Messages in this thread | | | Date | Tue, 06 Aug 2002 12:47:00 +0200 | From | Marcin Dalecki <> | Subject | Re: [PATCH] 2.5.30 IDE 113 |
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Uz.ytkownik Jens Axboe napisa?: > On Tue, Aug 06 2002, Petr Vandrovec wrote: > >>>After all ide_raw_taskfile only gets used for REQ_SPECIAL request >>>types. This does *not* contain normal data request from block IO. >>>As of master slave issues - well we have the data pre allocated per >>>device not per channel! If q->request_fn would properly return the >>>error count instead of void, we could even get rid ot the >>>checking for rq->errors after finishment... But well that's >>>entierly different story. >> >>For example do_cmd_ioctl() invokes ide_raw_taskfile, without any locking. >>Two programs, both issuing HDIO_DRIVE_CMD at same time, will compete >>over one drive->srequest struct: you'll get same drive->srequest structure >>submitted twice to blk_insert_request (hm, Jens, will this trigger >>BUG, or will this just damage request list?). > > > Just silently damage request list. We _could_ easily add code to detect > this, but it's not been a problem in the past so not worth looking for. > > AFAICS, Petr is completely right wrt this race.
For the ioctl case yes. But:
1. We already look for blk_queue_empty there. 2. We have just to deal properly with the queue plugging there to close it up. 3. I will just add spin locking on ide_lock to maintain that no two ioctl can overlapp at all.
OK?
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