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| author | Tejun Heo <tj@kernel.org> | 2009-04-19 08:46:02 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-04-19 08:46:02 +0900 |
| commit | 21d9c5d227593d15630ae83a336d1519653e9b8a (patch) | |
| tree | 00cae13e13a418768354b92bf5e48c2b85625a6d /drivers/ide/ide-atapi.c | |
| parent | 35ab8d3251833e4052aa64b09b08195e949518c7 (diff) | |
| download | linux-21d9c5d227593d15630ae83a336d1519653e9b8a.tar.bz2 | |
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 <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/ide/ide-atapi.c')
| -rw-r--r-- | drivers/ide/ide-atapi.c | 6 |
1 files changed, 1 insertions, 5 deletions
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); |