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

fs: dlm: memory cache for midcomms hotpath

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

This patch will introduce a kmem cache for allocating message handles
which are needed for midcomms layer to take track of lowcomms messages.

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

fs: dlm:Remove unneeded semicolon

2021-11-05T18:03:34+00:00

Eliminate the following coccinelle check warning:
fs/dlm/midcomms.c:972:2-3

Reported-by: Zeal Robot 
Signed-off-by: Zhang Mingyu 
Signed-off-by: David Teigland

fs: dlm: add debugfs rawmsg send functionality

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

This patch adds a dlm functionality to send a raw dlm message to a
specific cluster node. This raw message can be build by user space and
send out by writing the message to "rawmsg" dlm debugfs file.

There is a in progress scapy dlm module which provides a easy build of
DLM messages in user space. For example:

DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0xe4f48a18, ...)

The goal is to provide an easy reproducable state to crash DLM or to
fuzz the DLM kernel stack if there are possible ways to crash it.

Note: that if the sequence number is zero and dlm version is not set to
3.1 the kernel will automatic will set a right sequence number, otherwise
DLM stack testing is not possible.

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

fs: dlm: let handle callback data as void

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

This patch changes the dlm_lowcomms_new_msg() function pointer private data
from "struct mhandle *" to "void *" to provide different structures than
just "struct mhandle".

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

fs: dlm: move version conversion to compile time

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

This patch moves version conversion to little endian from a runtime
variable to compile time constant.

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

fs: dlm: debug improvements print nodeid

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

This patch improves the debug output for midcomms layer by also printing
out the nodeid where users counter belongs to.

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

fs: dlm: implement delayed ack handling

2021-08-19T16:33:03+00:00

This patch changes that we don't ack each message. Lowcomms will take
care about to send an ack back after a bulk of messages was processed.
Currently it's only when the whole receive buffer was processed, there
might better positions to send an ack back but only the lowcomms
implementation know when there are more data to receive. This patch has
also disadvantages that we might retransmit more on errors, however this
is a very rare case.

Tested with make_panic on gfs2 with three nodes by running:

trace-cmd record -p function -l 'dlm_send_ack' sleep 100

and

trace-cmd report | wc -l

Before patch:
- 20548
- 21376
- 21398

After patch:
- 18338
- 20679
- 19949

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

fs: dlm: invalid buffer access in lookup error

2021-06-11T17:44:47+00:00

This patch will evaluate the message length if a dlm opts header can fit
in before accessing it if a node lookup fails. The invalid sequence
error means that the version detection failed and an unexpected message
arrived. For debugging such situation the type of arrived message is
important to know.

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

fs: dlm: fix race in mhandle deletion

2021-06-11T17:44:47+00:00

This patch fixes a race between mhandle deletion in case of receiving an
acknowledge and flush of all pending mhandle in cases of an timeout or
resetting node states.

Fixes: 489d8e559c65 ("fs: dlm: add reliable connection if reconnect")
Reported-by: Guillaume Nault 
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