Merge branch 'stable/for-jens-4.2' of... (6443af98) · Commits · e / devices / android_kernel_sony_msm8998

drivers/block/xen-blkback/blkback.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -83,6 +83,13 @@ module_param_named(max_persistent_grants, xen_blkif_max_pgrants, int, 0644);
		MODULE_PARM_DESC(max_persistent_grants,
		"Maximum number of grants to map persistently");

		/*
		* Maximum order of pages to be used for the shared ring between front and
		* backend, 4KB page granularity is used.
		*/
		unsigned int xen_blkif_max_ring_order = XENBUS_MAX_RING_PAGE_ORDER;
		module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO);
		MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");
		/*
		* The LRU mechanism to clean the lists of persistent grants needs to
		* be executed periodically. The time interval between consecutive executions
		@@ -1438,6 +1445,12 @@ static int __init xen_blkif_init(void)
		if (!xen_domain())
		return -ENODEV;

		if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) {
		pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
		xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER);
		xen_blkif_max_ring_order = XENBUS_MAX_RING_PAGE_ORDER;
		}

		rc = xen_blkif_interface_init();
		if (rc)
		goto failed_init;

drivers/block/xen-blkback/common.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -44,6 +44,7 @@
		#include <xen/interface/io/blkif.h>
		#include <xen/interface/io/protocols.h>

		extern unsigned int xen_blkif_max_ring_order;
		/*
		* This is the maximum number of segments that would be allowed in indirect
		* requests. This value will also be passed to the frontend.
		@@ -248,7 +249,7 @@ struct backend_info;
		#define PERSISTENT_GNT_WAS_ACTIVE 1

		/* Number of requests that we can fit in a ring */
		#define XEN_BLKIF_REQS 32
		#define XEN_BLKIF_REQS_PER_PAGE 32

		struct persistent_gnt {
		struct page *page;
		@@ -320,6 +321,7 @@ struct xen_blkif {
		struct work_struct free_work;
		/* Thread shutdown wait queue. */
		wait_queue_head_t shutdown_wq;
		unsigned int nr_ring_pages;
		};

		struct seg_buf {

drivers/block/xen-blkback/xenbus.c

+105 −62

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@

		/* Enlarge the array size in order to fully show blkback name. */
		#define BLKBACK_NAME_LEN (20)
		#define RINGREF_NAME_LEN (20)

		struct backend_info {
		struct xenbus_device *dev;
		@@ -124,8 +125,6 @@ static void xen_update_blkif_status(struct xen_blkif *blkif)
		static struct xen_blkif *xen_blkif_alloc(domid_t domid)
		{
		struct xen_blkif *blkif;
		struct pending_req req, n;
		int i, j;

		BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST);

		@@ -151,55 +150,15 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)

		INIT_LIST_HEAD(&blkif->pending_free);
		INIT_WORK(&blkif->free_work, xen_blkif_deferred_free);

		for (i = 0; i < XEN_BLKIF_REQS; i++) {
		req = kzalloc(sizeof(*req), GFP_KERNEL);
		if (!req)
		goto fail;
		list_add_tail(&req->free_list,
		&blkif->pending_free);
		for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
		req->segments[j] = kzalloc(sizeof(*req->segments[0]),
		GFP_KERNEL);
		if (!req->segments[j])
		goto fail;
		}
		for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
		req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]),
		GFP_KERNEL);
		if (!req->indirect_pages[j])
		goto fail;
		}
		}
		spin_lock_init(&blkif->pending_free_lock);
		init_waitqueue_head(&blkif->pending_free_wq);
		init_waitqueue_head(&blkif->shutdown_wq);

		return blkif;

		fail:
		list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) {
		list_del(&req->free_list);
		for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
		if (!req->segments[j])
		break;
		kfree(req->segments[j]);
		}
		for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
		if (!req->indirect_pages[j])
		break;
		kfree(req->indirect_pages[j]);
		}
		kfree(req);
		}

		kmem_cache_free(xen_blkif_cachep, blkif);

		return ERR_PTR(-ENOMEM);
		}

		static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref,
		unsigned int evtchn)
		static int xen_blkif_map(struct xen_blkif blkif, grant_ref_t gref,
		unsigned int nr_grefs, unsigned int evtchn)
		{
		int err;

		@@ -207,7 +166,7 @@ static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref,
		if (blkif->irq)
		return 0;

		err = xenbus_map_ring_valloc(blkif->be->dev, &gref, 1,
		err = xenbus_map_ring_valloc(blkif->be->dev, gref, nr_grefs,
		&blkif->blk_ring);
		if (err < 0)
		return err;
		@@ -217,21 +176,21 @@ static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref,
		{
		struct blkif_sring *sring;
		sring = (struct blkif_sring *)blkif->blk_ring;
		BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE);
		BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE * nr_grefs);
		break;
		}
		case BLKIF_PROTOCOL_X86_32:
		{
		struct blkif_x86_32_sring *sring_x86_32;
		sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring;
		BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
		BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE * nr_grefs);
		break;
		}
		case BLKIF_PROTOCOL_X86_64:
		{
		struct blkif_x86_64_sring *sring_x86_64;
		sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring;
		BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
		BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE * nr_grefs);
		break;
		}
		default:
		@@ -312,7 +271,7 @@ static void xen_blkif_free(struct xen_blkif *blkif)
		i++;
		}

		WARN_ON(i != XEN_BLKIF_REQS);
		WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages));

		kmem_cache_free(xen_blkif_cachep, blkif);
		}
		@@ -597,6 +556,11 @@ static int xen_blkbk_probe(struct xenbus_device *dev,
		if (err)
		goto fail;

		err = xenbus_printf(XBT_NIL, dev->nodename, "max-ring-page-order", "%u",
		xen_blkif_max_ring_order);
		if (err)
		pr_warn("%s write out 'max-ring-page-order' failed\n", __func__);

		err = xenbus_switch_state(dev, XenbusStateInitWait);
		if (err)
		goto fail;
		@@ -860,22 +824,66 @@ again:
		static int connect_ring(struct backend_info *be)
		{
		struct xenbus_device *dev = be->dev;
		unsigned long ring_ref;
		unsigned int evtchn;
		unsigned int ring_ref[XENBUS_MAX_RING_PAGES];
		unsigned int evtchn, nr_grefs, ring_page_order;
		unsigned int pers_grants;
		char protocol[64] = "";
		int err;
		struct pending_req req, n;
		int err, i, j;

		pr_debug("%s %s\n", __func__, dev->otherend);

		err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu",
		&ring_ref, "event-channel", "%u", &evtchn, NULL);
		if (err) {
		xenbus_dev_fatal(dev, err,
		"reading %s/ring-ref and event-channel",
		err = xenbus_scanf(XBT_NIL, dev->otherend, "event-channel", "%u",
		&evtchn);
		if (err != 1) {
		err = -EINVAL;
		xenbus_dev_fatal(dev, err, "reading %s/event-channel",
		dev->otherend);
		return err;
		}
		pr_info("event-channel %u\n", evtchn);

		err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-page-order", "%u",
		&ring_page_order);
		if (err != 1) {
		err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref",
		"%u", &ring_ref[0]);
		if (err != 1) {
		err = -EINVAL;
		xenbus_dev_fatal(dev, err, "reading %s/ring-ref",
		dev->otherend);
		return err;
		}
		nr_grefs = 1;
		pr_info("%s:using single page: ring-ref %d\n", dev->otherend,
		ring_ref[0]);
		} else {
		unsigned int i;

		if (ring_page_order > xen_blkif_max_ring_order) {
		err = -EINVAL;
		xenbus_dev_fatal(dev, err, "%s/request %d ring page order exceed max:%d",
		dev->otherend, ring_page_order,
		xen_blkif_max_ring_order);
		return err;
		}

		nr_grefs = 1 << ring_page_order;
		for (i = 0; i < nr_grefs; i++) {
		char ring_ref_name[RINGREF_NAME_LEN];

		snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
		err = xenbus_scanf(XBT_NIL, dev->otherend, ring_ref_name,
		"%u", &ring_ref[i]);
		if (err != 1) {
		err = -EINVAL;
		xenbus_dev_fatal(dev, err, "reading %s/%s",
		dev->otherend, ring_ref_name);
		return err;
		}
		pr_info("ring-ref%u: %u\n", i, ring_ref[i]);
		}
		}

		be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT;
		err = xenbus_gather(XBT_NIL, dev->otherend, "protocol",
		@@ -900,20 +908,55 @@ static int connect_ring(struct backend_info *be)

		be->blkif->vbd.feature_gnt_persistent = pers_grants;
		be->blkif->vbd.overflow_max_grants = 0;
		be->blkif->nr_ring_pages = nr_grefs;

		pr_info("ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
		ring_ref, evtchn, be->blkif->blk_protocol, protocol,
		pr_info("ring-pages:%d, event-channel %d, protocol %d (%s) %s\n",
		nr_grefs, evtchn, be->blkif->blk_protocol, protocol,
		pers_grants ? "persistent grants" : "");

		for (i = 0; i < nr_grefs * XEN_BLKIF_REQS_PER_PAGE; i++) {
		req = kzalloc(sizeof(*req), GFP_KERNEL);
		if (!req)
		goto fail;
		list_add_tail(&req->free_list, &be->blkif->pending_free);
		for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
		req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL);
		if (!req->segments[j])
		goto fail;
		}
		for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
		req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]),
		GFP_KERNEL);
		if (!req->indirect_pages[j])
		goto fail;
		}
		}

		/* Map the shared frame, irq etc. */
		err = xen_blkif_map(be->blkif, ring_ref, evtchn);
		err = xen_blkif_map(be->blkif, ring_ref, nr_grefs, evtchn);
		if (err) {
		xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u",
		ring_ref, evtchn);
		xenbus_dev_fatal(dev, err, "mapping ring-ref port %u", evtchn);
		return err;
		}

		return 0;

		fail:
		list_for_each_entry_safe(req, n, &be->blkif->pending_free, free_list) {
		list_del(&req->free_list);
		for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) {
		if (!req->segments[j])
		break;
		kfree(req->segments[j]);
		}
		for (j = 0; j < MAX_INDIRECT_PAGES; j++) {
		if (!req->indirect_pages[j])
		break;
		kfree(req->indirect_pages[j]);
		}
		kfree(req);
		}
		return -ENOMEM;
		}

		static const struct xenbus_device_id xen_blkbk_ids[] = {

drivers/block/xen-blkfront.c

+104 −47

Original line number	Diff line number	Diff line
		@@ -98,7 +98,21 @@ static unsigned int xen_blkif_max_segments = 32;
		module_param_named(max, xen_blkif_max_segments, int, S_IRUGO);
		MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)");

		#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
		/*
		* Maximum order of pages to be used for the shared ring between front and
		* backend, 4KB page granularity is used.
		*/
		static unsigned int xen_blkif_max_ring_order;
		module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO);
		MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");

		#define BLK_RING_SIZE(info) __CONST_RING_SIZE(blkif, PAGE_SIZE * (info)->nr_ring_pages)
		#define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE * XENBUS_MAX_RING_PAGES)
		/*
		* ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
		* characters are enough. Define to 20 to keep consist with backend.
		*/
		#define RINGREF_NAME_LEN (20)

		/*
		* We have one of these per vbd, whether ide, scsi or 'other'. They
		@@ -114,13 +128,14 @@ struct blkfront_info
		int vdevice;
		blkif_vdev_t handle;
		enum blkif_state connected;
		int ring_ref;
		int ring_ref[XENBUS_MAX_RING_PAGES];
		unsigned int nr_ring_pages;
		struct blkif_front_ring ring;
		unsigned int evtchn, irq;
		struct request_queue *rq;
		struct work_struct work;
		struct gnttab_free_callback callback;
		struct blk_shadow shadow[BLK_RING_SIZE];
		struct blk_shadow shadow[BLK_MAX_RING_SIZE];
		struct list_head grants;
		struct list_head indirect_pages;
		unsigned int persistent_gnts_c;
		@@ -139,8 +154,6 @@ static unsigned int nr_minors;
		static unsigned long *minors;
		static DEFINE_SPINLOCK(minor_lock);

		#define MAXIMUM_OUTSTANDING_BLOCK_REQS \
		(BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE)
		#define GRANT_INVALID_REF 0

		#define PARTS_PER_DISK 16
		@@ -170,7 +183,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info);
		static int get_id_from_freelist(struct blkfront_info *info)
		{
		unsigned long free = info->shadow_free;
		BUG_ON(free >= BLK_RING_SIZE);
		BUG_ON(free >= BLK_RING_SIZE(info));
		info->shadow_free = info->shadow[free].req.u.rw.id;
		info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
		return free;
		@@ -983,7 +996,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
		}
		}

		for (i = 0; i < BLK_RING_SIZE; i++) {
		for (i = 0; i < BLK_RING_SIZE(info); i++) {
		/*
		* Clear persistent grants present in requests already
		* on the shared ring
		@@ -1033,12 +1046,15 @@ free_shadow:
		flush_work(&info->work);

		/* Free resources associated with old device channel. */
		if (info->ring_ref != GRANT_INVALID_REF) {
		gnttab_end_foreign_access(info->ring_ref, 0,
		(unsigned long)info->ring.sring);
		info->ring_ref = GRANT_INVALID_REF;
		info->ring.sring = NULL;
		for (i = 0; i < info->nr_ring_pages; i++) {
		if (info->ring_ref[i] != GRANT_INVALID_REF) {
		gnttab_end_foreign_access(info->ring_ref[i], 0, 0);
		info->ring_ref[i] = GRANT_INVALID_REF;
		}
		}
		free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
		info->ring.sring = NULL;

		if (info->irq)
		unbind_from_irqhandler(info->irq, info);
		info->evtchn = info->irq = 0;
		@@ -1157,7 +1173,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
		* never have given to it (we stamp it up to BLK_RING_SIZE -
		* look in get_id_from_freelist.
		*/
		if (id >= BLK_RING_SIZE) {
		if (id >= BLK_RING_SIZE(info)) {
		WARN(1, "%s: response to %s has incorrect id (%ld)\n",
		info->gd->disk_name, op_name(bret->operation), id);
		/* We can't safely get the 'struct request' as
		@@ -1245,26 +1261,30 @@ static int setup_blkring(struct xenbus_device *dev,
		struct blkfront_info *info)
		{
		struct blkif_sring *sring;
		grant_ref_t gref;
		int err;
		int err, i;
		unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE;
		grant_ref_t gref[XENBUS_MAX_RING_PAGES];

		info->ring_ref = GRANT_INVALID_REF;
		for (i = 0; i < info->nr_ring_pages; i++)
		info->ring_ref[i] = GRANT_INVALID_REF;

		sring = (struct blkif_sring *)__get_free_page(GFP_NOIO \| __GFP_HIGH);
		sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO \| __GFP_HIGH,
		get_order(ring_size));
		if (!sring) {
		xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
		return -ENOMEM;
		}
		SHARED_RING_INIT(sring);
		FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
		FRONT_RING_INIT(&info->ring, sring, ring_size);

		err = xenbus_grant_ring(dev, info->ring.sring, 1, &gref);
		err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref);
		if (err < 0) {
		free_page((unsigned long)sring);
		free_pages((unsigned long)sring, get_order(ring_size));
		info->ring.sring = NULL;
		goto fail;
		}
		info->ring_ref = gref;
		for (i = 0; i < info->nr_ring_pages; i++)
		info->ring_ref[i] = gref[i];

		err = xenbus_alloc_evtchn(dev, &info->evtchn);
		if (err)
		@@ -1292,7 +1312,18 @@ static int talk_to_blkback(struct xenbus_device *dev,
		{
		const char *message = NULL;
		struct xenbus_transaction xbt;
		int err;
		int err, i;
		unsigned int max_page_order = 0;
		unsigned int ring_page_order = 0;

		err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
		"max-ring-page-order", "%u", &max_page_order);
		if (err != 1)
		info->nr_ring_pages = 1;
		else {
		ring_page_order = min(xen_blkif_max_ring_order, max_page_order);
		info->nr_ring_pages = 1 << ring_page_order;
		}

		/* Create shared ring, alloc event channel. */
		err = setup_blkring(dev, info);
		@@ -1306,12 +1337,33 @@ again:
		goto destroy_blkring;
		}

		if (info->nr_ring_pages == 1) {
		err = xenbus_printf(xbt, dev->nodename,
		"ring-ref", "%u", info->ring_ref[0]);
		if (err) {
		message = "writing ring-ref";
		goto abort_transaction;
		}
		} else {
		err = xenbus_printf(xbt, dev->nodename,
		"ring-ref", "%u", info->ring_ref);
		"ring-page-order", "%u", ring_page_order);
		if (err) {
		message = "writing ring-page-order";
		goto abort_transaction;
		}

		for (i = 0; i < info->nr_ring_pages; i++) {
		char ring_ref_name[RINGREF_NAME_LEN];

		snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
		err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
		"%u", info->ring_ref[i]);
		if (err) {
		message = "writing ring-ref";
		goto abort_transaction;
		}
		}
		}
		err = xenbus_printf(xbt, dev->nodename,
		"event-channel", "%u", info->evtchn);
		if (err) {
		@@ -1338,6 +1390,9 @@ again:
		goto destroy_blkring;
		}

		for (i = 0; i < BLK_RING_SIZE(info); i++)
		info->shadow[i].req.u.rw.id = i+1;
		info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
		xenbus_switch_state(dev, XenbusStateInitialised);

		return 0;
		@@ -1361,7 +1416,7 @@ again:
		static int blkfront_probe(struct xenbus_device *dev,
		const struct xenbus_device_id *id)
		{
		int err, vdevice, i;
		int err, vdevice;
		struct blkfront_info *info;

		/* FIXME: Use dynamic device id if this is not set. */
		@@ -1422,21 +1477,10 @@ static int blkfront_probe(struct xenbus_device *dev,
		info->connected = BLKIF_STATE_DISCONNECTED;
		INIT_WORK(&info->work, blkif_restart_queue);

		for (i = 0; i < BLK_RING_SIZE; i++)
		info->shadow[i].req.u.rw.id = i+1;
		info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;

		/* Front end dir is a number, which is used as the id. */
		info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
		dev_set_drvdata(&dev->dev, info);

		err = talk_to_blkback(dev, info);
		if (err) {
		kfree(info);
		dev_set_drvdata(&dev->dev, NULL);
		return err;
		}

		return 0;
		}

		@@ -1476,10 +1520,10 @@ static int blkif_recover(struct blkfront_info *info)

		/* Stage 2: Set up free list. */
		memset(&info->shadow, 0, sizeof(info->shadow));
		for (i = 0; i < BLK_RING_SIZE; i++)
		for (i = 0; i < BLK_RING_SIZE(info); i++)
		info->shadow[i].req.u.rw.id = i+1;
		info->shadow_free = info->ring.req_prod_pvt;
		info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
		info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;

		rc = blkfront_setup_indirect(info);
		if (rc) {
		@@ -1491,7 +1535,7 @@ static int blkif_recover(struct blkfront_info *info)
		blk_queue_max_segments(info->rq, segs);
		bio_list_init(&bio_list);
		INIT_LIST_HEAD(&requests);
		for (i = 0; i < BLK_RING_SIZE; i++) {
		for (i = 0; i < BLK_RING_SIZE(info); i++) {
		/* Not in use? */
		if (!copy[i].request)
		continue;
		@@ -1697,7 +1741,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
		segs = info->max_indirect_segments;
		}

		err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
		err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info));
		if (err)
		goto out_of_memory;

		@@ -1707,7 +1751,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
		* grants, we need to allocate a set of pages that can be
		* used for mapping indirect grefs
		*/
		int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE;
		int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info);

		BUG_ON(!list_empty(&info->indirect_pages));
		for (i = 0; i < num; i++) {
		@@ -1718,7 +1762,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
		}
		}

		for (i = 0; i < BLK_RING_SIZE; i++) {
		for (i = 0; i < BLK_RING_SIZE(info); i++) {
		info->shadow[i].grants_used = kzalloc(
		sizeof(info->shadow[i].grants_used[0]) * segs,
		GFP_NOIO);
		@@ -1740,7 +1784,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
		return 0;

		out_of_memory:
		for (i = 0; i < BLK_RING_SIZE; i++) {
		for (i = 0; i < BLK_RING_SIZE(info); i++) {
		kfree(info->shadow[i].grants_used);
		info->shadow[i].grants_used = NULL;
		kfree(info->shadow[i].sg);
		@@ -1906,8 +1950,15 @@ static void blkback_changed(struct xenbus_device *dev,
		dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state);

		switch (backend_state) {
		case XenbusStateInitialising:
		case XenbusStateInitWait:
		if (dev->state != XenbusStateInitialising)
		break;
		if (talk_to_blkback(dev, info)) {
		kfree(info);
		dev_set_drvdata(&dev->dev, NULL);
		break;
		}
		case XenbusStateInitialising:
		case XenbusStateInitialised:
		case XenbusStateReconfiguring:
		case XenbusStateReconfigured:
		@@ -2091,6 +2142,12 @@ static int __init xlblk_init(void)
		if (!xen_domain())
		return -ENODEV;

		if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) {
		pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
		xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER);
		xen_blkif_max_ring_order = 0;
		}

		if (!xen_has_pv_disk_devices())
		return -ENODEV;