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 #include <minix/bdev.h>
   9
  10 /* This function is called when the filesystem is umounted. It releases the
  11  * super block. */
  12 int release_v_pri(v_pri)
  13      register struct iso9660_vd_pri *v_pri;
  14 {
  15   /* Release the root dir record */
  16   release_dir_record(v_pri->dir_rec_root);
  17   v_pri->count = 0;
  18   return OK;
  19 }
  20
  21 /* This function fullfill the super block data structure using the information
  22  * contained in the stream buf. Such stream is physically read from the device
  23  * . */
  24 int create_v_pri(v_pri,buf,address)
  25      register struct iso9660_vd_pri *v_pri;
  26      register char* buf;
  27      register unsigned long address;
  28 {
  29   struct dir_record *dir;
  30
  31   v_pri->vd_type = buf[0];
  32   memcpy(v_pri->standard_id,buf + 1,sizeof(v_pri->standard_id));
  33   v_pri->vd_version = buf[6];
  34   memcpy(v_pri->system_id,buf + 8,sizeof(v_pri->system_id));
  35   memcpy(v_pri->volume_id,buf + 40,sizeof(v_pri->volume_id));
  36   memcpy(&v_pri->volume_space_size_l,buf + 80,
  37          sizeof(v_pri->volume_space_size_l));
  38   memcpy(&v_pri->volume_space_size_m,buf + 84,
  39          sizeof(v_pri->volume_space_size_m));
  40   memcpy(&v_pri->volume_set_size,buf + 120,sizeof(v_pri->volume_set_size));
  41   memcpy(&v_pri->volume_sequence_number,buf + 124,
  42          sizeof(v_pri->volume_sequence_number));
  43   memcpy(&v_pri->logical_block_size_l,buf + 128,
  44          sizeof(v_pri->logical_block_size_l));
  45   memcpy(&v_pri->logical_block_size_m,buf + 130,
  46          sizeof(v_pri->logical_block_size_m));
  47   memcpy(&v_pri->path_table_size_l,buf + 132,
  48          sizeof(v_pri->path_table_size_l));
  49   memcpy(&v_pri->path_table_size_m,buf + 136,
  50          sizeof(v_pri->path_table_size_m));
  51   memcpy(&v_pri->loc_l_occ_path_table,buf + 140,
  52          sizeof(v_pri->loc_l_occ_path_table));
  53   memcpy(&v_pri->loc_opt_l_occ_path_table,buf + 144,
  54          sizeof(v_pri->loc_opt_l_occ_path_table));
  55   memcpy(&v_pri->loc_m_occ_path_table, buf + 148,
  56          sizeof(v_pri->loc_m_occ_path_table));
  57   memcpy(&v_pri->loc_opt_m_occ_path_table,buf + 152,
  58          sizeof(v_pri->loc_opt_m_occ_path_table));
  59
  60   dir = get_free_dir_record();
  61   if (dir == NULL) return EINVAL;
  62   create_dir_record(dir,buf + 156,(u32_t)(address + 156));
  63   v_pri->dir_rec_root = dir;
  64   dir->d_ino_nr = ROOT_INO_NR;
  65
  66   memcpy(v_pri->volume_set_id,buf + 190,sizeof(v_pri->volume_set_id));
  67   memcpy(v_pri->publisher_id,buf + 318,sizeof(v_pri->publisher_id));
  68   memcpy(v_pri->data_preparer_id,buf + 446,sizeof(v_pri->data_preparer_id));
  69   memcpy(v_pri->application_id,buf + 574,sizeof(v_pri->application_id));
  70   memcpy(v_pri->copyright_file_id,buf + 702,sizeof(v_pri->copyright_file_id));
  71   memcpy(v_pri->abstract_file_id,buf + 739,sizeof(v_pri->abstract_file_id));
  72   memcpy(v_pri->bibl_file_id,buf + 776,sizeof(v_pri->bibl_file_id));
  73   memcpy(v_pri->volume_cre_date,buf + 813,sizeof(v_pri->volume_cre_date));
  74   memcpy(v_pri->volume_mod_date,buf + 830,sizeof(v_pri->volume_mod_date));
  75   memcpy(v_pri->volume_exp_date,buf + 847,sizeof(v_pri->volume_exp_date));
  76   memcpy(v_pri->volume_eff_date,buf + 864,sizeof(v_pri->volume_eff_date));
  77   v_pri->file_struct_ver = buf[881];
  78   return OK;
  79 }
  80
  81 /* This function reads from a ISO9660 filesystem (in the device dev) the
  82  * super block and saves it in v_pri. */
  83 int read_vds(
  84   register struct iso9660_vd_pri *v_pri,
  85   register dev_t dev
  86 )
  87 {
  88   u64_t offset;
  89   int vol_ok = FALSE;
  90   int r;
  91   static char sbbuf[ISO9660_MIN_BLOCK_SIZE];
  92   int i = 0;
  93
  94   offset = cvul64(ISO9660_SUPER_BLOCK_POSITION);
  95   while (!vol_ok && i++<MAX_ATTEMPTS) {
  96
  97     /* Read the sector of the super block. */
  98     r = bdev_read(dev, offset, sbbuf, ISO9660_MIN_BLOCK_SIZE, BDEV_NOFLAGS);
  99
 100     if (r != ISO9660_MIN_BLOCK_SIZE) /* Damaged sector or what? */
 101       continue;
 102
 103     if ((sbbuf[0] & BYTE) == VD_PRIMARY) {
 104       create_v_pri(v_pri,sbbuf,cv64ul(offset)); /* copy the buffer in the data structure. */
 105     }
 106
 107     if ((sbbuf[0] & BYTE) == VD_SET_TERM)
 108       /* I dont need to save anything about it */
 109       vol_ok = TRUE;
 110
 111     offset = add64u(offset,ISO9660_MIN_BLOCK_SIZE);
 112   }
 113
 114   if (vol_ok == FALSE)
 115     return EINVAL;              /* If no superblock was found... */
 116   else
 117     return OK;                  /* otherwise. */
 118 }