diff --git a/drivers/staging/rdma/hfi1/mmu_rb.c b/drivers/staging/rdma/hfi1/mmu_rb.c
index c7ad0164ea9a..eac4d041d351 100644
--- a/drivers/staging/rdma/hfi1/mmu_rb.c
+++ b/drivers/staging/rdma/hfi1/mmu_rb.c
@@ -71,6 +71,7 @@ static inline void mmu_notifier_range_start(struct mmu_notifier *,
 					    struct mm_struct *,
 					    unsigned long, unsigned long);
 static void mmu_notifier_mem_invalidate(struct mmu_notifier *,
+					struct mm_struct *,
 					unsigned long, unsigned long);
 static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *,
 					   unsigned long, unsigned long);
@@ -137,7 +138,7 @@ void hfi1_mmu_rb_unregister(struct rb_root *root)
 			rbnode = rb_entry(node, struct mmu_rb_node, node);
 			rb_erase(node, root);
 			if (handler->ops->remove)
-				handler->ops->remove(root, rbnode, false);
+				handler->ops->remove(root, rbnode, NULL);
 		}
 	}
 
@@ -201,14 +202,14 @@ static struct mmu_rb_node *__mmu_rb_search(struct mmu_rb_handler *handler,
 }
 
 static void __mmu_rb_remove(struct mmu_rb_handler *handler,
-			    struct mmu_rb_node *node, bool arg)
+			    struct mmu_rb_node *node, struct mm_struct *mm)
 {
 	/* Validity of handler and node pointers has been checked by caller. */
 	hfi1_cdbg(MMU, "Removing node addr 0x%llx, len %u", node->addr,
 		  node->len);
 	__mmu_int_rb_remove(node, handler->root);
 	if (handler->ops->remove)
-		handler->ops->remove(handler->root, node, arg);
+		handler->ops->remove(handler->root, node, mm);
 }
 
 struct mmu_rb_node *hfi1_mmu_rb_search(struct rb_root *root, unsigned long addr,
@@ -237,7 +238,7 @@ void hfi1_mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node)
 		return;
 
 	spin_lock_irqsave(&handler->lock, flags);
-	__mmu_rb_remove(handler, node, false);
+	__mmu_rb_remove(handler, node, NULL);
 	spin_unlock_irqrestore(&handler->lock, flags);
 }
 
@@ -260,7 +261,7 @@ unlock:
 static inline void mmu_notifier_page(struct mmu_notifier *mn,
 				     struct mm_struct *mm, unsigned long addr)
 {
-	mmu_notifier_mem_invalidate(mn, addr, addr + PAGE_SIZE);
+	mmu_notifier_mem_invalidate(mn, mm, addr, addr + PAGE_SIZE);
 }
 
 static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
@@ -268,25 +269,28 @@ static inline void mmu_notifier_range_start(struct mmu_notifier *mn,
 					    unsigned long start,
 					    unsigned long end)
 {
-	mmu_notifier_mem_invalidate(mn, start, end);
+	mmu_notifier_mem_invalidate(mn, mm, start, end);
 }
 
 static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
+					struct mm_struct *mm,
 					unsigned long start, unsigned long end)
 {
 	struct mmu_rb_handler *handler =
 		container_of(mn, struct mmu_rb_handler, mn);
 	struct rb_root *root = handler->root;
-	struct mmu_rb_node *node;
+	struct mmu_rb_node *node, *ptr = NULL;
 	unsigned long flags;
 
 	spin_lock_irqsave(&handler->lock, flags);
-	for (node = __mmu_int_rb_iter_first(root, start, end - 1); node;
-	     node = __mmu_int_rb_iter_next(node, start, end - 1)) {
+	for (node = __mmu_int_rb_iter_first(root, start, end - 1);
+	     node; node = ptr) {
+		/* Guard against node removal. */
+		ptr = __mmu_int_rb_iter_next(node, start, end - 1);
 		hfi1_cdbg(MMU, "Invalidating node addr 0x%llx, len %u",
 			  node->addr, node->len);
 		if (handler->ops->invalidate(root, node))
-			__mmu_rb_remove(handler, node, true);
+			__mmu_rb_remove(handler, node, mm);
 	}
 	spin_unlock_irqrestore(&handler->lock, flags);
 }
diff --git a/drivers/staging/rdma/hfi1/mmu_rb.h b/drivers/staging/rdma/hfi1/mmu_rb.h
index f8523fdb8a18..19a306e83c7d 100644
--- a/drivers/staging/rdma/hfi1/mmu_rb.h
+++ b/drivers/staging/rdma/hfi1/mmu_rb.h
@@ -59,7 +59,8 @@ struct mmu_rb_node {
 struct mmu_rb_ops {
 	bool (*filter)(struct mmu_rb_node *, unsigned long, unsigned long);
 	int (*insert)(struct rb_root *, struct mmu_rb_node *);
-	void (*remove)(struct rb_root *, struct mmu_rb_node *, bool);
+	void (*remove)(struct rb_root *, struct mmu_rb_node *,
+		       struct mm_struct *);
 	int (*invalidate)(struct rb_root *, struct mmu_rb_node *);
 };
 
diff --git a/drivers/staging/rdma/hfi1/user_exp_rcv.c b/drivers/staging/rdma/hfi1/user_exp_rcv.c
index 0861e095df8d..5b72849bbd71 100644
--- a/drivers/staging/rdma/hfi1/user_exp_rcv.c
+++ b/drivers/staging/rdma/hfi1/user_exp_rcv.c
@@ -87,7 +87,8 @@ static u32 find_phys_blocks(struct page **, unsigned, struct tid_pageset *);
 static int set_rcvarray_entry(struct file *, unsigned long, u32,
 			      struct tid_group *, struct page **, unsigned);
 static int mmu_rb_insert(struct rb_root *, struct mmu_rb_node *);
-static void mmu_rb_remove(struct rb_root *, struct mmu_rb_node *, bool);
+static void mmu_rb_remove(struct rb_root *, struct mmu_rb_node *,
+			  struct mm_struct *);
 static int mmu_rb_invalidate(struct rb_root *, struct mmu_rb_node *);
 static int program_rcvarray(struct file *, unsigned long, struct tid_group *,
 			    struct tid_pageset *, unsigned, u16, struct page **,
@@ -899,7 +900,7 @@ static int unprogram_rcvarray(struct file *fp, u32 tidinfo,
 	if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 		return -EBADF;
 	if (HFI1_CAP_IS_USET(TID_UNMAP))
-		mmu_rb_remove(&fd->tid_rb_root, &node->mmu, false);
+		mmu_rb_remove(&fd->tid_rb_root, &node->mmu, NULL);
 	else
 		hfi1_mmu_rb_remove(&fd->tid_rb_root, &node->mmu);
 
@@ -965,7 +966,7 @@ static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 					continue;
 				if (HFI1_CAP_IS_USET(TID_UNMAP))
 					mmu_rb_remove(&fd->tid_rb_root,
-						      &node->mmu, false);
+						      &node->mmu, NULL);
 				else
 					hfi1_mmu_rb_remove(&fd->tid_rb_root,
 							   &node->mmu);
@@ -1032,7 +1033,7 @@ static int mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *node)
 }
 
 static void mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node,
-			  bool notifier)
+			  struct mm_struct *mm)
 {
 	struct hfi1_filedata *fdata =
 		container_of(root, struct hfi1_filedata, tid_rb_root);
diff --git a/drivers/staging/rdma/hfi1/user_sdma.c b/drivers/staging/rdma/hfi1/user_sdma.c
index ab6b6a42000f..e08c74fe4c6b 100644
--- a/drivers/staging/rdma/hfi1/user_sdma.c
+++ b/drivers/staging/rdma/hfi1/user_sdma.c
@@ -299,7 +299,8 @@ static int defer_packet_queue(
 static void activate_packet_queue(struct iowait *, int);
 static bool sdma_rb_filter(struct mmu_rb_node *, unsigned long, unsigned long);
 static int sdma_rb_insert(struct rb_root *, struct mmu_rb_node *);
-static void sdma_rb_remove(struct rb_root *, struct mmu_rb_node *, bool);
+static void sdma_rb_remove(struct rb_root *, struct mmu_rb_node *,
+			   struct mm_struct *);
 static int sdma_rb_invalidate(struct rb_root *, struct mmu_rb_node *);
 
 static struct mmu_rb_ops sdma_rb_ops = {
@@ -1063,8 +1064,10 @@ static int pin_vector_pages(struct user_sdma_request *req,
 	rb_node = hfi1_mmu_rb_search(&pq->sdma_rb_root,
 				     (unsigned long)iovec->iov.iov_base,
 				     iovec->iov.iov_len);
-	if (rb_node)
+	if (rb_node && !IS_ERR(rb_node))
 		node = container_of(rb_node, struct sdma_mmu_node, rb);
+	else
+		rb_node = NULL;
 
 	if (!node) {
 		node = kzalloc(sizeof(*node), GFP_KERNEL);
@@ -1502,7 +1505,7 @@ static void user_sdma_free_request(struct user_sdma_request *req, bool unpin)
 				&req->pq->sdma_rb_root,
 				(unsigned long)req->iovs[i].iov.iov_base,
 				req->iovs[i].iov.iov_len);
-			if (!mnode)
+			if (!mnode || IS_ERR(mnode))
 				continue;
 
 			node = container_of(mnode, struct sdma_mmu_node, rb);
@@ -1547,7 +1550,7 @@ static int sdma_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
 }
 
 static void sdma_rb_remove(struct rb_root *root, struct mmu_rb_node *mnode,
-			   bool notifier)
+			   struct mm_struct *mm)
 {
 	struct sdma_mmu_node *node =
 		container_of(mnode, struct sdma_mmu_node, rb);
@@ -1557,14 +1560,19 @@ static void sdma_rb_remove(struct rb_root *root, struct mmu_rb_node *mnode,
 	node->pq->n_locked -= node->npages;
 	spin_unlock(&node->pq->evict_lock);
 
-	unpin_vector_pages(notifier ? NULL : current->mm, node->pages,
-			   node->npages);
+	/*
+	 * If mm is set, we are being called by the MMU notifier and we
+	 * should not pass a mm_struct to unpin_vector_page(). This is to
+	 * prevent a deadlock when hfi1_release_user_pages() attempts to
+	 * take the mmap_sem, which the MMU notifier has already taken.
+	 */
+	unpin_vector_pages(mm ? NULL : current->mm, node->pages, node->npages);
 	/*
 	 * If called by the MMU notifier, we have to adjust the pinned
 	 * page count ourselves.
 	 */
-	if (notifier)
-		current->mm->pinned_vm -= node->npages;
+	if (mm)
+		mm->pinned_vm -= node->npages;
 	kfree(node);
 }