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

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>

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index efe1b4761735a79faa30867ad625fdd51e043081..e88556ac8318f7b43695de3b93e3dc6bedca6b61 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1093,8 +1093,10 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
                                 * 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);
                        }