IB/hfi1: Assign context does not clean up file descriptor correctly on error

In the error path for context allocation, the file descriptor pointer
should not point to a context when an error occurs.

Clean up the appropriate references on error.

Fixes: Commit 62239fc6e5545b2e59f83dfbc5db231a81f37a45 ("IB/hfi1: Clean up on context initialization failure")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/file_ops.c

@@ -94,6 +94,7 @@ static int find_sub_ctxt(struct hfi1_filedata *fd,
 			 const struct hfi1_user_info *uinfo);
 static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
 			 struct hfi1_user_info *uinfo);
+static void deallocate_ctxt(struct hfi1_ctxtdata *uctxt);
 static unsigned int poll_urgent(struct file *fp, struct poll_table_struct *pt);
 static unsigned int poll_next(struct file *fp, struct poll_table_struct *pt);
 static int user_event_ack(struct hfi1_ctxtdata *uctxt, u16 subctxt,
@@ -813,15 +814,9 @@ static int hfi1_file_close(struct inode *inode, struct file *fp)
 	uctxt->rcvnowait = 0;
 	uctxt->pionowait = 0;
 	uctxt->event_flags = 0;
-
-	hfi1_stats.sps_ctxts--;
-	if (++dd->freectxts == dd->num_user_contexts)
-		aspm_enable_all(dd);
-
-	/* _rcd_put() should be done after releasing mutex */
-	dd->rcd[uctxt->ctxt] = NULL;
 	mutex_unlock(&hfi1_mutex);
-	hfi1_rcd_put(uctxt);  /* dd reference */
+
+	deallocate_ctxt(uctxt);
 done:
 	mmdrop(fdata->mm);
 	kobject_put(&dd->kobj);
@@ -898,10 +893,9 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
 		if (!ret)
 			ret = init_user_ctxt(fd);
 
-		if (ret) {
+		if (ret)
 			clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
-			hfi1_rcd_put(fd->uctxt);
-		}
+
 	} else if (!ret) {
 		ret = setup_base_ctxt(fd);
 		if (fd->uctxt->subctxt_cnt) {
@@ -917,6 +911,14 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
 				  &fd->uctxt->event_flags);
 			wake_up(&fd->uctxt->wait);
 		}
+		if (ret)
+			deallocate_ctxt(fd->uctxt);
+	}
+
+	/* If an error occurred, clear the reference */
+	if (ret && fd->uctxt) {
+		hfi1_rcd_put(fd->uctxt);
+		fd->uctxt = NULL;
 	}
 
 	return ret;
@@ -1087,6 +1089,19 @@ ctxdata_free:
 	return ret;
 }
 
+static void deallocate_ctxt(struct hfi1_ctxtdata *uctxt)
+{
+	mutex_lock(&hfi1_mutex);
+	hfi1_stats.sps_ctxts--;
+	if (++uctxt->dd->freectxts == uctxt->dd->num_user_contexts)
+		aspm_enable_all(uctxt->dd);
+
+	/* _rcd_put() should be done after releasing mutex */
+	uctxt->dd->rcd[uctxt->ctxt] = NULL;
+	mutex_unlock(&hfi1_mutex);
+	hfi1_rcd_put(uctxt);  /* dd reference */
+}
+
 static int init_subctxts(struct hfi1_ctxtdata *uctxt,
 			 const struct hfi1_user_info *uinfo)
 {