IB/umem: Fix possible hang on process exit

[linux-2.6] / drivers / infiniband / core / umem.c

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index b4aec5103c9921dafc31210ba1c0f6d6f8cbbd40..d40652a801511b597b17de382c243d6d45adc3ef 100644 (file)
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -225,13 +225,15 @@ void ib_umem_release(struct ib_umem *umem)
         * up here and not be able to take the mmap_sem.  In that case
         * we defer the vm_locked accounting to the system workqueue.
         */
-       if (context->closing && !down_write_trylock(&mm->mmap_sem)) {
-               INIT_WORK(&umem->work, ib_umem_account);
-               umem->mm   = mm;
-               umem->diff = diff;
-
-               schedule_work(&umem->work);
-               return;
+       if (context->closing) {
+               if (!down_write_trylock(&mm->mmap_sem)) {
+                       INIT_WORK(&umem->work, ib_umem_account);
+                       umem->mm   = mm;
+                       umem->diff = diff;
+
+                       schedule_work(&umem->work);
+                       return;
+               }
        } else
                down_write(&mm->mmap_sem);