1 files changed, 9 insertions, 56 deletions

diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 49275a548751..06862a6af185 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -47,8 +47,6 @@
 #include "usnic_uiom.h"
 #include "usnic_uiom_interval_tree.h"
 
-static struct workqueue_struct *usnic_uiom_wq;
-
 #define USNIC_UIOM_PAGE_CHUNK						\
 	((PAGE_SIZE - offsetof(struct usnic_uiom_chunk, page_list))	/\
 	((void *) &((struct usnic_uiom_chunk *) 0)->page_list[1] -	\
@@ -127,9 +125,9 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 	npages = PAGE_ALIGN(size + (addr & ~PAGE_MASK)) >> PAGE_SHIFT;
 
 	uiomr->owning_mm = mm = current->mm;
-	down_write(&mm->mmap_sem);
+	down_read(&mm->mmap_sem);
 
-	locked = npages + current->mm->pinned_vm;
+	locked = atomic64_add_return(npages, &current->mm->pinned_vm);
 	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 
 	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
@@ -157,9 +155,8 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 		off = 0;
 
 		while (ret) {
-			chunk = kmalloc(sizeof(*chunk) +
-					sizeof(struct scatterlist) *
-					min_t(int, ret, USNIC_UIOM_PAGE_CHUNK),
+			chunk = kmalloc(struct_size(chunk, page_list,
+					min_t(int, ret, USNIC_UIOM_PAGE_CHUNK)),
 					GFP_KERNEL);
 			if (!chunk) {
 				ret = -ENOMEM;
@@ -185,14 +182,13 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable,
 	}
 
 out:
-	if (ret < 0)
+	if (ret < 0) {
 		usnic_uiom_put_pages(chunk_list, 0);
-	else {
-		mm->pinned_vm = locked;
+		atomic64_sub(npages, &current->mm->pinned_vm);
+	} else
 		mmgrab(uiomr->owning_mm);
-	}
 
-	up_write(&mm->mmap_sem);
+	up_read(&mm->mmap_sem);
 	free_page((unsigned long) page_list);
 	return ret;
 }
@@ -436,43 +432,12 @@ static inline size_t usnic_uiom_num_pages(struct usnic_uiom_reg *uiomr)
 	return PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
 }
 
-static void usnic_uiom_release_defer(struct work_struct *work)
-{
-	struct usnic_uiom_reg *uiomr =
-		container_of(work, struct usnic_uiom_reg, work);
-
-	down_write(&uiomr->owning_mm->mmap_sem);
-	uiomr->owning_mm->pinned_vm -= usnic_uiom_num_pages(uiomr);
-	up_write(&uiomr->owning_mm->mmap_sem);
-
-	__usnic_uiom_release_tail(uiomr);
-}
-
 void usnic_uiom_reg_release(struct usnic_uiom_reg *uiomr,
 			    struct ib_ucontext *context)
 {
 	__usnic_uiom_reg_release(uiomr->pd, uiomr, 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 to a workqueue.
-	 */
-	if (context->closing) {
-		if (!down_write_trylock(&uiomr->owning_mm->mmap_sem)) {
-			INIT_WORK(&uiomr->work, usnic_uiom_release_defer);
-			queue_work(usnic_uiom_wq, &uiomr->work);
-			return;
-		}
-	} else {
-		down_write(&uiomr->owning_mm->mmap_sem);
-	}
-	uiomr->owning_mm->pinned_vm -= usnic_uiom_num_pages(uiomr);
-	up_write(&uiomr->owning_mm->mmap_sem);
-
+	atomic64_sub(usnic_uiom_num_pages(uiomr), &uiomr->owning_mm->pinned_vm);
 	__usnic_uiom_release_tail(uiomr);
 }
 
@@ -601,17 +566,5 @@ int usnic_uiom_init(char *drv_name)
 		return -EPERM;
 	}
 
-	usnic_uiom_wq = create_workqueue(drv_name);
-	if (!usnic_uiom_wq) {
-		usnic_err("Unable to alloc wq for drv %s\n", drv_name);
-		return -ENOMEM;
-	}
-
 	return 0;
 }
-
-void usnic_uiom_fini(void)
-{
-	flush_workqueue(usnic_uiom_wq);
-	destroy_workqueue(usnic_uiom_wq);
-}