Merge branch 'development'

1 files changed, 387 insertions, 133 deletions

diff --git a/src/refdb_fs.c b/src/refdb_fs.c
index f00bd72a0..b9e283ac5 100644
--- a/src/refdb_fs.c
+++ b/src/refdb_fs.c
@@ -9,16 +9,18 @@
 #include "hash.h"
 #include "repository.h"
 #include "fileops.h"
+#include "filebuf.h"
 #include "pack.h"
 #include "reflog.h"
-#include "config.h"
 #include "refdb.h"
 #include "refdb_fs.h"
+#include "iterator.h"
 
 #include <git2/tag.h>
 #include <git2/object.h>
 #include <git2/refdb.h>
-#include <git2/refdb_backend.h>
+#include <git2/sys/refdb_backend.h>
+#include <git2/sys/refs.h>
 
 GIT__USE_STRMAP;
 
@@ -26,8 +28,16 @@ GIT__USE_STRMAP;
 #define MAX_NESTING_LEVEL		10
 
 enum {
-	GIT_PACKREF_HAS_PEEL = 1,
-	GIT_PACKREF_WAS_LOOSE = 2
+	PACKREF_HAS_PEEL = 1,
+	PACKREF_WAS_LOOSE = 2,
+	PACKREF_CANNOT_PEEL = 4,
+	PACKREF_SHADOWED = 8,
+};
+
+enum {
+	PEELING_NONE = 0,
+	PEELING_STANDARD,
+	PEELING_FULL
 };
 
 struct packref {
@@ -41,10 +51,10 @@ typedef struct refdb_fs_backend {
 	git_refdb_backend parent;
 
 	git_repository *repo;
-	const char *path;
-	git_refdb *refdb;
+	char *path;
 
 	git_refcache refcache;
+	int peeling_mode;
 } refdb_fs_backend;
 
 static int reference_read(
@@ -62,7 +72,7 @@ static int reference_read(
 	/* Determine the full path of the file */
 	if (git_buf_joinpath(&path, repo_path, ref_name) < 0)
 		return -1;
-	
+
 	result = git_futils_readbuffer_updated(file_content, path.ptr, mtime, NULL, updated);
 	git_buf_free(&path);
 
@@ -99,7 +109,7 @@ static int packed_parse_oid(
 
 	refname_len = refname_end - refname_begin;
 
-	ref = git__malloc(sizeof(struct packref) + refname_len + 1);
+	ref = git__calloc(1, sizeof(struct packref) + refname_len + 1);
 	GITERR_CHECK_ALLOC(ref);
 
 	memcpy(ref->name, refname_begin, refname_len);
@@ -107,11 +117,8 @@ static int packed_parse_oid(
 
 	git_oid_cpy(&ref->oid, &id);
 
-	ref->flags = 0;
-
 	*ref_out = ref;
 	*buffer_out = refname_end + 1;
-
 	return 0;
 
 corrupt:
@@ -133,10 +140,6 @@ static int packed_parse_peel(
 	if (tag_ref == NULL)
 		goto corrupt;
 
-	/* Ensure reference is a tag */
-	if (git__prefixcmp(tag_ref->name, GIT_REFS_TAGS_DIR) != 0)
-		goto corrupt;
-
 	if (buffer + GIT_OID_HEXSZ > buffer_end)
 		goto corrupt;
 
@@ -155,6 +158,7 @@ static int packed_parse_peel(
 			goto corrupt;
 	}
 
+	tag_ref->flags |= PACKREF_HAS_PEEL;
 	*buffer_out = buffer;
 	return 0;
 
@@ -175,7 +179,10 @@ static int packed_load(refdb_fs_backend *backend)
 		ref_cache->packfile = git_strmap_alloc();
 		GITERR_CHECK_ALLOC(ref_cache->packfile);
 	}
-	
+
+	if (backend->path == NULL)
+		return 0;
+
 	result = reference_read(&packfile, &ref_cache->packfile_time,
 		backend->path, GIT_PACKEDREFS_FILE, &updated);
 
@@ -193,7 +200,7 @@ static int packed_load(refdb_fs_backend *backend)
 
 	if (result < 0)
 		return -1;
-	
+
 	if (!updated)
 		return 0;
 
@@ -206,6 +213,30 @@ static int packed_load(refdb_fs_backend *backend)
 	buffer_start = (const char *)packfile.ptr;
 	buffer_end = (const char *)(buffer_start) + packfile.size;
 
+	backend->peeling_mode = PEELING_NONE;
+
+	if (buffer_start[0] == '#') {
+		static const char *traits_header = "# pack-refs with: ";
+
+		if (git__prefixcmp(buffer_start, traits_header) == 0) {
+			char *traits = (char *)buffer_start + strlen(traits_header);
+			char *traits_end = strchr(traits, '\n');
+
+			if (traits_end == NULL)
+				goto parse_failed;
+
+			*traits_end = '\0';
+
+			if (strstr(traits, " fully-peeled ") != NULL) {
+				backend->peeling_mode = PEELING_FULL;
+			} else if (strstr(traits, " peeled ") != NULL) {
+				backend->peeling_mode = PEELING_STANDARD;
+			}
+
+			buffer_start = traits_end + 1;
+		}
+	}
+
 	while (buffer_start < buffer_end && buffer_start[0] == '#') {
 		buffer_start = strchr(buffer_start, '\n');
 		if (buffer_start == NULL)
@@ -224,6 +255,10 @@ static int packed_load(refdb_fs_backend *backend)
 		if (buffer_start[0] == '^') {
 			if (packed_parse_peel(ref, &buffer_start, buffer_end) < 0)
 				goto parse_failed;
+		} else if (backend->peeling_mode == PEELING_FULL ||
+							(backend->peeling_mode == PEELING_STANDARD &&
+							git__prefixcmp(ref->name, GIT_REFS_TAGS_DIR) == 0)) {
+			ref->flags |= PACKREF_CANNOT_PEEL;
 		}
 
 		git_strmap_insert(ref_cache->packfile, ref->name, ref, err);
@@ -241,7 +276,7 @@ parse_failed:
 	return -1;
 }
 
-static int loose_parse_oid(git_oid *oid, git_buf *file_content)
+static int loose_parse_oid(git_oid *oid, const char *filename, git_buf *file_content)
 {
 	size_t len;
 	const char *str;
@@ -263,7 +298,7 @@ static int loose_parse_oid(git_oid *oid, git_buf *file_content)
 		return 0;
 
 corrupted:
-	giterr_set(GITERR_REFERENCE, "Corrupted loose reference file");
+	giterr_set(GITERR_REFERENCE, "Corrupted loose reference file: %s", filename);
 	return -1;
 }
 
@@ -284,19 +319,19 @@ static int loose_lookup_to_packfile(
 	git_buf_rtrim(&ref_file);
 
 	name_len = strlen(name);
-	ref = git__malloc(sizeof(struct packref) + name_len + 1);
+	ref = git__calloc(1, sizeof(struct packref) + name_len + 1);
 	GITERR_CHECK_ALLOC(ref);
 
 	memcpy(ref->name, name, name_len);
 	ref->name[name_len] = 0;
 
-	if (loose_parse_oid(&ref->oid, &ref_file) < 0) {
+	if (loose_parse_oid(&ref->oid, name, &ref_file) < 0) {
 		git_buf_free(&ref_file);
 		git__free(ref);
 		return -1;
 	}
 
-	ref->flags = GIT_PACKREF_WAS_LOOSE;
+	ref->flags = PACKREF_WAS_LOOSE;
 
 	*ref_out = ref;
 	git_buf_free(&ref_file);
@@ -430,12 +465,12 @@ static int loose_lookup(
 			goto done;
 		}
 
-		*out = git_reference__alloc(backend->refdb, ref_name, NULL, target);
+		*out = git_reference__alloc_symbolic(ref_name, target);
 	} else {
-		if ((error = loose_parse_oid(&oid, &ref_file)) < 0)
+		if ((error = loose_parse_oid(&oid, ref_name, &ref_file)) < 0)
 			goto done;
-		
-		*out = git_reference__alloc(backend->refdb, ref_name, &oid, NULL);
+
+		*out = git_reference__alloc(ref_name, &oid, NULL);
 	}
 
 	if (*out == NULL)
@@ -456,19 +491,19 @@ static int packed_map_entry(
 
 	if (packed_load(backend) < 0)
 		return -1;
-	
+
 	/* Look up on the packfile */
 	packfile_refs = backend->refcache.packfile;
 
 	*pos = git_strmap_lookup_index(packfile_refs, ref_name);
-	
+
 	if (!git_strmap_valid_index(packfile_refs, *pos)) {
 		giterr_set(GITERR_REFERENCE, "Reference '%s' not found", ref_name);
 		return GIT_ENOTFOUND;
 	}
 
 	*entry = git_strmap_value_at(packfile_refs, *pos);
-	
+
 	return 0;
 }
 
@@ -480,13 +515,14 @@ static int packed_lookup(
 	struct packref *entry;
 	khiter_t pos;
 	int error = 0;
-	
+
 	if ((error = packed_map_entry(&entry, &pos, backend, ref_name)) < 0)
 		return error;
 
-	if ((*out = git_reference__alloc(backend->refdb, ref_name, &entry->oid, NULL)) == NULL)
+	if ((*out = git_reference__alloc(ref_name,
+		&entry->oid, &entry->peel)) == NULL)
 		return -1;
-	
+
 	return 0;
 }
 
@@ -515,108 +551,239 @@ static int refdb_fs_backend__lookup(
 	return result;
 }
 
-struct dirent_list_data {
-	refdb_fs_backend *backend;
-	size_t repo_path_len;
-	unsigned int list_type:2;
+typedef struct {
+	git_reference_iterator parent;
 
-	git_reference_foreach_cb callback;
-	void *callback_payload;
-	int callback_error;
-};
+	char *glob;
+	git_vector loose;
+	unsigned int loose_pos;
+	khiter_t packed_pos;
+} refdb_fs_iter;
 
-static git_ref_t loose_guess_rtype(const git_buf *full_path)
+static void refdb_fs_backend__iterator_free(git_reference_iterator *_iter)
 {
-	git_buf ref_file = GIT_BUF_INIT;
-	git_ref_t type;
+	refdb_fs_iter *iter = (refdb_fs_iter *) _iter;
+	char *loose_path;
+	size_t i;
+
+	git_vector_foreach(&iter->loose, i, loose_path) {
+		git__free(loose_path);
+	}
 
-	type = GIT_REF_INVALID;
+	git_vector_free(&iter->loose);
 
-	if (git_futils_readbuffer(&ref_file, full_path->ptr) == 0) {
-		if (git__prefixcmp((const char *)(ref_file.ptr), GIT_SYMREF) == 0)
-			type = GIT_REF_SYMBOLIC;
-		else
-			type = GIT_REF_OID;
+	git__free(iter->glob);
+	git__free(iter);
+}
+
+static int iter_load_loose_paths(refdb_fs_backend *backend, refdb_fs_iter *iter)
+{
+	git_strmap *packfile = backend->refcache.packfile;
+	git_buf path = GIT_BUF_INIT;
+	git_iterator *fsit;
+	const git_index_entry *entry = NULL;
+
+	if (!backend->path) /* do nothing if no path for loose refs */
+		return 0;
+
+	if (git_buf_printf(&path, "%s/refs", backend->path) < 0)
+		return -1;
+
+	if (git_iterator_for_filesystem(&fsit, git_buf_cstr(&path), 0, NULL, NULL) < 0)
+		return -1;
+
+	git_vector_init(&iter->loose, 8, NULL);
+	git_buf_sets(&path, GIT_REFS_DIR);
+
+	while (!git_iterator_advance(&entry, fsit)) {
+		const char *ref_name;
+		khiter_t pos;
+
+		git_buf_truncate(&path, strlen(GIT_REFS_DIR));
+		git_buf_puts(&path, entry->path);
+		ref_name = git_buf_cstr(&path);
+
+		if (git__suffixcmp(ref_name, ".lock") == 0 ||
+			(iter->glob && p_fnmatch(iter->glob, ref_name, 0) != 0))
+			continue;
+
+		pos = git_strmap_lookup_index(packfile, ref_name);
+		if (git_strmap_valid_index(packfile, pos)) {
+			struct packref *ref = git_strmap_value_at(packfile, pos);
+			ref->flags |= PACKREF_SHADOWED;
+		}
+
+		git_vector_insert(&iter->loose, git__strdup(ref_name));
 	}
 
-	git_buf_free(&ref_file);
-	return type;
+	git_iterator_free(fsit);
+	git_buf_free(&path);
+
+	return 0;
 }
 
-static int _dirent_loose_listall(void *_data, git_buf *full_path)
+static int refdb_fs_backend__iterator_next(
+	git_reference **out, git_reference_iterator *_iter)
 {
-	struct dirent_list_data *data = (struct dirent_list_data *)_data;
-	const char *file_path = full_path->ptr + data->repo_path_len;
+	refdb_fs_iter *iter = (refdb_fs_iter *)_iter;
+	refdb_fs_backend *backend = (refdb_fs_backend *)iter->parent.db->backend;
+	git_strmap *packfile = backend->refcache.packfile;
 
-	if (git_path_isdir(full_path->ptr) == true)
-		return git_path_direach(full_path, _dirent_loose_listall, _data);
+	while (iter->loose_pos < iter->loose.length) {
+		const char *path = git_vector_get(&iter->loose, iter->loose_pos++);
 
-	/* do not add twice a reference that exists already in the packfile */
-	if (git_strmap_exists(data->backend->refcache.packfile, file_path))
-		return 0;
+		if (loose_lookup(out, backend, path) == 0)
+			return 0;
 
-	if (data->list_type != GIT_REF_LISTALL) {
-		if ((data->list_type & loose_guess_rtype(full_path)) == 0)
-			return 0; /* we are filtering out this reference */
+		giterr_clear();
 	}
 
-	/* Locked references aren't returned */
-	if (!git__suffixcmp(file_path, GIT_FILELOCK_EXTENSION))
+	while (iter->packed_pos < kh_end(packfile)) {
+		struct packref *ref = NULL;
+
+		while (!kh_exist(packfile, iter->packed_pos)) {
+			iter->packed_pos++;
+			if (iter->packed_pos == kh_end(packfile))
+				return GIT_ITEROVER;
+		}
+
+		ref = kh_val(packfile, iter->packed_pos);
+		iter->packed_pos++;
+
+		if (ref->flags & PACKREF_SHADOWED)
+			continue;
+
+		if (iter->glob && p_fnmatch(iter->glob, ref->name, 0) != 0)
+			continue;
+
+		*out = git_reference__alloc(ref->name, &ref->oid, &ref->peel);
+		if (*out == NULL)
+			return -1;
+
+		return 0;
+	}
+
+	return GIT_ITEROVER;
+}
+
+static int refdb_fs_backend__iterator_next_name(
+	const char **out, git_reference_iterator *_iter)
+{
+	refdb_fs_iter *iter = (refdb_fs_iter *)_iter;
+	refdb_fs_backend *backend = (refdb_fs_backend *)iter->parent.db->backend;
+	git_strmap *packfile = backend->refcache.packfile;
+
+	while (iter->loose_pos < iter->loose.length) {
+		const char *path = git_vector_get(&iter->loose, iter->loose_pos++);
+
+		if (git_strmap_exists(packfile, path))
+			continue;
+
+		*out = path;
 		return 0;
+	}
+
+	while (iter->packed_pos < kh_end(packfile)) {
+		while (!kh_exist(packfile, iter->packed_pos)) {
+			iter->packed_pos++;
+			if (iter->packed_pos == kh_end(packfile))
+				return GIT_ITEROVER;
+		}
+
+		*out = kh_key(packfile, iter->packed_pos);
+		iter->packed_pos++;
 
-	if (data->callback(file_path, data->callback_payload))
-		data->callback_error = GIT_EUSER;
+		if (iter->glob && p_fnmatch(iter->glob, *out, 0) != 0)
+			continue;
+
+		return 0;
+	}
 
-	return data->callback_error;
+	return GIT_ITEROVER;
 }
 
-static int refdb_fs_backend__foreach(
-	git_refdb_backend *_backend,
-	unsigned int list_type,
-	git_reference_foreach_cb callback,
-	void *payload)
+static int refdb_fs_backend__iterator(
+	git_reference_iterator **out, git_refdb_backend *_backend, const char *glob)
 {
+	refdb_fs_iter *iter;
 	refdb_fs_backend *backend;
-	int result;
-	struct dirent_list_data data;
-	git_buf refs_path = GIT_BUF_INIT;
-	const char *ref_name;
-	void *ref = NULL;
-	
-	GIT_UNUSED(ref);
 
 	assert(_backend);
 	backend = (refdb_fs_backend *)_backend;
 
 	if (packed_load(backend) < 0)
 		return -1;
-	
-	/* list all the packed references first */
-	if (list_type & GIT_REF_OID) {
-		git_strmap_foreach(backend->refcache.packfile, ref_name, ref, {
-			if (callback(ref_name, payload))
-				return GIT_EUSER;
-		});
+
+	iter = git__calloc(1, sizeof(refdb_fs_iter));
+	GITERR_CHECK_ALLOC(iter);
+
+	if (glob != NULL)
+		iter->glob = git__strdup(glob);
+
+	iter->parent.next = refdb_fs_backend__iterator_next;
+	iter->parent.next_name = refdb_fs_backend__iterator_next_name;
+	iter->parent.free = refdb_fs_backend__iterator_free;
+
+	if (iter_load_loose_paths(backend, iter) < 0) {
+		refdb_fs_backend__iterator_free((git_reference_iterator *)iter);
+		return -1;
 	}
 
-	/* now list the loose references, trying not to
-	 * duplicate the ref names already in the packed-refs file */
+	*out = (git_reference_iterator *)iter;
+	return 0;
+}
 
-	data.repo_path_len = strlen(backend->path);
-	data.list_type = list_type;
-	data.backend = backend;
-	data.callback = callback;
-	data.callback_payload = payload;
-	data.callback_error = 0;
+static bool ref_is_available(
+	const char *old_ref, const char *new_ref, const char *this_ref)
+{
+	if (old_ref == NULL || strcmp(old_ref, this_ref)) {
+		size_t reflen = strlen(this_ref);
+		size_t newlen = strlen(new_ref);
+		size_t cmplen = reflen < newlen ? reflen : newlen;
+		const char *lead = reflen < newlen ? new_ref : this_ref;
+
+		if (!strncmp(new_ref, this_ref, cmplen) && lead[cmplen] == '/') {
+			return false;
+		}
+	}
 
-	if (git_buf_joinpath(&refs_path, backend->path, GIT_REFS_DIR) < 0)
+	return true;
+}
+
+static int reference_path_available(
+	refdb_fs_backend *backend,
+	const char *new_ref,
+	const char* old_ref,
+	int force)
+{
+	struct packref *this_ref;
+
+	if (packed_load(backend) < 0)
 		return -1;
 
-	result = git_path_direach(&refs_path, _dirent_loose_listall, &data);
+	if (!force) {
+		int exists;
 
-	git_buf_free(&refs_path);
+		if (refdb_fs_backend__exists(&exists, (git_refdb_backend *)backend, new_ref) < 0)
+			return -1;
+
+		if (exists) {
+			giterr_set(GITERR_REFERENCE,
+				"Failed to write reference '%s': a reference with "
+				" that name already exists.", new_ref);
+			return GIT_EEXISTS;
+		}
+	}
 
-	return data.callback_error ? GIT_EUSER : result;
+	git_strmap_foreach_value(backend->refcache.packfile, this_ref, {
+		if (!ref_is_available(old_ref, new_ref, this_ref->name)) {
+			giterr_set(GITERR_REFERENCE,
+				"The path to reference '%s' collides with an existing one", new_ref);
+			return -1;
+		}
+	});
+	
+	return 0;
 }
 
 static int loose_write(refdb_fs_backend *backend, const git_reference *ref)
@@ -627,8 +794,7 @@ static int loose_write(refdb_fs_backend *backend, const git_reference *ref)
 	/* Remove a possibly existing empty directory hierarchy
 	 * which name would collide with the reference name
 	 */
-	if (git_futils_rmdir_r(ref->name, backend->path,
-		GIT_RMDIR_SKIP_NONEMPTY) < 0)
+	if (git_futils_rmdir_r(ref->name, backend->path, GIT_RMDIR_SKIP_NONEMPTY) < 0)
 		return -1;
 
 	if (git_buf_joinpath(&ref_path, backend->path, ref->name) < 0)
@@ -678,14 +844,7 @@ static int packed_find_peel(refdb_fs_backend *backend, struct packref *ref)
 {
 	git_object *object;
 
-	if (ref->flags & GIT_PACKREF_HAS_PEEL)
-		return 0;
-
-	/*
-	 * Only applies to tags, i.e. references
-	 * in the /refs/tags folder
-	 */
-	if (git__prefixcmp(ref->name, GIT_REFS_TAGS_DIR) != 0)
+	if (ref->flags & PACKREF_HAS_PEEL || ref->flags & PACKREF_CANNOT_PEEL)
 		return 0;
 
 	/*
@@ -706,7 +865,7 @@ static int packed_find_peel(refdb_fs_backend *backend, struct packref *ref)
 		 * Find the object pointed at by this tag
 		 */
 		git_oid_cpy(&ref->peel, git_tag_target_id(tag));
-		ref->flags |= GIT_PACKREF_HAS_PEEL;
+		ref->flags |= PACKREF_HAS_PEEL;
 
 		/*
 		 * The reference has now cached the resolved OID, and is
@@ -739,7 +898,7 @@ static int packed_write_ref(struct packref *ref, git_filebuf *file)
 	 * This obviously only applies to tags.
 	 * The required peels have already been loaded into `ref->peel_target`.
 	 */
-	if (ref->flags & GIT_PACKREF_HAS_PEEL) {
+	if (ref->flags & PACKREF_HAS_PEEL) {
 		char peel[GIT_OID_HEXSZ + 1];
 		git_oid_fmt(peel, &ref->peel);
 		peel[GIT_OID_HEXSZ] = 0;
@@ -776,7 +935,7 @@ static int packed_remove_loose(
 	for (i = 0; i < packing_list->length; ++i) {
 		struct packref *ref = git_vector_get(packing_list, i);
 
-		if ((ref->flags & GIT_PACKREF_WAS_LOOSE) == 0)
+		if ((ref->flags & PACKREF_WAS_LOOSE) == 0)
 			continue;
 
 		if (git_buf_joinpath(&full_path, backend->path, ref->name) < 0)
@@ -895,66 +1054,113 @@ cleanup_memory:
 
 static int refdb_fs_backend__write(
 	git_refdb_backend *_backend,
-	const git_reference *ref)
+	const git_reference *ref,
+	int force)
 {
 	refdb_fs_backend *backend;
+	int error;
 
 	assert(_backend);
 	backend = (refdb_fs_backend *)_backend;
 
+	error = reference_path_available(backend, ref->name, NULL, force);
+	if (error < 0)
+		return error;
+
 	return loose_write(backend, ref);
 }
 
 static int refdb_fs_backend__delete(
 	git_refdb_backend *_backend,
-	const git_reference *ref)
+	const char *ref_name)
 {
 	refdb_fs_backend *backend;
-	git_repository *repo;
 	git_buf loose_path = GIT_BUF_INIT;
 	struct packref *pack_ref;
 	khiter_t pack_ref_pos;
-	int error = 0, pack_error;
-	bool loose_deleted;
+	int error = 0;
+	bool loose_deleted = 0;
 
 	assert(_backend);
-	assert(ref);
+	assert(ref_name);
 
 	backend = (refdb_fs_backend *)_backend;
-	repo = backend->repo;
 
 	/* If a loose reference exists, remove it from the filesystem */
-	
-	if (git_buf_joinpath(&loose_path, repo->path_repository, ref->name) < 0)
+	if (git_buf_joinpath(&loose_path, backend->path, ref_name) < 0)
 		return -1;
 
 	if (git_path_isfile(loose_path.ptr)) {
 		error = p_unlink(loose_path.ptr);
 		loose_deleted = 1;
 	}
-	
+
 	git_buf_free(&loose_path);
 
 	if (error != 0)
 		return error;
 
 	/* If a packed reference exists, remove it from the packfile and repack */
+	error = packed_map_entry(&pack_ref, &pack_ref_pos, backend, ref_name);
+
+	if (error == GIT_ENOTFOUND)
+		return loose_deleted ? 0 : GIT_ENOTFOUND;
 
-	if ((pack_error = packed_map_entry(&pack_ref, &pack_ref_pos, backend, ref->name)) == 0) {
+	if (error == 0) {
 		git_strmap_delete_at(backend->refcache.packfile, pack_ref_pos);
 		git__free(pack_ref);
-
 		error = packed_write(backend);
 	}
-	
-	if (pack_error == GIT_ENOTFOUND)
-		error = loose_deleted ? 0 : GIT_ENOTFOUND;
-	else
-		error = pack_error;
 
 	return error;
 }
 
+static int refdb_fs_backend__rename(
+	git_reference **out,
+	git_refdb_backend *_backend,
+	const char *old_name,
+	const char *new_name,
+	int force)
+{
+	refdb_fs_backend *backend;
+	git_reference *old, *new;
+	int error;
+
+	assert(_backend);
+	backend = (refdb_fs_backend *)_backend;
+
+	error = reference_path_available(backend, new_name, old_name, force);
+	if (error < 0)
+		return error;
+
+	error = refdb_fs_backend__lookup(&old, _backend, old_name);
+	if (error < 0)
+		return error;
+
+	error = refdb_fs_backend__delete(_backend, old_name);
+	if (error < 0) {
+		git_reference_free(old);
+		return error;
+	}
+
+	new = realloc(old, sizeof(git_reference) + strlen(new_name) + 1);
+	memcpy(new->name, new_name, strlen(new_name) + 1);
+
+	error = loose_write(backend, new);
+	if (error < 0) {
+		git_reference_free(new);
+		return error;
+	}
+
+	if (out) {
+		*out = new;
+	} else {
+		git_reference_free(new);
+	}
+
+	return 0;
+}
+
 static int refdb_fs_backend__compress(git_refdb_backend *_backend)
 {
 	refdb_fs_backend *backend;
@@ -993,28 +1199,76 @@ static void refdb_fs_backend__free(git_refdb_backend *_backend)
 	backend = (refdb_fs_backend *)_backend;
 
 	refcache_free(&backend->refcache);
+	git__free(backend->path);
 	git__free(backend);
 }
 
+static int setup_namespace(git_buf *path, git_repository *repo)
+{
+	char *parts, *start, *end;
+
+	/* Not all repositories have a path */
+	if (repo->path_repository == NULL)
+		return 0;
+
+	/* Load the path to the repo first */
+	git_buf_puts(path, repo->path_repository);
+
+	/* if the repo is not namespaced, nothing else to do */
+	if (repo->namespace == NULL)
+		return 0;
+
+	parts = end = git__strdup(repo->namespace);
+	if (parts == NULL)
+		return -1;
+
+	/**
+	 * From `man gitnamespaces`:
+	 *  namespaces which include a / will expand to a hierarchy
+	 *  of namespaces; for example, GIT_NAMESPACE=foo/bar will store
+	 *  refs under refs/namespaces/foo/refs/namespaces/bar/
+	 */
+	while ((start = git__strsep(&end, "/")) != NULL) {
+		git_buf_printf(path, "refs/namespaces/%s/", start);
+	}
+
+	git_buf_printf(path, "refs/namespaces/%s/refs", end);
+	git__free(parts);
+
+	/* Make sure that the folder with the namespace exists */
+	if (git_futils_mkdir_r(git_buf_cstr(path), repo->path_repository, 0777) < 0)
+		return -1;
+
+	/* Return the root of the namespaced path, i.e. without the trailing '/refs' */
+	git_buf_rtruncate_at_char(path, '/');
+	return 0;
+}
+
 int git_refdb_backend_fs(
 	git_refdb_backend **backend_out,
-	git_repository *repository,
-	git_refdb *refdb)
+	git_repository *repository)
 {
+	git_buf path = GIT_BUF_INIT;
 	refdb_fs_backend *backend;
 
 	backend = git__calloc(1, sizeof(refdb_fs_backend));
 	GITERR_CHECK_ALLOC(backend);
 
 	backend->repo = repository;
-	backend->path = repository->path_repository;
-	backend->refdb = refdb;
+
+	if (setup_namespace(&path, repository) < 0) {
+		git__free(backend);
+		return -1;
+	}
+
+	backend->path = git_buf_detach(&path);
 
 	backend->parent.exists = &refdb_fs_backend__exists;
 	backend->parent.lookup = &refdb_fs_backend__lookup;
-	backend->parent.foreach = &refdb_fs_backend__foreach;
+	backend->parent.iterator = &refdb_fs_backend__iterator;
 	backend->parent.write = &refdb_fs_backend__write;
 	backend->parent.delete = &refdb_fs_backend__delete;
+	backend->parent.rename = &refdb_fs_backend__rename;
 	backend->parent.compress = &refdb_fs_backend__compress;
 	backend->parent.free = &refdb_fs_backend__free;