On Wed, 2008-02-27 at 03:24 +0100, Mike Galbraith wrote:
Hm. After rummaging around some more in both kernel and userland, I
think this patchlet is not only functional, but (random accident)
technically correct. What the heck, let's see if it flies...
snippet from userland:
/*
* Return the residual DMA count for last command.
* If this count is < 0, then a DMA overrun occured.
*/
EXPORT int
scg_getresid(scgp)
SCSI *scgp;
{
return (scgp->scmd->resid);
}
This function is used all over the place in cdrecord to determine
transfer size.
(patchlet takes wing, and... goes splat?)
Fix CD burning regression introduced by
6b00769fe1502b4ad97bb327ef7ac971b208bfb5. raw_data_len must be updated
to reflect residual data upon IO completion because it is used by
blk_complete_sghdr_rq() to set hdr->resid which eventually becomes
visible to userland.
Signed-off-by: Mike Galbraith <efault@gmx.de>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ba21d97..7a6f784 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -871,7 +871,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd,
unsigned int good_bytes)
scsi_end_bidi_request(cmd);
return;
}
- req->data_len = scsi_get_resid(cmd);
+ req->data_len = req->raw_data_len = scsi_get_resid(cmd);
}
BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet
*/
-Mike
--
