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

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.

CC: stable@vger.kernel.org
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>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f45f4e67c5d4..44b33d39441b 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1135,8 +1135,10 @@ 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);
                         }