Optimise PV -> VG lookups by using a UUID (hash) map.

diff --git a/daemons/lvmetad/lvmetad-core.c b/daemons/lvmetad/lvmetad-core.c
index 5940b3f5c7d7fa9dc235c75402b832f896c23a51..c3226e0140f0792cb9f041b608c66c5f5d296e45 100644 (file)
--- a/daemons/lvmetad/lvmetad-core.c
+++ b/daemons/lvmetad/lvmetad-core.c
@@ -9,7 +9,7 @@
 typedef struct {
        struct dm_hash_table *pvs;
        struct dm_hash_table *vgs;
-       struct dm_hash_table *pvid_to_vgid;
+       struct dm_hash_table *pvid_map;
 } lvmetad_state;
 
 static response vg_by_uuid(lvmetad_state *s, request r)
@@ -39,7 +39,7 @@ static response vg_by_uuid(lvmetad_state *s, request r)
 }
 
 static void set_flag(struct config_tree *cft, struct config_node *parent,
-                    const char *field, const char *flag, int want) {
+                    char *field, const char *flag, int want) {
        struct config_value *value = NULL, *pred = NULL;
        struct config_node *node = find_config_node(parent->child, field);
        int found = 0;
@@ -128,11 +128,14 @@ static int vg_status(lvmetad_state *s, const char *vgid)
 static void update_pv_status(lvmetad_state *s, const char *pvid)
 {
        if (pvid) {
-               const char *vgid = dm_hash_lookup(s->pvid_to_vgid, pvid);
-               assert(vgid);
+               const char *vgid = dm_hash_lookup(s->pvid_map, pvid);
+               if (!vgid)
+                       return; /* nothing to update */
+
                struct config_tree *vg = dm_hash_lookup(s->vgs, vgid);
                assert(vg);
-               update_pv_status_in_vg(s, vg->root);
+
+               update_pv_status_in_vg(s, vg);
        } else {
                struct dm_hash_node *n = dm_hash_get_first(s->vgs);
                while (n) {
@@ -143,24 +146,21 @@ static void update_pv_status(lvmetad_state *s, const char *pvid)
        }
 }
 
-struct config_tree *vg_from_pvid(lvmetad_state *s, const char *pvid)
+int update_pvid_map(lvmetad_state *s, struct config_tree *vg)
 {
-       struct dm_hash_node *n = dm_hash_get_first(s->vgs);
+       struct config_node *pv = pvs(vg);
+       char *vgid = find_config_str(vg->root, "metadata/id", NULL);
 
-       while (n) {
-               struct config_tree *vg = dm_hash_get_data(s->vgs, n);
-               struct config_node *pv = pvs(vg);
-
-               while (pv) {
-                       const char *uuid = find_config_str(pv->child, "id", "N/A");
-                       if (!strcmp(uuid, pvid))
-                               return vg;
-                       pv = pv->sib;
-               }
+       if (!vgid)
+               return 0;
 
-               n = dm_hash_get_next(s->vgs, n);
+       while (pv) {
+               char *pvid = find_config_str(pv->child, "id", NULL);
+               dm_hash_insert(s->pvid_map, pvid, vgid);
+               pv = pv->sib;
        }
-       return NULL;
+
+       return 1;
 }
 
 static int update_metadata(lvmetad_state *s, const char *vgid, struct config_node *metadata)
@@ -195,6 +195,7 @@ static int update_metadata(lvmetad_state *s, const char *vgid, struct config_nod
        struct config_tree *cft = create_config_tree(NULL, 0);
        cft->root = clone_config_node(cft, metadata, 0);
        dm_hash_insert(s->vgs, vgid, cft);
+       update_pvid_map(s, cft);
 
        return 1;
 }
@@ -208,7 +209,7 @@ static response pv_add(lvmetad_state *s, request r)
        if (!pvid)
                return daemon_reply_simple("failed", "reason = %s", "need PV UUID", NULL);
 
-       dm_hash_insert(s->pvs, pvid, 1);
+       dm_hash_insert(s->pvs, pvid, (void*)1);
 
        if (metadata) {
                if (!vgid)
@@ -219,13 +220,10 @@ static response pv_add(lvmetad_state *s, request r)
                if (!update_metadata(s, vgid, metadata))
                        return daemon_reply_simple("failed", "reason = %s",
                                                   "metadata update failed", NULL);
-       } else {
-               struct config_tree *vg = vg_from_pvid(s, pvid);
-               if (vg)
-                       vgid = find_config_str(vg->root, "metadata/id", NULL);
-       }
+       } else
+               vgid = dm_hash_lookup(s->pvid_map, pvid);
 
-       update_pv_status(s, NULL);
+       update_pv_status(s, pvid);
        int complete = vgid ? vg_status(s, vgid) : 0;
 
        return daemon_reply_simple("OK",
@@ -261,6 +259,7 @@ static int init(daemon_state *s)
 
        ls->pvs = dm_hash_create(32);
        ls->vgs = dm_hash_create(32);
+       ls->pvid_map = dm_hash_create(32);
        fprintf(stderr, "[D] initialised state: vgs = %p\n", ls->vgs);
        if (!ls->pvs || !ls->vgs)
                return 0;