LU-2986 mdc: Kernel Oops on ioctl LL_IOC_GET_MDTIDX

ll_get_mdt_idx() calls md_getattr() with a NULL 3rd
parameter as a (struct ptlrpc_request **), this can
lead to a SEGV if lmv is skipped, like for a
single-MDS system without an LMV, and mdc_gettatr()
is called straight.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: I0f9e5f6a4ae09c9e9a26b231d26b803418827c23
Reviewed-on: http://review.whamcloud.com/5769
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Ned Bass <bass6@llnl.gov>

diff --git a/lustre/mdc/mdc_request.c b/lustre/mdc/mdc_request.c
index 9f3dea4..f068026 100644 (file)
--- a/lustre/mdc/mdc_request.c
+++ b/lustre/mdc/mdc_request.c
@@ -225,6 +225,11 @@ int mdc_getattr(struct obd_export *exp, struct md_op_data *op_data,
         int                    rc;
         ENTRY;
 
         int                    rc;
         ENTRY;
 

+       /* Single MDS without an LMV case */
+       if (op_data->op_flags & MF_GET_MDT_IDX) {
+               op_data->op_mds = 0;
+               RETURN(0);
+       }

         *request = NULL;
         req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_GETATTR);
         if (req == NULL)
         *request = NULL;
         req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_GETATTR);
         if (req == NULL)