[LU-16077] Cannot use tbf to filter brw request per effective uid/gid, inode attr ids is used instead

Related — Wed, 27 Sep 2023 11:18:32 +0000

Recently, we had to limit a user on an OST of products (lot of libs in it). But we were not able to do that with TBF. After some tries, we were able to set a limit, but with the GID's owner.
Setting this limit, globally decrease the bandwidth for everybody (all files in the products have the same uid/gid).

The TBF rules on an OST get the uid/gid values from:

static int ost_tbf_id_cli_set(struct ptlrpc_request *req,
                              struct tbf_id *id)         
        struct ost_body *body; 
...
                 id->ti_uid = body->oa.o_uid;
                 id->ti_gid = body->oa.o_gid;

These values are filled by the osc here:

int osc_build_rpc(const struct lu_env *env, struct client_obd *cli,
                  struct list_head *ext_list, int cmd)             
....
         crattr->cra_oa = oa;                      
         cl_req_attr_set(env, osc2cl(obj), crattr);


static int                                                            
osc_brw_prep_request(int cmd, struct client_obd *cli, struct obdo *oa,
                     u32 page_count, struct brw_page **pga,           
                     struct ptlrpc_request **reqp, int resend)        
.....
        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa, oa); 
                                                                                
        /* For READ and WRITE, we can't fill o_uid and o_gid using from_kuid()  
         * and from_kgid(), because they are asynchronous. Fortunately, variable
         * oa contains valid o_uid and o_gid in these two operations.           
         * Besides, filling o_uid and o_gid is enough for nrs-tbf, see LU-9658. 
         * OBD_MD_FLUID and OBD_MD_FLUID is not set in order to avoid breaking  
         * other process logic */                                               
        body->oa.o_uid = oa->o_uid;                                             
        body->oa.o_gid = oa->o_gid;

So the uid/gid use to filter the request came directly from the inode attr.

Whamcloud Community JIRA

[LU-16077] Cannot use tbf to filter brw request per effective uid/gid, inode attr ids is used instead