xen/blkback: add stack variable 'blkif' in connect_ring()

As 'be->blkif' is used for many times in connect_ring(), the stack variable
'blkif' is added to substitute 'be-blkif'.

Suggested-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index a4bc74e72c39..a4aadac772e5 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -1023,6 +1023,7 @@ fail:
 static int connect_ring(struct backend_info *be)
 {
         struct xenbus_device *dev = be->dev;
+        struct xen_blkif *blkif = be->blkif;
         unsigned int pers_grants;
         char protocol[64] = "";
         int err, i;
@@ -1033,25 +1034,25 @@ static int connect_ring(struct backend_info *be)
 
         pr_debug("%s %s\n", __func__, dev->otherend);
 
-        be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT;
+        blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT;
         err = xenbus_scanf(XBT_NIL, dev->otherend, "protocol",
                            "%63s", protocol);
         if (err <= 0)
                 strcpy(protocol, "unspecified, assuming default");
         else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE))
-                be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE;
+                blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE;
         else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32))
-                be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32;
+                blkif->blk_protocol = BLKIF_PROTOCOL_X86_32;
         else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64))
-                be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64;
+                blkif->blk_protocol = BLKIF_PROTOCOL_X86_64;
         else {
                 xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol);
                 return -ENOSYS;
         }
         pers_grants = xenbus_read_unsigned(dev->otherend, "feature-persistent",
                                            0);
-        be->blkif->vbd.feature_gnt_persistent = pers_grants;
-        be->blkif->vbd.overflow_max_grants = 0;
+        blkif->vbd.feature_gnt_persistent = pers_grants;
+        blkif->vbd.overflow_max_grants = 0;
 
         /*
          * Read the number of hardware queues from frontend.
@@ -1067,16 +1068,16 @@ static int connect_ring(struct backend_info *be)
                                 requested_num_queues, xenblk_max_queues);
                 return -ENOSYS;
         }
-        be->blkif->nr_rings = requested_num_queues;
-        if (xen_blkif_alloc_rings(be->blkif))
+        blkif->nr_rings = requested_num_queues;
+        if (xen_blkif_alloc_rings(blkif))
                 return -ENOMEM;
 
         pr_info("%s: using %d queues, protocol %d (%s) %s\n", dev->nodename,
-                 be->blkif->nr_rings, be->blkif->blk_protocol, protocol,
+                 blkif->nr_rings, blkif->blk_protocol, protocol,
                  pers_grants ? "persistent grants" : "");
 
-        if (be->blkif->nr_rings == 1)
-                return read_per_ring_refs(&be->blkif->rings[0], dev->otherend);
+        if (blkif->nr_rings == 1)
+                return read_per_ring_refs(&blkif->rings[0], dev->otherend);
         else {
                 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
                 xspath = kmalloc(xspathsize, GFP_KERNEL);
@@ -1085,10 +1086,10 @@ static int connect_ring(struct backend_info *be)
                         return -ENOMEM;
                 }
 
-                for (i = 0; i < be->blkif->nr_rings; i++) {
+                for (i = 0; i < blkif->nr_rings; i++) {
                         memset(xspath, 0, xspathsize);
                         snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend, i);
-                        err = read_per_ring_refs(&be->blkif->rings[i], xspath);
+                        err = read_per_ring_refs(&blkif->rings[i], xspath);
                         if (err) {
                                 kfree(xspath);
                                 return err;