From 55687b66569d7c816522b390149477128223cce6 Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Fri, 14 Jun 2024 10:59:35 -0500
Subject: [PATCH] lvmlockd: disable lvb for sanlock

The lvb is used to hold lock versions, but lock verions are
no longer used (since the removal of lvmetad), so the lvb
is not actually useful.  Disable their use for sanlock to
avoid the extra i/o required to maintain the lvb.
---
 daemons/lvmlockd/lvmlockd-client.h  |  2 ++
 daemons/lvmlockd/lvmlockd-core.c    |  2 ++
 daemons/lvmlockd/lvmlockd-sanlock.c | 11 ++++++++---
 lib/locking/lvmlockd.c              | 14 ++++++++++++--
 4 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/daemons/lvmlockd/lvmlockd-client.h b/daemons/lvmlockd/lvmlockd-client.h
index 3a6406564..187c07f03 100644
--- a/daemons/lvmlockd/lvmlockd-client.h
+++ b/daemons/lvmlockd/lvmlockd-client.h
@@ -16,6 +16,8 @@
 #define LVMLOCKD_SOCKET DEFAULT_RUN_DIR "/lvmlockd.socket"
 #define LVMLOCKD_ADOPT_FILE DEFAULT_RUN_DIR "/lvmlockd.adopt"
 
+#define LVMLOCKD_USE_SANLOCK_LVB 0
+
 /* Wrappers to open/close connection */
 
 static inline __attribute__((always_inline))
diff --git a/daemons/lvmlockd/lvmlockd-core.c b/daemons/lvmlockd/lvmlockd-core.c
index 327311b2f..6f0500689 100644
--- a/daemons/lvmlockd/lvmlockd-core.c
+++ b/daemons/lvmlockd/lvmlockd-core.c
@@ -1320,7 +1320,9 @@ static int res_lock(struct lockspace *ls, struct resource *r, struct action *act
 		 * once someone uses the lock and writes a new lvb value.
 		 * Do nothing.
 		 */
+		/*
 		log_debug("S %s R %s res_lock version_zero_valid still zero", ls->name, r->name);
+		*/
 
 	} else if (r->version_zero_valid && vb.r_version) {
 		/*
diff --git a/daemons/lvmlockd/lvmlockd-sanlock.c b/daemons/lvmlockd/lvmlockd-sanlock.c
index b7bc7804e..b1f60ee05 100644
--- a/daemons/lvmlockd/lvmlockd-sanlock.c
+++ b/daemons/lvmlockd/lvmlockd-sanlock.c
@@ -1610,12 +1610,17 @@ static int lm_add_resource_sanlock(struct lockspace *ls, struct resource *r)
 
 	/* LD_RT_LV offset is set in each lm_lock call from lv_args. */
 
+	/*
+	 * Disable sanlock lvb since lock versions are not currently used for
+	 * anything, and it's nice to avoid the extra i/o used for lvb's.
+	 */
+#if LVMLOCKD_USE_SANLOCK_LVB
 	if (r->type == LD_RT_GL || r->type == LD_RT_VG) {
 		rds->vb = zalloc(sizeof(struct val_blk));
 		if (!rds->vb)
 			return -ENOMEM;
 	}
-
+#endif
 	return 0;
 }
 
@@ -1624,9 +1629,9 @@ int lm_rem_resource_sanlock(struct lockspace *ls, struct resource *r)
 	struct rd_sanlock *rds = (struct rd_sanlock *)r->lm_data;
 
 	/* FIXME: assert r->mode == UN or unlock if it's not? */
-
+#ifdef LVMLOCKD_USE_SANLOCK_LVB
 	free(rds->vb);
-
+#endif
 	memset(rds, 0, sizeof(struct rd_sanlock));
 	r->lm_init = 0;
 	return 0;
diff --git a/lib/locking/lvmlockd.c b/lib/locking/lvmlockd.c
index 7a10e0a31..2443c9794 100644
--- a/lib/locking/lvmlockd.c
+++ b/lib/locking/lvmlockd.c
@@ -2301,12 +2301,22 @@ int lockd_vg_update(struct volume_group *vg)
 	int result;
 	int ret;
 
-	if (!vg_is_shared(vg))
-		return 1;
 	if (!_use_lvmlockd)
 		return 0;
 	if (!_lvmlockd_connected)
 		return 0;
+	if (!vg_is_shared(vg))
+		return 1;
+
+#if !LVMLOCKD_USE_SANLOCK_LVB
+	/*
+	 * lvb (for lock version) is disabled for sanlock since
+	 * lock versions are not used any more, and it's more
+	 * costly for sanlock to implement (extra i/o.)
+	 */
+	if (!strcmp(vg->lock_type, "sanlock"))
+		return 1;
+#endif
 
 	reply = _lockd_send("vg_update",
 				"pid = " FMTd64, (int64_t) getpid(),