LU-16634 misc: standardize iocontrol param handling

[fs/lustre-release.git] / lustre / mdc / mdc_request.c

diff --git a/lustre/mdc/mdc_request.c b/lustre/mdc/mdc_request.c
index dd69a1d..f87acc7 100644 (file)
--- a/lustre/mdc/mdc_request.c
+++ b/lustre/mdc/mdc_request.c
@@ -2197,7 +2197,7 @@ static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
                         void *karg, void __user *uarg)
 {
        struct obd_device *obd = exp->exp_obd;
-       struct obd_ioctl_data *data = karg;
+       struct obd_ioctl_data *data;
        struct obd_import *imp = obd->u.cli.cl_import;
        int rc;
 
@@ -2205,6 +2205,19 @@ static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
        CDEBUG(D_IOCTL, "%s: cmd=%x len=%u karg=%pK uarg=%pK\n",
               obd->obd_name, cmd, len, karg, uarg);
 
+       /* handle commands that do not need @karg first */
+       switch (cmd) {
+       case LL_IOC_GET_CONNECT_FLAGS:
+               if (copy_to_user(uarg, exp_connect_flags_ptr(exp),
+                                sizeof(*exp_connect_flags_ptr(exp))))
+                       RETURN(-EFAULT);
+               RETURN(0);
+       }
+
+       if (unlikely(karg == NULL))
+               RETURN(OBD_IOC_ERROR(obd->obd_name, cmd, "karg=NULL", -EINVAL));
+       data = karg;
+
        if (!try_module_get(THIS_MODULE)) {
                CERROR("%s: cannot get module '%s'\n", obd->obd_name,
                       module_name(THIS_MODULE));
@@ -2294,12 +2307,6 @@ static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
                OBD_FREE_PTR(oqctl);
                GOTO(out, rc);
        }
-       case LL_IOC_GET_CONNECT_FLAGS:
-               if (copy_to_user(uarg, exp_connect_flags_ptr(exp),
-                                sizeof(*exp_connect_flags_ptr(exp))))
-                       GOTO(out, rc = -EFAULT);
-
-               GOTO(out, rc = 0);
        case LL_IOC_LOV_SWAP_LAYOUTS:
                rc = mdc_ioc_swap_layouts(exp, karg);
                GOTO(out, rc);