ide-atapi,tape,floppy: allow ->pc_callback() to change rq->data_len

Impact: allow residual count implementation in ->pc_callback()

rq->data_len has two duties - carrying the number of input bytes on
issue and carrying residual count back to the issuer on completion.
ide-atapi completion callback ->pc_callback() is the right place to do
this but currently ide-atapi depends on rq->data_len carrying the
original request size after calling ->pc_callback() to complete the pc
request.

This patch makes ide_pc_intr(), ide_tape_issue_pc() and
ide_floppy_issue_pc() cache length to complete before calling
->pc_callback() so that it can modify rq->data_len as necessary.

Note: As using rq->data_len for two purposes can make cases like this
      incorrect in subtle ways, future changes will introduce separate
      field for residual count.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Tejun Heo
2009-04-19 08:46:02 +09:00
committed by Jens Axboe
parent 08f370f0a2
commit eb6a61bb95
3 changed files with 18 additions and 8 deletions

View File

@@ -622,6 +622,8 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
(pc->flags & PC_FLAG_ABORT)) {
unsigned int done = blk_rq_bytes(drive->hwif->rq);
/*
* We will "abort" retrying a packet command in case legitimate
* error code was received (crossing a filemark, or end of the
@@ -641,9 +643,10 @@ static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
/* Giving up */
pc->error = IDE_DRV_ERROR_GENERAL;
}
drive->failed_pc = NULL;
drive->pc_callback(drive, 0);
ide_complete_rq(drive, -EIO, blk_rq_bytes(drive->hwif->rq));
ide_complete_rq(drive, -EIO, done);
return ide_stopped;
}
debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);