xen/blkback: add stack variable 'blkif' in connect_ring() (5b8e432d) · Commits · 戴 / test

drivers/block/xen-blkback/xenbus.c

+14 −13

Original line number	Diff line number	Diff line
		@@ -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;

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