From 0e9474d3772d6662f6f3141f37f0e5f8894847cd Mon Sep 17 00:00:00 2001
From: "S.J.R. van Schaik" <stephan@whiteboxsystems.nl>
Date: Fri, 9 Jun 2017 16:29:37 +0200
Subject: [PATCH] mufs: add support for path resolution

---
 source/fs/mufs/dir.c | 127 +++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 103 insertions(+), 24 deletions(-)

diff --git a/source/fs/mufs/dir.c b/source/fs/mufs/dir.c
index 17248dc..189ad5f 100644
--- a/source/fs/mufs/dir.c
+++ b/source/fs/mufs/dir.c
@@ -17,18 +17,7 @@ struct mufs_dir {
 	uint32_t va;
 };
 
-static int resolve(struct mufs *fs, struct mufs_tree *tree, const char *path)
-{
-	if (!path || *path == '\0') {
-		memcpy(tree, &fs->root, sizeof *tree);
-		return 0;
-	}
-
-	/* TODO: resolve directories. */
-	return -1;
-}
-
-struct mufs_dir *mufs_opendir(struct mufs *fs, const char *path)
+static struct mufs_dir *mufs_opendir2(struct mufs *fs, struct mufs_dirent *entry)
 {
 	struct mufs_dir *dir;
 
@@ -36,13 +25,101 @@ struct mufs_dir *mufs_opendir(struct mufs *fs, const char *path)
 		return NULL;
 
 	dir->fs = fs;
+	dir->va = 0;
+
+	if (entry) {
+		if (!(dir->tree = malloc(sizeof *dir->tree)))
+			goto err_free_dir;
+
+		memcpy(dir->tree, &entry->tree, sizeof *dir->tree);
+	} else {
+		dir->tree = &fs->root;
+	}
+
+	return dir;
+
+err_free_dir:
+	free(dir);
+	return NULL;
+}
+
+static struct mufs_tree *resolve_path(struct mufs *fs, const char *path)
+{
+	struct mufs_dir *dir;
+	struct mufs_dirent entry;
+	struct mufs_tree *tree;
+	char *s, *p, *end;
+	int ret;
+
+	if (!path || *path == '\0')
+		return NULL;
+
+	while (*path == '/')
+		++path;
+
+	if (*path == '\0')
+		return &fs->root;
+
+	if (!(s = strdup(path)))
+		return NULL;
+
+	if (!(dir = mufs_opendir2(fs, NULL)))
+		goto err_free_s;
+
+	for (p = s; *p != '\0'; p = end) {
+		end = p + strcspn(p, "/");
+
+		while (*end == '/')
+			*end++ = '\0';
+
+		while ((ret = mufs_readdir(dir, &entry)) == 0) {
+			if (strcmp(entry.path, p) != 0)
+				continue;
+
+			mufs_closedir(dir);
+
+			if (!(dir = mufs_opendir2(fs, &entry)))
+				goto err_free_s;
+
+			break;
+		}
+
+		if (ret < 0)
+			goto err_close_dir;
+	}
+
+	tree = dir->tree;
+
+	mufs_closedir(dir);
+
+	return tree;
+
+err_close_dir:
+	mufs_closedir(dir);
+err_free_s:
+	free(s);
+	return NULL;
+}
+
+struct mufs_dir *mufs_opendir(struct mufs *fs, const char *path)
+{
+	struct mufs_dir *dir;
+
+	if (!(dir = malloc(sizeof(*dir))))
+		return NULL;
+
+	dir->fs = fs;
+
+	if (!(dir->tree = resolve_path(fs, path)))
+		goto err_free_dir;
 
-	/* TODO: resolve path */
-	(void)path;
-	memcpy(&dir->tree, &fs->root, sizeof dir->tree);
 	dir->va = 0;
 
 	return dir;
+
+err_free_dir:
+	free(dir);
+	return NULL;
 }
 
 void mufs_closedir(struct mufs_dir *dir)
@@ -87,7 +164,8 @@ static size_t read_dirent(struct mufs *fs, struct mufs_tree *tree,
 
 	struct flash_dev *dev = fs->dev;
 
-	if (mufs_lookup_page(tree, &dirent->tree.va, base & ~((UINT32_C(1) << dev->log2_block_size) - 1)) < 0)
+	if (mufs_lookup_page(tree, &dirent->tree.va,
+		base & ~((UINT32_C(1) << dev->log2_block_size) - 1)) < 0)
 		return 0;
 
 	dirent->tree.fs = fs;
@@ -130,8 +208,6 @@ static size_t write_dirent(struct mufs_tree *tree,
 	dtree.root = tree->root;
 	dtree.depth = tree->depth;
 
-	printf("tree->va=%u\n", tree->va);
-
 	if (flash_write(tree->fs->dev, tree->va, &dtree, sizeof dtree) == 0)
 		return 0;
 
@@ -157,14 +233,13 @@ int mufs_readdir(struct mufs_dir *dir, struct mufs_dirent *dirent)
 		return 0;
 	}
 
-	printf("return?\n");
 	return -1;
 }
 
 int mufs_mkdir(struct mufs *fs, const char *path)
 {
 	struct mufs_dirent dirent;
-	struct mufs_tree tree;
+	struct mufs_tree *tree;
 	size_t len;
 	char *s;
 	char *name;
@@ -172,6 +247,10 @@ int mufs_mkdir(struct mufs *fs, const char *path)
 	if (!path)
 		return -1;
 
+	/* TODO: already exists. */
+	if (resolve_path(fs, path))
+		return 0;
+
 	if (!(s = strdup(path)))
 		return -1;
 
@@ -185,7 +264,7 @@ int mufs_mkdir(struct mufs *fs, const char *path)
 	if (*name == '\0')
 		return -1;
 
-	if (resolve(fs, &tree, s) < 0)
+	if (!(tree = resolve_path(fs, s)))
 		return -1;
 
 	len = min(strlen(name), sizeof(dirent.path) - 1);
@@ -198,11 +277,11 @@ int mufs_mkdir(struct mufs *fs, const char *path)
 	dirent.tree.root = 0;
 	dirent.tree.depth = 0;
 
-	if (!is_aligned(tree.file_size, fs->dev->log2_block_size) &&
-		write_dirent(&tree, tree.file_size, &dirent) > 0)
+	if (!is_aligned(tree->file_size, fs->dev->log2_block_size) &&
+		write_dirent(tree, tree->file_size, &dirent) > 0)
 		return 0;
 
-	if (write_dirent(&tree, align_up(tree.file_size,
+	if (write_dirent(tree, align_up(tree->file_size,
 		fs->dev->log2_block_size), &dirent) > 0)
 		return 0;