From 1ef6c9e9f0f405d1fed403c13c57a233a484bed7 Mon Sep 17 00:00:00 2001 From: Jan Drzewiecki Date: Sun, 8 Aug 2010 17:47:08 +0200 Subject: [PATCH] cdrom_id: Fix detection of reblanked DVD+RW and DVD-RAM Once formatted, DVD+RW and DVD-RAM discs are always reported "complete" by the drive. Check the if the Volume Descriptor or Volume Descriptor Anchor sectors are empty, and if so, set the status to blank. If the disc is unformatted the blank status is maintained and no reads are issued. If the disc is formatted and read command fails, the status remains set to complete to avoid accidental blanking. Bug-Ubuntu: https://launchpad.net/bugs/581925 Signed-off-by: Martin Pitt --- extras/cdrom_id/cdrom_id.c | 105 +++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) diff --git a/extras/cdrom_id/cdrom_id.c b/extras/cdrom_id/cdrom_id.c index 2bea2e4b..9c4f6f31 100644 --- a/extras/cdrom_id/cdrom_id.c +++ b/extras/cdrom_id/cdrom_id.c @@ -532,6 +532,111 @@ static int cd_media_info(struct udev *udev, int fd) if (!cd_media_cd_rom) cd_media_state = media_status[header[2] & 3]; + /* DVD+RW discs once formatted are always "complete", DVD-RAM are + * "other" or "complete" if the disc is write protected; we need to + * check the contents if it is blank */ + if ((cd_media_dvd_plus_rw || cd_media_dvd_plus_rw_dl || cd_media_dvd_ram) && (header[2] & 3) > 1) { + unsigned char buffer[17 * 2048]; + unsigned char result, len; + int block, offset; + + if (cd_media_dvd_ram) { + /* a write protected dvd-ram may report "complete" status */ + + unsigned char dvdstruct[8]; + unsigned char format[12]; + + scsi_cmd_init(udev, &sc, dvdstruct, sizeof(dvdstruct)); + scsi_cmd_set(udev, &sc, 0, 0xAD); + scsi_cmd_set(udev, &sc, 7, 0xC0); + scsi_cmd_set(udev, &sc, 9, sizeof(dvdstruct)); + scsi_cmd_set(udev, &sc, 11, 0); + err = scsi_cmd_run(udev, &sc, fd, dvdstruct, sizeof(dvdstruct)); + if ((err != 0)) { + info_scsi_cmd_err(udev, "READ DVD STRUCTURE", err); + return -1; + } + if (dvdstruct[4] & 0x02) { + cd_media_state = media_status[2]; + info(udev, "write-protected DVD-RAM media inserted\n"); + goto determined; + } + + /* let's make sure we don't try to read unformatted media */ + scsi_cmd_init(udev, &sc, format, sizeof(format)); + scsi_cmd_set(udev, &sc, 0, 0x23); + scsi_cmd_set(udev, &sc, 8, sizeof(format)); + scsi_cmd_set(udev, &sc, 9, 0); + err = scsi_cmd_run(udev, &sc, fd, format, sizeof(format)); + if ((err != 0)) { + info_scsi_cmd_err(udev, "READ DVD FORMAT CAPACITIES", err); + return -1; + } + + len = format[3]; + if (len & 7 || len < 16) { + info(udev, "invalid format capacities length\n"); + return -1; + } + + switch(format[8] & 3) { + case 1: + info(udev, "unformatted DVD-RAM media inserted\n"); + /* This means that last format was interrupted + * or failed, blank dvd-ram discs are factory + * formatted. Take no action here as it takes + * quite a while to reformat a dvd-ram and it's + * not automatically started */ + goto determined; + + case 2: + info(udev, "formatted DVD-RAM media inserted\n"); + break; + + case 3: + cd_media = 0; //return no media + info(udev, "format capacities returned no media\n"); + return -1; + } + } + + /* Take a closer look at formatted media (unformatted DVD+RW + * has "blank" status", DVD-RAM was examined earlier) and check + * for ISO and UDF PVDs or a fs superblock presence and do it + * in one ioctl (we need just sectors 0 and 16) */ + scsi_cmd_init(udev, &sc, buffer, sizeof(buffer)); + scsi_cmd_set(udev, &sc, 0, 0x28); + scsi_cmd_set(udev, &sc, 5, 0); + scsi_cmd_set(udev, &sc, 8, 17); + scsi_cmd_set(udev, &sc, 9, 0); + err = scsi_cmd_run(udev, &sc, fd, buffer, sizeof(buffer)); + if ((err != 0)) { + info_scsi_cmd_err(udev, "READ FIRST 32 BLOCKS", err); + return -1; + } + + /* if any non-zero data is found in sector 16 (iso and udf) or + * eventually 0 (fat32 boot sector, ext2 superblock, etc), disc + * is assumed non-blank */ + result = 0; + + for (block = 32768; block >= 0 && !result; block -= 32768) { + offset = block; + while (offset < (block + 2048) && !result) { + result = buffer [offset]; + offset++; + } + } + + if (!result) { + cd_media_state = media_status[0]; + info(udev, "no data in blocks 0 or 16, assuming blank\n"); + } else { + info(udev, "data in blocks 0 or 16, assuming complete\n"); + } + } + +determined: if ((header[2] & 3) != 2) cd_media_session_next = header[10] << 8 | header[5]; cd_media_session_count = header[9] << 8 | header[4]; -- 2.39.5