linux.git/fs/dlm/midcomms.c, branch v6.3

fs: dlm: remove unnecessary waker_up() calls

2023-01-23T22:27:28+00:00

The wake_up() is already handled inside of midcomms_node_reset() when
switching the state to CLOSED state. So there is not need to call it
after midcomms_node_reset() again.

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

fs: dlm: move state change into else branch

2023-01-23T22:27:27+00:00

Currently we can switch at first into DLM_CLOSE_WAIT state and then do
another state change if a condition is true. Instead of doing two state
changes we handle the other state change inside an else branch of this
condition.

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

fs: dlm: remove newline in log_print

2023-01-23T22:27:26+00:00

There is an API difference between log_print() and other printk()s to
put a newline or not. This one was introduced by mistake because
log_print() adds a newline.

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

fs: dlm: reduce the shutdown timeout to 5 secs

2023-01-23T22:27:20+00:00

When a shutdown is stuck, time out after 5 seconds instead of
3 minutes.  After this timeout we try a forced shutdown.

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

fs: dlm: wait until all midcomms nodes detect version

2023-01-23T20:58:19+00:00

The current dlm version detection is very complex due to backwards
compatablilty with earlier dlm protocol versions. It takes some time to
detect if a peer node has a specific DLM version. If it's not detected,
we just cut the socket connection. There could be cases where the local
node has not detected the version yet, but the peer node has.  In these
cases, we are trying to shutdown the dlm connection with a FIN/ACK message
exchange to be sure the other peer is ready to shutdown the connection on
dlm application level.  However this mechanism is only available on DLM
protocol version 3.2 and we need to be sure the DLM version is detected
before.

To make it more robust we introduce a a "best effort" wait to wait for the
version detection before shutdown the dlm connection. This need to be
done before the kthread recoverd for recovery handling is stopped,
because recovery handling will trigger enough messages to have a version
detection going on.

It is a corner case which was detected by modprobe dlm_locktroture module
and rmmod dlm_locktorture module directly afterwards (in a looping
behaviour). In practice probably nobody would leave a lockspace immediately
after joining it.

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

fs: dlm: ignore unexpected non dlm opts msgs

2023-01-23T20:42:02+00:00

This patch ignores unexpected RCOM_NAMES/RCOM_STATUS messages.
To be backwards compatible, those messages are not part of the new
reliable DLM OPTS encapsulation header, and have their own
retransmit handling using sequence number matching  When we get
unexpected non dlm opts messages, we should allow them and let
RCOM message handling filter them out using sequence numbers.

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

fs: dlm: bring back previous shutdown handling

2023-01-23T20:36:37+00:00

This patch mostly reverts commit 4f567acb0b86 ("fs: dlm: remove socket
shutdown handling"). There can be situations where the dlm midcomms nodes
hash and lowcomms connection hash are not equal, but we need to guarantee
that the lowcomms are all closed on a last release of a dlm lockspace,
when a shutdown is invoked. This patch guarantees that we always close
all sockets managed by the lowcomms connection hash, and calls shutdown
for the last message sent. This ensures we don't cut the socket, which
could cause the peer to get a connection reset.

In future we should try to merge the midcomms/lowcomms hashes into one
hash and not handle both in separate hashes.

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

fs: dlm: send FIN ack back in right cases

2023-01-23T20:30:07+00:00

This patch moves to send a ack back for receiving a FIN message only
when we are in valid states. In other cases and there might be a sender
waiting for a ack we just let it timeout at the senders time and
hopefully all other cleanups will remove the FIN message on their
sending queue. As an example we should never send out an ACK being in
LAST_ACK state or we cannot assume a working socket communication when
we are in CLOSED state.

Cc: stable@vger.kernel.org
Fixes: 489d8e559c65 ("fs: dlm: add reliable connection if reconnect")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: move sending fin message into state change handling

2023-01-23T20:30:06+00:00

This patch moves the send fin handling, which should appear in a specific
state change, into the state change handling while the per node
state_lock is held. I experienced issues with other messages because
we changed the state and a fin message was sent out in a different state.

Cc: stable@vger.kernel.org
Fixes: 489d8e559c65 ("fs: dlm: add reliable connection if reconnect")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland

fs: dlm: don't set stop rx flag after node reset

2023-01-23T19:59:26+00:00

Similar to the stop tx flag, the rx flag should warn about a dlm message
being received at DLM_FIN state change, when we are assuming no other
dlm application messages. If we receive a FIN message and we are in the
state DLM_FIN_WAIT2 we call midcomms_node_reset() which puts the
midcomms node into DLM_CLOSED state. Afterwards we should not set the
DLM_NODE_FLAG_STOP_RX flag any more.  This patch changes the setting
DLM_NODE_FLAG_STOP_RX in those state changes when we receive a FIN
message and we assume there will be no other dlm application messages
received until we hit DLM_CLOSED state.

Cc: stable@vger.kernel.org
Fixes: 489d8e559c65 ("fs: dlm: add reliable connection if reconnect")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland