do that it could be that the
compiler read this value more than one time, because some optimizations,
from the configure data which might can be changed during this time.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch renames DEFAULT_BUFFER_SIZE to DLM_MAX_SOCKET_BUFSIZE and
LOWCOMMS_MAX_TX_BUFFER_LEN to DLM_MAX_APP_BUFSIZE as they are proper
names to define what's behind those values. The DLM_MAX_SOCKET_BUFSIZE
defines the maximum size of buffer which can be handled on socket layer,
the DLM_MAX_APP_BUFSIZE defines the maximum size of buffer which can be
handled by the DLM application layer.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch introduce to make a tcp lowcomms connection reliable even if
reconnects occurs. This is done by an application layer re-transmission
handling and sequence numbers in dlm protocols. There are three new dlm
commands:
DLM_OPTS:
This will encapsulate an existing dlm message (and rcom message if they
don't have an own application side re-transmission handling). As optional
handling additional tlv's (type length fields) can be appended. This can
be for example a sequence number field. However because in DLM_OPTS the
lockspace field is unused and a sequence number is a mandatory field it
isn't made as a tlv and we put the sequence number inside the lockspace
id. The possibility to add optional options are still there for future
purposes.
DLM_ACK:
Just a dlm header to acknowledge the receive of a DLM_OPTS message to
it's sender.
DLM_FIN:
This provides a 4 way handshake for connection termination inclusive
support for half-closed connections. It's provided on application layer
because SCTP doesn't support half-closed sockets, the shutdown() call
can interrupted by e.g. TCP resets itself and a hard logic to implement
it because the othercon paradigm in lowcomms. The 4-way termination
handshake also solve problems to synchronize peer EOF arrival and that
the cluster manager removes the peer in the node membership handling of
DLM. In some cases messages can be still transmitted in this time and we
need to wait for the node membership event.
To provide a reliable connection the node will retransmit all
unacknowledges message to it's peer on reconnect. The receiver will then
filtering out the next received message and drop all messages which are
duplicates.
As RCOM_STATUS and RCOM_NAMES messages are the first messages which are
exchanged and they have they own re-transmission handling, there exists
logic that these messages must be first. If these messages arrives we
store the dlm version field. This handling is on DLM 3.1 and after this
patch 3.2 the same. A backwards compatibility handling has been added
which seems to work on tests without tcpkill, however it's not recommended
to use DLM 3.1 and 3.2 at the same time, because DLM 3.2 tries to fix long
term bugs in the DLM protocol.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch prepares hooks to redirect to the midcomms layer which will
be used by the midcomms re-transmit handling.
There exists the new concept of stateless buffers allocation and
commits. This can be used to bypass the midcomms re-transmit handling. It
is used by RCOM_STATUS and RCOM_NAMES messages, because they have their
own ping-like re-transmit handling. As well these two messages will be
used to determine the DLM version per node, because these two messages
are per observation the first messages which are exchanged.
Cluster manager events for node membership are added to add support for
half-closed connections in cases that the peer connection get to
an end of file but DLM still holds membership of the node. In
this time DLM can still trigger new message which we should allow. After
the cluster manager node removal event occurs it safe to close the
connection.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will set the maximum transmit buffer size for rcom messages
with "names" to 4096 bytes. It's a leftover change of
commit 4798cbbfbd ("fs: dlm: rework receive handling"). Fact is that we
cannot allocate a contiguous transmit buffer length above of 4096 bytes.
It seems at some places the upper layer protocol will calculate according
to dlm_config.ci_buffer_size the possible payload of a dlm recovery
message. As compiler setting we will use now the maximum possible
message which dlm can send out. Commit 4e192ee68e ("fs: dlm: disallow
buffer size below default") disallow a buffer setting smaller than the
4096 bytes and above 4096 bytes is definitely wrong because we will then
write out of buffer space as we cannot allocate a contiguous buffer above
4096 bytes. The ci_buffer_size is still there to define the possible
maximum receive buffer size of a recvmsg() which should be at least the
maximum possible dlm message size.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Currently the error return path from kobject_init_and_add() is not
followed by a call to kobject_put() - which means we are leaking
the kobject.
Set do_unreg = 1 before kobject_init_and_add() to ensure that
kobject_put() can be called in its error patch.
Fixes: 901195ed7f ("Kobject: change GFS2 to use kobject_init_and_add")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: David Teigland <teigland@redhat.com>
We saw an issue in a production server on a customer deployment where
DLM 4.0.7 gets "stuck" and unable to join new lockspaces.
There is no useful response for the dlm in do_event() if
wait_event_interruptible() is interrupted, so switch to
wait_event().
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David Teigland <teigland@redhat.com>
The kobj_type default_attrs field is being replaced by the
default_groups field, so replace the default_attrs field in dlm_ktype
with default_groups. Use the ATTRIBUTE_GROUPS macro to create
dlm_groups.
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
NULL check before some freeing functions is not needed.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: David Teigland <teigland@redhat.com>
If allocation fails on last elements of array need to free already
allocated elements.
v2: just move existing out_rsbtbl label to right place
Fixes 789924ba635f ("dlm: fix race between remove and lookup")
Cc: stable@kernel.org # 3.6
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Teigland <teigland@redhat.com>
kobject doesn't like zero length object names, so let's test for that.
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: David Teigland <teigland@redhat.com>
Declare kset_uevent_ops structure as const as it is only passed as an
argument to the function kset_create_and_add. This argument is of type
const, so declare the structure as const.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Print a message when a cluster name is not specified by
the caller. In this case the cluster name configured
for the dlm is used without any validation that it is
the cluster expected by the application.
Signed-off-by: Zhu Lingshan <lszhu@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This change will try to make this error message more clear,
since the upper applications (e.g. ocfs2) invoke dlm_new_lockspace
to create a new lockspace with passing a cluster name. Sometimes,
dlm_new_lockspace return failure while two cluster names dismatch,
the user is a little confused since this line error message is not
enough obvious.
Signed-off-by: Gang He <ghe@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.
In the case of some code where it is modular, we can extend that to
also include files that are building basic support functionality but
not related to loading or registering the final module; such files
also have no need whatsoever for module.h
The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.
Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace as needed.
In the dlm case, we remove module.h from a global header and only
introduce it in the files where it is explicitly required, since
there is nothing modular in dlm_internal.h itself.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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>
When dlm_release_lockspace(ls, 1) is invoked on a busy system
immediately after the last dlm_unlock() AST has finished it can occur
that lkb_idr_is_local() is invoked for the unlocked LKB since removal
from ls_lkbidr only occurs after the AST has returned. If that happens
dlm_release_lockspace(ls, 1) will return -EBUSY instead of releasing
the lockspace. Fix this race condition by changing lkb_idr_is_local()
such that it only returns true for LKB's that have not yet been
unlocked.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David Teigland <teigland@redhat.com>
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.
The conversion isn't completely trivial for recover_idr_clear() as it's
the only place in kernel which makes legitimate use of idr_remove_all()
w/o idr_destroy(). Replace it with idr_remove() call inside
idr_for_each_entry() loop. It goes on top so that it matches the
operation order in recover_idr_del().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The in_recovery rw_semaphore has always been acquired and
released by different threads by design. To work around
the "BUG: bad unlock balance detected!" messages, adjust
things so the dlm_recoverd thread always does both down_write
and up_write.
Signed-off-by: David Teigland <teigland@redhat.com>
It was possible for a remove message on an old
rsb to be sent after a lookup message on a new
rsb, where the rsbs were for the same resource
name. This could lead to a missing directory
entry for the new rsb.
It is fixed by keeping a copy of the resource
name being removed until after the remove has
been sent. A lookup checks if this in-progress
remove matches the name it is looking up.
Signed-off-by: David Teigland <teigland@redhat.com>
When a large number of resources are being recovered,
a linear search of the recover_list takes a long time.
Use an idr in place of a list.
Signed-off-by: David Teigland <teigland@redhat.com>
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>
The "nodir" mode (statically assign master nodes instead
of using the resource directory) has always been highly
experimental, and never seriously used. This commit
fixes a number of problems, making nodir much more usable.
- Major change to recovery: recover all locks and restart
all in-progress operations after recovery. In some
cases it's not possible to know which in-progess locks
to recover, so recover all. (Most require recovery
in nodir mode anyway since rehashing changes most
master nodes.)
- Change the way nodir mode is enabled, from a command
line mount arg passed through gfs2, into a sysfs
file managed by dlm_controld, consistent with the
other config settings.
- Allow recovering MSTCPY locks on an rsb that has not
yet been turned into a master copy.
- Ignore RCOM_LOCK and RCOM_LOCK_REPLY recovery messages
from a previous, aborted recovery cycle. Base this
on the local recovery status not being in the state
where any nodes should be sending LOCK messages for the
current recovery cycle.
- Hold rsb lock around dlm_purge_mstcpy_locks() because it
may run concurrently with dlm_recover_master_copy().
- Maintain highbast on process-copy lkb's (in addition to
the master as is usual), because the lkb can switch
back and forth between being a master and being a
process copy as the master node changes in recovery.
- When recovering MSTCPY locks, flag rsb's that have
non-empty convert or waiting queues for granting
at the end of recovery. (Rename flag from LOCKS_PURGED
to RECOVER_GRANT and similar for the recovery function,
because it's not only resources with purged locks
that need grant a grant attempt.)
- Replace a couple of unnecessary assertion panics with
error messages.
Signed-off-by: David Teigland <teigland@redhat.com>
These new callbacks notify the dlm user about lock recovery.
GFS2, and possibly others, need to be aware of when the dlm
will be doing lock recovery for a failed lockspace member.
In the past, this coordination has been done between dlm and
file system daemons in userspace, which then direct their
kernel counterparts. These callbacks allow the same
coordination directly, and more simply.
Signed-off-by: David Teigland <teigland@redhat.com>
Slot numbers are assigned to nodes when they join the lockspace.
The slot number chosen is the minimum unused value starting at 1.
Once a node is assigned a slot, that slot number will not change
while the node remains a lockspace member. If the node leaves
and rejoins it can be assigned a new slot number.
A new generation number is also added to a lockspace. It is
set and incremented during each recovery along with the slot
collection/assignment.
The slot numbers will be passed to gfs2 which will use them as
journal id's.
Signed-off-by: David Teigland <teigland@redhat.com>
Change the linked lists to rb_tree's in the rsb
hash table to speed up searches. Slow rsb searches
were having a large impact on gfs2 performance due
to the large number of dlm locks gfs2 uses.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Instead of creating our own kthread (dlm_astd) to deliver
callbacks for all lockspaces, use a per-lockspace workqueue
to deliver the callbacks. This eliminates complications and
slowdowns from many lockspaces sharing the same thread.
Signed-off-by: David Teigland <teigland@redhat.com>
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>
This is simpler and quicker than the hash table, and
avoids needing to search the hash list for every new
lkid to check if it's used.
Signed-off-by: David Teigland <teigland@redhat.com>
Allocate dlm hash tables in the vmalloc area to allow a greater
maximum size without restructuring of the hash table code.
Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Add an option (disabled by default) to print a warning message
when a lock has been waiting a configurable amount of time for
a reply message from another node. This is mainly for debugging.
Signed-off-by: David Teigland <teigland@redhat.com>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Although it is possible to get this information from the path,
its much easier to provide the lockspace as a seperate env
variable.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
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>
When a lockspace was joined multiple times, the global dlm
use count was incremented when it should not have been. This
caused the global dlm threads to not be stopped when all
lockspaces were eventually be removed.
Signed-off-by: David Teigland <teigland@redhat.com>
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>
The rwlock is almost always used in write mode, so there's no reason
to not use a spinlock instead.
Signed-off-by: David Teigland <teigland@redhat.com>
Fixes a regression from commit 0f8e0d9a31,
"dlm: allow multiple lockspace creates".
An extraneous 'else' slipped into a code fragment being moved from
release_lockspace() to dlm_release_lockspace(). The result of the
unwanted 'else' is that dlm threads and structures are not stopped
and cleaned up when the final dlm lockspace is removed. Trying to
create a new lockspace again afterward will fail with
"kmem_cache_create: duplicate cache dlm_conn" because the cache
was not previously destroyed.
Signed-off-by: David Teigland <teigland@redhat.com>
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>
Add a count for lockspace create and release so that create can
be called multiple times to use the lockspace from different places.
Also add the new flag DLM_LSFL_NEWEXCL to create a lockspace with
the previous behavior of returning -EEXIST if the lockspace already
exists.
Signed-off-by: David Teigland <teigland@redhat.com>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexander Aring