RDMA/ucontext: Get rid of the old disassociate flow

The disassociate_ucontext function in every driver is now empty, so we
don't need this ugly and wrong code that was messing with tgids.

rdma_user_mmap_io does this same work in a better way.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index 06d31fe..6a3acf4 100644 (file)
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -794,44 +794,6 @@ void uverbs_close_fd(struct file *f)
        uverbs_uobject_put(uobj);
 }
 
-static void ufile_disassociate_ucontext(struct ib_ucontext *ibcontext)
-{
-       struct ib_device *ib_dev = ibcontext->device;
-       struct task_struct *owning_process  = NULL;
-       struct mm_struct   *owning_mm       = NULL;
-
-       owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
-       if (!owning_process)
-               return;
-
-       owning_mm = get_task_mm(owning_process);
-       if (!owning_mm) {
-               pr_info("no mm, disassociate ucontext is pending task termination\n");
-               while (1) {
-                       put_task_struct(owning_process);
-                       usleep_range(1000, 2000);
-                       owning_process = get_pid_task(ibcontext->tgid,
-                                                     PIDTYPE_PID);
-                       if (!owning_process ||
-                           owning_process->state == TASK_DEAD) {
-                               pr_info("disassociate ucontext done, task was terminated\n");
-                               /* in case task was dead need to release the
-                                * task struct.
-                                */
-                               if (owning_process)
-                                       put_task_struct(owning_process);
-                               return;
-                       }
-               }
-       }
-
-       down_write(&owning_mm->mmap_sem);
-       ib_dev->disassociate_ucontext(ibcontext);
-       up_write(&owning_mm->mmap_sem);
-       mmput(owning_mm);
-       put_task_struct(owning_process);
-}
-
 /*
  * Drop the ucontext off the ufile and completely disconnect it from the
  * ib_device
@@ -840,22 +802,29 @@ static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile,
                                   enum rdma_remove_reason reason)
 {
        struct ib_ucontext *ucontext = ufile->ucontext;
+       struct ib_device *ib_dev = ucontext->device;
        int ret;
 
+       /*
+        * If we are closing the FD then the user mmap VMAs must have
+        * already been destroyed as they hold on to the filep, otherwise
+        * they need to be zap'd.
+        */
        if (reason == RDMA_REMOVE_DRIVER_REMOVE) {
                uverbs_user_mmap_disassociate(ufile);
-               ufile_disassociate_ucontext(ucontext);
+               if (ib_dev->disassociate_ucontext)
+                       ib_dev->disassociate_ucontext(ucontext);
        }
 
        put_pid(ucontext->tgid);
-       ib_rdmacg_uncharge(&ucontext->cg_obj, ucontext->device,
+       ib_rdmacg_uncharge(&ucontext->cg_obj, ib_dev,
                           RDMACG_RESOURCE_HCA_HANDLE);
 
        /*
         * FIXME: Drivers are not permitted to fail dealloc_ucontext, remove
         * the error return.
         */
-       ret = ucontext->device->dealloc_ucontext(ucontext);
+       ret = ib_dev->dealloc_ucontext(ucontext);
        WARN_ON(ret);
 
        ufile->ucontext = NULL;