diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 067b9e322a..3dd84495b8 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1706,8 +1706,8 @@ static int want_object_in_pack_mtime(const struct object_id *oid,
 				     uint32_t found_mtime)
 {
 	int want;
+	struct odb_source *source;
 	struct list_head *pos;
-	struct multi_pack_index *m;
 
 	if (!exclude && local && has_loose_object_nonlocal(oid))
 		return 0;
@@ -1727,9 +1727,13 @@ static int want_object_in_pack_mtime(const struct object_id *oid,
 		*found_offset = 0;
 	}
 
-	for (m = get_multi_pack_index(the_repository); m; m = m->next) {
+	odb_prepare_alternates(the_repository->objects);
+
+	for (source = the_repository->objects->sources; source; source = source->next) {
+		struct multi_pack_index *m = get_multi_pack_index(source);
 		struct pack_entry e;
-		if (fill_midx_entry(the_repository, oid, &e, m)) {
+
+		if (m && fill_midx_entry(the_repository, oid, &e, m)) {
 			want = want_object_in_pack_one(e.p, oid, exclude, found_pack, found_offset, found_mtime);
 			if (want != -1)
 				return want;
diff --git a/builtin/repack.c b/builtin/repack.c
index 75158d7776..21723866b9 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -223,9 +223,9 @@ static void mark_packs_for_deletion(struct existing_packs *existing,
 static void remove_redundant_pack(const char *dir_name, const char *base_name)
 {
 	struct strbuf buf = STRBUF_INIT;
-	struct multi_pack_index *m = get_local_multi_pack_index(the_repository);
+	struct multi_pack_index *m = get_multi_pack_index(the_repository->objects->sources);
 	strbuf_addf(&buf, "%s.pack", base_name);
-	if (m && midx_contains_pack(m, buf.buf))
+	if (m && m->local && midx_contains_pack(m, buf.buf))
 		clear_midx_file(the_repository);
 	strbuf_insertf(&buf, 0, "%s/", dir_name);
 	unlink_pack_path(buf.buf, 1);
@@ -1531,7 +1531,7 @@ int cmd_repack(int argc,
 		 * midx_has_unknown_packs() will make the decision for
 		 * us.
 		 */
-		if (!get_local_multi_pack_index(the_repository))
+		if (!get_multi_pack_index(the_repository->objects->sources))
 			midx_must_contain_cruft = 1;
 	}
 
@@ -1614,9 +1614,9 @@ int cmd_repack(int argc,
 
 	string_list_sort(&names);
 
-	if (get_local_multi_pack_index(the_repository)) {
+	if (get_multi_pack_index(the_repository->objects->sources)) {
 		struct multi_pack_index *m =
-			get_local_multi_pack_index(the_repository);
+			get_multi_pack_index(the_repository->objects->sources);
 
 		ALLOC_ARRAY(midx_pack_names,
 			    m->num_packs + m->num_packs_in_base);
diff --git a/midx-write.c b/midx-write.c
index f2cfb85476..c1ae62d354 100644
--- a/midx-write.c
+++ b/midx-write.c
@@ -916,26 +916,8 @@ cleanup:
 static struct multi_pack_index *lookup_multi_pack_index(struct repository *r,
 							const char *object_dir)
 {
-	struct multi_pack_index *result = NULL;
-	struct multi_pack_index *cur;
-	char *obj_dir_real = real_pathdup(object_dir, 1);
-	struct strbuf cur_path_real = STRBUF_INIT;
-
-	/* Ensure the given object_dir is local, or a known alternate. */
-	odb_find_source(r->objects, obj_dir_real);
-
-	for (cur = get_multi_pack_index(r); cur; cur = cur->next) {
-		strbuf_realpath(&cur_path_real, cur->object_dir, 1);
-		if (!strcmp(obj_dir_real, cur_path_real.buf)) {
-			result = cur;
-			goto cleanup;
-		}
-	}
-
-cleanup:
-	free(obj_dir_real);
-	strbuf_release(&cur_path_real);
-	return result;
+	struct odb_source *source = odb_find_source(r->objects, object_dir);
+	return get_multi_pack_index(source);
 }
 
 static int fill_packs_from_midx(struct write_midx_context *ctx,
diff --git a/midx.c b/midx.c
index 3c5bc82173..7d407682e6 100644
--- a/midx.c
+++ b/midx.c
@@ -401,7 +401,6 @@ void close_midx(struct multi_pack_index *m)
 	if (!m)
 		return;
 
-	close_midx(m->next);
 	close_midx(m->base_midx);
 
 	munmap((unsigned char *)m->data, m->data_len);
@@ -724,32 +723,20 @@ int midx_preferred_pack(struct multi_pack_index *m, uint32_t *pack_int_id)
 	return 0;
 }
 
-int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local)
+int prepare_multi_pack_index_one(struct odb_source *source, int local)
 {
-	struct multi_pack_index *m;
-	struct multi_pack_index *m_search;
+	struct repository *r = source->odb->repo;
 
 	prepare_repo_settings(r);
 	if (!r->settings.core_multi_pack_index)
 		return 0;
 
-	for (m_search = r->objects->multi_pack_index; m_search; m_search = m_search->next)
-		if (!strcmp(object_dir, m_search->object_dir))
-			return 1;
-
-	m = load_multi_pack_index(r, object_dir, local);
-
-	if (m) {
-		struct multi_pack_index *mp = r->objects->multi_pack_index;
-		if (mp) {
-			m->next = mp->next;
-			mp->next = m;
-		} else
-			r->objects->multi_pack_index = m;
+	if (source->midx)
 		return 1;
-	}
 
-	return 0;
+	source->midx = load_multi_pack_index(r, source->path, local);
+
+	return !!source->midx;
 }
 
 int midx_checksum_valid(struct multi_pack_index *m)
@@ -834,9 +821,14 @@ void clear_midx_file(struct repository *r)
 
 	get_midx_filename(r->hash_algo, &midx, r->objects->sources->path);
 
-	if (r->objects && r->objects->multi_pack_index) {
-		close_midx(r->objects->multi_pack_index);
-		r->objects->multi_pack_index = NULL;
+	if (r->objects) {
+		struct odb_source *source;
+
+		for (source = r->objects->sources; source; source = source->next) {
+			if (source->midx)
+				close_midx(source->midx);
+			source->midx = NULL;
+		}
 	}
 
 	if (remove_path(midx.buf))
diff --git a/midx.h b/midx.h
index 9d1374cbd5..076382de8a 100644
--- a/midx.h
+++ b/midx.h
@@ -8,6 +8,7 @@ struct pack_entry;
 struct repository;
 struct bitmapped_pack;
 struct git_hash_algo;
+struct odb_source;
 
 #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */
 #define MIDX_VERSION 1
@@ -34,8 +35,6 @@ struct git_hash_algo;
 	"GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL"
 
 struct multi_pack_index {
-	struct multi_pack_index *next;
-
 	const unsigned char *data;
 	size_t data_len;
 
@@ -123,7 +122,7 @@ int fill_midx_entry(struct repository *r, const struct object_id *oid, struct pa
 int midx_contains_pack(struct multi_pack_index *m,
 		       const char *idx_or_pack_name);
 int midx_preferred_pack(struct multi_pack_index *m, uint32_t *pack_int_id);
-int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local);
+int prepare_multi_pack_index_one(struct odb_source *source, int local);
 
 /*
  * Variant of write_midx_file which writes a MIDX containing only the packs
diff --git a/object-name.c b/object-name.c
index 41930609e3..11aa0e6afc 100644
--- a/object-name.c
+++ b/object-name.c
@@ -199,16 +199,20 @@ static void unique_in_pack(struct packed_git *p,
 
 static void find_short_packed_object(struct disambiguate_state *ds)
 {
-	struct multi_pack_index *m;
+	struct odb_source *source;
 	struct packed_git *p;
 
 	/* Skip, unless oids from the storage hash algorithm are wanted */
 	if (ds->bin_pfx.algo && (&hash_algos[ds->bin_pfx.algo] != ds->repo->hash_algo))
 		return;
 
-	for (m = get_multi_pack_index(ds->repo); m && !ds->ambiguous;
-	     m = m->next)
-		unique_in_midx(m, ds);
+	odb_prepare_alternates(ds->repo->objects);
+	for (source = ds->repo->objects->sources; source && !ds->ambiguous; source = source->next) {
+		struct multi_pack_index *m = get_multi_pack_index(source);
+		if (m)
+			unique_in_midx(m, ds);
+	}
+
 	for (p = get_packed_git(ds->repo); p && !ds->ambiguous;
 	     p = p->next)
 		unique_in_pack(p, ds);
@@ -793,11 +797,15 @@ static void find_abbrev_len_for_pack(struct packed_git *p,
 
 static void find_abbrev_len_packed(struct min_abbrev_data *mad)
 {
-	struct multi_pack_index *m;
 	struct packed_git *p;
 
-	for (m = get_multi_pack_index(mad->repo); m; m = m->next)
-		find_abbrev_len_for_midx(m, mad);
+	odb_prepare_alternates(mad->repo->objects);
+	for (struct odb_source *source = mad->repo->objects->sources; source; source = source->next) {
+		struct multi_pack_index *m = get_multi_pack_index(source);
+		if (m)
+			find_abbrev_len_for_midx(m, mad);
+	}
+
 	for (p = get_packed_git(mad->repo); p; p = p->next)
 		find_abbrev_len_for_pack(p, mad);
 }
diff --git a/odb.h b/odb.h
index e922f25680..09177bf430 100644
--- a/odb.h
+++ b/odb.h
@@ -13,6 +13,7 @@ struct oidmap;
 struct oidtree;
 struct strbuf;
 struct repository;
+struct multi_pack_index;
 
 /*
  * Compute the exact path an alternate is at and returns it. In case of
@@ -55,6 +56,13 @@ struct odb_source {
 	/* Map between object IDs for loose objects. */
 	struct loose_object_map *loose_map;
 
+	/*
+	 * private data
+	 *
+	 * should only be accessed directly by packfile.c and midx.c
+	 */
+	struct multi_pack_index *midx;
+
 	/*
 	 * This is a temporary object store created by the tmp_objdir
 	 * facility. Disable ref updates since the objects in the store
@@ -75,7 +83,6 @@ struct odb_source {
 };
 
 struct packed_git;
-struct multi_pack_index;
 struct cached_object_entry;
 
 /*
@@ -116,13 +123,6 @@ struct object_database {
 	struct commit_graph *commit_graph;
 	unsigned commit_graph_attempted : 1; /* if loading has been attempted */
 
-	/*
-	 * private data
-	 *
-	 * should only be accessed directly by packfile.c and midx.c
-	 */
-	struct multi_pack_index *multi_pack_index;
-
 	/*
 	 * private data
 	 *
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 15cf51166e..d14421ee20 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -683,13 +683,15 @@ static int open_pack_bitmap(struct repository *r,
 static int open_midx_bitmap(struct repository *r,
 			    struct bitmap_index *bitmap_git)
 {
+	struct odb_source *source;
 	int ret = -1;
-	struct multi_pack_index *midx;
 
 	assert(!bitmap_git->map);
 
-	for (midx = get_multi_pack_index(r); midx; midx = midx->next) {
-		if (!open_midx_bitmap_1(bitmap_git, midx))
+	odb_prepare_alternates(r->objects);
+	for (source = r->objects->sources; source; source = source->next) {
+		struct multi_pack_index *midx = get_multi_pack_index(source);
+		if (midx && !open_midx_bitmap_1(bitmap_git, midx))
 			ret = 0;
 	}
 	return ret;
@@ -3345,11 +3347,18 @@ static int verify_bitmap_file(const struct git_hash_algo *algop,
 
 int verify_bitmap_files(struct repository *r)
 {
+	struct odb_source *source;
 	int res = 0;
 
-	for (struct multi_pack_index *m = get_multi_pack_index(r);
-	     m; m = m->next) {
-		char *midx_bitmap_name = midx_bitmap_filename(m);
+	odb_prepare_alternates(r->objects);
+	for (source = r->objects->sources; source; source = source->next) {
+		struct multi_pack_index *m = get_multi_pack_index(source);
+		char *midx_bitmap_name;
+
+		if (!m)
+			continue;
+
+		midx_bitmap_name = midx_bitmap_filename(m);
 		res |= verify_bitmap_file(r->hash_algo, midx_bitmap_name);
 		free(midx_bitmap_name);
 	}
diff --git a/packfile.c b/packfile.c
index af9ccfdba6..5d73932f50 100644
--- a/packfile.c
+++ b/packfile.c
@@ -361,6 +361,7 @@ void close_pack(struct packed_git *p)
 
 void close_object_store(struct object_database *o)
 {
+	struct odb_source *source;
 	struct packed_git *p;
 
 	for (p = o->packed_git; p; p = p->next)
@@ -369,9 +370,10 @@ void close_object_store(struct object_database *o)
 		else
 			close_pack(p);
 
-	if (o->multi_pack_index) {
-		close_midx(o->multi_pack_index);
-		o->multi_pack_index = NULL;
+	for (source = o->sources; source; source = source->next) {
+		if (source->midx)
+			close_midx(source->midx);
+		source->midx = NULL;
 	}
 
 	close_commit_graph(o);
@@ -933,22 +935,17 @@ static void prepare_pack(const char *full_name, size_t full_name_len,
 		report_garbage(PACKDIR_FILE_GARBAGE, full_name);
 }
 
-static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
+static void prepare_packed_git_one(struct odb_source *source, int local)
 {
-	struct prepare_pack_data data;
 	struct string_list garbage = STRING_LIST_INIT_DUP;
+	struct prepare_pack_data data = {
+		.m = source->midx,
+		.r = source->odb->repo,
+		.garbage = &garbage,
+		.local = local,
+	};
 
-	data.m = r->objects->multi_pack_index;
-
-	/* look for the multi-pack-index for this object directory */
-	while (data.m && strcmp(data.m->object_dir, objdir))
-		data.m = data.m->next;
-
-	data.r = r;
-	data.garbage = &garbage;
-	data.local = local;
-
-	for_each_file_in_pack_dir(objdir, prepare_pack, &data);
+	for_each_file_in_pack_dir(source->path, prepare_pack, &data);
 
 	report_pack_garbage(data.garbage);
 	string_list_clear(data.garbage, 0);
@@ -965,14 +962,18 @@ static void prepare_packed_git(struct repository *r);
 unsigned long repo_approximate_object_count(struct repository *r)
 {
 	if (!r->objects->approximate_object_count_valid) {
-		unsigned long count;
-		struct multi_pack_index *m;
+		struct odb_source *source;
+		unsigned long count = 0;
 		struct packed_git *p;
 
 		prepare_packed_git(r);
-		count = 0;
-		for (m = get_multi_pack_index(r); m; m = m->next)
-			count += m->num_objects;
+
+		for (source = r->objects->sources; source; source = source->next) {
+			struct multi_pack_index *m = get_multi_pack_index(source);
+			if (m)
+				count += m->num_objects;
+		}
+
 		for (p = r->objects->packed_git; p; p = p->next) {
 			if (open_pack_index(p))
 				continue;
@@ -1037,8 +1038,8 @@ static void prepare_packed_git(struct repository *r)
 	odb_prepare_alternates(r->objects);
 	for (source = r->objects->sources; source; source = source->next) {
 		int local = (source == r->objects->sources);
-		prepare_multi_pack_index_one(r, source->path, local);
-		prepare_packed_git_one(r, source->path, local);
+		prepare_multi_pack_index_one(source, local);
+		prepare_packed_git_one(source, local);
 	}
 	rearrange_packed_git(r);
 
@@ -1076,31 +1077,21 @@ struct packed_git *get_packed_git(struct repository *r)
 	return r->objects->packed_git;
 }
 
-struct multi_pack_index *get_multi_pack_index(struct repository *r)
+struct multi_pack_index *get_multi_pack_index(struct odb_source *source)
 {
-	prepare_packed_git(r);
-	return r->objects->multi_pack_index;
-}
-
-struct multi_pack_index *get_local_multi_pack_index(struct repository *r)
-{
-	struct multi_pack_index *m = get_multi_pack_index(r);
-
-	/* no need to iterate; we always put the local one first (if any) */
-	if (m && m->local)
-		return m;
-
-	return NULL;
+	prepare_packed_git(source->odb->repo);
+	return source->midx;
 }
 
 struct packed_git *get_all_packs(struct repository *r)
 {
-	struct multi_pack_index *m;
-
 	prepare_packed_git(r);
-	for (m = r->objects->multi_pack_index; m; m = m->next) {
-		uint32_t i;
-		for (i = 0; i < m->num_packs + m->num_packs_in_base; i++)
+
+	for (struct odb_source *source = r->objects->sources; source; source = source->next) {
+		struct multi_pack_index *m = source->midx;
+		if (!m)
+			continue;
+		for (uint32_t i = 0; i < m->num_packs + m->num_packs_in_base; i++)
 			prepare_midx_pack(r, m, i);
 	}
 
@@ -2083,16 +2074,15 @@ static int fill_pack_entry(const struct object_id *oid,
 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
 {
 	struct list_head *pos;
-	struct multi_pack_index *m;
 
 	prepare_packed_git(r);
-	if (!r->objects->packed_git && !r->objects->multi_pack_index)
-		return 0;
 
-	for (m = r->objects->multi_pack_index; m; m = m->next) {
-		if (fill_midx_entry(r, oid, e, m))
+	for (struct odb_source *source = r->objects->sources; source; source = source->next)
+		if (source->midx && fill_midx_entry(r, oid, e, source->midx))
 			return 1;
-	}
+
+	if (!r->objects->packed_git)
+		return 0;
 
 	list_for_each(pos, &r->objects->packed_git_mru) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
diff --git a/packfile.h b/packfile.h
index 53c3b7d3b4..f16753f2a9 100644
--- a/packfile.h
+++ b/packfile.h
@@ -147,8 +147,7 @@ void install_packed_git(struct repository *r, struct packed_git *pack);
 
 struct packed_git *get_packed_git(struct repository *r);
 struct list_head *get_packed_git_mru(struct repository *r);
-struct multi_pack_index *get_multi_pack_index(struct repository *r);
-struct multi_pack_index *get_local_multi_pack_index(struct repository *r);
+struct multi_pack_index *get_multi_pack_index(struct odb_source *source);
 struct packed_git *get_all_packs(struct repository *r);
 
 /*