文件系统几个关键结构体注释

百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码博客输出站点(国内):http://weharmonyos.com 博客输出站点(国外):https://weharmony.github.io 注解文件系统:https://gitee.com/weharmony/third_party_NuttX 注解协议栈:https://gitee.com/weharmony/third_party_lwip 注解编译子系统:https://gitee.com/weharmony/build_lite

文件系统几个关键结构体注释
百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码博客输出站点(国内):http://weharmonyos.com 博客输出站点(国外):https://weharmony.github.io 注解文件系统:https://gitee.com/weharmony/third_party_NuttX 注解协议栈:https://gitee.com/weharmony/third_party_lwip 注解编译子系统:https://gitee.com/weharmony/build_lite
e244de3a · 鸿蒙内核源码分析 · 20a8f18d · e244de3a · e244de3a · e244de3a
6 changed file
--- a/README.md
+++ b/README.md
-[OpenHarmony | 鸿蒙研究站 | WeHarmony](http://weharmonyos.com/) **[ < 国内](http://weharmonyos.com/)[ | 国外 >](http://weharmonyos.com/)**
-
 [![在这里插入图片描述](https://gitee.com/weharmony/docs/raw/master/pic/other/io.png)](http://weharmonyos.com/)

 百篇博客系列篇.本篇为:
@@ -8,7 +6,7 @@

 ### **同步官方源码历史**
 * 每月至少同步一次
-* `2021/7/15` -- 本次官方改动不大,新增 `blackbox`,`hidumper`,对一些宏(`LOSCFG_KERNEL_SMP` ..)规范化使用 
+* `2021/7/15` -- 本次官方改动不大,新增blackbox,hidumper,对一些宏(LOSCFG_KERNEL_SMP ..)规范化使用 
 * `2021/6/27` -- 本次官方对文件系统/设备驱动改动较大,目录结构进行了重新整理.
 * `2021/6/08` -- 本次官方对编译构建,任务,信号模块有较大的改动.
 * `2021/5/28` -- 本次官方改动不大,主要针对一些错误单词拼写纠正.
@@ -22,11 +20,11 @@

 * 百篇博客分析地址：
  *  国内: [ http://weharmonyos.com/weharmony](http://weharmonyos.com/weharmony)   
-  *  国外: [ http://weharmonyos.com/weharmony](http://weharmonyos.com/weharmony)   
+  *  国外: [ https://weharmony.github.io/weharmony](http://weharmonyos.com/weharmony)   
  
 * [OpenHarmony开发者文档](http://weharmonyos.com/openharmony) 是对官方文档 [docs](https://gitee.com/openharmony/docs) 做的非常炫酷的静态站点，支持侧边栏/面包屑/搜索/中英文，非常方便的查看官方文档，大大提高学习和开发效率. 
  * 国内: [http://weharmonyos.com/openharmony](http://weharmonyos.com/openharmony) 
-  * 国外: [http://weharmonyos.com/openharmony](http://weharmonyos.com/openharmony) 
+  * 国外: [https://weharmony.github.io/openharmony](http://weharmonyos.com/openharmony) 
    
 *  [下载.鸿蒙源码分析.离线文档 < 国内](http://weharmonyos.com/history.html)[ | 国外 > ](http://weharmonyos.com/history.html)

@@ -77,13 +75,15 @@

 与代码有bug需不断debug一样，文章和注解内容会存在不少错漏之处，请多包涵，但会反复修正，持续更新，`.xx`代表修改的次数，精雕细琢，言简意赅，力求打造精品内容。

-* [v61.xx 鸿蒙内核源码分析(ninja应用篇) | 简单而快速的构建系统 ](https://my.oschina.net/weharmony/blog/5139034) **[  | 51](https://harmonyos.51cto.com/posts/7328)[ .c](https://blog.csdn.net/kuangyufei/article/details/118970589)[  .h](http://weharmonyos.com/blog/60_ninja应用篇.html)[ .o](https://my.oschina.net/weharmony)**
+* [v62.xx 鸿蒙内核源码分析(文件概念篇) | 为什么说一切皆是文件 ](https://my.oschina.net/weharmony/blog/5152858) **[  | 51](https://harmonyos.51cto.com/posts/7460)[ .c](https://blog.csdn.net/kuangyufei/article/details/119217155)[  .h](http://weharmonyos.com/blog/62_文件概念篇.html)[ .o](https://my.oschina.net/weharmony)**
+
+* [v61.xx 鸿蒙内核源码分析(忍者ninja篇) | 都忍者了能不快吗 ](https://my.oschina.net/weharmony/blog/5139034) **[  | 51](https://harmonyos.51cto.com/posts/7328)[ .c](https://blog.csdn.net/kuangyufei/article/details/118970589)[  .h](http://weharmonyos.com/blog/61_忍者ninja篇.html)[ .o](https://my.oschina.net/weharmony)**

 * [v60.xx 鸿蒙内核源码分析(gn应用篇) | gn语法及在鸿蒙的使用 ](https://my.oschina.net/weharmony/blog/5137565) **[  | 51](https://harmonyos.51cto.com/posts/7310)[ .c](https://blog.csdn.net/kuangyufei/article/details/118932416)[  .h](http://weharmonyos.com/blog/60_gn应用篇.html)[ .o](https://my.oschina.net/weharmony)**

 * [v59.xx 鸿蒙内核源码分析(构建工具篇) | 顺瓜摸藤调试鸿蒙构建过程 ](https://my.oschina.net/weharmony/blog/5135157) **[  | 51](https://harmonyos.51cto.com/posts/7287)[ .c](https://blog.csdn.net/kuangyufei/article/details/118878233)[  .h](http://weharmonyos.com/blog/59_构建工具篇.html)[ .o](https://my.oschina.net/weharmony)**

-* [v58.xx 鸿蒙内核源码分析(环境脚本篇) | 有了它编译鸿蒙好简单 ](https://my.oschina.net/weharmony/blog/5132725) **[  | 51](https://harmonyos.51cto.com/posts/7248)[ .c](https://blog.csdn.net/kuangyufei/article/details/118765692)[  .h](http://weharmonyos.com/blog/58_编译脚本篇.html)[ .o](https://my.oschina.net/weharmony)**
+* [v58.xx 鸿蒙内核源码分析(环境脚本篇) | 编译鸿蒙原来如此简单 ](https://my.oschina.net/weharmony/blog/5132725) **[  | 51](https://harmonyos.51cto.com/posts/7248)[ .c](https://blog.csdn.net/kuangyufei/article/details/118765692)[  .h](http://weharmonyos.com/blog/58_编译脚本篇.html)[ .o](https://my.oschina.net/weharmony)**

 * [v57.xx 鸿蒙内核源码分析(编译过程篇) | 简单案例窥视GCC编译全过程 ](https://my.oschina.net/weharmony/blog/5064209) **[  | 51](https://harmonyos.51cto.com/posts/5032)[ .c](https://blog.csdn.net/kuangyufei/article/details/117419679)[  .h](http://weharmonyos.com/blog/57_编译过程篇.html)[ .o](https://my.oschina.net/weharmony)**
  

--- a/fs/include/fs/driver.h
+++ b/fs/include/fs/driver.h
@@ -46,16 +46,35 @@
 extern "C" {
 #endif /* __cplusplus */
 #endif /* __cplusplus */
+/****************************************************************
+geometry应该翻译为几何数据，其实就是指的CHS(Cylinder、Head、Sector/Track)
+C-Cylinder柱面数表示硬盘每面盘片上有几条磁道，编号从0开始，最大为1023，表示有1024个磁道(用10个二进制位存储)
+H-Head磁头数表示硬盘总共有几个磁头，也就是几面盘片，编号从0开始，最大为255，表示有256个磁头(用8个二进制位存储)；
+S-Sector/Track扇区数表示每条磁道上有几个扇区，编号从1开始，最大为63，表示63个扇区(用6个二进制位存储)，
+	每个扇区512字节，它是硬盘的最小存储单位。
+	
+我们可以算一下：1024个柱面×63个扇区×256个磁头×512byte=8455716864byte。即通常的8.4GB(实际上应该是7.8GB左右)限制。
+实际上磁头数通常只用到255个(由汇编语言的寻址寄存器决定),即使把这3个字节按线性寻址，依然力不从心。
+当然现在的硬盘早就超过8.4GB了。
+从大到小
+H-Head（磁头）---》C-Cylinder（柱面数或者磁道数，即每个磁头的磁道数）------》S-Sector/Track（扇区，也就是每个磁道有多少扇区）--------》扇区大小（512bit）磁盘空间
+
+Geometry:
+Cylinder Number - 1020 (0-1024)
+Head Number - 16 (0-256)
+Sector Number - 63 (1-64)
+
+*****************************************************************/

 /* This structure provides information about the state of a block driver */

 struct geometry
 {
-  bool               geo_available;    /* true: The device is available */
-  bool               geo_mediachanged; /* true: The media has changed since last query */
-  bool               geo_writeenabled; /* true: It is okay to write to this device */
-  unsigned long long geo_nsectors;     /* Number of sectors on the device */
-  size_t             geo_sectorsize;   /* Size of one sector */
+  bool               geo_available;    /* true: The device is available *///设备是否有效
+  bool               geo_mediachanged; /* true: The media has changed since last query *///自上次查询以来媒体已更改
+  bool               geo_writeenabled; /* true: It is okay to write to this device *///是否可写
+  unsigned long long geo_nsectors;     /* Number of sectors on the device *///扇区的数量
+  size_t             geo_sectorsize;   /* Size of one sector *///扇区的大小
 };

 /* This structure is provided by block devices when they register with the
@@ -64,7 +83,8 @@ struct geometry
 * that it deals in struct Vnode vs. struct filep.
 */

-struct block_operations
+//块驱动操作方式,以 vnode方式操作
+struct block_operations //块操作接口类,块是文件系统层面的概念,块（Block）是文件系统存取数据的最小单位，一般大小是4KB
 {
  int     (*open)(struct Vnode *vnode);
  int     (*close)(struct Vnode *vnode);
@@ -77,11 +97,13 @@ struct block_operations
  int     (*unlink)(struct Vnode *vnode);
 };

+//该结构由文件系统提供，用于描述挂载点。请注意，此结构与 file_operations 的不同之处仅在于 open 方法的形式。
+//打开文件后，它可以作为 struct file_operations 或 struct mountpt_operations 访问
 struct drv_data
 {
-  const void *ops;
-  mode_t mode;
-  void *priv;
+  const void *ops;	//驱动程序 ( block_operations | file_operations_vfs | ... )
+  mode_t mode;		//RWE_RW_RW  0755
+  void *priv;		//私有数据域 (struct file)
 };

 /****************************************************************************

--- a/fs/include/fs/file.h
+++ b/fs/include/fs/file.h
@@ -99,39 +99,41 @@ struct filelist
 extern struct filelist tg_filelist;
 #endif

-/* This structure is provided by devices when they are registered with the
- * system.  It is used to call back to perform device specific operations.
- */
-
-struct file_operations_vfs
-{
-  /* The device driver open method differs from the mountpoint open method */
-
-  int     (*open)(struct file *filep);
+/* This structure is provided by devices when they are registered with the
+ * system.  It is used to call back to perform device specific operations.
+ */
+//该结构由设备在向系统注册时提供,它用于回调以执行特定于设备的操作。
+struct file_operations_vfs //vfs 文件操作接口,字符操作数据,各文件系统/设备需要实现这些接口
+{
+  /* The device driver open method differs from the mountpoint open method */
+  //设备驱动打开方式与挂载点打开方式不同
+  int     (*open)(struct file *filep);	//打开文件
+  //通过文件名打开文件，实际上是分成三步实现：首先，操作系统找到这个文件名对应的inode号码；
+  //其次，通过inode号码，获取inode信息；最后，根据inode信息，找到文件数据所在的block，读出数据。
+  /* The following methods must be identical in signature and position because
+   * the struct file_operations and struct mountp_operations are treated like
+   * unions.
+   *///@note_thinking 没明白
+  //以下方法的签名和位置必须相同，因为 struct file_operations 和 struct mountp_operations 被视为联合
+  int     (*close)(struct file *filep);	//关闭文件
+  ssize_t (*read)(struct file *filep, char *buffer, size_t buflen);	//读文件
+  ssize_t (*write)(struct file *filep, const char *buffer, size_t buflen);//写文件
+  off_t   (*seek)(struct file *filep, off_t offset, int whence);//寻找,检索 文件
+  int     (*ioctl)(struct file *filep, int cmd, unsigned long arg);//对文件的控制命令
+  int     (*mmap)(struct file* filep, struct VmMapRegion *region);//内存映射实现<文件/设备 - 线性区的映射>
+  /* The two structures need not be common after this point */
+
+#ifndef CONFIG_DISABLE_POLL
+  int     (*poll)(struct file *filep, poll_table *fds);	//轮询接口
+#endif
+  int     (*stat)(struct file *filep, struct stat* st);	//统计接口
+  int     (*fallocate)(struct file* filep, int mode, off_t offset, off_t len);
+  int     (*fallocate64)(struct file *filep, int mode, off64_t offset, off64_t len);
+  int     (*fsync)(struct file *filep);
+  ssize_t (*readpage)(struct file *filep, char *buffer, size_t buflen);
+  int     (*unlink)(struct Vnode *vnode);
+};

-  /* The following methods must be identical in signature and position because
-   * the struct file_operations and struct mountp_operations are treated like
-   * unions.
-   */
-
-  int     (*close)(struct file *filep);
-  ssize_t (*read)(struct file *filep, char *buffer, size_t buflen);
-  ssize_t (*write)(struct file *filep, const char *buffer, size_t buflen);
-  off_t   (*seek)(struct file *filep, off_t offset, int whence);
-  int     (*ioctl)(struct file *filep, int cmd, unsigned long arg);
-  int     (*mmap)(struct file* filep, struct VmMapRegion *region);
-  /* The two structures need not be common after this point */
-
-#ifndef CONFIG_DISABLE_POLL
-  int     (*poll)(struct file *filep, poll_table *fds);
-#endif
-  int     (*stat)(struct file *filep, struct stat* st);
-  int     (*fallocate)(struct file* filep, int mode, off_t offset, off_t len);
-  int     (*fallocate64)(struct file *filep, int mode, off64_t offset, off64_t len);
-  int     (*fsync)(struct file *filep);
-  ssize_t (*readpage)(struct file *filep, char *buffer, size_t buflen);
-  int     (*unlink)(struct Vnode *vnode);
-};

 /* file mapped in VMM pages */
 struct page_mapping {

--- a/fs/include/fs/fs.h
+++ b/fs/include/fs/fs.h
-../../../../../third_party/NuttX/include/nuttx/fs/fs.h
\ No newline at end of file
+../../../../../third_party/NuttX/include/nuttx/fs/fs.h
--- a/kernel/common/los_config.c
+++ b/kernel/common/los_config.c
@@ -239,12 +239,12 @@ LITE_OS_SEC_TEXT_INIT INT32 OsMain(VOID)
        return ret;
    }

-    ret = OsSystemProcessCreate();
+    ret = OsSystemProcessCreate();//创建系统进程 
    if (ret != LOS_OK) {
        return ret;
    }

-    ret = ArchInit();
+    ret = ArchInit();	//MMU架构初始化
    if (ret != LOS_OK) {
        return ret;
    }

--- a/zzz/git/push.sh
+++ b/zzz/git/push.sh
 git add -A
-git commit -m  ' 注解根文件系统制作过程  
+git commit -m  ' 文件系统几个关键结构体注释  
    百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码
    博客输出站点(国内):http://weharmonyos.com
    博客输出站点(国外):https://weharmony.github.io