1 files changed, 16 insertions, 44 deletions

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index c6144df47ea4..fe5551562dbc 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -72,15 +72,16 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
  * If access flags indicate ODP memory, avoid pinning. Instead, stores
  * the mm for future page fault handling in conjunction with MMU notifiers.
  *
- * @context: userspace context to pin memory for
+ * @udata: userspace context to pin memory for
  * @addr: userspace virtual address to start at
  * @size: length of region to pin
  * @access: IB_ACCESS_xxx flags for memory being pinned
  * @dmasync: flush in-flight DMA when the memory region is written
  */
-struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
+struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
 			    size_t size, int access, int dmasync)
 {
+	struct ib_ucontext *context;
 	struct ib_umem *umem;
 	struct page **page_list;
 	struct vm_area_struct **vma_list;
@@ -95,6 +96,14 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 	struct scatterlist *sg, *sg_list_start;
 	unsigned int gup_flags = FOLL_WRITE;
 
+	if (!udata)
+		return ERR_PTR(-EIO);
+
+	context = container_of(udata, struct uverbs_attr_bundle, driver_udata)
+			  ->context;
+	if (!context)
+		return ERR_PTR(-EIO);
+
 	if (dmasync)
 		dma_attrs |= DMA_ATTR_WRITE_BARRIER;
 
@@ -160,15 +169,12 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 
 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
-	down_write(&mm->mmap_sem);
-	if (check_add_overflow(mm->pinned_vm, npages, &new_pinned) ||
-	    (new_pinned > lock_limit && !capable(CAP_IPC_LOCK))) {
-		up_write(&mm->mmap_sem);
+	new_pinned = atomic64_add_return(npages, &mm->pinned_vm);
+	if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
+		atomic64_sub(npages, &mm->pinned_vm);
 		ret = -ENOMEM;
 		goto out;
 	}
-	mm->pinned_vm = new_pinned;
-	up_write(&mm->mmap_sem);
 
 	cur_base = addr & PAGE_MASK;
 
@@ -228,9 +234,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
 umem_release:
 	__ib_umem_release(context->device, umem, 0);
 vma:
-	down_write(&mm->mmap_sem);
-	mm->pinned_vm -= ib_umem_num_pages(umem);
-	up_write(&mm->mmap_sem);
+	atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
 out:
 	if (vma_list)
 		free_page((unsigned long) vma_list);
@@ -253,25 +257,12 @@ static void __ib_umem_release_tail(struct ib_umem *umem)
 		kfree(umem);
 }
 
-static void ib_umem_release_defer(struct work_struct *work)
-{
-	struct ib_umem *umem = container_of(work, struct ib_umem, work);
-
-	down_write(&umem->owning_mm->mmap_sem);
-	umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
-	up_write(&umem->owning_mm->mmap_sem);
-
-	__ib_umem_release_tail(umem);
-}
-
 /**
  * ib_umem_release - release memory pinned with ib_umem_get
  * @umem: umem struct to release
  */
 void ib_umem_release(struct ib_umem *umem)
 {
-	struct ib_ucontext *context = umem->context;
-
 	if (umem->is_odp) {
 		ib_umem_odp_release(to_ib_umem_odp(umem));
 		__ib_umem_release_tail(umem);
@@ -280,26 +271,7 @@ void ib_umem_release(struct ib_umem *umem)
 
 	__ib_umem_release(umem->context->device, umem, 1);
 
-	/*
-	 * We may be called with the mm's mmap_sem already held.  This
-	 * can happen when a userspace munmap() is the call that drops
-	 * the last reference to our file and calls our release
-	 * method.  If there are memory regions to destroy, we'll end
-	 * up here and not be able to take the mmap_sem.  In that case
-	 * we defer the vm_locked accounting a workqueue.
-	 */
-	if (context->closing) {
-		if (!down_write_trylock(&umem->owning_mm->mmap_sem)) {
-			INIT_WORK(&umem->work, ib_umem_release_defer);
-			queue_work(ib_wq, &umem->work);
-			return;
-		}
-	} else {
-		down_write(&umem->owning_mm->mmap_sem);
-	}
-	umem->owning_mm->pinned_vm -= ib_umem_num_pages(umem);
-	up_write(&umem->owning_mm->mmap_sem);
-
+	atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
 	__ib_umem_release_tail(umem);
 }
 EXPORT_SYMBOL(ib_umem_release);