servers/mfs/inode.h

   1 /* Inode table.  This table holds inodes that are currently in use.  In some
   2  * cases they have been opened by an open() or creat() system call, in other
   3  * cases the file system itself needs the inode for one reason or another,
   4  * such as to search a directory for a path name.
   5  * The first part of the struct holds fields that are present on the
   6  * disk; the second part holds fields not present on the disk.
   7  * The disk inode part is also declared in "type.h" as 'd1_inode' for V1
   8  * file systems and 'd2_inode' for V2 file systems.
   9  */
  10
  11 #include "queue.h"
  12
  13 EXTERN struct inode {
  14   mode_t i_mode;                /* file type, protection, etc. */
  15   nlink_t i_nlinks;             /* how many links to this file */
  16   uid_t i_uid;                  /* user id of the file's owner */
  17   gid_t i_gid;                  /* group number */
  18   off_t i_size;                 /* current file size in bytes */
  19   time_t i_atime;               /* time of last access (V2 only) */
  20   time_t i_mtime;               /* when was file data last changed */
  21   time_t i_ctime;               /* when was inode itself changed (V2 only)*/
  22   zone_t i_zone[V2_NR_TZONES]; /* zone numbers for direct, ind, and dbl ind */
  23
  24   /* The following items are not present on the disk. */
  25   dev_t i_dev;                  /* which device is the inode on */
  26   ino_t i_num;                  /* inode number on its (minor) device */
  27   int i_count;                  /* # times inode used; 0 means slot is free */
  28   int i_ndzones;                /* # direct zones (Vx_NR_DZONES) */
  29   int i_nindirs;                /* # indirect zones per indirect block */
  30   struct super_block *i_sp;     /* pointer to super block for inode's device */
  31   char i_dirt;                  /* CLEAN or DIRTY */
  32   char i_pipe;                  /* set to I_PIPE if pipe */
  33
  34   char i_mount;                 /* this bit is set if file mounted on */
  35   short i_vmnt_ind;             /* index of the vmnt mounted on */
  36
  37   char i_seek;                  /* set on LSEEK, cleared on READ/WRITE */
  38   char i_update;                /* the ATIME, CTIME, and MTIME bits are here */
  39
  40   LIST_ENTRY(inode) i_hash;     /* hash list */
  41   TAILQ_ENTRY(inode) i_unused;  /* free and unused list */
  42
  43 } inode[NR_INODES];
  44
  45 /* list of unused/free inodes */
  46 EXTERN TAILQ_HEAD(unused_inodes_t, inode)  unused_inodes;
  47
  48 /* inode hashtable */
  49 EXTERN LIST_HEAD(inodelist, inode)         hash_inodes[INODE_HASH_SIZE];
  50
  51 EXTERN unsigned int inode_cache_hit;
  52 EXTERN unsigned int inode_cache_miss;
  53
  54 #define NIL_INODE (struct inode *) 0    /* indicates absence of inode slot */
  55
  56 /* Field values.  Note that CLEAN and DIRTY are defined in "const.h" */
  57 #define NO_PIPE            0    /* i_pipe is NO_PIPE if inode is not a pipe */
  58 #define I_PIPE             1    /* i_pipe is I_PIPE if inode is a pipe */
  59 #define NO_MOUNT           0    /* i_mount is NO_MOUNT if file not mounted on*/
  60 #define I_MOUNT            1    /* i_mount is I_MOUNT if file mounted on */
  61 #define NO_SEEK            0    /* i_seek = NO_SEEK if last op was not SEEK */
  62 #define ISEEK              1    /* i_seek = ISEEK if last op was SEEK */