From f7e7868b4743f1cc5e59e6e0ddd3ccf9cfe53a1b Mon Sep 17 00:00:00 2001 From: Georgios Toptsidis Date: Fri, 25 Sep 2015 10:50:08 +0300 Subject: [PATCH] cdrom: Random writing support for BD-RE media Recently, i bought a blu-ray writer and noticed that while cdrecord worked perfectly, random writing didn't work on rewritable bd-re media. For example, dd if=/dev/zero of=/dev/sr0 bs=32768 count=2 gave the usual "read-only file system" message. After checking if the problem lies with my burner or firmware, i grep-ed the kernel source for EROFS. One of the results was in the cdrom driver. I tried to follow the function chain and ended in the cdrom_is_dvd_rw function where writing is permitted only for DVD-RAM and DVD+RW media. I added a new case label for 0x43 which is the profile name of BD-RE and now it works correctly for BD-RE too. Maybe there is a better way of implementing this, like a new function checking for blu-ray support and called from cdrom_open_write like it happens for mrw and dvdram media, but adding the case label worked. Thank you for your time. Signed-off-by: Jens Axboe --- drivers/cdrom/cdrom.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 5d28a45d2960..c206ccda899b 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -885,6 +885,7 @@ static int cdrom_is_dvd_rw(struct cdrom_device_info *cdi) switch (cdi->mmc3_profile) { case 0x12: /* DVD-RAM */ case 0x1A: /* DVD+RW */ + case 0x43: /* BD-RE */ return 0; default: return 1; -- 2.20.1