xen-blkback: init persistent_purge_work work_struct

Initialize persistent_purge_work work_struct on xen_blkif_alloc (and
remove the previous initialization done in purge_persistent_gnt). This
prevents flush_work from complaining even if purge_persistent_gnt has
not been used.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 3 insertions, 2 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 765fc7348b66..64c60edcdfbc 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -299,7 +299,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
         BUG_ON(num != 0);
 }
 
-static void unmap_purged_grants(struct work_struct *work)
+void xen_blkbk_unmap_purged_grants(struct work_struct *work)
 {
         struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
         struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
@@ -420,7 +420,6 @@ finished:
         blkif->vbd.overflow_max_grants = 0;
 
         /* We can defer this work */
-        INIT_WORK(&blkif->persistent_purge_work, unmap_purged_grants);
         schedule_work(&blkif->persistent_purge_work);
         pr_debug(DRV_PFX "Purged %u/%u\n", (total - num_clean), total);
         return;
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 9eb34e24b4fe..be052773ad03 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -385,6 +385,7 @@ int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
 int xen_blkbk_barrier(struct xenbus_transaction xbt,
                       struct backend_info *be, int state);
 struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
+void xen_blkbk_unmap_purged_grants(struct work_struct *work);
 
 static inline void blkif_get_x86_32_req(struct blkif_request *dst,
                                         struct blkif_x86_32_request *src)
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 84973c6a856a..9a547e6b6ebf 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -129,6 +129,7 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
         blkif->free_pages_num = 0;
         atomic_set(&blkif->persistent_gnt_in_use, 0);
         atomic_set(&blkif->inflight, 0);
+        INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants);
 
         INIT_LIST_HEAD(&blkif->pending_free);