linux.git/fs/dlm/lockspace.c, branch v5.17

Merge tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2022-01-12T19:11:34+00:00

Pull driver core updates from Greg KH:
 "Here is the set of changes for the driver core for 5.17-rc1.

  Lots of little things here, including:

   - kobj_type cleanups

   - auxiliary_bus documentation updates

   - auxiliary_device conversions for some drivers (relevant subsystems
     all have provided acks for these)

   - kernfs lock contention reduction for some workloads

   - other tiny cleanups and changes.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits)
  kobject documentation: remove default_attrs information
  drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb
  debugfs: lockdown: Allow reading debugfs files that are not world readable
  driver core: Make bus notifiers in right order in really_probe()
  driver core: Move driver_sysfs_remove() after driver_sysfs_add()
  firmware: edd: remove empty default_attrs array
  firmware: dmi-sysfs: use default_groups in kobj_type
  qemu_fw_cfg: use default_groups in kobj_type
  firmware: memmap: use default_groups in kobj_type
  sh: sq: use default_groups in kobj_type
  headers/uninline: Uninline single-use function: kobject_has_children()
  devtmpfs: mount with noexec and nosuid
  driver core: Simplify async probe test code by using ktime_ms_delta()
  nilfs2: use default_groups in kobj_type
  kobject: remove kset from struct kset_uevent_ops callbacks
  driver core: make kobj_type constant.
  driver core: platform: document registration-failure requirement
  vdpa/mlx5: Use auxiliary_device driver data helpers
  net/mlx5e: Use auxiliary_device driver data helpers
  soundwire: intel: Use auxiliary_device driver data helpers
  ...

kobject: remove kset from struct kset_uevent_ops callbacks

2021-12-28T10:26:18+00:00

There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
entirely.

Reviewed-by: Rafael J. Wysocki 
Reviewed-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

fs: dlm: use event based wait for pending remove

2021-12-07T18:42:26+00:00

This patch will use an event based waitqueue to wait for a possible clash
with the ls_remove_name field of dlm_ls instead of doing busy waiting.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: ls_count busy wait to event based wait

2021-11-02T19:39:20+00:00

This patch changes the ls_count busy wait to use atomic counter values
and wait_event() to wait until ls_count reach zero. It will slightly
reduce the number of holding lslist_lock. At remove lockspace we need to
retry the wait because it a lockspace get could interefere between
wait_event() and holding the lock which deletes the lockspace list entry.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: requestqueue busy wait to event based wait

2021-11-02T19:39:20+00:00

This patch changes the requestqueue busy waiting algorithm to use
atomic counter values and wait_event() to wait until the requestqueue is
empty. It will slightly reduce the number of holding ls_requestqueue_mutex
mutex.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: fix small lockspace typo

2021-11-02T19:39:20+00:00

This patch fixes a typo from lockspace to lockspace.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: avoid comms shutdown delay in release_lockspace

2021-09-01T16:29:14+00:00

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 
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: use READ_ONCE for config var

2021-07-19T16:53:43+00:00

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 
Signed-off-by: David Teigland

fs: dlm: rename socket and app buffer defines

2021-06-02T16:53:04+00:00

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 
Signed-off-by: David Teigland

fs: dlm: add reliable connection if reconnect

2021-05-25T14:22:20+00:00

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 
Signed-off-by: David Teigland