v3, 11 partsMany promisor remotes

fetch-object.c, fetch-object.h, sha1-file.c

diff --git a/fetch-object.c b/fetch-object.c
index 4266548800..eac4d448ef 100644
--- a/fetch-object.c
+++ b/fetch-object.c
@@ -5,11 +5,12 @@
 #include "transport.h"
 #include "fetch-object.h"
 
-static void fetch_refs(const char *remote_name, struct ref *ref)
+static int fetch_refs(const char *remote_name, struct ref *ref)
 {
 	struct remote *remote;
 	struct transport *transport;
 	int original_fetch_if_missing = fetch_if_missing;
+	int res;
 
 	fetch_if_missing = 0;
 	remote = remote_get(remote_name);
@@ -19,12 +20,14 @@ static void fetch_refs(const char *remote_name, struct ref *ref)
 
 	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
 	transport_set_option(transport, TRANS_OPT_NO_DEPENDENTS, "1");
-	transport_fetch_refs(transport, ref);
+	res = transport_fetch_refs(transport, ref);
 	fetch_if_missing = original_fetch_if_missing;
+
+	return res;
 }
 
-void fetch_objects(const char *remote_name, const struct object_id *oids,
-		   int oid_nr)
+int fetch_objects(const char *remote_name, const struct object_id *oids,
+		  int oid_nr)
 {
 	struct ref *ref = NULL;
 	int i;
@@ -36,5 +39,5 @@ void fetch_objects(const char *remote_name, const struct object_id *oids,
 		new_ref->next = ref;
 		ref = new_ref;
 	}
-	fetch_refs(remote_name, ref);
+	return fetch_refs(remote_name, ref);
 }
diff --git a/fetch-object.h b/fetch-object.h
index d6444caa5a..7bcc7cadb0 100644
--- a/fetch-object.h
+++ b/fetch-object.h
@@ -3,7 +3,7 @@
 
 struct object_id;
 
-void fetch_objects(const char *remote_name, const struct object_id *oids,
-		   int oid_nr);
+int fetch_objects(const char *remote_name, const struct object_id *oids,
+		  int oid_nr);
 
 #endif
diff --git a/sha1-file.c b/sha1-file.c
index 494606f771..01cc0590f4 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -1372,8 +1372,8 @@ int oid_object_info_extended(struct repository *r, const struct object_id *oid,
 		if (fetch_if_missing && repository_format_partial_clone &&
 		    !already_retried && r == the_repository) {
 			/*
-			 * TODO Investigate having fetch_object() return
-			 * TODO error/success and stopping the music here.
+			 * TODO Investigate checking fetch_object() return
+			 * TODO value and stopping on error here.
 			 * TODO Pass a repository struct through fetch_object,
 			 * such that arbitrary repositories work.
 			 */

promisor-remote.c, promisor-remote.h

diff --git a/promisor-remote.c b/promisor-remote.c
index d2f574651e..f86f9d0b84 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "promisor-remote.h"
 #include "config.h"
+#include "fetch-object.h"
 
 static struct promisor_remote *promisors;
 static struct promisor_remote **promisors_tail = &promisors;
@@ -98,3 +99,19 @@ int has_promisor_remote(void)
 {
 	return !!promisor_remote_find(NULL);
 }
+
+int promisor_remote_get_direct(const struct object_id *oids, int oid_nr)
+{
+	struct promisor_remote *o;
+
+	promisor_remote_init();
+
+	for (o = promisors; o; o = o->next) {
+		if (fetch_objects(o->remote_name, oids, oid_nr) < 0)
+			continue;
+		return 0;
+	}
+
+	return -1;
+}
+
diff --git a/promisor-remote.h b/promisor-remote.h
index bfbf7c0f21..f9f5825417 100644
--- a/promisor-remote.h
+++ b/promisor-remote.h
@@ -13,5 +13,6 @@ struct promisor_remote {
 extern struct promisor_remote *promisor_remote_new(const char *remote_name);
 extern struct promisor_remote *promisor_remote_find(const char *remote_name);
 extern int has_promisor_remote(void);
+extern int promisor_remote_get_direct(const struct object_id *oids, int oid_nr);
 
 #endif /* PROMISOR_REMOTE_H */

Makefile, promisor-remote.c, promisor-remote.h

diff --git a/Makefile b/Makefile
index 537493822b..4f24ccb3dc 100644
--- a/Makefile
+++ b/Makefile
@@ -972,6 +972,7 @@ LIB_OBJS += preload-index.o
 LIB_OBJS += pretty.o
 LIB_OBJS += prio-queue.o
 LIB_OBJS += progress.o
+LIB_OBJS += promisor-remote.o
 LIB_OBJS += prompt.o
 LIB_OBJS += protocol.o
 LIB_OBJS += quote.o
diff --git a/promisor-remote.c b/promisor-remote.c
new file mode 100644
index 0000000000..d2f574651e
--- /dev/null
+++ b/promisor-remote.c
@@ -0,0 +1,100 @@
+#include "cache.h"
+#include "promisor-remote.h"
+#include "config.h"
+
+static struct promisor_remote *promisors;
+static struct promisor_remote **promisors_tail = &promisors;
+
+struct promisor_remote *promisor_remote_new(const char *remote_name)
+{
+	struct promisor_remote *o;
+
+	o = xcalloc(1, sizeof(*o));
+	o->remote_name = xstrdup(remote_name);
+
+	*promisors_tail = o;
+	promisors_tail = &o->next;
+
+	return o;
+}
+
+static struct promisor_remote *promisor_remote_look_up(const char *remote_name,
+						       struct promisor_remote **previous)
+{
+	struct promisor_remote *o, *p;
+
+	for (p = NULL, o = promisors; o; p = o, o = o->next)
+		if (o->remote_name && !strcmp(o->remote_name, remote_name)) {
+			if (previous)
+				*previous = p;
+			return o;
+		}
+
+	return NULL;
+}
+
+static void promisor_remote_move_to_tail(struct promisor_remote *o,
+					 struct promisor_remote *previous)
+{
+	if (previous)
+		previous->next = o->next;
+	else
+		promisors = o->next ? o->next : o;
+	o->next = NULL;
+	*promisors_tail = o;
+	promisors_tail = &o->next;
+}
+
+static int promisor_remote_config(const char *var, const char *value, void *data)
+{
+	struct promisor_remote *o;
+	const char *name;
+	int namelen;
+	const char *subkey;
+
+	if (parse_config_key(var, "remote", &name, &namelen, &subkey) < 0)
+		return 0;
+
+	if (!strcmp(subkey, "promisor")) {
+		char *remote_name;
+
+		if (!git_config_bool(var, value))
+			return 0;
+
+		remote_name = xmemdupz(name, namelen);
+
+		if (!promisor_remote_look_up(remote_name, NULL))
+			promisor_remote_new(remote_name);
+
+		free(remote_name);
+		return 0;
+	}
+
+	return 0;
+}
+
+static void promisor_remote_init(void)
+{
+	static int initialized;
+
+	if (initialized)
+		return;
+	initialized = 1;
+
+	git_config(promisor_remote_config, NULL);
+}
+
+struct promisor_remote *promisor_remote_find(const char *remote_name)
+{
+	promisor_remote_init();
+
+	if (!remote_name)
+		return promisors;
+
+	return promisor_remote_look_up(remote_name, NULL);
+}
+
+int has_promisor_remote(void)
+{
+	return !!promisor_remote_find(NULL);
+}
diff --git a/promisor-remote.h b/promisor-remote.h
new file mode 100644
index 0000000000..bfbf7c0f21
--- /dev/null
+++ b/promisor-remote.h
@@ -0,0 +1,17 @@
+#ifndef PROMISOR_REMOTE_H
+#define PROMISOR_REMOTE_H
+
+/*
+ * Promisor remote linked list
+ * Its information come from remote.XXX config entries.
+ */
+struct promisor_remote {
+	const char *remote_name;
+	struct promisor_remote *next;
+};
+
+extern struct promisor_remote *promisor_remote_new(const char *remote_name);
+extern struct promisor_remote *promisor_remote_find(const char *remote_name);
+extern int has_promisor_remote(void);
+
+#endif /* PROMISOR_REMOTE_H */

promisor-remote.c, promisor-remote.h

diff --git a/promisor-remote.c b/promisor-remote.c
index f86f9d0b84..ea74f6d8a8 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -74,17 +74,27 @@ static int promisor_remote_config(const char *var, const char *value, void *data
 	return 0;
 }
 
-static void promisor_remote_init(void)
+static void promisor_remote_do_init(int force)
 {
 	static int initialized;
 
-	if (initialized)
+	if (!force && initialized)
 		return;
 	initialized = 1;
 
 	git_config(promisor_remote_config, NULL);
 }
 
+static inline void promisor_remote_init(void)
+{
+	promisor_remote_do_init(0);
+}
+
+void promisor_remote_reinit(void)
+{
+	promisor_remote_do_init(1);
+}
+
 struct promisor_remote *promisor_remote_find(const char *remote_name)
 {
 	promisor_remote_init();
diff --git a/promisor-remote.h b/promisor-remote.h
index f9f5825417..f96722bc66 100644
--- a/promisor-remote.h
+++ b/promisor-remote.h
@@ -10,6 +10,7 @@ struct promisor_remote {
 	struct promisor_remote *next;
 };
 
+extern void promisor_remote_reinit(void);
 extern struct promisor_remote *promisor_remote_new(const char *remote_name);
 extern struct promisor_remote *promisor_remote_find(const char *remote_name);
 extern int has_promisor_remote(void);

diff --git a/promisor-remote.c b/promisor-remote.c
index ea74f6d8a8..dcf6ef6521 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -83,6 +83,17 @@ static void promisor_remote_do_init(int force)
 	initialized = 1;
 
 	git_config(promisor_remote_config, NULL);
+
+	if (repository_format_partial_clone) {
+		struct promisor_remote *o, *previous;
+
+		o = promisor_remote_look_up(repository_format_partial_clone,
+					    &previous);
+		if (o)
+			promisor_remote_move_to_tail(o, previous);
+		else
+			promisor_remote_new(repository_format_partial_clone);
+	}
 }
 
 static inline void promisor_remote_init(void)

builtin/fetch.c, list-objects-filter-options.c, list-objects-filter-options.h, promisor-remote.c, promisor-remote.h, t/t0410-partial-clone.sh, t/t5601-clone.sh, t/t5616-partial-clone.sh

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 7edf70ae6c..9d436bd727 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1491,7 +1491,7 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 	 * the config.
 	 */
 	if (!filter_options.choice)
-		partial_clone_get_default_filter_spec(&filter_options);
+		partial_clone_get_default_filter_spec(&filter_options, remote->name);
 	return;
 }
 
diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index f41a831fce..02f48b7c40 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -30,6 +30,9 @@ static int gently_parse_list_objects_filter(
 {
 	const char *v0;
 
+	if (!arg)
+		return 0;
+
 	if (filter_options->choice) {
 		if (errbuf) {
 			strbuf_addstr(
@@ -146,6 +149,7 @@ void partial_clone_register(
 	const struct list_objects_filter_options *filter_options)
 {
 	char *cfg_name;
+	char *filter_name;
 
 	/* Check if it is already registered */
 	if (!promisor_remote_find(remote)) {
@@ -160,27 +164,26 @@ void partial_clone_register(
 	/*
 	 * Record the initial filter-spec in the config as
 	 * the default for subsequent fetches from this remote.
-	 *
-	 * TODO: record it into remote.<name>.partialclonefilter
 	 */
-	core_partial_clone_filter_default =
-		xstrdup(filter_options->filter_spec);
-	git_config_set("core.partialclonefilter",
-		       core_partial_clone_filter_default);
+	filter_name = xstrfmt("remote.%s.partialclonefilter", remote);
+	git_config_set(filter_name, filter_options->filter_spec);
+	free(filter_name);
 
 	/* Make sure the config info are reset */
 	promisor_remote_reinit();
 }
 
 void partial_clone_get_default_filter_spec(
-	struct list_objects_filter_options *filter_options)
+	struct list_objects_filter_options *filter_options,
+	const char *remote)
 {
+	struct promisor_remote *promisor = promisor_remote_find(remote);
+
 	/*
 	 * Parse default value, but silently ignore it if it is invalid.
 	 */
-	if (!core_partial_clone_filter_default)
-		return;
-	gently_parse_list_objects_filter(filter_options,
-					 core_partial_clone_filter_default,
-					 NULL);
+	if (promisor)
+		gently_parse_list_objects_filter(filter_options,
+						 promisor->partial_clone_filter,
+						 NULL);
 }
diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h
index e3adc78ebf..70d27f44ef 100644
--- a/list-objects-filter-options.h
+++ b/list-objects-filter-options.h
@@ -89,6 +89,7 @@ void partial_clone_register(
 	const char *remote,
 	const struct list_objects_filter_options *filter_options);
 void partial_clone_get_default_filter_spec(
-	struct list_objects_filter_options *filter_options);
+	struct list_objects_filter_options *filter_options,
+	const char *remote);
 
 #endif /* LIST_OBJECTS_FILTER_OPTIONS_H */
diff --git a/promisor-remote.c b/promisor-remote.c
index dcf6ef6521..ed33dfa86c 100644
--- a/promisor-remote.c
+++ b/promisor-remote.c
@@ -70,6 +70,16 @@ static int promisor_remote_config(const char *var, const char *value, void *data
 		free(remote_name);
 		return 0;
 	}
+	if (!strcmp(subkey, "partialclonefilter")) {
+		char *remote_name = xmemdupz(name, namelen);
+
+		o = promisor_remote_look_up(remote_name, NULL);
+		if (!o)
+			o = promisor_remote_new(remote_name);
+
+		free(remote_name);
+		return git_config_string(&o->partial_clone_filter, var, value);
+	}
 
 	return 0;
 }
diff --git a/promisor-remote.h b/promisor-remote.h
index f96722bc66..f0d609a3f5 100644
--- a/promisor-remote.h
+++ b/promisor-remote.h
@@ -3,10 +3,13 @@
 
 /*
  * Promisor remote linked list
- * Its information come from remote.XXX config entries.
+ *
+ * Information in its fields come from remote.XXX config entries or
+ * from extensions.partialclone or core.partialclonefilter.
  */
 struct promisor_remote {
 	const char *remote_name;
+	const char *partial_clone_filter;
 	struct promisor_remote *next;
 };
 
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index bce02788e6..9266037714 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -26,7 +26,7 @@ promise_and_delete () {
 test_expect_success 'extensions.partialclone without filter' '
 	test_create_repo server &&
 	git clone --filter="blob:none" "file://$(pwd)/server" client &&
-	git -C client config --unset core.partialclonefilter &&
+	git -C client config --unset remote.origin.partialclonefilter &&
 	git -C client fetch origin
 '
 
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index dd658f8b32..2e82c70f33 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -654,6 +654,7 @@ partial_clone () {
 
 	# Ensure that unneeded blobs are not inadvertently fetched.
 	test_config -C client remote.origin.promisor "false" &&
+	git -C client config --unset remote.origin.partialclonefilter &&
 	test_must_fail git -C client cat-file -e "$HASH1" &&
 
 	# But this blob was fetched, because clone performs an initial checkout
diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
index e8ca825ab7..ba0489b41a 100755
--- a/t/t5616-partial-clone.sh
+++ b/t/t5616-partial-clone.sh
@@ -43,7 +43,7 @@ test_expect_success 'do partial clone 1' '
 	test_cmp expect_1.oids observed.oids &&
 	test "$(git -C pc1 config --local core.repositoryformatversion)" = "1" &&
 	test "$(git -C pc1 config --local remote.origin.promisor)" = "true" &&
-	test "$(git -C pc1 config --local core.partialclonefilter)" = "blob:none"
+	test "$(git -C pc1 config --local remote.origin.partialclonefilter)" = "blob:none"
 '
 
 # checkout master to force dynamic object fetch of blobs at HEAD.

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 9d436bd727..56c6827165 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1465,26 +1465,16 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 		return;
 
 	/*
-	 * If this is the FIRST partial-fetch request, we enable partial
-	 * on this repo and remember the given filter-spec as the default
-	 * for subsequent fetches to this remote.
+	 * If this is a partial-fetch request, we enable partial on
+	 * this repo if not already enabled and remember the given
+	 * filter-spec as the default for subsequent fetches to this
+	 * remote.
 	 */
-	if (!has_promisor_remote() && filter_options.choice) {
+	if (filter_options.choice) {
 		partial_clone_register(remote->name, &filter_options);
 		return;
 	}
 
-	/*
-	 * We are currently limited to only ONE promisor remote and only
-	 * allow partial-fetches from the promisor remote.
-	 */
-	if (!promisor_remote_find(remote->name)) {
-		if (filter_options.choice)
-			die(_("--filter can only be used with the remote "
-			      "configured in extensions.partialClone"));
-		return;
-	}
-
 	/*
 	 * Do a partial-fetch from the promisor remote using either the
 	 * explicitly given filter-spec or inherit the filter-spec from

builtin/cat-file.c, builtin/fetch.c, builtin/gc.c, builtin/repack.c, cache-tree.c, connected.c, list-objects-filter-options.c, packfile.c, sha1-file.c, t/t5601-clone.sh, t/t5616-partial-clone.sh, unpack-trees.c

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 0f092382e1..85ae10bf0b 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -15,6 +15,7 @@
 #include "sha1-array.h"
 #include "packfile.h"
 #include "object-store.h"
+#include "promisor-remote.h"
 
 struct batch_options {
 	int enabled;
@@ -523,8 +524,8 @@ static int batch_objects(struct batch_options *opt)
 	if (opt->all_objects) {
 		struct object_cb_data cb;
 
-		if (repository_format_partial_clone)
-			warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
+		if (has_promisor_remote())
+			warning("This repository uses promisor remotes. Some objects may not be loaded.");
 
 		cb.opt = opt;
 		cb.expand = &data;
diff --git a/builtin/fetch.c b/builtin/fetch.c
index b620fd54b4..7edf70ae6c 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -23,6 +23,7 @@
 #include "packfile.h"
 #include "list-objects-filter-options.h"
 #include "commit-reach.h"
+#include "promisor-remote.h"
 
 static const char * const builtin_fetch_usage[] = {
 	N_("git fetch [<options>] [<repository> [<refspec>...]]"),
@@ -1460,7 +1461,7 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 	 * If no prior partial clone/fetch and the current fetch DID NOT
 	 * request a partial-fetch, do a normal fetch.
 	 */
-	if (!repository_format_partial_clone && !filter_options.choice)
+	if (!has_promisor_remote() && !filter_options.choice)
 		return;
 
 	/*
@@ -1468,7 +1469,7 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 	 * on this repo and remember the given filter-spec as the default
 	 * for subsequent fetches to this remote.
 	 */
-	if (!repository_format_partial_clone && filter_options.choice) {
+	if (!has_promisor_remote() && filter_options.choice) {
 		partial_clone_register(remote->name, &filter_options);
 		return;
 	}
@@ -1477,7 +1478,7 @@ static inline void fetch_one_setup_partial(struct remote *remote)
 	 * We are currently limited to only ONE promisor remote and only
 	 * allow partial-fetches from the promisor remote.
 	 */
-	if (strcmp(remote->name, repository_format_partial_clone)) {
+	if (!promisor_remote_find(remote->name)) {
 		if (filter_options.choice)
 			die(_("--filter can only be used with the remote "
 			      "configured in extensions.partialClone"));
@@ -1609,7 +1610,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	if (depth || deepen_since || deepen_not.nr)
 		deepen = 1;
 
-	if (filter_options.choice && !repository_format_partial_clone)
+	if (filter_options.choice && !has_promisor_remote())
 		die("--filter can only be used when extensions.partialClone is set");
 
 	if (all) {
@@ -1643,7 +1644,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	}
 
 	if (remote) {
-		if (filter_options.choice || repository_format_partial_clone)
+		if (filter_options.choice || has_promisor_remote())
 			fetch_one_setup_partial(remote);
 		result = fetch_one(remote, argc, argv, prune_tags_ok);
 	} else {
diff --git a/builtin/gc.c b/builtin/gc.c
index 020f725acc..0bec41b25f 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -27,6 +27,7 @@
 #include "pack-objects.h"
 #include "blob.h"
 #include "tree.h"
+#include "promisor-remote.h"
 
 #define FAILED_RUN "failed to run %s"
 
@@ -640,7 +641,7 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			argv_array_push(&prune, prune_expire);
 			if (quiet)
 				argv_array_push(&prune, "--no-progress");
-			if (repository_format_partial_clone)
+			if (has_promisor_remote())
 				argv_array_push(&prune,
 						"--exclude-promisor-objects");
 			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
diff --git a/builtin/repack.c b/builtin/repack.c
index 67f8978043..3b935690c8 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -11,6 +11,7 @@
 #include "midx.h"
 #include "packfile.h"
 #include "object-store.h"
+#include "promisor-remote.h"
 
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
@@ -366,7 +367,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	argv_array_push(&cmd.args, "--all");
 	argv_array_push(&cmd.args, "--reflog");
 	argv_array_push(&cmd.args, "--indexed-objects");
-	if (repository_format_partial_clone)
+	if (has_promisor_remote())
 		argv_array_push(&cmd.args, "--exclude-promisor-objects");
 	if (write_bitmaps)
 		argv_array_push(&cmd.args, "--write-bitmap-index");
diff --git a/cache-tree.c b/cache-tree.c
index b13bfaf71e..64c285a746 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -5,6 +5,7 @@
 #include "cache-tree.h"
 #include "object-store.h"
 #include "replace-object.h"
+#include "promisor-remote.h"
 
 #ifndef DEBUG
 #define DEBUG 0
@@ -357,7 +358,7 @@ static int update_one(struct cache_tree *it,
 		}
 
 		ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
-			(repository_format_partial_clone &&
+			(has_promisor_remote() &&
 			 ce_skip_worktree(ce));
 		if (is_null_oid(oid) ||
 		    (!ce_missing_ok && !has_object_file(oid))) {
diff --git a/connected.c b/connected.c
index 1bba888eff..0eaaedee6a 100644
--- a/connected.c
+++ b/connected.c
@@ -4,6 +4,7 @@
 #include "connected.h"
 #include "transport.h"
 #include "packfile.h"
+#include "promisor-remote.h"
 
 /*
  * If we feed all the commits we want to verify to this command
@@ -56,7 +57,7 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 	argv_array_push(&rev_list.args,"rev-list");
 	argv_array_push(&rev_list.args, "--objects");
 	argv_array_push(&rev_list.args, "--stdin");
-	if (repository_format_partial_clone)
+	if (has_promisor_remote())
 		argv_array_push(&rev_list.args, "--exclude-promisor-objects");
 	if (!opt->is_deepening_fetch) {
 		argv_array_push(&rev_list.args, "--not");
diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index c0036f7378..f41a831fce 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -6,6 +6,7 @@
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "promisor-remote.h"
 
 /*
  * Parse value of the argument to the "filter" keyword.
@@ -144,30 +145,31 @@ void partial_clone_register(
 	const char *remote,
 	const struct list_objects_filter_options *filter_options)
 {
-	/*
-	 * Record the name of the partial clone remote in the
-	 * config and in the global variable -- the latter is
-	 * used throughout to indicate that partial clone is
-	 * enabled and to expect missing objects.
-	 */
-	if (repository_format_partial_clone &&
-	    *repository_format_partial_clone &&
-	    strcmp(remote, repository_format_partial_clone))
-		die(_("cannot change partial clone promisor remote"));
+	char *cfg_name;
 
-	git_config_set("core.repositoryformatversion", "1");
-	git_config_set("extensions.partialclone", remote);
+	/* Check if it is already registered */
+	if (!promisor_remote_find(remote)) {
+		git_config_set("core.repositoryformatversion", "1");
 
-	repository_format_partial_clone = xstrdup(remote);
+		/* Add promisor config for the remote */
+		cfg_name = xstrfmt("remote.%s.promisor", remote);
+		git_config_set(cfg_name, "true");
+		free(cfg_name);
+	}
 
 	/*
 	 * Record the initial filter-spec in the config as
 	 * the default for subsequent fetches from this remote.
+	 *
+	 * TODO: record it into remote.<name>.partialclonefilter
 	 */
 	core_partial_clone_filter_default =
 		xstrdup(filter_options->filter_spec);
 	git_config_set("core.partialclonefilter",
 		       core_partial_clone_filter_default);
+
+	/* Make sure the config info are reset */
+	promisor_remote_reinit();
 }
 
 void partial_clone_get_default_filter_spec(
diff --git a/packfile.c b/packfile.c
index 16bcb75262..0f95cdc1c9 100644
--- a/packfile.c
+++ b/packfile.c
@@ -16,6 +16,7 @@
 #include "tree.h"
 #include "object-store.h"
 #include "midx.h"
+#include "promisor-remote.h"
 
 char *odb_pack_name(struct strbuf *buf,
 		    const unsigned char *sha1,
@@ -2119,7 +2120,7 @@ int is_promisor_object(const struct object_id *oid)
 	static int promisor_objects_prepared;
 
 	if (!promisor_objects_prepared) {
-		if (repository_format_partial_clone) {
+		if (has_promisor_remote()) {
 			for_each_packed_object(add_promisor_object,
 					       &promisor_objects,
 					       FOR_EACH_OBJECT_PROMISOR_ONLY);
diff --git a/sha1-file.c b/sha1-file.c
index 01cc0590f4..715a2b882a 100644
--- a/sha1-file.c
+++ b/sha1-file.c
@@ -32,6 +32,7 @@
 #include "packfile.h"
 #include "fetch-object.h"
 #include "object-store.h"
+#include "promisor-remote.h"
 
 /* The maximum size for an object header. */
 #define MAX_HEADER_LEN 32
@@ -1369,15 +1370,16 @@ int oid_object_info_extended(struct repository *r, const struct object_id *oid,
 		}
 
 		/* Check if it is a missing object */
-		if (fetch_if_missing && repository_format_partial_clone &&
+		if (fetch_if_missing && has_promisor_remote() &&
 		    !already_retried && r == the_repository) {
 			/*
-			 * TODO Investigate checking fetch_object() return
-			 * TODO value and stopping on error here.
-			 * TODO Pass a repository struct through fetch_object,
-			 * such that arbitrary repositories work.
+			 * TODO Investigate checking promisor_remote_get_direct()
+			 * TODO return value and stopping on error here.
+			 * TODO Pass a repository struct through
+			 * promisor_remote_get_direct(), such that arbitrary
+			 * repositories work.
 			 */
-			fetch_objects(repository_format_partial_clone, real, 1);
+			promisor_remote_get_direct(real, 1);
 			already_retried = 1;
 			continue;
 		}
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index d6948cbdab..dd658f8b32 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -653,7 +653,7 @@ partial_clone () {
 	git -C client fsck &&
 
 	# Ensure that unneeded blobs are not inadvertently fetched.
-	test_config -C client extensions.partialclone "not a remote" &&
+	test_config -C client remote.origin.promisor "false" &&
 	test_must_fail git -C client cat-file -e "$HASH1" &&
 
 	# But this blob was fetched, because clone performs an initial checkout
diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh
index 9643acb161..e8ca825ab7 100755
--- a/t/t5616-partial-clone.sh
+++ b/t/t5616-partial-clone.sh
@@ -42,7 +42,7 @@ test_expect_success 'do partial clone 1' '
 
 	test_cmp expect_1.oids observed.oids &&
 	test "$(git -C pc1 config --local core.repositoryformatversion)" = "1" &&
-	test "$(git -C pc1 config --local extensions.partialclone)" = "origin" &&
+	test "$(git -C pc1 config --local remote.origin.promisor)" = "true" &&
 	test "$(git -C pc1 config --local core.partialclonefilter)" = "blob:none"
 '
 
diff --git a/unpack-trees.c b/unpack-trees.c
index 22c41a3ba8..47353d85c3 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -17,6 +17,7 @@
 #include "fsmonitor.h"
 #include "object-store.h"
 #include "fetch-object.h"
+#include "promisor-remote.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -398,7 +399,7 @@ static int check_updates(struct unpack_trees_options *o)
 		load_gitmodules_file(index, &state);
 
 	enable_delayed_checkout(&state);
-	if (repository_format_partial_clone && o->update && !o->dry_run) {
+	if (has_promisor_remote() && o->update && !o->dry_run) {
 		/*
 		 * Prefetch the objects that are to be checked out in the loop
 		 * below.
@@ -415,8 +416,7 @@ static int check_updates(struct unpack_trees_options *o)
 			}
 		}
 		if (to_fetch.nr)
-			fetch_objects(repository_format_partial_clone,
-				      to_fetch.oid, to_fetch.nr);
+			promisor_remote_get_direct(to_fetch.oid, to_fetch.nr);
 		fetch_if_missing = fetch_if_missing_store;
 		oid_array_clear(&to_fetch);
 	}

diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 9266037714..146b0a1e03 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -182,8 +182,53 @@ test_expect_success 'fetching of missing objects works with ref-in-want enabled'
 	grep "git< fetch=.*ref-in-want" trace
 '
 
+test_expect_success 'fetching of missing objects from another promisor remote' '
+	git clone "file://$(pwd)/server" server2 &&
+	test_commit -C server2 bar &&
+	git -C server2 repack -a -d --write-bitmap-index &&
+	HASH2=$(git -C server2 rev-parse bar) &&
+
+	git -C repo remote add server2 "file://$(pwd)/server2" &&
+	git -C repo config remote.server2.promisor true &&
+	git -C repo cat-file -p "$HASH2" &&
+
+	git -C repo fetch server2 &&
+	rm -rf repo/.git/objects/* &&
+	git -C repo cat-file -p "$HASH2" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH2"
+'
+
+test_expect_success 'fetching of missing objects configures a promisor remote' '
+	git clone "file://$(pwd)/server" server3 &&
+	test_commit -C server3 baz &&
+	git -C server3 repack -a -d --write-bitmap-index &&
+	HASH3=$(git -C server3 rev-parse baz) &&
+	git -C server3 config uploadpack.allowfilter 1 &&
+
+	rm repo/.git/objects/pack/pack-*.promisor &&
+
+	git -C repo remote add server3 "file://$(pwd)/server3" &&
+	git -C repo fetch --filter="blob:none" server3 $HASH3 &&
+
+	test "$(git -C repo config remote.server3.promisor)" = "true" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH3"
+'
+
 test_expect_success 'fetching of missing blobs works' '
-	rm -rf server repo &&
+	rm -rf server server2 repo &&
+	rm -rf server server3 repo &&
 	test_create_repo server &&
 	test_commit -C server foo &&
 	git -C server repack -a -d --write-bitmap-index &&

diff --git a/Documentation/technical/partial-clone.txt b/Documentation/technical/partial-clone.txt
index 896c7b3878..58adcc5ce1 100644
--- a/Documentation/technical/partial-clone.txt
+++ b/Documentation/technical/partial-clone.txt
@@ -100,18 +100,18 @@ or commits that reference missing trees.
 Handling Missing Objects
 ------------------------
 
-- An object may be missing due to a partial clone or fetch, or missing due
-  to repository corruption.  To differentiate these cases, the local
-  repository specially indicates such filtered packfiles obtained from the
-  promisor remote as "promisor packfiles".
+- An object may be missing due to a partial clone or fetch, or missing
+  due to repository corruption.  To differentiate these cases, the
+  local repository specially indicates such filtered packfiles
+  obtained from promisor remotes as "promisor packfiles".
 +
 These promisor packfiles consist of a "<name>.promisor" file with
 arbitrary contents (like the "<name>.keep" files), in addition to
 their "<name>.pack" and "<name>.idx" files.
 
 - The local repository considers a "promisor object" to be an object that
-  it knows (to the best of its ability) that the promisor remote has promised
-  that it has, either because the local repository has that object in one of
+  it knows (to the best of its ability) that promisor remotes have promised
+  that they have, either because the local repository has that object in one of
   its promisor packfiles, or because another promisor object refers to it.
 +
 When Git encounters a missing object, Git can see if it is a promisor object
@@ -123,7 +123,7 @@ expensive-to-modify list of missing objects.[a]
 - Since almost all Git code currently expects any referenced object to be
   present locally and because we do not want to force every command to do
   a dry-run first, a fallback mechanism is added to allow Git to attempt
-  to dynamically fetch missing objects from the promisor remote.
+  to dynamically fetch missing objects from promisor remotes.
 +
 When the normal object lookup fails to find an object, Git invokes
 fetch-object to try to get the object from the server and then retry
@@ -157,8 +157,7 @@ and prefetch those objects in bulk.
 +
 We are not happy with this global variable and would like to remove it,
 but that requires significant refactoring of the object code to pass an
-additional flag.  We hope that concurrent efforts to add an ODB API can
-encompass this.
+additional flag.
 
 
 Fetching Missing Objects
@@ -182,21 +181,53 @@ has been updated to not use any object flags when the corresponding argument
   though they are not necessary.
 
 
+Using many promisor remotes
+---------------------------
+
+Many promisor remotes can be configured and used.
+
+This allows for example a user to have multiple geographically-close
+cache servers for fetching missing blobs while continuing to do
+filtered `git-fetch` commands from the central server.
+
+When fetching objects, promisor remotes are tried one after the other
+until all the objects have been fetched.
+
+Remotes that are considered "promisor" remotes are those specified by
+the following configuration variables:
+
+- `extensions.partialClone = <name>`
+
+- `remote.<name>.promisor = true`
+
+- `remote.<name>.partialCloneFilter = ...`
+
+Only one promisor remote can be configured using the
+`extensions.partialClone` config variable. This promisor remote will
+be the last one tried when fetching objects.
+
+The other promisor remotes will be tried in the order they appear in
+the config file.
+
 Current Limitations
 -------------------
 
-- The remote used for a partial clone (or the first partial fetch
-  following a regular clone) is marked as the "promisor remote".
+- It is not possible to specify the order in which the promisor
+  remotes are tried in other ways than the order in which they appear
+  in the config file.
 +
-We are currently limited to a single promisor remote and only that
-remote may be used for subsequent partial fetches.
+It is also not possible to specify an order to be used when fetching
+from one remote and a different order when fetching from another
+remote.
+
+- It is not possible to push only specific objects to a promisor
+  remote.
 +
-We accept this limitation because we believe initial users of this
-feature will be using it on repositories with a strong single central
-server.
+It is not possible to push at the same time to multiple promisor
+remote in a specific order.
 
-- Dynamic object fetching will only ask the promisor remote for missing
-  objects.  We assume that the promisor remote has a complete view of the
+- Dynamic object fetching will only ask promisor remotes for missing
+  objects.  We assume that promisor remotes have a complete view of the
   repository and can satisfy all such requests.
 
 - Repack essentially treats promisor and non-promisor packfiles as 2
@@ -218,15 +249,17 @@ server.
 Future Work
 -----------
 
-- Allow more than one promisor remote and define a strategy for fetching
-  missing objects from specific promisor remotes or of iterating over the
-  set of promisor remotes until a missing object is found.
+- Improve the way to specify the order in which promisor remotes are
+  tried.
 +
-A user might want to have multiple geographically-close cache servers
-for fetching missing blobs while continuing to do filtered `git-fetch`
-commands from the central server, for example.
+For example this could allow to specify explicitly something like:
+"When fetching from this remote, I want to use these promisor remotes
+in this order, though, when pushing or fetching to that remote, I want
+to use those promisor remotes in that order."
+
+- Allow pushing to promisor remotes.
 +
-Or the user might want to work in a triangular work flow with multiple
+The user might want to work in a triangular work flow with multiple
 promisor remotes that each have an incomplete view of the repository.
 
 - Allow repack to work on promisor packfiles (while keeping them distinct

diff --git a/Documentation/config/remote.txt b/Documentation/config/remote.txt
index 6c4cad83a2..a8e6437a90 100644
--- a/Documentation/config/remote.txt
+++ b/Documentation/config/remote.txt
@@ -76,3 +76,11 @@ remote.<name>.pruneTags::
 +
 See also `remote.<name>.prune` and the PRUNING section of
 linkgit:git-fetch[1].
+
+remote.<name>.promisor::
+	When set to true, this remote will be used to fetch promisor
+	objects.
+
+remote.<name>.partialclonefilter::
+	The filter that will be applied when fetching from this
+	promisor remote.