code:struct inode - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

5600 /*

5601  * Inode structure as it appears on

5602  * the disk. Not used by the system,

5603  * but by things like check, df, dump.

5604  */

5605 struct inode

5606 {

5607     int i_mode;

5608     char i_nlink;

5609     char i_uid;

5610     char i_gid;

5611     char i_size0;

5612     char *i_size1;

5613     int i_addr[8];

5614     int i_atime[2];

5615     int i_mtime[2];

5616 };

5617 /* ------------------------- */

5650 /* The I node is the focus of all

5651  * file activity in unix. There is a unique

5652  * inode allocated for each active file,

5653  * each current directory, each mounted-on

5654  * file, text file, and the root. An inode is ’named’

5655  * by its dev/inumber pair. (iget/iget.c)

5656  * Data, from mode on, is read in

5657  * from permanent inode on volume.

5658  */

5659 struct inode

5660 {

5661     char i_flag;

• 标志位
  • IACC : 该INODE已被存取
  • IUPD : 该INODE已被修改

5662     char i_count; /* reference count */

• 系统 file结构 引用该INODE的引用数
• 参考 文件系统之内存打开文件结构

5663     int i_dev; /* device where inode resides */

• 对应的设备的设备号

5664     int i_number; /* i number, 1-to-1 with device

5665                     address */

• 该INODE在设备INODE区的序号，从1开始

5666     int i_mode;

• 该文件/目录的模式标志
• 关于模式常量，参考inode.h
• 参看 文件系统之inode类型

5667     char i_nlink; /* directory entries */

• 该INODE块的勾连数
• 参看文件系统之勾连

5668     char i_uid; /* owner */

• 该文件/目录的拥有者

5669     char i_gid; /* group of owner */

• 该文件/目录的拥有组

5670     char i_size0; /* most significant of size */

5671     char *i_size1; /* least sig */

• 该文件/目录的大小

5672     int i_addr[8];/* device addresses constituting file */

• 该文件/目录的磁盘块索引数组，参见文件系统之文件索引结构

5673     int i_lastr; /* last logical block read (for

5674                     read-ahead) */

• 最后读取的块号
• 用于预读(breada)判断

5675 } inode[NINODE];

5676 /* ------------------------- */

• 文件系统

• code:unlink
• code:chdir
• code:chmod
• code:chown
• code:smdate
• code:core
• code:open1
• code:link
• code:mknod
• code:stat
• code:stat1
• code:sumount
• code:getmdev
• code:readi
• code:writei
• code:bmap
• code:closef
• code:closei
• code:openi
• code:owner
• code:update
• code:iget
• code:iput
• code:maknode
• code:namei
• code:pipe
• code:readp
• code:writep
• code:plock
• code:prele
• code:sgtty