libata: fix bug with non-ncq devices

The recent commit 2fca5ccf97 ("libata:
switch to using block layer tagging support") to enable support for
block layer tagging in libata was broken for non-NCQ devices

The block layer initializes the tag field to -1 to detect invalid uses
of a tag, and if the libata devices does NOT support NCQ, we just used
that field to index the internal command list.  So we need to check for
-1 first and only use the tag field if it's valid.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Tested-by: Dave Young <hidave.darkstar@gmail.com>
Tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jens Axboe 2008-10-24 09:22:42 +02:00 committed by Linus Torvalds
parent 57f8f7b60d
commit e013e13bf6

View File

@ -708,7 +708,11 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
{
struct ata_queued_cmd *qc;
qc = ata_qc_new_init(dev, cmd->request->tag);
if (cmd->request->tag != -1)
qc = ata_qc_new_init(dev, cmd->request->tag);
else
qc = ata_qc_new_init(dev, 0);
if (qc) {
qc->scsicmd = cmd;
qc->scsidone = done;