Patch "xen-blkfront: don't add indirect pages to list when" has been added to the 4.1-stable tree

[<gregkh@linuxfoundation.org>]

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

    xen-blkfront: don't add indirect pages to list when

to the 4.1-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:
     xen-blkfront-don-t-add-indirect-pages-to-list-when.patch
and it can be found in the queue-4.1 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 7b0767502b5db11cb1f0daef2d01f6d71b1192dc Mon Sep 17 00:00:00 2001
From: Bob Liu <bob.liu@oracle.com>
Date: Wed, 22 Jul 2015 14:40:09 +0800
Subject: xen-blkfront: don't add indirect pages to list when
 !feature_persistent
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Bob Liu <bob.liu@oracle.com>

commit 7b0767502b5db11cb1f0daef2d01f6d71b1192dc upstream.

We should consider info->feature_persistent when adding indirect page to list
info->indirect_pages, else the BUG_ON() in blkif_free() would be triggered.

When we are using persistent grants the indirect_pages list
should always be empty because blkfront has pre-allocated enough
persistent pages to fill all requests on the ring.

Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/block/xen-blkfront.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1118,8 +1118,10 @@ static void blkif_completion(struct blk_
 				 * Add the used indirect page back to the list of
 				 * available pages for indirect grefs.
 				 */
-				indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
-				list_add(&indirect_page->lru, &info->indirect_pages);
+				if (!info->feature_persistent) {
+					indirect_page = pfn_to_page(s->indirect_grants[i]->pfn);
+					list_add(&indirect_page->lru, &info->indirect_pages);
+				}
 				s->indirect_grants[i]->gref = GRANT_INVALID_REF;
 				list_add_tail(&s->indirect_grants[i]->node, &info->grants);
 			}


Patches currently in stable-queue which might be from bob.liu@oracle.com are

queue-4.1/xen-blkback-replace-work_pending-with-work_busy-in-purge_persistent_gnt.patch
queue-4.1/xen-blkfront-don-t-add-indirect-pages-to-list-when.patch