Patch "libata: drop WARN from protocol error in ata_sff_qc_issue()" has been added to the 4.9-stable tree

Patch "libata: drop WARN from protocol error in ata_sff_qc_issue()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    libata: drop WARN from protocol error in ata_sff_qc_issue()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     libata-drop-warn-from-protocol-error-in-ata_sff_qc_issue.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Dec 12 13:26:17 CET 2017
From: Tejun Heo <tj@kernel.org>
Date: Mon, 6 Mar 2017 15:26:54 -0500
Subject: libata: drop WARN from protocol error in ata_sff_qc_issue()

From: Tejun Heo <tj@kernel.org>


[ Upstream commit 0580b762a4d6b70817476b90042813f8573283fa ]

ata_sff_qc_issue() expects upper layers to never issue commands on a
command protocol that it doesn't implement.  While the assumption
holds fine with the usual IO path, nothing filters based on the
command protocol in the passthrough path (which was added later),
allowing the warning to be tripped with a passthrough command with the
right (well, wrong) protocol.

Failing with AC_ERR_SYSTEM is the right thing to do anyway.  Remove
the unnecessary WARN.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Link: http://lkml.kernel.org/r/CACT4Y+bXkvevNZU8uP6X0QVqsj6wNoUA_1exfTSOzc+SmUtMOA@mail.gmail.com
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/ata/libata-sff.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -1481,7 +1481,6 @@ unsigned int ata_sff_qc_issue(struct ata
 		break;
 
 	default:
-		WARN_ON_ONCE(1);
 		return AC_ERR_SYSTEM;
 	}
 


Patches currently in stable-queue which might be from tj@kernel.org are

queue-4.9/libata-drop-warn-from-protocol-error-in-ata_sff_qc_issue.patch
queue-4.9/workqueue-trigger-warn-if-queue_delayed_work-is-called-with-null-wq.patch