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.
cs558i · Jun 27, 2024 · 55687b6 · 55687b6
1 parent 58e75f6
commit 55687b6
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Showing 4 changed files with 24 additions and 5 deletions.
diff --git 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
@@ -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
@@ -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
@@ -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(),