[3.11.y.z extended stable] Patch "mtip32xx: Unmap the DMA segments before completing the IO request" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    mtip32xx: Unmap the DMA segments before completing the IO request

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 52adaba9449cc379a88910fa23fee0435ec3c761 Mon Sep 17 00:00:00 2001
From: Felipe Franciosi <felipe at paradoxo.org>
Date: Thu, 13 Mar 2014 14:34:21 +0000
Subject: mtip32xx: Unmap the DMA segments before completing the IO request

commit 368c89d7ac70f937c93cd6f3b65bcfdfb3ba794f upstream.

If the buffers are unmapped after completing a request, then stale data
might be in the request.

Signed-off-by: Felipe Franciosi <felipe at paradoxo.org>
Signed-off-by: Jens Axboe <axboe at fb.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index bd3d207..4d26c25 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -621,6 +621,12 @@ static void mtip_timeout_function(unsigned long int data)
 			 */
 			writel(1 << bit, port->completed[group]);

+			/* Unmap the DMA scatter list entries */
+			dma_unmap_sg(&port->dd->pdev->dev,
+					command->sg,
+					command->scatter_ents,
+					command->direction);
+
 			/* Call the async completion callback. */
 			if (likely(command->async_callback))
 				command->async_callback(command->async_data,
@@ -628,12 +634,6 @@ static void mtip_timeout_function(unsigned long int data)
 			command->async_callback = NULL;
 			command->comp_func = NULL;

-			/* Unmap the DMA scatter list entries */
-			dma_unmap_sg(&port->dd->pdev->dev,
-					command->sg,
-					command->scatter_ents,
-					command->direction);
-
 			/*
 			 * Clear the allocated bit and active tag for the
 			 * command.
@@ -711,6 +711,12 @@ static void mtip_async_complete(struct mtip_port *port,
 			"Command tag %d failed due to TFE\n", tag);
 	}

+	/* Unmap the DMA scatter list entries */
+	dma_unmap_sg(&dd->pdev->dev,
+		command->sg,
+		command->scatter_ents,
+		command->direction);
+
 	/* Upper layer callback */
 	if (likely(command->async_callback))
 		command->async_callback(command->async_data, cb_status);
@@ -718,12 +724,6 @@ static void mtip_async_complete(struct mtip_port *port,
 	command->async_callback = NULL;
 	command->comp_func = NULL;

-	/* Unmap the DMA scatter list entries */
-	dma_unmap_sg(&dd->pdev->dev,
-		command->sg,
-		command->scatter_ents,
-		command->direction);
-
 	/* Clear the allocated and active bits for the command */
 	atomic_set(&port->commands[tag].active, 0);
 	release_slot(port, tag);
--
1.9.1