Re: 2.6.27-rc1 (2fca5c): libata: kernel cant boot

[Jens Axboe <jens.axboe@oracle.com>]

On Fri, Oct 24 2008, Elias Oltmanns wrote:
> Jens Axboe <jens.axboe@oracle.com> wrote:
> > From e598055dde1951c47c8b3522616f6ebff0ed9847 Mon Sep 17 00:00:00 2001
> > From: Jens Axboe <jens.axboe@oracle.com>
> > Date: Fri, 24 Oct 2008 09:22:42 +0200
> > Subject: [PATCH] libata: fix bug with non-ncq devices
> >
> > The recent commit 201f1b98822078c808b5e2d379a6ddbfc0a06ee1 to enable
> 
> Wouldn't that be commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e?

Yes that is correct, the other commit is actually a private one in my
tree for other libata changes. Updated patch below, thanks for checking!

>From e598055dde1951c47c8b3522616f6ebff0ed9847 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Fri, 24 Oct 2008 09:22:42 +0200
Subject: [PATCH] libata: fix bug with non-ncq devices

The recent commit 2fca5ccf97d2c28bcfce44f5b07d85e74e3cd18e 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>
---
 drivers/ata/libata-scsi.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d5b9b72..4b95c43 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -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;
-- 
1.6.0.2.588.g3102


-- 
Jens Axboe