Messages in this thread | | | Date | Wed, 4 Jun 2003 21:55:46 +0200 | From | Jens Axboe <> | Subject | Re: 2.5.69-70 ide-cd to guarantee fault-free CD/DVD burning experience? |
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On Wed, Jun 04 2003, Andy Polyakov wrote: > > ... accept ... patch which makes it possible to access the > > sense data returned by IDE CD/DVD units from user-land with SG_IO ioctl. > > The originally proposed modifications were indeed sufficient to get > DVD+RW units working, but apparently not DVD-RW ones:-( Note though > that [another] problem discussed here is not specific to DVD-RW > recordings. It's generic bug/deficiency. Once a packet commands is > terminated with an error condition the whole bio should be purged at > once and not only the first chunk as it's currently implemented. > > Attached patch should be considered as a "denoting" patch, not > "final." Well, because it was verified with single application, > growisofs of dvd+rw-tools, which uses mmap-ed, in other words > page-aligned, buffer(s). I mean I'm not 100% sure if hard_nr_sectors > is appropriate even for general case of 4-byte aligned buffers... > Then if-statement should probably be extended even to REQ_PC case... > > Cheers. A. > 8<--------8<--------8<--------8<--------8<--------8<--------8<-------- > --- ./drivers/ide/ide-cd.c.orig Tue Jun 3 12:21:56 2003 > +++ ./drivers/ide/ide-cd.c Wed Jun 4 16:14:41 2003 > @@ -657,6 +657,9 @@ > struct request *rq = HWGROUP(drive)->rq; > int nsectors = rq->hard_cur_sectors; > > + if (rq->flags&REQ_BLOCK_PC) > + nsectors = rq->hard_nr_sectors; /* purge it all ... */ > + else > if ((rq->flags & REQ_SENSE) && uptodate) { > /* > * For REQ_SENSE, "rq->buffer" points to the original failed
The *sector* values don't really work well for REQ_BLOCK_PC, it doesn't even have to be set at all. One solution would be to add more rq members (yuck), a nicer one is probably to make cdrom_end_request return ide_end_request ret value, and simply make the error locations kill the requests... It's not very nice, but should work.
-- Jens Axboe
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