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>
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 5cefe12..3df5442 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -409,6 +409,16 @@
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 @@
if (blk_special_request(rq)) {
rq->errors = 0;
- done = blk_rq_bytes(rq);
error = 0;
} else {
@@ -426,11 +435,6 @@
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;
}
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index d20704a..537b7c5 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -134,14 +134,17 @@
drive->pc = pc;
if (pc->retries > IDEFLOPPY_MAX_PC_RETRIES) {
+ unsigned int done = blk_rq_bytes(drive->hwif->rq);
+
if (!(pc->flags & PC_FLAG_SUPPRESS_ERROR))
ide_floppy_report_error(floppy, pc);
+
/* 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;
}
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 2b9a136..8226d52 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -622,6 +622,8 @@
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 @@
/* 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]);