git_futils_mkdir_*: make a relative-to-base mkdir

Untangle git_futils_mkdir from git_futils_mkdir_ext - the latter
assumes that we own everything beneath the base, as if it were
being called with a base of the repository or working directory,
and is tailored towards checkout and ensuring that there is no
bogosity beneath the base that must be cleaned up.

This is (at best) slow and (at worst) unsafe in the larger context
of a filesystem where we do not own things and cannot do things like
unlink symlinks that are in our way.

6 files changed, 32 insertions, 31 deletions

diff --git a/src/checkout.c b/src/checkout.c
index 8c06b3335..2a8bfd558 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -1366,7 +1366,7 @@ static int checkout_mkdir(
 	mkdir_opts.dir_map = data->mkdir_map;
 	mkdir_opts.pool = &data->pool;
 
-	error = git_futils_mkdir_ext(
+	error = git_futils_mkdir_relative(
 		path, base, mode, flags, &mkdir_opts);
 
 	data->perfdata.mkdir_calls += mkdir_opts.perfdata.mkdir_calls;
diff --git a/src/fileops.c b/src/fileops.c
index b7b55159f..b986a6546 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -18,7 +18,7 @@ GIT__USE_STRMAP
 int git_futils_mkpath2file(const char *file_path, const mode_t mode)
 {
 	return git_futils_mkdir(
-		file_path, NULL, mode,
+		file_path, mode,
 		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
 }
 
@@ -331,8 +331,8 @@ GIT_INLINE(int) validate_existing(
 	return 0;
 }
 
-int git_futils_mkdir_ext(
-	const char *path,
+int git_futils_mkdir_relative(
+	const char *relative_path,
 	const char *base,
 	mode_t mode,
 	uint32_t flags,
@@ -343,9 +343,13 @@ int git_futils_mkdir_ext(
 	ssize_t root = 0, min_root_len, root_len;
 	char lastch = '/', *tail;
 	struct stat st;
+	struct git_futils_mkdir_options empty_opts = {0};
+
+	if (!opts)
+		opts = &empty_opts;
 
 	/* build path and find "root" where we should start calling mkdir */
-	if (git_path_join_unrooted(&make_path, path, base, &root) < 0)
+	if (git_path_join_unrooted(&make_path, relative_path, base, &root) < 0)
 		return -1;
 
 	if (make_path.size == 0) {
@@ -503,17 +507,16 @@ done:
 
 int git_futils_mkdir(
 	const char *path,
-	const char *base,
 	mode_t mode,
 	uint32_t flags)
 {
 	struct git_futils_mkdir_options options = {0};
-	return git_futils_mkdir_ext(path, base, mode, flags, &options);
+	return git_futils_mkdir_relative(path, NULL, mode, flags, &options);
 }
 
-int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
+int git_futils_mkdir_r(const char *path, const mode_t mode)
 {
-	return git_futils_mkdir(path, base, mode, GIT_MKDIR_PATH);
+	return git_futils_mkdir(path, mode, GIT_MKDIR_PATH);
 }
 
 typedef struct {
@@ -777,7 +780,7 @@ static int _cp_r_mkdir(cp_r_info *info, git_buf *from)
 	/* create root directory the first time we need to create a directory */
 	if ((info->flags & GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT) == 0) {
 		error = git_futils_mkdir(
-			info->to_root, NULL, info->dirmode,
+			info->to_root, info->dirmode,
 			(info->flags & GIT_CPDIR_CHMOD_DIRS) ? GIT_MKDIR_CHMOD : 0);
 
 		info->flags |= GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT;
@@ -785,9 +788,9 @@ static int _cp_r_mkdir(cp_r_info *info, git_buf *from)
 
 	/* create directory with root as base to prevent excess chmods */
 	if (!error)
-		error = git_futils_mkdir(
+		error = git_futils_mkdir_relative(
 			from->ptr + info->from_prefix, info->to_root,
-			info->dirmode, info->mkdir_flags);
+			info->dirmode, info->mkdir_flags, NULL);
 
 	return error;
 }
diff --git a/src/fileops.h b/src/fileops.h
index 0f6466c59..572ff01a5 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -55,12 +55,9 @@ extern int git_futils_creat_locked(const char *path, const mode_t mode);
 extern int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode);
 
 /**
- * Create a path recursively
- *
- * If a base parameter is being passed, it's expected to be valued with a
- * path pointing to an already existing directory.
+ * Create a path recursively.
  */
-extern int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode);
+extern int git_futils_mkdir_r(const char *path, const mode_t mode);
 
 /**
  * Flags to pass to `git_futils_mkdir`.
@@ -111,20 +108,20 @@ struct git_futils_mkdir_options
  * and optionally chmods the directory immediately after (or each part of the
  * path if requested).
  *
- * @param path The path to create.
+ * @param path The path to create, relative to base.
  * @param base Root for relative path.  These directories will never be made.
  * @param mode The mode to use for created directories.
  * @param flags Combination of the mkdir flags above.
- * @param opts Extended options, use `git_futils_mkdir` if you are not interested.
+ * @param opts Extended options, or null.
  * @return 0 on success, else error code
  */
-extern int git_futils_mkdir_ext(const char *path, const char *base, mode_t mode, uint32_t flags, struct git_futils_mkdir_options *opts);
+extern int git_futils_mkdir_relative(const char *path, const char *base, mode_t mode, uint32_t flags, struct git_futils_mkdir_options *opts);
 
 /**
- * Create a directory or entire path.  Similar to `git_futils_mkdir_withperf`
+ * Create a directory or entire path.  Similar to `git_futils_mkdir_relative`
  * without performance data.
  */
-extern int git_futils_mkdir(const char *path, const char *base, mode_t mode, uint32_t flags);
+extern int git_futils_mkdir(const char *path, mode_t mode, uint32_t flags);
 
 /**
  * Create all the folders required to contain
diff --git a/src/odb_loose.c b/src/odb_loose.c
index 99b8f7c91..730c4b1e1 100644
--- a/src/odb_loose.c
+++ b/src/odb_loose.c
@@ -84,9 +84,9 @@ static int object_file_name(
 
 static int object_mkdir(const git_buf *name, const loose_backend *be)
 {
-	return git_futils_mkdir(
+	return git_futils_mkdir_relative(
 		name->ptr + be->objects_dirlen, be->objects_dir, be->object_dir_mode,
-		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
+		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR, NULL);
 }
 
 static size_t get_binary_object_header(obj_hdr *hdr, git_buf *obj)
diff --git a/src/refdb_fs.c b/src/refdb_fs.c
index 1ddce4649..921f7862b 100644
--- a/src/refdb_fs.c
+++ b/src/refdb_fs.c
@@ -1413,7 +1413,8 @@ static int setup_namespace(git_buf *path, git_repository *repo)
 	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)
+	if (git_futils_mkdir_relative(git_buf_cstr(path), repo->path_repository,
+			0777, GIT_MKDIR_PATH, NULL) < 0)
 		return -1;
 
 	/* Return root of the namespaced path, i.e. without the trailing '/refs' */
diff --git a/src/repository.c b/src/repository.c
index 0f37cfbfe..d0bf7dc79 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -1441,8 +1441,8 @@ static int repo_init_structure(
 			if (chmod)
 				mkdir_flags |= GIT_MKDIR_CHMOD;
 
-			error = git_futils_mkdir(
-				tpl->path, repo_dir, dmode, mkdir_flags);
+			error = git_futils_mkdir_relative(
+				tpl->path, repo_dir, dmode, mkdir_flags, NULL);
 		}
 		else if (!external_tpl) {
 			const char *content = tpl->content;
@@ -1464,7 +1464,7 @@ static int mkdir_parent(git_buf *buf, uint32_t mode, bool skip2)
 	 * don't try to set gid or grant world write access
 	 */
 	return git_futils_mkdir(
-		buf->ptr, NULL, mode & ~(S_ISGID | 0002),
+		buf->ptr, mode & ~(S_ISGID | 0002),
 		GIT_MKDIR_PATH | GIT_MKDIR_VERIFY_DIR |
 		(skip2 ? GIT_MKDIR_SKIP_LAST2 : GIT_MKDIR_SKIP_LAST));
 }
@@ -1568,14 +1568,14 @@ static int repo_init_directories(
 		/* create path #4 */
 		if (wd_path->size > 0 &&
 			(error = git_futils_mkdir(
-				wd_path->ptr, NULL, dirmode & ~S_ISGID,
+				wd_path->ptr, dirmode & ~S_ISGID,
 				GIT_MKDIR_VERIFY_DIR)) < 0)
 			return error;
 
 		/* create path #2 (if not the same as #4) */
 		if (!natural_wd &&
 			(error = git_futils_mkdir(
-				repo_path->ptr, NULL, dirmode & ~S_ISGID,
+				repo_path->ptr, dirmode & ~S_ISGID,
 				GIT_MKDIR_VERIFY_DIR | GIT_MKDIR_SKIP_LAST)) < 0)
 			return error;
 	}
@@ -1585,7 +1585,7 @@ static int repo_init_directories(
 		has_dotgit)
 	{
 		/* create path #1 */
-		error = git_futils_mkdir(repo_path->ptr, NULL, dirmode,
+		error = git_futils_mkdir(repo_path->ptr, dirmode,
 			GIT_MKDIR_VERIFY_DIR | ((dirmode & S_ISGID) ? GIT_MKDIR_CHMOD : 0));
 	}