diff --git linux-libre-5.4.99-gnu/Makefile linux-libre-5.4.100-gnu/Makefile
index e59b4380a1ff..b4814611618a 100644
--- linux-libre-5.4.99-gnu/Makefile
+++ linux-libre-5.4.100-gnu/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 4
-SUBLEVEL = 99
+SUBLEVEL = 100
 EXTRAVERSION = -gnu
 NAME = Kleptomaniac Octopus
 
diff --git linux-libre-5.4.99-gnu/arch/arm/xen/p2m.c linux-libre-5.4.100-gnu/arch/arm/xen/p2m.c
index e52950a43f2e..fd6e3aafe272 100644
--- linux-libre-5.4.99-gnu/arch/arm/xen/p2m.c
+++ linux-libre-5.4.100-gnu/arch/arm/xen/p2m.c
@@ -95,8 +95,10 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
 	for (i = 0; i < count; i++) {
 		if (map_ops[i].status)
 			continue;
-		set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
-				    map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT);
+		if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+				    map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
+			return -ENOMEM;
+		}
 	}
 
 	return 0;
diff --git linux-libre-5.4.99-gnu/arch/x86/kvm/svm.c linux-libre-5.4.100-gnu/arch/x86/kvm/svm.c
index 296b0d7570d0..1da558f28aa5 100644
--- linux-libre-5.4.99-gnu/arch/x86/kvm/svm.c
+++ linux-libre-5.4.100-gnu/arch/x86/kvm/svm.c
@@ -7104,7 +7104,6 @@ static int svm_register_enc_region(struct kvm *kvm,
 	region->uaddr = range->addr;
 	region->size = range->size;
 
-	mutex_lock(&kvm->lock);
 	list_add_tail(&region->list, &sev->regions_list);
 	mutex_unlock(&kvm->lock);
 
diff --git linux-libre-5.4.99-gnu/arch/x86/xen/p2m.c linux-libre-5.4.100-gnu/arch/x86/xen/p2m.c
index 0acba2c712ab..7fe5be8e6d3d 100644
--- linux-libre-5.4.99-gnu/arch/x86/xen/p2m.c
+++ linux-libre-5.4.100-gnu/arch/x86/xen/p2m.c
@@ -716,7 +716,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
 		unsigned long mfn, pfn;
 
 		/* Do not add to override if the map failed. */
-		if (map_ops[i].status)
+		if (map_ops[i].status != GNTST_okay ||
+		    (kmap_ops && kmap_ops[i].status != GNTST_okay))
 			continue;
 
 		if (map_ops[i].flags & GNTMAP_contains_pte) {
@@ -754,17 +755,15 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
 		unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
 		unsigned long pfn = page_to_pfn(pages[i]);
 
-		if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
+		if (mfn != INVALID_P2M_ENTRY && (mfn & FOREIGN_FRAME_BIT))
+			set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+		else
 			ret = -EINVAL;
-			goto out;
-		}
-
-		set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 	}
 	if (kunmap_ops)
 		ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
-						kunmap_ops, count);
-out:
+						kunmap_ops, count) ?: ret;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
diff --git linux-libre-5.4.99-gnu/drivers/block/xen-blkback/blkback.c linux-libre-5.4.100-gnu/drivers/block/xen-blkback/blkback.c
index b18f0162cb9c..208f3eea3641 100644
--- linux-libre-5.4.99-gnu/drivers/block/xen-blkback/blkback.c
+++ linux-libre-5.4.100-gnu/drivers/block/xen-blkback/blkback.c
@@ -850,8 +850,11 @@ again:
 			pages[i]->page = persistent_gnt->page;
 			pages[i]->persistent_gnt = persistent_gnt;
 		} else {
-			if (get_free_page(ring, &pages[i]->page))
-				goto out_of_memory;
+			if (get_free_page(ring, &pages[i]->page)) {
+				put_free_pages(ring, pages_to_gnt, segs_to_map);
+				ret = -ENOMEM;
+				goto out;
+			}
 			addr = vaddr(pages[i]->page);
 			pages_to_gnt[segs_to_map] = pages[i]->page;
 			pages[i]->persistent_gnt = NULL;
@@ -867,10 +870,8 @@ again:
 			break;
 	}
 
-	if (segs_to_map) {
+	if (segs_to_map)
 		ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
-		BUG_ON(ret);
-	}
 
 	/*
 	 * Now swizzle the MFN in our domain with the MFN from the other domain
@@ -885,7 +886,7 @@ again:
 				pr_debug("invalid buffer -- could not remap it\n");
 				put_free_pages(ring, &pages[seg_idx]->page, 1);
 				pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
-				ret |= 1;
+				ret |= !ret;
 				goto next;
 			}
 			pages[seg_idx]->handle = map[new_map_idx].handle;
@@ -937,17 +938,18 @@ next:
 	}
 	segs_to_map = 0;
 	last_map = map_until;
-	if (map_until != num)
+	if (!ret && map_until != num)
 		goto again;
 
-	return ret;
-
-out_of_memory:
-	pr_alert("%s: out of memory\n", __func__);
-	put_free_pages(ring, pages_to_gnt, segs_to_map);
-	for (i = last_map; i < num; i++)
+out:
+	for (i = last_map; i < num; i++) {
+		/* Don't zap current batch's valid persistent grants. */
+		if(i >= last_map + segs_to_map)
+			pages[i]->persistent_gnt = NULL;
 		pages[i]->handle = BLKBACK_INVALID_HANDLE;
-	return -ENOMEM;
+	}
+
+	return ret;
 }
 
 static int xen_blkbk_map_seg(struct pending_req *pending_req)
diff --git linux-libre-5.4.99-gnu/drivers/media/usb/pwc/pwc-if.c linux-libre-5.4.100-gnu/drivers/media/usb/pwc/pwc-if.c
index 9b76cf133d52..3df7ca2357da 100644
--- linux-libre-5.4.99-gnu/drivers/media/usb/pwc/pwc-if.c
+++ linux-libre-5.4.100-gnu/drivers/media/usb/pwc/pwc-if.c
@@ -147,16 +147,17 @@ static const struct video_device pwc_template = {
 /***************************************************************************/
 /* Private functions */
 
-static void *pwc_alloc_urb_buffer(struct device *dev,
+static void *pwc_alloc_urb_buffer(struct usb_device *dev,
 				  size_t size, dma_addr_t *dma_handle)
 {
+	struct device *dmadev = dev->bus->sysdev;
 	void *buffer = kmalloc(size, GFP_KERNEL);
 
 	if (!buffer)
 		return NULL;
 
-	*dma_handle = dma_map_single(dev, buffer, size, DMA_FROM_DEVICE);
-	if (dma_mapping_error(dev, *dma_handle)) {
+	*dma_handle = dma_map_single(dmadev, buffer, size, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dmadev, *dma_handle)) {
 		kfree(buffer);
 		return NULL;
 	}
@@ -164,12 +165,14 @@ static void *pwc_alloc_urb_buffer(struct device *dev,
 	return buffer;
 }
 
-static void pwc_free_urb_buffer(struct device *dev,
+static void pwc_free_urb_buffer(struct usb_device *dev,
 				size_t size,
 				void *buffer,
 				dma_addr_t dma_handle)
 {
-	dma_unmap_single(dev, dma_handle, size, DMA_FROM_DEVICE);
+	struct device *dmadev = dev->bus->sysdev;
+
+	dma_unmap_single(dmadev, dma_handle, size, DMA_FROM_DEVICE);
 	kfree(buffer);
 }
 
@@ -274,6 +277,7 @@ static void pwc_frame_complete(struct pwc_device *pdev)
 static void pwc_isoc_handler(struct urb *urb)
 {
 	struct pwc_device *pdev = (struct pwc_device *)urb->context;
+	struct device *dmadev = urb->dev->bus->sysdev;
 	int i, fst, flen;
 	unsigned char *iso_buf = NULL;
 
@@ -320,7 +324,7 @@ static void pwc_isoc_handler(struct urb *urb)
 	/* Reset ISOC error counter. We did get here, after all. */
 	pdev->visoc_errors = 0;
 
-	dma_sync_single_for_cpu(&urb->dev->dev,
+	dma_sync_single_for_cpu(dmadev,
 				urb->transfer_dma,
 				urb->transfer_buffer_length,
 				DMA_FROM_DEVICE);
@@ -371,7 +375,7 @@ static void pwc_isoc_handler(struct urb *urb)
 		pdev->vlast_packet_size = flen;
 	}
 
-	dma_sync_single_for_device(&urb->dev->dev,
+	dma_sync_single_for_device(dmadev,
 				   urb->transfer_dma,
 				   urb->transfer_buffer_length,
 				   DMA_FROM_DEVICE);
@@ -453,7 +457,7 @@ retry:
 		urb->pipe = usb_rcvisocpipe(udev, pdev->vendpoint);
 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
-		urb->transfer_buffer = pwc_alloc_urb_buffer(&udev->dev,
+		urb->transfer_buffer = pwc_alloc_urb_buffer(udev,
 							    urb->transfer_buffer_length,
 							    &urb->transfer_dma);
 		if (urb->transfer_buffer == NULL) {
@@ -516,7 +520,7 @@ static void pwc_iso_free(struct pwc_device *pdev)
 		if (urb) {
 			PWC_DEBUG_MEMORY("Freeing URB\n");
 			if (urb->transfer_buffer)
-				pwc_free_urb_buffer(&urb->dev->dev,
+				pwc_free_urb_buffer(urb->dev,
 						    urb->transfer_buffer_length,
 						    urb->transfer_buffer,
 						    urb->transfer_dma);
diff --git linux-libre-5.4.99-gnu/drivers/net/xen-netback/netback.c linux-libre-5.4.100-gnu/drivers/net/xen-netback/netback.c
index fa1ac0abc924..4bfafcd6317f 100644
--- linux-libre-5.4.99-gnu/drivers/net/xen-netback/netback.c
+++ linux-libre-5.4.100-gnu/drivers/net/xen-netback/netback.c
@@ -1335,13 +1335,11 @@ int xenvif_tx_action(struct xenvif_queue *queue, int budget)
 		return 0;
 
 	gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
-	if (nr_mops != 0) {
+	if (nr_mops != 0)
 		ret = gnttab_map_refs(queue->tx_map_ops,
 				      NULL,
 				      queue->pages_to_map,
 				      nr_mops);
-		BUG_ON(ret);
-	}
 
 	work_done = xenvif_tx_submit(queue);
 
diff --git linux-libre-5.4.99-gnu/drivers/xen/gntdev.c linux-libre-5.4.100-gnu/drivers/xen/gntdev.c
index 246864bbb3e4..e953ea34b3e4 100644
--- linux-libre-5.4.99-gnu/drivers/xen/gntdev.c
+++ linux-libre-5.4.100-gnu/drivers/xen/gntdev.c
@@ -319,44 +319,47 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
 		 * to the kernel linear addresses of the struct pages.
 		 * These ptes are completely different from the user ptes dealt
 		 * with find_grant_ptes.
+		 * Note that GNTMAP_device_map isn't needed here: The
+		 * dev_bus_addr output field gets consumed only from ->map_ops,
+		 * and by not requesting it when mapping we also avoid needing
+		 * to mirror dev_bus_addr into ->unmap_ops (and holding an extra
+		 * reference to the page in the hypervisor).
 		 */
+		unsigned int flags = (map->flags & ~GNTMAP_device_map) |
+				     GNTMAP_host_map;
+
 		for (i = 0; i < map->count; i++) {
 			unsigned long address = (unsigned long)
 				pfn_to_kaddr(page_to_pfn(map->pages[i]));
 			BUG_ON(PageHighMem(map->pages[i]));
 
-			gnttab_set_map_op(&map->kmap_ops[i], address,
-				map->flags | GNTMAP_host_map,
+			gnttab_set_map_op(&map->kmap_ops[i], address, flags,
 				map->grants[i].ref,
 				map->grants[i].domid);
 			gnttab_set_unmap_op(&map->kunmap_ops[i], address,
-				map->flags | GNTMAP_host_map, -1);
+				flags, -1);
 		}
 	}
 
 	pr_debug("map %d+%d\n", map->index, map->count);
 	err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
 			map->pages, map->count);
-	if (err)
-		return err;
 
 	for (i = 0; i < map->count; i++) {
-		if (map->map_ops[i].status) {
+		if (map->map_ops[i].status == GNTST_okay)
+			map->unmap_ops[i].handle = map->map_ops[i].handle;
+		else if (!err)
 			err = -EINVAL;
-			continue;
-		}
 
-		map->unmap_ops[i].handle = map->map_ops[i].handle;
-		if (use_ptemod)
-			map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
-#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
-		else if (map->dma_vaddr) {
-			unsigned long bfn;
+		if (map->flags & GNTMAP_device_map)
+			map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr;
 
-			bfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
-			map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(bfn);
+		if (use_ptemod) {
+			if (map->kmap_ops[i].status == GNTST_okay)
+				map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+			else if (!err)
+				err = -EINVAL;
 		}
-#endif
 	}
 	return err;
 }
diff --git linux-libre-5.4.99-gnu/drivers/xen/xen-scsiback.c linux-libre-5.4.100-gnu/drivers/xen/xen-scsiback.c
index 33d6499d8472..32aba2e8c075 100644
--- linux-libre-5.4.99-gnu/drivers/xen/xen-scsiback.c
+++ linux-libre-5.4.100-gnu/drivers/xen/xen-scsiback.c
@@ -422,12 +422,12 @@ static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
 		return 0;
 
 	err = gnttab_map_refs(map, NULL, pg, cnt);
-	BUG_ON(err);
 	for (i = 0; i < cnt; i++) {
 		if (unlikely(map[i].status != GNTST_okay)) {
 			pr_err("invalid buffer -- could not remap it\n");
 			map[i].handle = SCSIBACK_INVALID_HANDLE;
-			err = -ENOMEM;
+			if (!err)
+				err = -ENOMEM;
 		} else {
 			get_page(pg[i]);
 		}
diff --git linux-libre-5.4.99-gnu/fs/btrfs/ctree.h linux-libre-5.4.100-gnu/fs/btrfs/ctree.h
index cda5534d3d0e..7960359dbc70 100644
--- linux-libre-5.4.99-gnu/fs/btrfs/ctree.h
+++ linux-libre-5.4.100-gnu/fs/btrfs/ctree.h
@@ -136,9 +136,6 @@ enum {
 	BTRFS_FS_STATE_DEV_REPLACING,
 	/* The btrfs_fs_info created for self-tests */
 	BTRFS_FS_STATE_DUMMY_FS_INFO,
-
-	/* Indicate that we can't trust the free space tree for caching yet */
-	BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED,
 };
 
 #define BTRFS_BACKREF_REV_MAX		256
@@ -527,6 +524,9 @@ enum {
 	 * so we don't need to offload checksums to workqueues.
 	 */
 	BTRFS_FS_CSUM_IMPL_FAST,
+
+	/* Indicate that we can't trust the free space tree for caching yet */
+	BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED,
 };
 
 struct btrfs_fs_info {
diff --git linux-libre-5.4.99-gnu/include/xen/grant_table.h linux-libre-5.4.100-gnu/include/xen/grant_table.h
index 9bc5bc07d4d3..a9978350b45b 100644
--- linux-libre-5.4.99-gnu/include/xen/grant_table.h
+++ linux-libre-5.4.100-gnu/include/xen/grant_table.h
@@ -157,6 +157,7 @@ gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 	map->flags = flags;
 	map->ref = ref;
 	map->dom = domid;
+	map->status = 1; /* arbitrary positive value */
 }
 
 static inline void
diff --git linux-libre-5.4.99-gnu/net/bridge/br.c linux-libre-5.4.100-gnu/net/bridge/br.c
index 8a8f9e5f264f..cccbb9bf3ca4 100644
--- linux-libre-5.4.99-gnu/net/bridge/br.c
+++ linux-libre-5.4.100-gnu/net/bridge/br.c
@@ -43,7 +43,10 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 
 		if (event == NETDEV_REGISTER) {
 			/* register of bridge completed, add sysfs entries */
-			br_sysfs_addbr(dev);
+			err = br_sysfs_addbr(dev);
+			if (err)
+				return notifier_from_errno(err);
+
 			return NOTIFY_DONE;
 		}
 	}
diff --git linux-libre-5.4.99-gnu/net/qrtr/qrtr.c linux-libre-5.4.100-gnu/net/qrtr/qrtr.c
index d6d2736ec927..ef602976bb2c 100644
--- linux-libre-5.4.99-gnu/net/qrtr/qrtr.c
+++ linux-libre-5.4.100-gnu/net/qrtr/qrtr.c
@@ -187,7 +187,7 @@ static int qrtr_node_enqueue(struct qrtr_node *node, struct sk_buff *skb,
 	hdr->src_port_id = cpu_to_le32(from->sq_port);
 	if (to->sq_port == QRTR_PORT_CTRL) {
 		hdr->dst_node_id = cpu_to_le32(node->nid);
-		hdr->dst_port_id = cpu_to_le32(QRTR_NODE_BCAST);
+		hdr->dst_port_id = cpu_to_le32(QRTR_PORT_CTRL);
 	} else {
 		hdr->dst_node_id = cpu_to_le32(to->sq_node);
 		hdr->dst_port_id = cpu_to_le32(to->sq_port);
