thodg/libgit2

diff --git a/src/checkout.c b/src/checkout.c
index 2893c63..dab83c6 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -1860,11 +1860,6 @@ static int checkout_create_submodules(
 	git_diff_delta *delta;
 	size_t i;
 
-	/* initial reload of submodules if .gitmodules was changed */
-	if (data->reload_submodules &&
-		(error = git_submodule_reload_all(data->repo, 1)) < 0)
-		return error;
-
 	git_vector_foreach(&data->diff->deltas, i, delta) {
 		if (actions[i] & CHECKOUT_ACTION__DEFER_REMOVE) {
 			/* this has a blocker directory that should only be removed iff
@@ -1885,8 +1880,7 @@ static int checkout_create_submodules(
 		}
 	}
 
-	/* final reload once submodules have been updated */
-	return git_submodule_reload_all(data->repo, 1);
+	return 0;
 }
 
 static int checkout_lookup_head_tree(git_tree **out, git_repository *repo)
diff --git a/src/repository.c b/src/repository.c
index c608fa0..85c8671 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -109,7 +109,6 @@ void git_repository__cleanup(git_repository *repo)
 
 	git_cache_clear(&repo->objects);
 	git_attr_cache_flush(repo);
-	git_submodule_cache_free(repo);
 
 	set_config(repo, NULL);
 	set_index(repo, NULL);
diff --git a/src/repository.h b/src/repository.h
index 2532873..fd679b4 100644
--- a/src/repository.h
+++ b/src/repository.h
@@ -121,7 +121,6 @@ struct git_repository {
 	git_refdb *_refdb;
 	git_config *_config;
 	git_index *_index;
-	git_submodule_cache *_submodules;
 
 	git_cache objects;
 	git_attr_cache *attrcache;
diff --git a/src/submodule.c b/src/submodule.c
index 246502e..9a14854 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -87,17 +87,16 @@ __KHASH_IMPL(
 	str, static kh_inline, const char *, void *, 1,
 	str_hash_no_trailing_slash, str_equal_no_trailing_slash)
 
-static int submodule_cache_init(git_repository *repo, int refresh);
-static void submodule_cache_free(git_submodule_cache *cache);
-
-static git_config_backend *open_gitmodules(git_submodule_cache *, int gitmod);
+static int submodule_alloc(git_submodule **out, git_repository *repo, const char *name);
+static git_config_backend *open_gitmodules(git_repository *repo, int gitmod);
 static int get_url_base(git_buf *url, git_repository *repo);
 static int lookup_head_remote_key(git_buf *remote_key, git_repository *repo);
-static int submodule_get(git_submodule **, git_submodule_cache *, const char *, const char *);
 static int submodule_load_from_config(const git_config_entry *, void *);
 static int submodule_load_from_wd_lite(git_submodule *);
 static void submodule_get_index_status(unsigned int *, git_submodule *);
 static void submodule_get_wd_status(unsigned int *, git_submodule *, git_repository *, git_submodule_ignore_t);
+static void submodule_update_from_index_entry(git_submodule *sm, const git_index_entry *ie);
+static void submodule_update_from_head_data(git_submodule *sm, mode_t mode, const git_oid *id);
 
 static int submodule_cmp(const void *a, const void *b)
 {
@@ -111,69 +110,10 @@ static int submodule_config_key_trunc_puts(git_buf *key, const char *suffix)
 	return git_buf_puts(key, suffix);
 }
 
-/* lookup submodule or return ENOTFOUND if it doesn't exist */
-static int submodule_lookup(
-	git_submodule **out,
-	git_submodule_cache *cache,
-	const char *name,
-	const char *alternate)
-{
-	khiter_t pos;
-
-	/* lock cache */
-
-	pos = git_strmap_lookup_index(cache->submodules, name);
-
-	if (!git_strmap_valid_index(cache->submodules, pos) && alternate)
-		pos = git_strmap_lookup_index(cache->submodules, alternate);
-
-	if (!git_strmap_valid_index(cache->submodules, pos)) {
-		/* unlock cache */
-		return GIT_ENOTFOUND; /* don't set error - caller will cope */
-	}
-
-	if (out != NULL) {
-		git_submodule *sm = git_strmap_value_at(cache->submodules, pos);
-		GIT_REFCOUNT_INC(sm);
-		*out = sm;
-	}
-
-	/* unlock cache */
-
-	return 0;
-}
-
-/* clear a set of flags on all submodules */
-static void submodule_cache_clear_flags(
-	git_submodule_cache *cache, uint32_t mask)
-{
-	git_submodule *sm;
-	uint32_t inverted_mask = ~mask;
-
-	git_strmap_foreach_value(cache->submodules, sm, {
-		sm->flags &= inverted_mask;
-	});
-}
-
 /*
  * PUBLIC APIS
  */
 
-bool git_submodule__is_submodule(git_repository *repo, const char *name)
-{
-	git_strmap *map;
-
-	if (submodule_cache_init(repo, CACHE_OK) < 0) {
-		giterr_clear();
-		return false;
-	}
-
-	if (!repo->_submodules || !(map = repo->_submodules->submodules))
-		return false;
-
-	return git_strmap_valid_index(map, git_strmap_lookup_index(map, name));
-}
-
 static void submodule_set_lookup_error(int error, const char *name)
 {
 	if (!error)
@@ -184,44 +124,39 @@ static void submodule_set_lookup_error(int error, const char *name)
 		"Submodule '%s' has not been added yet", name);
 }
 
-int git_submodule__lookup(
+int git_submodule_lookup(
 	git_submodule **out, /* NULL if user only wants to test existence */
 	git_repository *repo,
 	const char *name)    /* trailing slash is allowed */
 {
 	int error;
+	git_submodule *sm;
+	git_config_backend *mods;
 
 	assert(repo && name);
 
-	if ((error = submodule_cache_init(repo, CACHE_OK)) < 0)
-		return error;
-
-	if ((error = submodule_lookup(out, repo->_submodules, name, NULL)) < 0)
-		submodule_set_lookup_error(error, name);
-
-	return error;
-}
-
-int git_submodule_lookup(
-	git_submodule **out, /* NULL if user only wants to test existence */
-	git_repository *repo,
-	const char *name)    /* trailing slash is allowed */
-{
-	int error;
+	mods = open_gitmodules(repo, GITMODULES_EXISTING);
+	if (!mods)
+		return -1;
 
-	assert(repo && name);
+	if ((error = submodule_alloc(&sm, repo, name)) < 0)
+		return error;
 
-	if ((error = submodule_cache_init(repo, CACHE_REFRESH)) < 0)
+	if ((error = git_submodule_reload(sm, false)) < 0) {
+		git_submodule_free(sm);
 		return error;
+	}
 
-	if ((error = submodule_lookup(out, repo->_submodules, name, NULL)) < 0) {
+	/* If we didn't find the url, consider it missing */
+	if (!sm->url) {
+		git_submodule_free(sm);
+		error = GIT_ENOTFOUND;
 
-		/* check if a plausible submodule exists at path */
+		/* If it's not configured, we still check if there's a repo at the path */
 		if (git_repository_workdir(repo)) {
 			git_buf path = GIT_BUF_INIT;
-
 			if (git_buf_join3(&path,
-					'/', git_repository_workdir(repo), name, DOT_GIT) < 0)
+					  '/', git_repository_workdir(repo), name, DOT_GIT) < 0)
 				return -1;
 
 			if (git_path_exists(path.ptr))
@@ -231,9 +166,15 @@ int git_submodule_lookup(
 		}
 
 		submodule_set_lookup_error(error, name);
+		return error;
 	}
 
-	return error;
+	if (out)
+		*out = sm;
+	else
+		git_submodule_free(sm);
+
+	return 0;
 }
 
 static void submodule_free_dup(void *sm)
@@ -241,41 +182,221 @@ static void submodule_free_dup(void *sm)
 	git_submodule_free(sm);
 }
 
+static int submodule_get_or_create(git_submodule **out, git_repository *repo, git_strmap *map, const char *name)
+{
+	int error = 0;
+	khiter_t pos;
+	git_submodule *sm = NULL;
+
+	pos = git_strmap_lookup_index(map, name);
+	if (git_strmap_valid_index(map, pos)) {
+		sm = git_strmap_value_at(map, pos);
+		goto done;
+	}
+
+	/* if the submodule doesn't exist yet in the map, create it */
+	if ((error = submodule_alloc(&sm, repo, name)) < 0)
+		return error;
+
+	pos = kh_put(str, map, sm->name, &error);
+	/* nobody can beat us to adding it */
+	assert(error != 0);
+	if (error < 0) {
+		git_submodule_free(sm);
+		return error;
+	}
+
+	git_strmap_set_value_at(map, pos, sm);
+
+done:
+	GIT_REFCOUNT_INC(sm);
+	*out = sm;
+	return 0;
+}
+
+static int submodules_from_index(git_strmap *map, git_index *idx)
+{
+       int error;
+       git_iterator *i;
+       const git_index_entry *entry;
+
+       if ((error = git_iterator_for_index(&i, idx, 0, NULL, NULL)) < 0)
+               return error;
+
+       while (!(error = git_iterator_advance(&entry, i))) {
+               khiter_t pos = git_strmap_lookup_index(map, entry->path);
+               git_submodule *sm;
+
+               if (git_strmap_valid_index(map, pos)) {
+                       sm = git_strmap_value_at(map, pos);
+
+                       if (S_ISGITLINK(entry->mode))
+                               submodule_update_from_index_entry(sm, entry);
+                       else
+                               sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
+               } else if (S_ISGITLINK(entry->mode)) {
+                       if (!submodule_get_or_create(&sm, git_index_owner(idx), map, entry->path)) {
+                               submodule_update_from_index_entry(sm, entry);
+                               git_submodule_free(sm);
+                       }
+               }
+       }
+
+       if (error == GIT_ITEROVER)
+               error = 0;
+
+       git_iterator_free(i);
+
+       return error;
+}
+
+static int submodules_from_head(git_strmap *map, git_tree *head)
+{
+       int error;
+       git_iterator *i;
+       const git_index_entry *entry;
+
+       if ((error = git_iterator_for_tree(&i, head, 0, NULL, NULL)) < 0)
+               return error;
+
+       while (!(error = git_iterator_advance(&entry, i))) {
+               khiter_t pos = git_strmap_lookup_index(map, entry->path);
+               git_submodule *sm;
+
+               if (git_strmap_valid_index(map, pos)) {
+                       sm = git_strmap_value_at(map, pos);
+
+                       if (S_ISGITLINK(entry->mode))
+                               submodule_update_from_head_data(sm, entry->mode, &entry->id);
+                       else
+                               sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
+               } else if (S_ISGITLINK(entry->mode)) {
+                       if (!submodule_get_or_create(&sm, git_tree_owner(head), map, entry->path)) {
+                               submodule_update_from_head_data(
+                                       sm, entry->mode, &entry->id);
+                               git_submodule_free(sm);
+                       }
+               }
+       }
+
+       if (error == GIT_ITEROVER)
+               error = 0;
+
+       git_iterator_free(i);
+
+       return error;
+}
+
+/* If have_sm is true, sm is populated, otherwise map an repo are. */
+typedef struct {
+	int have_sm;
+	git_submodule *sm;
+	git_strmap *map;
+	git_repository *repo;
+} lfc_data;
+
+static int all_submodules(git_repository *repo, git_strmap *map)
+{
+	int error = 0;
+	git_index *idx = NULL;
+	git_tree *head = NULL;
+	const char *wd = NULL;
+	git_buf path = GIT_BUF_INIT;
+	git_submodule *sm;
+	git_config_backend *mods = NULL;
+	uint32_t mask;
+
+	assert(repo && map);
+
+	/* get sources that we will need to check */
+	if (git_repository_index(&idx, repo) < 0)
+		giterr_clear();
+	if (git_repository_head_tree(&head, repo) < 0)
+		giterr_clear();
+
+	wd = git_repository_workdir(repo);
+	if (wd && (error = git_buf_joinpath(&path, wd, GIT_MODULES_FILE)) < 0)
+		goto cleanup;
+
+	/* clear submodule flags that are to be refreshed */
+	mask = 0;
+	mask |= GIT_SUBMODULE_STATUS_IN_INDEX |
+		GIT_SUBMODULE_STATUS__INDEX_FLAGS |
+		GIT_SUBMODULE_STATUS__INDEX_OID_VALID |
+		GIT_SUBMODULE_STATUS__INDEX_MULTIPLE_ENTRIES;
+
+	mask |= GIT_SUBMODULE_STATUS_IN_HEAD |
+		GIT_SUBMODULE_STATUS__HEAD_OID_VALID;
+	mask |= GIT_SUBMODULE_STATUS_IN_CONFIG;
+	if (mask != 0)
+		mask |= GIT_SUBMODULE_STATUS_IN_WD |
+			GIT_SUBMODULE_STATUS__WD_SCANNED |
+			GIT_SUBMODULE_STATUS__WD_FLAGS |
+			GIT_SUBMODULE_STATUS__WD_OID_VALID;
+
+	/* add back submodule information from index */
+	if (idx) {
+		if ((error = submodules_from_index(map, idx)) < 0)
+			goto cleanup;
+	}
+	/* add submodule information from HEAD */
+	if (head) {
+		if ((error = submodules_from_head(map, head)) < 0)
+			goto cleanup;
+	}
+	/* add submodule information from .gitmodules */
+	if (wd) {
+		lfc_data data = { 0 };
+		data.map = map;
+		data.repo = repo;
+		if ((mods = open_gitmodules(repo, false)) != NULL &&
+		    (error = git_config_file_foreach(
+			    mods, submodule_load_from_config, &data)) < 0)
+			goto cleanup;
+	}
+	/* shallow scan submodules in work tree as needed */
+	if (wd && mask != 0) {
+		git_strmap_foreach_value(map, sm, {
+				submodule_load_from_wd_lite(sm);
+			});
+	}
+
+cleanup:
+	git_config_file_free(mods);
+	/* TODO: if we got an error, mark submodule config as invalid? */
+	git_index_free(idx);
+	git_tree_free(head);
+	git_buf_free(&path);
+	return error;
+}
+
 int git_submodule_foreach(
 	git_repository *repo,
 	int (*callback)(git_submodule *sm, const char *name, void *payload),
 	void *payload)
 {
+	git_vector snapshot = GIT_VECTOR_INIT;
+	git_strmap *submodules;
+	git_submodule *sm;
 	int error;
 	size_t i;
-	git_submodule *sm;
-	git_submodule_cache *cache;
-	git_vector snapshot = GIT_VECTOR_INIT;
 
-	assert(repo && callback);
-
-	if ((error = submodule_cache_init(repo, CACHE_REFRESH)) < 0)
+	if ((error = git_strmap_alloc(&submodules)) < 0)
 		return error;
 
-	cache = repo->_submodules;
-
-	if (git_mutex_lock(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to acquire lock on submodule cache");
-		return -1;
-	}
+	if ((error = all_submodules(repo, submodules)) < 0)
+		goto done;
 
 	if (!(error = git_vector_init(
-			&snapshot, kh_size(cache->submodules), submodule_cmp))) {
+			&snapshot, kh_size(submodules), submodule_cmp))) {
 
-		git_strmap_foreach_value(cache->submodules, sm, {
+		git_strmap_foreach_value(submodules, sm, {
 			if ((error = git_vector_insert(&snapshot, sm)) < 0)
 				break;
 			GIT_REFCOUNT_INC(sm);
 		});
 	}
 
-	git_mutex_unlock(&cache->lock);
-
 	if (error < 0)
 		goto done;
 
@@ -293,17 +414,12 @@ done:
 		git_submodule_free(sm);
 	git_vector_free(&snapshot);
 
-	return error;
-}
-
-void git_submodule_cache_free(git_repository *repo)
-{
-	git_submodule_cache *cache;
-
-	assert(repo);
+	git_strmap_foreach_value(submodules, sm, {
+		git_submodule_free(sm);
+	});
+	git_strmap_free(submodules);
 
-	if ((cache = git__swap(repo->_submodules, NULL)) != NULL)
-		submodule_cache_free(cache);
+	return error;
 }
 
 static int submodule_repo_init(
@@ -394,7 +510,7 @@ int git_submodule_add_setup(
 
 	/* update .gitmodules */
 
-	if (!(mods = open_gitmodules(repo->_submodules, GITMODULES_CREATE))) {
+	if (!(mods = open_gitmodules(repo, GITMODULES_CREATE))) {
 		giterr_set(GITERR_SUBMODULE,
 			"Adding submodules to a bare repository is not supported");
 		return -1;
@@ -430,19 +546,10 @@ int git_submodule_add_setup(
 			goto cleanup;
 	}
 
-	/* add submodule to hash and "reload" it */
-
-	if (git_mutex_lock(&repo->_submodules->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to acquire lock on submodule cache");
-		error = -1;
+	if ((error = git_submodule_lookup(&sm, repo, path)) < 0)
 		goto cleanup;
-	}
-
-	if (!(error = submodule_get(&sm, repo->_submodules, path, NULL)) &&
-		!(error = git_submodule_reload(sm, false)))
-		error = git_submodule_init(sm, false);
 
-	git_mutex_unlock(&repo->_submodules->lock);
+	error = git_submodule_init(sm, false);
 
 cleanup:
 	if (error && sm) {
@@ -608,7 +715,7 @@ int git_submodule_save(git_submodule *submodule)
 
 	assert(submodule);
 
-	mods = open_gitmodules(submodule->repo->_submodules, GITMODULES_CREATE);
+	mods = open_gitmodules(submodule->repo, GITMODULES_CREATE);
 	if (!mods) {
 		giterr_set(GITERR_SUBMODULE,
 			"Adding submodules to a bare repository is not supported");
@@ -1197,11 +1304,6 @@ int git_submodule_open(git_repository **subrepo, git_submodule *sm)
 	return git_submodule__open(subrepo, sm, false);
 }
 
-int git_submodule_reload_all(git_repository *repo, int force)
-{
-	return submodule_cache_init(repo, force ? CACHE_FLUSH : CACHE_REFRESH);
-}
-
 static void submodule_update_from_index_entry(
 	git_submodule *sm, const git_index_entry *ie)
 {
@@ -1280,14 +1382,12 @@ int git_submodule_reload(git_submodule *sm, int force)
 {
 	int error = 0;
 	git_config_backend *mods;
-	git_submodule_cache *cache;
+	lfc_data data = { 0 };
 
 	GIT_UNUSED(force);
 
 	assert(sm);
 
-	cache = sm->repo->_submodules;
-
 	/* refresh index data */
 	if ((error = submodule_update_index(sm)) < 0)
 		return error;
@@ -1301,7 +1401,7 @@ int git_submodule_reload(git_submodule *sm, int force)
 		return error;
 
 	/* refresh config data */
-	mods = open_gitmodules(cache, GITMODULES_EXISTING);
+	mods = open_gitmodules(sm->repo, GITMODULES_EXISTING);
 	if (mods != NULL) {
 		git_buf path = GIT_BUF_INIT;
 
@@ -1309,11 +1409,14 @@ int git_submodule_reload(git_submodule *sm, int force)
 		git_buf_text_puts_escape_regex(&path, sm->name);
 		git_buf_puts(&path, ".*");
 
-		if (git_buf_oom(&path))
+		if (git_buf_oom(&path)) {
 			error = -1;
-		else
+		} else {
+			data.have_sm = 1;
+			data.sm = sm;
 			error = git_config_file_foreach_match(
-				mods, path.ptr, submodule_load_from_config, cache);
+				mods, path.ptr, submodule_load_from_config, &data);
+		}
 
 		git_buf_free(&path);
 		git_config_file_free(mods);
@@ -1422,7 +1525,7 @@ int git_submodule_location(unsigned int *location, git_submodule *sm)
  */
 
 static int submodule_alloc(
-	git_submodule **out, git_submodule_cache *cache, const char *name)
+	git_submodule **out, git_repository *repo, const char *name)
 {
 	size_t namelen;
 	git_submodule *sm;
@@ -1445,56 +1548,20 @@ static int submodule_alloc(
 	sm->ignore = sm->ignore_default = GIT_SUBMODULE_IGNORE_NONE;
 	sm->update = sm->update_default = GIT_SUBMODULE_UPDATE_CHECKOUT;
 	sm->fetch_recurse = sm->fetch_recurse_default = GIT_SUBMODULE_RECURSE_NO;
-	sm->repo   = cache->repo;
+	sm->repo   = repo;
 	sm->branch = NULL;
 
 	*out = sm;
 	return 0;
 }
 
-static void submodule_cache_remove_item(
-	git_submodule_cache *cache,
-	git_submodule *item,
-	bool free_after_remove)
-{
-	git_strmap *map;
-	const char *name, *alt;
-
-	if (!cache || !(map = cache->submodules) || !item)
-		return;
-
-	name = item->name;
-	alt  = (item->path != item->name) ? item->path : NULL;
-
-	for (; name; name = alt, alt = NULL) {
-		khiter_t pos = git_strmap_lookup_index(map, name);
-		git_submodule *found;
-
-		if (!git_strmap_valid_index(map, pos))
-			continue;
-
-		found = git_strmap_value_at(map, pos);
-
-		if (found != item)
-			continue;
-
-		git_strmap_set_value_at(map, pos, NULL);
-		git_strmap_delete_at(map, pos);
-
-		if (free_after_remove)
-			git_submodule_free(found);
-	}
-}
-
 static void submodule_release(git_submodule *sm)
 {
 	if (!sm)
 		return;
 
 	if (sm->repo) {
-		git_submodule_cache *cache = sm->repo->_submodules;
 		sm->repo = NULL;
-		submodule_cache_remove_item(cache, sm, false);
 	}
 
 	if (sm->path != sm->name)
@@ -1513,54 +1580,6 @@ void git_submodule_free(git_submodule *sm)
 	GIT_REFCOUNT_DEC(sm, submodule_release);
 }
 
-static int submodule_get(
-	git_submodule **out,
-	git_submodule_cache *cache,
-	const char *name,
-	const char *alternate)
-{
-	int error = 0;
-	khiter_t pos;
-	git_submodule *sm;
-
-	pos = git_strmap_lookup_index(cache->submodules, name);
-
-	if (!git_strmap_valid_index(cache->submodules, pos) && alternate)
-		pos = git_strmap_lookup_index(cache->submodules, alternate);
-
-	if (!git_strmap_valid_index(cache->submodules, pos)) {
-		if ((error = submodule_alloc(&sm, cache, name)) < 0)
-			return error;
-
-		/* insert value at name - if another thread beats us to it, then use
-		 * their record and release our own.
-		 */
-		pos = kh_put(str, cache->submodules, sm->name, &error);
-
-		if (error < 0)
-			goto done;
-		else if (error == 0) {
-			git_submodule_free(sm);
-			sm = git_strmap_value_at(cache->submodules, pos);
-		} else {
-			error = 0;
-			git_strmap_set_value_at(cache->submodules, pos, sm);
-		}
-	} else {
-		sm = git_strmap_value_at(cache->submodules, pos);
-	}
-
-done:
-	if (error < 0)
-		git_submodule_free(sm);
-	else if (out) {
-		GIT_REFCOUNT_INC(sm);
-		*out = sm;
-	}
-
-	return error;
-}
-
 static int submodule_config_error(const char *property, const char *value)
 {
 	giterr_set(GITERR_INVALID,
@@ -1613,12 +1632,12 @@ int git_submodule_parse_recurse(git_submodule_recurse_t *out, const char *value)
 static int submodule_load_from_config(
 	const git_config_entry *entry, void *payload)
 {
-	git_submodule_cache *cache = payload;
 	const char *namestart, *property;
 	const char *key = entry->name, *value = entry->value, *path;
 	char *alternate = NULL, *replaced = NULL;
 	git_buf name = GIT_BUF_INIT;
-	git_submodule *sm = NULL;
+	lfc_data *data = payload;
+	git_submodule *sm;
 	int error = 0;
 
 	if (git__prefixcmp(key, "submodule.") != 0)
@@ -1633,10 +1652,29 @@ static int submodule_load_from_config(
 	property++;
 	path = !strcasecmp(property, "path") ? value : NULL;
 
-	if ((error = git_buf_set(&name, namestart, property - namestart - 1)) < 0 ||
-		(error = submodule_get(&sm, cache, name.ptr, path)) < 0)
+	if ((error = git_buf_set(&name, namestart, property - namestart -1)) < 0)
 		goto done;
 
+	if (data->have_sm) {
+		sm = data->sm;
+	} else {
+		khiter_t pos;
+		git_strmap *map = data->map;
+		pos = git_strmap_lookup_index(map, name.ptr);
+		if (git_strmap_valid_index(map, pos)) {
+			sm = git_strmap_value_at(map, pos);
+		} else {
+			if ((error = submodule_alloc(&sm, data->repo, name.ptr)) < 0)
+				goto done;
+
+			git_strmap_insert(map, sm->name, sm, error);
+			assert(error != 0);
+			if (error < 0)
+				goto done;
+			error = 0;
+		}
+	}
+
 	sm->flags |= GIT_SUBMODULE_STATUS_IN_CONFIG;
 
 	/* Only from config might we get differing names & paths.  If so, then
@@ -1648,7 +1686,7 @@ static int submodule_load_from_config(
 	 */
 
 	if (strcmp(sm->name, name.ptr) != 0) { /* name changed */
-		if (!strcmp(sm->path, name.ptr)) { /* already set as path */
+		if (sm->path && !strcmp(sm->path, name.ptr)) { /* already set as path */
 			replaced = sm->name;
 			sm->name = sm->path;
 		} else {
@@ -1674,7 +1712,6 @@ static int submodule_load_from_config(
 
 	/* Deregister under name being replaced */
 	if (replaced) {
-		git_strmap_delete(cache->submodules, replaced);
 		git_submodule_free(sm);
 		git__free(replaced);
 	}
@@ -1682,7 +1719,6 @@ static int submodule_load_from_config(
 	/* Insert under alternate key */
 	if (alternate) {
 		void *old_sm = NULL;
-		git_strmap_insert2(cache->submodules, alternate, sm, old_sm, error);
 
 		if (error < 0)
 			goto done;
@@ -1742,7 +1778,6 @@ static int submodule_load_from_config(
 	/* ignore other unknown submodule properties */
 
 done:
-	git_submodule_free(sm); /* offset refcount inc from submodule_get() */
 	git_buf_free(&name);
 	return error;
 }
@@ -1764,86 +1799,11 @@ static int submodule_load_from_wd_lite(git_submodule *sm)
 	return 0;
 }
 
-static int submodule_cache_refresh_from_index(
-	git_submodule_cache *cache, git_index *idx)
-{
-	int error;
-	git_iterator *i;
-	const git_index_entry *entry;
-
-	if ((error = git_iterator_for_index(&i, idx, 0, NULL, NULL)) < 0)
-		return error;
-
-	while (!(error = git_iterator_advance(&entry, i))) {
-		khiter_t pos = git_strmap_lookup_index(cache->submodules, entry->path);
-		git_submodule *sm;
-
-		if (git_strmap_valid_index(cache->submodules, pos)) {
-			sm = git_strmap_value_at(cache->submodules, pos);
-
-			if (S_ISGITLINK(entry->mode))
-				submodule_update_from_index_entry(sm, entry);
-			else
-				sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
-		} else if (S_ISGITLINK(entry->mode)) {
-			if (!submodule_get(&sm, cache, entry->path, NULL)) {
-				submodule_update_from_index_entry(sm, entry);
-				git_submodule_free(sm);
-			}
-		}
-	}
-
-	if (error == GIT_ITEROVER)
-		error = 0;
-
-	git_iterator_free(i);
-
-	return error;
-}
-
-static int submodule_cache_refresh_from_head(
-	git_submodule_cache *cache, git_tree *head)
-{
-	int error;
-	git_iterator *i;
-	const git_index_entry *entry;
-
-	if ((error = git_iterator_for_tree(&i, head, 0, NULL, NULL)) < 0)
-		return error;
-
-	while (!(error = git_iterator_advance(&entry, i))) {
-		khiter_t pos = git_strmap_lookup_index(cache->submodules, entry->path);
-		git_submodule *sm;
-
-		if (git_strmap_valid_index(cache->submodules, pos)) {
-			sm = git_strmap_value_at(cache->submodules, pos);
-
-			if (S_ISGITLINK(entry->mode))
-				submodule_update_from_head_data(sm, entry->mode, &entry->id);
-			else
-				sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
-		} else if (S_ISGITLINK(entry->mode)) {
-			if (!submodule_get(&sm, cache, entry->path, NULL)) {
-				submodule_update_from_head_data(
-					sm, entry->mode, &entry->id);
-				git_submodule_free(sm);
-			}
-		}
-	}
-
-	if (error == GIT_ITEROVER)
-		error = 0;
-
-	git_iterator_free(i);
-
-	return error;
-}
-
 static git_config_backend *open_gitmodules(
-	git_submodule_cache *cache,
+	git_repository *repo,
 	int okay_to_create)
 {
-	const char *workdir = git_repository_workdir(cache->repo);
+	const char *workdir = git_repository_workdir(repo);
 	git_buf path = GIT_BUF_INIT;
 	git_config_backend *mods = NULL;
 
@@ -1868,198 +1828,6 @@ static git_config_backend *open_gitmodules(
 	return mods;
 }
 
-static void submodule_cache_free(git_submodule_cache *cache)
-{
-	git_submodule *sm;
-
-	if (!cache)
-		return;
-
-	git_strmap_foreach_value(cache->submodules, sm, {
-		sm->repo = NULL; /* disconnect from repo */
-		git_submodule_free(sm);
-	});
-	git_strmap_free(cache->submodules);
-
-	git_buf_free(&cache->gitmodules_path);
-	git_mutex_free(&cache->lock);
-	git__free(cache);
-}
-
-static int submodule_cache_alloc(
-	git_submodule_cache **out, git_repository *repo)
-{
-	git_submodule_cache *cache = git__calloc(1, sizeof(git_submodule_cache));
-	GITERR_CHECK_ALLOC(cache);
-
-	if (git_mutex_init(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to initialize submodule cache lock");
-		git__free(cache);
-		return -1;
-	}
-
-	if (git_strmap_alloc(&cache->submodules) < 0) {
-		submodule_cache_free(cache);
-		return -1;
-	}
-
-	cache->repo = repo;
-	git_buf_init(&cache->gitmodules_path, 0);
-
-	*out = cache;
-	return 0;
-}
-
-static int submodule_cache_refresh(git_submodule_cache *cache, int refresh)
-{
-	int error = 0, update_index, update_head, update_gitmod;
-	git_index *idx = NULL;
-	git_tree *head = NULL;
-	const char *wd = NULL;
-	git_buf path = GIT_BUF_INIT;
-	git_submodule *sm;
-	git_config_backend *mods = NULL;
-	uint32_t mask;
-
-	if (!cache || !cache->repo || !refresh)
-		return 0;
-
-	if (git_mutex_lock(&cache->lock) < 0) {
-		giterr_set(GITERR_OS, "Unable to acquire lock on submodule cache");
-		return -1;
-	}
-
-	/* get sources that we will need to check */
-
-	if (git_repository_index(&idx, cache->repo) < 0)
-		giterr_clear();
-	if (git_repository_head_tree(&head, cache->repo) < 0)
-		giterr_clear();
-
-	wd = git_repository_workdir(cache->repo);
-	if (wd && (error = git_buf_joinpath(&path, wd, GIT_MODULES_FILE)) < 0)
-		goto cleanup;
-
-	/* check for invalidation */
-
-	if (refresh == CACHE_FLUSH)
-		update_index = update_head = update_gitmod = true;
-	else {
-		update_index =
-			!idx || git_index__changed_relative_to(idx, &cache->index_checksum);
-		update_head =
-			!head || !git_oid_equal(&cache->head_id, git_tree_id(head));
-
-		update_gitmod = (wd != NULL) ?
-			git_futils_filestamp_check(&cache->gitmodules_stamp, path.ptr) :
-			(cache->gitmodules_stamp.mtime != 0);
-	}
-
-	/* clear submodule flags that are to be refreshed */
-
-	mask = 0;
-	if (!idx || update_index)
-		mask |= GIT_SUBMODULE_STATUS_IN_INDEX |
-			GIT_SUBMODULE_STATUS__INDEX_FLAGS |
-			GIT_SUBMODULE_STATUS__INDEX_OID_VALID |
-			GIT_SUBMODULE_STATUS__INDEX_MULTIPLE_ENTRIES;
-	if (!head || update_head)
-		mask |= GIT_SUBMODULE_STATUS_IN_HEAD |
-			GIT_SUBMODULE_STATUS__HEAD_OID_VALID;
-	if (update_gitmod)
-		mask |= GIT_SUBMODULE_STATUS_IN_CONFIG;
-	if (mask != 0)
-		mask |= GIT_SUBMODULE_STATUS_IN_WD |
-			GIT_SUBMODULE_STATUS__WD_SCANNED |
-			GIT_SUBMODULE_STATUS__WD_FLAGS |
-			GIT_SUBMODULE_STATUS__WD_OID_VALID;
-	else
-		goto cleanup; /* nothing to do */
-
-	submodule_cache_clear_flags(cache, mask);
-
-	/* add back submodule information from index */
-
-	if (idx && update_index) {
-		if ((error = submodule_cache_refresh_from_index(cache, idx)) < 0)
-			goto cleanup;
-
-		git_oid_cpy(&cache->index_checksum, git_index_checksum(idx));
-	}
-
-	/* add submodule information from HEAD */
-
-	if (head && update_head) {
-		if ((error = submodule_cache_refresh_from_head(cache, head)) < 0)
-			goto cleanup;
-
-		git_oid_cpy(&cache->head_id, git_tree_id(head));
-	}
-
-	/* add submodule information from .gitmodules */
-
-	if (wd && update_gitmod > 0) {
-		if ((mods = open_gitmodules(cache, false)) != NULL &&
-			(error = git_config_file_foreach(
-				mods, submodule_load_from_config, cache)) < 0)
-			goto cleanup;
-	}
-
-	/* shallow scan submodules in work tree as needed */
-
-	if (wd && mask != 0) {
-		git_strmap_foreach_value(cache->submodules, sm, {
-			submodule_load_from_wd_lite(sm);
-		});
-	}
-
-	/* remove submodules that no longer exist */
-
-	git_strmap_foreach_value(cache->submodules, sm, {
-		/* purge unless in HEAD, index, or .gitmodules; no sm for wd only */
-		if (sm != NULL &&
-			!(sm->flags &
-			 (GIT_SUBMODULE_STATUS_IN_HEAD |
-			  GIT_SUBMODULE_STATUS_IN_INDEX |
-			  GIT_SUBMODULE_STATUS_IN_CONFIG)))
-			submodule_cache_remove_item(cache, sm, true);
-	});
-
-cleanup:
-	git_config_file_free(mods);
-
-	/* TODO: if we got an error, mark submodule config as invalid? */
-
-	git_mutex_unlock(&cache->lock);
-
-	git_index_free(idx);
-	git_tree_free(head);
-	git_buf_free(&path);
-
-	return error;
-}
-
-static int submodule_cache_init(git_repository *repo, int cache_refresh)
-{
-	int error = 0;
-	git_submodule_cache *cache = NULL;
-
-	/* if submodules already exist, just refresh as requested */
-	if (repo->_submodules)
-		return submodule_cache_refresh(repo->_submodules, cache_refresh);
-
-	/* otherwise create a new cache, load it, and atomically swap it in */
-	if (!(error = submodule_cache_alloc(&cache, repo)) &&
-		!(error = submodule_cache_refresh(cache, CACHE_FLUSH)))
-		cache = git__compare_and_swap(&repo->_submodules, NULL, cache);
-
-	/* might have raced with another thread to set cache, so free if needed */
-	if (cache)
-		submodule_cache_free(cache);
-
-	return error;
-}
-
 /* Lookup name of remote of the local tracking branch HEAD points to */
 static int lookup_head_remote_key(git_buf *remote_name, git_repository *repo)
 {
diff --git a/src/submodule.h b/src/submodule.h
index 7a9bf9c..d677961 100644
--- a/src/submodule.h
+++ b/src/submodule.h
@@ -99,23 +99,6 @@ struct git_submodule {
 	git_oid wd_oid;
 };
 
-/**
- * The git_submodule_cache stores known submodules along with timestamps,
- * etc. about when they were loaded
- */
-typedef struct {
-	git_repository *repo;
-	git_strmap *submodules;
-	git_mutex  lock;
-
-	/* cache invalidation data */
-	git_oid head_id;
-	git_oid index_checksum;
-	git_buf gitmodules_path;
-	git_futils_filestamp gitmodules_stamp;
-	git_futils_filestamp config_stamp;
-} git_submodule_cache;
-
 /* Force revalidation of submodule data cache (alloc as needed) */
 extern int git_submodule_cache_refresh(git_repository *repo);
 
@@ -137,9 +120,6 @@ enum {
 #define GIT_SUBMODULE_STATUS__CLEAR_INTERNAL(S) \
 	((S) & ~(0xFFFFFFFFu << 20))
 
-/* Internal submodule check does not attempt to refresh cached data */
-extern bool git_submodule__is_submodule(git_repository *repo, const char *name);
-
 /* Internal lookup does not attempt to refresh cached data */
 extern int git_submodule__lookup(
 	git_submodule **out, git_repository *repo, const char *path);
diff --git a/tests/submodule/modify.c b/tests/submodule/modify.c
index bbbb2d5..8f24d9b 100644
--- a/tests/submodule/modify.c
+++ b/tests/submodule/modify.c
@@ -50,8 +50,6 @@ void test_submodule_modify__init(void)
 	/* call init and see that settings are copied */
 	cl_git_pass(git_submodule_foreach(g_repo, init_one_submodule, NULL));
 
-	git_submodule_reload_all(g_repo, 1);
-
 	/* confirm submodule data in config */
 	cl_git_pass(git_repository_config_snapshot(&cfg, g_repo));
 	cl_git_pass(git_config_get_string(&str, cfg, "submodule.sm_unchanged.url"));
diff --git a/tests/submodule/nosubs.c b/tests/submodule/nosubs.c
index e343c16..538825c 100644
--- a/tests/submodule/nosubs.c
+++ b/tests/submodule/nosubs.c
@@ -21,19 +21,11 @@ void test_submodule_nosubs__lookup(void)
 
 	cl_assert_equal_i(GIT_EEXISTS, git_submodule_lookup(&sm, repo, "subrepo"));
 
-	cl_git_pass(git_submodule_reload_all(repo, 0));
-
 	cl_assert_equal_i(GIT_ENOTFOUND, git_submodule_lookup(&sm, repo, "subdir"));
 
 	cl_assert_equal_i(GIT_EEXISTS, git_submodule_lookup(&sm, repo, "subrepo"));
 }
 
-void test_submodule_nosubs__immediate_reload(void)
-{
-	git_repository *repo = cl_git_sandbox_init("status");
-	cl_git_pass(git_submodule_reload_all(repo, 0));
-}
-
 static int fake_submod_cb(git_submodule *sm, const char *n, void *p)
 {
 	GIT_UNUSED(sm); GIT_UNUSED(n); GIT_UNUSED(p);
@@ -57,41 +49,7 @@ void test_submodule_nosubs__add(void)
 	git_submodule_free(sm2);
 
 	cl_git_pass(git_submodule_foreach(repo, fake_submod_cb, NULL));
-	cl_git_pass(git_submodule_reload_all(repo, 0));
-
-	git_submodule_free(sm);
-}
-
-void test_submodule_nosubs__reload_add_reload(void)
-{
-	git_repository *repo = cl_git_sandbox_init("status");
-	git_submodule *sm;
-
-	cl_git_pass(git_submodule_reload_all(repo, 0));
-
-	/* try one add with a reload (to make sure no errors happen) */
-
-	cl_git_pass(git_submodule_add_setup(&sm, repo,
-		"https://github.com/libgit2/libgit2.git", "submodules/libgit2", 1));
-
-	cl_git_pass(git_submodule_reload_all(repo, 0));
-
-	cl_assert_equal_s("submodules/libgit2", git_submodule_name(sm));
-	git_submodule_free(sm);
-
-	cl_git_pass(git_submodule_lookup(&sm, repo, "submodules/libgit2"));
-	cl_assert_equal_s("submodules/libgit2", git_submodule_name(sm));
-	git_submodule_free(sm);
-
-	/* try one add without a reload (to make sure cache inval works, too) */
-
-	cl_git_pass(git_submodule_add_setup(&sm, repo,
-		"https://github.com/libgit2/libgit2.git", "libgit2-again", 1));
-	cl_assert_equal_s("libgit2-again", git_submodule_name(sm));
-	git_submodule_free(sm);
 
-	cl_git_pass(git_submodule_lookup(&sm, repo, "libgit2-again"));
-	cl_assert_equal_s("libgit2-again", git_submodule_name(sm));
 	git_submodule_free(sm);
 }
 
@@ -100,10 +58,8 @@ void test_submodule_nosubs__bad_gitmodules(void)
 	git_repository *repo = cl_git_sandbox_init("status");
 
 	cl_git_mkfile("status/.gitmodules", "[submodule \"foobar\"]\tpath=blargle\n\turl=\n\tbranch=\n\tupdate=flooble\n\n");
-	cl_git_fail(git_submodule_reload_all(repo, 0));
 
 	cl_git_rewritefile("status/.gitmodules", "[submodule \"foobar\"]\tpath=blargle\n\turl=\n\tbranch=\n\tupdate=rebase\n\n");
-	cl_git_pass(git_submodule_reload_all(repo, 0));
 
 	cl_git_pass(git_submodule_lookup(NULL, repo, "foobar"));
 	cl_assert_equal_i(GIT_ENOTFOUND, git_submodule_lookup(NULL, repo, "subdir"));