Merge tag 'platform-drivers-x86-v4.13-3' of git://git.infradead.org/linux-platform...

[sfrench/cifs-2.6.git] / drivers / block / xen-blkfront.c

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index c852ed3c01d55f23c69e4c9133b2fd88137402f9..98e34e4c62b8b228a6ee6d37256e860ee7d3c2b7 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -111,7 +111,7 @@ struct blk_shadow {
 };
 
 struct blkif_req {
-       int     error;
+       blk_status_t    error;
 };
 
 static inline struct blkif_req *blkif_req(struct request *rq)
@@ -708,6 +708,7 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
         * existing persistent grants, or if we have to get new grants,
         * as there are not sufficiently many free.
         */
+       bool new_persistent_gnts = false;
        struct scatterlist *sg;
        int num_sg, max_grefs, num_grant;
 
@@ -719,19 +720,21 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
                 */
                max_grefs += INDIRECT_GREFS(max_grefs);
 
-       /*
-        * We have to reserve 'max_grefs' grants because persistent
-        * grants are shared by all rings.
-        */
-       if (max_grefs > 0)
-               if (gnttab_alloc_grant_references(max_grefs, &setup.gref_head) < 0) {
+       /* Check if we have enough persistent grants to allocate a requests */
+       if (rinfo->persistent_gnts_c < max_grefs) {
+               new_persistent_gnts = true;
+
+               if (gnttab_alloc_grant_references(
+                   max_grefs - rinfo->persistent_gnts_c,
+                   &setup.gref_head) < 0) {
                        gnttab_request_free_callback(
                                &rinfo->callback,
                                blkif_restart_queue_callback,
                                rinfo,
-                               max_grefs);
+                               max_grefs - rinfo->persistent_gnts_c);
                        return 1;
                }
+       }
 
        /* Fill out a communications ring structure. */
        id = blkif_ring_get_request(rinfo, req, &ring_req);
@@ -832,7 +835,7 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri
        if (unlikely(require_extra_req))
                rinfo->shadow[extra_id].req = *extra_ring_req;
 
-       if (max_grefs > 0)
+       if (new_persistent_gnts)
                gnttab_free_grant_references(setup.gref_head);
 
        return 0;
@@ -906,8 +909,8 @@ out_err:
        return BLK_STS_IOERR;
 
 out_busy:
-       spin_unlock_irqrestore(&rinfo->ring_lock, flags);
        blk_mq_stop_hw_queue(hctx);
+       spin_unlock_irqrestore(&rinfo->ring_lock, flags);
        return BLK_STS_RESOURCE;
 }
 
@@ -1616,7 +1619,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
                        if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
                                printk(KERN_WARNING "blkfront: %s: %s op failed\n",
                                       info->gd->disk_name, op_name(bret->operation));
-                               blkif_req(req)->error = -EOPNOTSUPP;
+                               blkif_req(req)->error = BLK_STS_NOTSUPP;
                        }
                        if (unlikely(bret->status == BLKIF_RSP_ERROR &&
                                     rinfo->shadow[id].req.u.rw.nr_segments == 0)) {