From b3071d190d6757b14af002a9d79832f12de61bce Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 19 Apr 2009 08:46:02 +0900 Subject: 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 Cc: Jens Axboe --- drivers/ide/ide-atapi.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'drivers/ide/ide-atapi.c') diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index 5cefe12f562..3df5442de71 100644 --- a/drivers/ide/ide-atapi.c +++ b/drivers/ide/ide-atapi.c @@ -409,6 +409,16 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive) if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0) dsc = 1; + /* + * ->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); + /* Command finished - Call the callback function */ uptodate = drive->pc_callback(drive, dsc); @@ -417,7 +427,6 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive) if (blk_special_request(rq)) { rq->errors = 0; - done = blk_rq_bytes(rq); error = 0; } else { @@ -426,11 +435,6 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive) rq->errors = -EIO; } - if (drive->media == ide_tape && !rq->bio) - done = ide_rq_bytes(rq); /* FIXME */ - else - done = blk_rq_bytes(rq); - error = uptodate ? 0 : -EIO; } -- cgit v1.2.3