new: 将sys_rmdir更改为sys_unlink,.且完成删除文件操作的vfs部分 (#69)

user/libs/libc/fcntl.h

@@ -30,6 +30,29 @@
 #define O_DIRECTORY 00040000 // 打开的必须是一个目录
 #define O_NOFOLLOW 00100000 // Do not follow symbolic links
 
+/*
+ * The constants AT_REMOVEDIR and AT_EACCESS have the same value.  AT_EACCESS is
+ * meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
+ * unlinkat.  The two functions do completely different things and therefore,
+ * the flags can be allowed to overlap.  For example, passing AT_REMOVEDIR to
+ * faccessat would be undefined behavior and thus treating it equivalent to
+ * AT_EACCESS is valid undefined behavior.
+ */
+// 作为当前工作目录的文件描述符（用于指代cwd）
+#define AT_FDCWD -100
+#define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links.  */
+#define AT_EACCESS 0x200          /* Test access permitted for effective IDs, not real IDs.  */
+#define AT_REMOVEDIR 0x200        /* Remove directory instead of unlinking file.  */
+#define AT_SYMLINK_FOLLOW 0x400   /* Follow symbolic links.  */
+#define AT_NO_AUTOMOUNT 0x800     /* Suppress terminal automount traversal */
+#define AT_EMPTY_PATH 0x1000      /* Allow empty relative pathname */
+
+#define AT_STATX_SYNC_TYPE 0x6000    /* Type of synchronisation required from statx() */
+#define AT_STATX_SYNC_AS_STAT 0x0000 /* - Do whatever stat() does */
+#define AT_STATX_FORCE_SYNC 0x2000   /* - Force the attributes to be sync'd with the server */
+#define AT_STATX_DONT_SYNC 0x4000    /* - Don't sync attributes with the server */
+
+#define AT_RECURSIVE 0x8000 /* Apply to the entire subtree */
 
 /**
  * @brief 打开文件的接口

user/libs/libc/unistd.c

@@ -4,6 +4,7 @@
 #include <libc/stdio.h>
 #include <libc/stddef.h>
 #include <libc/string.h>
+#include <libc/fcntl.h>
 
 /**
  * @brief 关闭文件接口
@@ -157,7 +158,7 @@ int execv(const char *path, char *const argv[])
  */
 int rmdir(const char *path)
 {
-    return syscall_invoke(SYS_RMDIR, (uint64_t)path, 0, 0, 0, 0, 0, 0, 0);
+    return syscall_invoke(SYS_UNLINK_AT, 0, (uint64_t)path, AT_REMOVEDIR, 0, 0, 0, 0, 0);
 }
 
 /**

user/libs/libsystem/syscall.h

@@ -27,7 +27,7 @@
 #define SYS_PIPE 20
 
 #define SYS_MSTAT 21    // 获取系统的内存状态信息
-#define SYS_RMDIR 22    // 删除文件夹
+#define SYS_UNLINK_AT 22    // 删除文件夹/删除文件链接
 
 /**
  * @brief 用户态系统调用函数