minix/fs/isofs/utility.c

   1 #include "inc.h"
   2
   3 void free_extent(struct dir_extent *e) {
   4         if (e == NULL)
   5                 return;
   6
   7         free_extent(e->next);
   8         free(e);
   9 }
  10
  11 /* Free the contents of an inode dir entry, but not the pointer itself. */
  12 void free_inode_dir_entry(struct inode_dir_entry *e) {
  13         if (e == NULL)
  14                 return;
  15
  16         free(e->r_name);
  17         e->r_name = NULL;
  18 }
  19
  20 struct buf* read_extent_block(struct dir_extent *e, size_t block) {
  21         size_t block_id = get_extent_absolute_block_id(e, block);
  22         struct buf *bp;
  23
  24         if (block_id == 0 || block_id >= v_pri.volume_space_size_l)
  25                 return NULL;
  26
  27         if(lmfs_get_block(&bp, fs_dev, block_id, NORMAL) != OK)
  28                 return NULL;
  29
  30         return bp;
  31 }
  32
  33 size_t get_extent_absolute_block_id(struct dir_extent *e, size_t block) {
  34         size_t extent_offset = 0;
  35         block /= v_pri.logical_block_size_l;
  36
  37         if (e == NULL)
  38                 return 0;
  39
  40         /* Retrieve the extent on which the block lies. */
  41         while(block >= extent_offset + e->length) {
  42                 if (e->next == NULL)
  43                         return 0;
  44
  45                 extent_offset += e->length;
  46                 e = e->next;
  47         }
  48
  49         return e->location + block - extent_offset;
  50 }
  51
  52 time_t date7_to_time_t(const u8_t *date) {
  53         /*
  54          * This function converts from the ISO 9660 7-byte time format to a
  55          * time_t.
  56          */
  57         struct tm ltime;
  58         signed char time_zone = (signed char)date[6];
  59
  60         ltime.tm_year = date[0];
  61         ltime.tm_mon = date[1] - 1;
  62         ltime.tm_mday = date[2];
  63         ltime.tm_hour = date[3];
  64         ltime.tm_min = date[4];
  65         ltime.tm_sec = date[5];
  66         ltime.tm_isdst = 0;
  67
  68         /* Offset from Greenwich Mean Time */
  69         if (time_zone >= -52 && time_zone <= 52)
  70                 ltime.tm_hour += time_zone;
  71
  72         return mktime(&ltime);
  73 }
  74
  75 void* alloc_mem(size_t s) {
  76         void *ptr = calloc(1, s);
  77         assert(ptr != NULL);
  78
  79         return ptr;
  80 }