posix: fs: Fixes stat command to return file information

Fixes zephyrproject-rtos#58911. Previously the stat command returned
information on the filesystem, but not the file itself.
Because block size is still set this function is
backwards compatible with the previous faulty
behavior.

Signed-off-by: Vincent van Beveren <v.van.beveren@nikhef.nl>

lib/posix/fs.c

@@ -349,22 +349,45 @@ int unlink(const char *path)
 int stat(const char *path, struct stat *buf)
 {
 	int rc;
-	struct fs_statvfs stat;
+	struct fs_statvfs stat_vfs;
+	struct fs_dirent stat_fil
 
 	if (buf == NULL) {
 		errno = EBADF;
 		return -1;
 	}
 
-	rc = fs_statvfs(path, &stat);
+	rc = fs_statvfs(path, &stat_vfs);
 	if (rc < 0) {
 		errno = -rc;
 		return -1;
 	}
 
-	buf->st_size = stat.f_bsize * stat.f_blocks;
-	buf->st_blksize = stat.f_bsize;
-	buf->st_blocks = stat.f_blocks;
+	rc = fs_stat(path, &stat_file);
+	if (rc < 0) {
+		errno = -rc;
+		return -1;
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	switch (stat_file.type) {
+	case FS_DIR_ENTRY_FILE:
+		buf->st_mode = S_IFREG;
+		break;
+	case FS_DIR_ENTRY_DIR:
+		buf->st_mode = S_IFDIR;
+		break;
+	default:
+		/* what about this? */
+		break;
+	}
+	buf->st_size = stat_file.size;
+	buf->st_blksize = stat_vfs.f_bsize;
+	/* big if */
+	buf->st_blocks = (stat_file.size + stat_vfs.f_bsize - 1) / stat_vfs.f_bsize;
+
+	/*  stat has many more fields, like time, gui, uid how to retrieve??? */
 	return 0;
 }