New TOC layout with volume id and sbsector=, new option -rom_toc_scan

xorriso/xorriso.1

@@ -144,11 +144,13 @@ There are two families of media in the MMC standard:
 .br
 \fBMulti-session\fR media are CD-R, CD-RW, DVD-R, DVD+R, DVD+R/DL, and
 unformatted DVD-RW. These media provide a table of content which
-describes their existing sessions.
+describes their existing sessions. See option \fB-toc\fR.
 .br
 \fBOverwriteable\fR media are DVD-RAM, DVD+RW, and formatted DVD-RW.
 They allow random write access but do not provide information about their
-session history.
+session history. If they contain one or more ISO 9660 sessions and if the
+first session was written by modern xorriso, then a table of content can
+be emulated. Else only a single overall session will be visible.
 .br
 DVD-RW media can be formatted by -format full. 
 They can be made unformatted by -blank deformat.
@@ -183,6 +185,10 @@ written with option -close on. If the drive is incapable of writing it will
 probably show any media as closed CD-ROM resp. DVD-ROM.
 .br
 Overwriteable media assume this state only in such read-only drives.
+.br
+\fBRead-only\fR drives may or may not show session histories of multi-session
+media. Often only the first and the last session are visible. Sometimes
+not even that. Option -rom_toc_scan might or might not help in such cases.
 .SS
 .B Creating, Growing, Modifying:
 .br
@@ -431,6 +437,21 @@ apply. See above paragraph "Libburn drives".
 An empty address string "" gives up the current output drive
 without aquiring a new one. No writing is possible without an output drive.
 .TP
+\fB\-rom_toc_scan\fR "on"|"off"
+Read-only drives do not tell the actual media type but show any media as
+ROM (e.g. as DVD-ROM). The session history of MMC multi-session media might
+be truncated to first and last session or even be completely false.
+The eventual emulated history of overwriteable media is not affected by this.
+.br
+To have in case of failure a chance of getting the session history and
+especially the address of the last session, there is a scan for ISO 9660
+filesystem headers which might help but also might yield worse results
+than the drive's table of content. At its end it can cause read attempts
+to invalid addresses and thus ugly drive behavior.
+.br
+To be in effect, -rom_toc_scan has to be enabled by "on" before the -*dev
+command which aquires drive and media.
+.TP
 \fB\-ban_stdio_write\fR
 Allow for writing only the usage of MMC optical drives. Disallow
 to write the result into files of nearly arbitrary type.
@@ -1311,14 +1332,20 @@ use -rollback to revoke the whole session.
 .TP
 \fB\-toc\fR
 .br
-Show media specific table of content. This is the media
-structure, not the ISO image directory tree. In case of
-overwriteable media holding a valid ISO image, a single
-session gets fabricated from the ISO image size info.
+Show media specific table of content. This is the media session history,
+not the ISO image directory tree.
+.br
+In case of overwriteable media holding a valid ISO image, a single session
+gets fabricated from the ISO image size info. If the first session on the
+overwriteable media was written by modern xorriso then a complete session
+history can be emulated.
 .br
 A drive which is incapable of writing may show any media as CD-ROM or DVD-ROM
 with only one or two sessions on it. The last of these sessions is supposed
 to be the most recent real session then.
+.br
+Some read-only drives and media show no usable session history at all.
+Eventually option -rom_toc_scan might help.
 .TP
 \fB\-devices\fR
 Show list of available MMC drives with the addresses of
@@ -1933,8 +1960,9 @@ on media and if the expected changes are much smaller than the full backup.
 An update run will probably save no time but last longer than a full backup.
 .br 
 With \fBmount\fR option \fB"sbsector="\fR it is possible to access the session
-trees which represent the older backup versions. Multi-session media can tell
-the sbsector by xorriso option -toc, as "data   lba:". For other media one
+trees which represent the older backup versions. Multi-session media and
+overwriteable media iwritten by modern xorriso can tell
+the sbsector by xorriso option -toc. For other media one
 may set before writing a suitable path for xorriso option -session_log where
 the sbsector number gets recorded as the second word in each line.
 .br

xorriso/xorriso.c

@@ -2695,6 +2695,7 @@ int Xorriso_new(struct XorrisO ** xorriso,char *progname, int flag)
  m->global_file_mode= 0444;
  m->do_overwrite= 2;
  m->do_reassure= 0;
+ m->toc_emulation_flag= 0;
  m->indev[0]= 0;
  m->in_drive_handle= NULL;
  m->in_volset_handle= NULL;
@@ -4034,6 +4035,12 @@ int Xorriso_status(struct XorrisO *xorriso, char *filter, FILE *fp, int flag)
 
 #endif /* Xorriso_with_readlinE */
 
+ is_default= !(xorriso->toc_emulation_flag&1);
+ sprintf(line,"-rom_toc_scan %s\n",
+         xorriso->toc_emulation_flag&1 ? "on" : "off");
+ if(!(is_default && no_defaults))
+   Xorriso_status_result(xorriso,filter,fp,flag&2);
+
  if(strcmp(xorriso->indev,xorriso->outdev)==0) { 
    sprintf(line,"-dev %s\n", Text_shellsafe(xorriso->indev,sfe,0));
    Xorriso_status_result(xorriso,filter,fp,flag&2);
@@ -8977,6 +8984,8 @@ int Xorriso_option_help(struct XorrisO *xorriso, int flag)
 "                 growing to modifying.",
 "  -outdev address",
 "                 Set output drive and switch from growing to modifying.",
+"  -rom_toc_scan \"on\"|\"off\"",
+"                 Enable scanning for ISO sessions on read-only drives/media.",
 "  -ban_stdio_write",
 "                 Allow for writing only the usage of optical drives.",
 "  -blank \"fast\"|\"all\"|\"deformat\"|\"deformat_quickest\"",
@@ -10365,6 +10374,22 @@ int Xorriso_option_rollback(struct XorrisO *xorriso, int flag)
 }
 
 
+/* Option -rom_toc_scan */
+int Xorriso_option_rom_toc_scan(struct XorrisO *xorriso, char *mode, int flag)
+{
+ if(strcmp(mode, "off")==0)
+   xorriso->toc_emulation_flag= 0;
+ else if(strcmp(mode, "on")==0)
+   xorriso->toc_emulation_flag= 1;
+ else {
+   sprintf(xorriso->info_text, "-rom_toc_scan: unknown mode '%s'", mode);
+   Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "FAILURE", 0);
+   return(0);
+ }
+ return(1);
+}
+
+
 /* Option -session_log */
 int Xorriso_option_session_log(struct XorrisO *xorriso, char *path, int flag)
 {
@@ -11149,6 +11174,10 @@ next_command:;
    if(end_ret!=2)
      {ret= 3; goto ex;}
 
+ } else if(strcmp(cmd,"rom_toc_scan")==0) {
+   (*idx)++;
+   Xorriso_option_rom_toc_scan(xorriso, arg1, 0);
+
  } else if(strcmp(cmd,"session_log")==0) {
    (*idx)++;
    ret= Xorriso_option_session_log(xorriso, arg1, 0);

xorriso/xorriso.h

@@ -421,6 +421,10 @@ int Xorriso_option_rmi(struct XorrisO *xorriso, int argc, char **argv,
 */
 int Xorriso_option_rollback(struct XorrisO *xorriso, int flag);
 
+/* Option -rom_toc_scan */
+int Xorriso_option_rom_toc_scan(struct XorrisO *xorriso, char *mode,
+                                int flag);
+
 /* Option -session_log */
 int Xorriso_option_session_log(struct XorrisO *xorriso, char *path, int flag);
 

xorriso/xorriso_eng.html

@@ -251,6 +251,13 @@ old ISO copies to match the new disk trees. On CD-R[W], DVD-R[W] and DVD+R
 older states can be retrieved by help of mount option "session=".
 So this constitutes true incremental backup.
 On overwriteable media only the newest state is accessible.
+
+<!--
+Older states can be retrieved by help of mount option "session=" from CD-R[W],
+by help of "sbsector=" from other media.
+So this constitutes true incremental backup.
+-->
+
 </DT>
 <DD>$<KBD>&nbsp;xorriso -dev /dev/sr0 \</KBD></DD>
 <DD><KBD>&nbsp;&nbsp; -update_r /home/thomas/open_source_projects /open_source_projects \</KBD></DD>

xorriso/xorriso_private.h

@@ -112,6 +112,10 @@ struct XorrisO { /* the global context of xorriso */
 
  /* >>> put libburn/isoburn aspects here */
 
+ int toc_emulation_flag; /* bit0= bit3 for isoburn_drive_aquire()
+                                  scan -ROM profiles for ISO sessions
+                         */
+
  char indev[SfileadrL];
  void *in_drive_handle;  /* interpreted only by xorrisoburn.c */
  void *in_volset_handle; /* interpreted only by xorrisoburn.c */

xorriso/xorriso_timestamp.h

@@ -1 +1 @@
-#define Xorriso_timestamP "2008.05.08.141054"
+#define Xorriso_timestamP "2008.05.08.141920"

xorriso/xorrisoburn.c

@@ -499,7 +499,7 @@ int Xorriso_create_empty_iso(struct XorrisO *xorriso, int flag)
 */
 int Xorriso_aquire_drive(struct XorrisO *xorriso, char *adr, int flag)
 {
- int ret, hret, not_writeable= 0, has_what;
+ int ret, hret, not_writeable= 0, has_what, aquire_flag;
  uint32_t size;
  struct burn_drive_info *dinfo= NULL, *out_dinfo, *in_dinfo;
  struct burn_drive *drive, *out_drive, *in_drive;
@@ -550,7 +550,8 @@ int Xorriso_aquire_drive(struct XorrisO *xorriso, char *adr, int flag)
  }
 
  if(dinfo==NULL) {
-   ret= isoburn_drive_aquire(&dinfo, libburn_adr, 1|((flag&(8|4))>>1));
+   aquire_flag= 1 | ((flag&(8|4))>>1) | ((xorriso->toc_emulation_flag&1)<<3);
+   ret= isoburn_drive_aquire(&dinfo, libburn_adr, aquire_flag);
    Xorriso_process_msg_queues(xorriso,0);
    if(ret<=0) {
      sprintf(xorriso->info_text,"Cannot aquire drive '%s'", adr); 
@@ -2336,7 +2337,7 @@ int Xorriso_toc(struct XorrisO *xorriso, int flag)
 #ifdef Xorriso_new_toc_formaT
  
  sprintf(respt, "TOC layout   : %3s , %9s , %10s , %s\n",
-         "Idx", "Start LBA", "Size", "Volume Id");
+         "Idx", "sbsector=", "Size", "Volume Id");
  if(!(flag&1))
    Xorriso_result(xorriso,0);
 #endif
@@ -2359,7 +2360,10 @@ int Xorriso_toc(struct XorrisO *xorriso, int flag)
 
 #ifdef Xorriso_new_toc_formaT
 
-   ret= isoburn_read_iso_head(drive, 0, &image_blocks, volume_id, 1);
+   if(flag&1)
+     ret= 0;
+   else
+     ret= isoburn_read_iso_head(drive, 0, &image_blocks, volume_id, 1);
    if(ret>0) {
      sprintf(respt, "ISO session  : %3d , %9d , %9ds , %s\n",
              1, 0, image_blocks, volume_id);
@@ -2374,7 +2378,6 @@ int Xorriso_toc(struct XorrisO *xorriso, int flag)
    sprintf(respt+strlen(respt), "track    %2d %s  lba: %8d\n", 1, "data ", 0);
    if(!(flag&1))
      Xorriso_result(xorriso,0);
-   last_track_start= lba;
    sprintf(respt, "Media content: session %2d  ", 1);
    sprintf(respt+strlen(respt), "leadout            lba: %9d\n", nwa);
 
@@ -2382,6 +2385,7 @@ int Xorriso_toc(struct XorrisO *xorriso, int flag)
 
    if(!(flag&1))
      Xorriso_result(xorriso,0);
+   last_track_start= lba;
    num_payload= num_data= last_track_size= nwa;
    num_sessions= 1;
  } else {
@@ -2445,7 +2449,10 @@ int Xorriso_toc(struct XorrisO *xorriso, int flag)
 
 #ifdef Xorriso_new_toc_formaT
 
-       ret= isoburn_read_iso_head(drive, lba, &image_blocks, volume_id, 1);
+       if(flag&1)
+         ret= 0;
+       else
+         ret= isoburn_read_iso_head(drive, lba, &image_blocks, volume_id, 1);
        if(ret>0 && track_no==num_tracks-1) {
          sprintf(respt, "ISO session  : %3d , %9d , %9ds , %s\n",
                  session_no+1, lba, image_blocks , volume_id);