LU-12275 sec: atomicity of encryption context getting/setting

[fs/lustre-release.git] / lustre / mdt / mdt_lib.c

diff --git a/lustre/mdt/mdt_lib.c b/lustre/mdt/mdt_lib.c
index 96d4078..f3a0d42 100644 (file)
--- a/lustre/mdt/mdt_lib.c
+++ b/lustre/mdt/mdt_lib.c
@@ -795,6 +795,12 @@ int mdt_fix_reply(struct mdt_thread_info *info)
            !(body->mbo_valid & OBD_MD_SECCTX))
                req_capsule_shrink(pill, &RMF_FILE_SECCTX, 0, RCL_SERVER);
 
+       /* Shrink optional ENCCTX buffer if it is not used */
+       if (req_capsule_has_field(pill, &RMF_FILE_ENCCTX, RCL_SERVER) &&
+           req_capsule_get_size(pill, &RMF_FILE_ENCCTX, RCL_SERVER) != 0 &&
+           !(body->mbo_valid & OBD_MD_ENCCTX))
+               req_capsule_shrink(pill, &RMF_FILE_ENCCTX, 0, RCL_SERVER);
+
        /*
         * Some more field should be shrinked if needed.
         * This should be done by those who added fields to reply message.
@@ -1085,6 +1091,28 @@ static int mdt_file_secctx_unpack(struct req_capsule *pill,
        return 0;
 }
 
+static int mdt_file_encctx_unpack(struct req_capsule *pill,
+                                 void **encctx, size_t *encctx_size)
+{
+       *encctx = NULL;
+       *encctx_size = 0;
+
+       if (!exp_connect_encrypt(pill->rc_req->rq_export))
+               return 0;
+
+       if (!req_capsule_has_field(pill, &RMF_FILE_ENCCTX, RCL_CLIENT) ||
+           !req_capsule_field_present(pill, &RMF_FILE_ENCCTX, RCL_CLIENT))
+               return -EPROTO;
+
+       *encctx_size = req_capsule_get_size(pill, &RMF_FILE_ENCCTX, RCL_CLIENT);
+       if (*encctx_size == 0)
+               return 0;
+
+       *encctx = req_capsule_client_get(pill, &RMF_FILE_ENCCTX);
+
+       return 0;
+}
+
 static int mdt_setattr_unpack_rec(struct mdt_thread_info *info)
 {
        struct lu_ucred *uc = mdt_ucred(info);
@@ -1318,6 +1346,11 @@ static int mdt_create_unpack(struct mdt_thread_info *info)
        if (rc < 0)
                RETURN(rc);
 
+       rc = mdt_file_encctx_unpack(pill, &sp->sp_cr_file_encctx,
+                                   &sp->sp_cr_file_encctx_size);
+       if (rc < 0)
+               RETURN(rc);
+
        rc = req_check_sepol(pill);
        if (rc)
                RETURN(rc);
@@ -1648,6 +1681,11 @@ static int mdt_open_unpack(struct mdt_thread_info *info)
        if (rc < 0)
                RETURN(rc);
 
+       rc = mdt_file_encctx_unpack(pill, &sp->sp_cr_file_encctx,
+                                   &sp->sp_cr_file_encctx_size);
+       if (rc < 0)
+               RETURN(rc);
+
        rc = req_check_sepol(pill);
        if (rc)
                RETURN(rc);
@@ -1963,3 +2001,72 @@ int mdt_is_remote_object(struct mdt_thread_info *info,
 
        RETURN(0);
 }
+
+int mdt_pack_encctx_in_reply(struct mdt_thread_info *info,
+                            struct mdt_object *child)
+{
+       struct lu_buf *buffer;
+       struct mdt_body *repbody;
+       struct req_capsule *pill = info->mti_pill;
+       struct obd_export *exp = mdt_info_req(info)->rq_export;
+       int rc = 0;
+
+       if (!exp_connect_encrypt(exp))
+               return rc;
+
+       if (req_capsule_has_field(pill, &RMF_FILE_ENCCTX, RCL_SERVER) &&
+           req_capsule_get_size(pill, &RMF_FILE_ENCCTX, RCL_SERVER) != 0) {
+               struct lu_attr la = { 0 };
+               struct dt_object *dt = mdt_obj2dt(child);
+
+               if (dt && dt->do_ops && dt->do_ops->do_attr_get)
+                       dt_attr_get(info->mti_env, mdt_obj2dt(child), &la);
+
+               if (la.la_valid & LA_FLAGS && la.la_flags & LUSTRE_ENCRYPT_FL) {
+                       buffer = &info->mti_buf;
+
+                       /* fill reply buffer with encryption context now */
+                       buffer->lb_len =
+                               req_capsule_get_size(pill, &RMF_FILE_ENCCTX,
+                                                    RCL_SERVER);
+                       buffer->lb_buf =
+                               req_capsule_server_get(pill, &RMF_FILE_ENCCTX);
+                       rc = mo_xattr_get(info->mti_env,
+                                         mdt_object_child(child),
+                                         buffer,
+                                         LL_XATTR_NAME_ENCRYPTION_CONTEXT);
+                       if (rc >= 0) {
+                               CDEBUG(D_SEC,
+                                      "found encryption ctx of size %d for "DFID"\n",
+                                      rc, PFID(mdt_object_fid(child)));
+
+                               repbody = req_capsule_server_get(pill,
+                                                                &RMF_MDT_BODY);
+                               repbody->mbo_valid |= OBD_MD_ENCCTX;
+                               if (rc < buffer->lb_len)
+                                       req_capsule_shrink(pill,
+                                                          &RMF_FILE_ENCCTX, rc,
+                                                          RCL_SERVER);
+                               rc = 0;
+                       } else {
+                               CDEBUG(D_SEC,
+                                      "encryption ctx not found for "DFID": rc = %d\n",
+                                      PFID(mdt_object_fid(child)), rc);
+                               req_capsule_shrink(pill, &RMF_FILE_ENCCTX, 0,
+                                                  RCL_SERVER);
+                               /* handling -ENOENT is important because it may
+                                * change object state in DNE env dropping
+                                * LOHA_EXISTS flag, it is important to return
+                                * that to the caller.
+                                * Check LU-13115 for details.
+                                */
+                               if (rc != -ENOENT)
+                                       rc = 0;
+                       }
+               } else {
+                       req_capsule_shrink(pill, &RMF_FILE_ENCCTX, 0,
+                                          RCL_SERVER);
+               }
+       }
+       return rc;
+}