linux/fs/dlm
Alexander Aring 1696c75f18 fs: dlm: add send ack threshold and append acks to msgs
This patch changes the time when we sending an ack back to tell the
other side it can free some message because it is arrived on the
receiver node, due random reconnects e.g. TCP resets this is handled as
well on application layer to not let DLM run into a deadlock state.

The current handling has the following problems:

1. We end in situations that we only send an ack back message of 16
   bytes out and no other messages. Whereas DLM has logic to combine
   so much messages as it can in one send() socket call. This behaviour
   can be discovered by "trace-cmd start -e dlm_recv" and observing the
   ret field being 16 bytes.

2. When processing of DLM messages will never end because we receive a
   lot of messages, we will not send an ack back as it happens when
   the processing loop ends.

This patch introduces a likely and unlikely threshold case. The likely
case will send an ack back on a transmit path if the threshold is
triggered of amount of processed upper layer protocol. This will solve
issue 1 because it will be send when another normal DLM message will be
sent. It solves issue 2 because it is not part of the processing loop.

There is however a unlikely case, the unlikely case has a bigger
threshold and will be triggered when we only receive messages and do not
sent any message back. This case avoids that the sending node will keep
a lot of message for a long time as we send sometimes ack backs to tell
the sender to finally release messages.

The atomic cmpxchg() is there to provide a atomically ack send with
reset of the upper layer protocol delivery counter.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
2023-06-14 10:17:33 -05:00
..
ast.c fs: dlm: move dlm_purge_lkb_callbacks to user module 2023-06-14 10:17:33 -05:00
ast.h fs: dlm: move dlm_purge_lkb_callbacks to user module 2023-06-14 10:17:33 -05:00
config.c fs: dlm: filter ourself midcomms calls 2023-06-14 10:17:33 -05:00
config.h fs: dlm: remove deprecated code parts 2023-03-06 15:49:07 -06:00
debug_fs.c fs: dlm: move internal flags to atomic ops 2023-03-06 15:49:07 -06:00
dir.c dlm: use __le types for dlm header 2022-04-06 14:02:28 -05:00
dir.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
dlm_internal.h fs: dlm: handle lkb wait count as atomic_t 2023-06-14 10:17:33 -05:00
Kconfig fs: dlm: remove deprecated code parts 2023-03-06 15:49:07 -06:00
lock.c fs: dlm: handle lkb wait count as atomic_t 2023-06-14 10:17:33 -05:00
lock.h fs: dlm: remove deprecated code parts 2023-03-06 15:49:07 -06:00
lockspace.c fs: dlm: revert check required context while close 2023-06-14 10:17:33 -05:00
lockspace.h fs: dlm: revert check required context while close 2023-06-14 10:17:33 -05:00
lowcomms.c fs: dlm: add send ack threshold and append acks to msgs 2023-06-14 10:17:33 -05:00
lowcomms.h fs: dlm: remove socket shutdown handling 2022-11-21 09:45:49 -06:00
lvb_table.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
main.c fs: dlm: unregister memory at the very last 2023-06-14 10:17:33 -05:00
Makefile fs: dlm: remove deprecated code parts 2023-03-06 15:49:07 -06:00
member.c fs: dlm: filter ourself midcomms calls 2023-06-14 10:17:33 -05:00
member.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
memory.c fs: dlm: change dflags to use atomic bits 2023-03-06 15:49:07 -06:00
memory.h fs: dlm: allow different allocation context per _create_message 2022-11-08 12:59:41 -06:00
midcomms.c fs: dlm: add send ack threshold and append acks to msgs 2023-06-14 10:17:33 -05:00
midcomms.h fs: dlm: wait until all midcomms nodes detect version 2023-01-23 14:58:19 -06:00
plock.c fs: dlm: fix mismatch of plock results from userspace 2023-05-24 14:27:07 -05:00
rcom.c fs: dlm: change dflags to use atomic bits 2023-03-06 15:49:07 -06:00
rcom.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
recover.c fs: dlm: move internal flags to atomic ops 2023-03-06 15:49:07 -06:00
recover.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
recoverd.c fs: dlm: remove deprecated code parts 2023-03-06 15:49:07 -06:00
recoverd.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
requestqueue.c fs: dlm: avoid false-positive checker warning 2022-11-21 09:45:49 -06:00
requestqueue.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193 2019-05-30 11:29:21 -07:00
user.c fs: dlm: move dlm_purge_lkb_callbacks to user module 2023-06-14 10:17:33 -05:00
user.h fs: dlm: move dlm_purge_lkb_callbacks to user module 2023-06-14 10:17:33 -05:00
util.c dlm: use __le types for dlm messages 2022-04-06 14:02:37 -05:00
util.h dlm: use __le types for dlm messages 2022-04-06 14:02:37 -05:00