servers/iso9660fs/super.c

   1 /* Functions to manage the superblock of the filesystem. These functions are
   2  * are called at the beginning and at the end of the server. */
   3
   4 #include "inc.h"
   5 #include <string.h>
   6 #include <minix/com.h>
   7 #include <minix/u64.h>
   8
   9 /* This function is called when the filesystem is umounted. It releases the
  10  * super block. */
  11 PUBLIC int release_v_pri(v_pri)
  12      register struct iso9660_vd_pri *v_pri;
  13 {
  14   /* Release the root dir record */
  15   release_dir_record(v_pri->dir_rec_root);
  16   v_pri->count = 0;
  17   return OK;
  18 }
  19
  20 /* This function fullfill the super block data structure using the information
  21  * contained in the stream buf. Such stream is physically read from the device
  22  * . */
  23 PUBLIC int create_v_pri(v_pri,buf,address)
  24      register struct iso9660_vd_pri *v_pri;
  25      register char* buf;
  26      register unsigned long address;
  27 {
  28   struct dir_record *dir;
  29
  30   v_pri->vd_type = buf[0];
  31   memcpy(v_pri->standard_id,buf + 1,sizeof(v_pri->standard_id));
  32   v_pri->vd_version = buf[6];
  33   memcpy(v_pri->system_id,buf + 8,sizeof(v_pri->system_id));
  34   memcpy(v_pri->volume_id,buf + 40,sizeof(v_pri->volume_id));
  35   memcpy(&v_pri->volume_space_size_l,buf + 80,
  36          sizeof(v_pri->volume_space_size_l));
  37   memcpy(&v_pri->volume_space_size_m,buf + 84,
  38          sizeof(v_pri->volume_space_size_m));
  39   memcpy(&v_pri->volume_set_size,buf + 120,sizeof(v_pri->volume_set_size));
  40   memcpy(&v_pri->volume_sequence_number,buf + 124,
  41          sizeof(v_pri->volume_sequence_number));
  42   memcpy(&v_pri->logical_block_size_l,buf + 128,
  43          sizeof(v_pri->logical_block_size_l));
  44   memcpy(&v_pri->logical_block_size_m,buf + 130,
  45          sizeof(v_pri->logical_block_size_m));
  46   memcpy(&v_pri->path_table_size_l,buf + 132,
  47          sizeof(v_pri->path_table_size_l));
  48   memcpy(&v_pri->path_table_size_m,buf + 136,
  49          sizeof(v_pri->path_table_size_m));
  50   memcpy(&v_pri->loc_l_occ_path_table,buf + 140,
  51          sizeof(v_pri->loc_l_occ_path_table));
  52   memcpy(&v_pri->loc_opt_l_occ_path_table,buf + 144,
  53          sizeof(v_pri->loc_opt_l_occ_path_table));
  54   memcpy(&v_pri->loc_m_occ_path_table, buf + 148,
  55          sizeof(v_pri->loc_m_occ_path_table));
  56   memcpy(&v_pri->loc_opt_m_occ_path_table,buf + 152,
  57          sizeof(v_pri->loc_opt_m_occ_path_table));
  58
  59   dir = get_free_dir_record();
  60   if (dir == NULL) return EINVAL;
  61   create_dir_record(dir,buf + 156,(u32_t)(address + 156));
  62   v_pri->dir_rec_root = dir;
  63   dir->d_ino_nr = ROOT_INO_NR;
  64
  65   memcpy(v_pri->volume_set_id,buf + 190,sizeof(v_pri->volume_set_id));
  66   memcpy(v_pri->publisher_id,buf + 318,sizeof(v_pri->publisher_id));
  67   memcpy(v_pri->data_preparer_id,buf + 446,sizeof(v_pri->data_preparer_id));
  68   memcpy(v_pri->application_id,buf + 574,sizeof(v_pri->application_id));
  69   memcpy(v_pri->copyright_file_id,buf + 702,sizeof(v_pri->copyright_file_id));
  70   memcpy(v_pri->abstract_file_id,buf + 739,sizeof(v_pri->abstract_file_id));
  71   memcpy(v_pri->bibl_file_id,buf + 776,sizeof(v_pri->bibl_file_id));
  72   memcpy(v_pri->volume_cre_date,buf + 813,sizeof(v_pri->volume_cre_date));
  73   memcpy(v_pri->volume_mod_date,buf + 830,sizeof(v_pri->volume_mod_date));
  74   memcpy(v_pri->volume_exp_date,buf + 847,sizeof(v_pri->volume_exp_date));
  75   memcpy(v_pri->volume_eff_date,buf + 864,sizeof(v_pri->volume_eff_date));
  76   v_pri->file_struct_ver = buf[881];
  77   return OK;
  78 }
  79
  80 /* This function reads from a ISO9660 filesystem (in the device dev) the
  81  * super block and saves it in v_pri. */
  82 PUBLIC int read_vds(v_pri,dev)
  83      register struct iso9660_vd_pri *v_pri;
  84      register dev_t dev;
  85 {
  86   u64_t offset;
  87   int vol_ok = FALSE;
  88   int r;
  89   static char sbbuf[ISO9660_MIN_BLOCK_SIZE];
  90   int i = 0;
  91
  92   offset = cvul64(ISO9660_SUPER_BLOCK_POSITION);
  93   while (!vol_ok && i++<MAX_ATTEMPTS) {
  94
  95     /* Read the sector of the super block. */
  96     r = block_dev_io(MFS_DEV_READ, dev, SELF_E, sbbuf, offset, ISO9660_MIN_BLOCK_SIZE, 0);
  97
  98     if (r != ISO9660_MIN_BLOCK_SIZE) /* Damaged sector or what? */
  99       continue;
 100
 101     if ((sbbuf[0] & BYTE) == VD_PRIMARY) {
 102       create_v_pri(v_pri,sbbuf,cv64ul(offset)); /* copy the buffer in the data structure. */
 103     }
 104
 105     if ((sbbuf[0] & BYTE) == VD_SET_TERM)
 106       /* I dont need to save anything about it */
 107       vol_ok = TRUE;
 108
 109     offset = add64u(offset,ISO9660_MIN_BLOCK_SIZE);
 110   }
 111
 112   if (vol_ok == FALSE)
 113     return EINVAL;              /* If no superblock was found... */
 114   else
 115     return OK;                  /* otherwise. */
 116 }