fd: dlm: trace send/recv of dlm message and rcom

[ Upstream commit e01c4b7bd41522ae0299c07e2ee8c721fee02595 ]

This patch adds tracepoints for send and recv cases of dlm messages and
dlm rcom messages. In case of send and dlm message we add the dlm rsb
resource name this dlm messages belongs to. This has the advantage to
follow dlm messages on a per lock basis. In case of recv message the
resource name can be extracted by follow the send message sequence
number.

The dlm message DLM_MSG_PURGE doesn't belong to a lock request and will
not set the resource name in a dlm_message trace. The same for all rcom
messages.

There is additional handling required for this debugging functionality
which is tried to be small as possible. Also the midcomms layer gets
aware of lock resource names, for now this is required to make a
connection between sequence number and lock resource names. It is for
debugging purpose only.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Stable-dep-of: 724b6bab0d75 ("fs: dlm: fix use after free in midcomms commit")
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 11 insertions, 10 deletions

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index b246d71b5e17..0b1bc24536ce 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -3611,9 +3611,10 @@ static int create_message(struct dlm_rsb *r, struct dlm_lkb *lkb,
 /* further lowcomms enhancements or alternate implementations may make
    the return value from this function useful at some point */
 
-static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms)
+static int send_message(struct dlm_mhandle *mh, struct dlm_message *ms,
+			const void *name, int namelen)
 {
-	dlm_midcomms_commit_mhandle(mh);
+	dlm_midcomms_commit_mhandle(mh, name, namelen);
 	return 0;
 }
 
@@ -3679,7 +3680,7 @@ static int send_common(struct dlm_rsb *r, struct dlm_lkb *lkb, int mstype)
 
 	send_args(r, lkb, ms);
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
 	if (error)
 		goto fail;
 	return 0;
@@ -3742,7 +3743,7 @@ static int send_grant(struct dlm_rsb *r, struct dlm_lkb *lkb)
 
 	ms->m_result = 0;
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
  out:
 	return error;
 }
@@ -3763,7 +3764,7 @@ static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode)
 
 	ms->m_bastmode = cpu_to_le32(mode);
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
  out:
 	return error;
 }
@@ -3786,7 +3787,7 @@ static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb)
 
 	send_args(r, lkb, ms);
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
 	if (error)
 		goto fail;
 	return 0;
@@ -3811,7 +3812,7 @@ static int send_remove(struct dlm_rsb *r)
 	memcpy(ms->m_extra, r->res_name, r->res_length);
 	ms->m_hash = cpu_to_le32(r->res_hash);
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
  out:
 	return error;
 }
@@ -3833,7 +3834,7 @@ static int send_common_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
 
 	ms->m_result = cpu_to_le32(to_dlm_errno(rv));
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, r->res_name, r->res_length);
  out:
 	return error;
 }
@@ -3874,7 +3875,7 @@ static int send_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms_in,
 	ms->m_result = cpu_to_le32(to_dlm_errno(rv));
 	ms->m_nodeid = cpu_to_le32(ret_nodeid);
 
-	error = send_message(mh, ms);
+	error = send_message(mh, ms, ms_in->m_extra, receive_extralen(ms_in));
  out:
 	return error;
 }
@@ -6300,7 +6301,7 @@ static int send_purge(struct dlm_ls *ls, int nodeid, int pid)
 	ms->m_nodeid = cpu_to_le32(nodeid);
 	ms->m_pid = cpu_to_le32(pid);
 
-	return send_message(mh, ms);
+	return send_message(mh, ms, NULL, 0);
 }
 
 int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc,