From e998f30b45efb99a3c3ce7b5483f76317a17abed Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 08:46:02 +0900 Subject: ide-tape: use standard data transfer mechanism Impact: use standard way to transfer data ide-tape uses rq in an interesting way. For r/w requests, rq->special is used to carry a private buffer management structure idetape_bh and rq->nr_sectors and current_nr_sectors are initialized to the number of idetape blocks which isn't necessary 512 bytes. Also, rq->current_nr_sectors is used to report back the residual count in units of idetape blocks. This peculiarity taxes both block layer and ide. ide-atapi has different paths and hooks to accomodate it and what a rq means becomes quite confusing and making changes at the block layer becomes quite difficult and error-prone. This patch makes ide-tape use bio instead. With the previous patch, ide-tape currently is using single contiguos buffer so replacing it isn't difficult. Data buffer is mapped into bio using blk_rq_map_kern() in idetape_queue_rw_tail(). idetape_io_buffers() and idetape_update_buffers() are dropped and pc->bh is set to null to tell ide-atapi to use standard data transfer mechanism and idetape_bh byte counts are updated by the issuer on completion using the residual count. This change also nicely removes the FIXME in ide_pc_intr() where ide-tape rqs need to be completed using ide_rq_bytes() instead of blk_rq_bytes() (although this didn't really matter as the request didn't have bio). Signed-off-by: Tejun Heo Cc: Jens Axboe --- drivers/ide/ide-atapi.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/ide/ide-atapi.c') diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index 3df5442de710..b9dd4503cbc7 100644 --- a/drivers/ide/ide-atapi.c +++ b/drivers/ide/ide-atapi.c @@ -413,11 +413,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive) * ->pc_callback() might change rq->data_len for * residual count, cache total length. */ - if (!blk_special_request(rq) && - (drive->media == ide_tape && !rq->bio)) - done = ide_rq_bytes(rq); /* FIXME */ - else - done = blk_rq_bytes(rq); + done = blk_rq_bytes(rq); /* Command finished - Call the callback function */ uptodate = drive->pc_callback(drive, dsc); -- cgit