path: root/xlators/experimental/jbr-server/src/all-templates.c

/*
 * You can put anything here - it doesn't even have to be a comment - and it
 * will be ignored until we reach the first template-name comment.
 */


/* template-name read-fop */
int32_t
jbr_@NAME@ (call_frame_t *frame, xlator_t *this,
            @LONG_ARGS@)
{
        jbr_private_t   *priv     = NULL;
        gf_boolean_t     in_recon = _gf_false;
        int32_t          op_errno = 0;
        int32_t          recon_term, recon_index;

        GF_VALIDATE_OR_GOTO ("jbr", this, err);
        priv = this->private;
        GF_VALIDATE_OR_GOTO (this->name, priv, err);
        GF_VALIDATE_OR_GOTO (this->name, frame, err);

        op_errno = EREMOTE;

        /* allow reads during reconciliation       *
         * TBD: allow "dirty" reads on non-leaders *
         */
        if (xdata &&
            (dict_get_int32(xdata, RECON_TERM_XATTR, &recon_term) == 0) &&
            (dict_get_int32(xdata, RECON_INDEX_XATTR, &recon_index) == 0)) {
                in_recon = _gf_true;
        }

        if ((!priv->leader) && (in_recon == _gf_false)) {
                goto err;
        }

        STACK_WIND (frame, default_@NAME@_cbk,
                    FIRST_CHILD(this), FIRST_CHILD(this)->fops->@NAME@,
                    @SHORT_ARGS@);
        return 0;

err:
        STACK_UNWIND_STRICT (@NAME@, frame, -1, op_errno,
                             @ERROR_ARGS@);
        return 0;
}

/* template-name read-perform_local_op */
/* No "perform_local_op" function needed for @NAME@ */

/* template-name read-dispatch */
/* No "dispatch" function needed for @NAME@ */

/* template-name read-call_dispatch */
/* No "call_dispatch" function needed for @NAME@ */

/* template-name read-fan-in */
/* No "fan-in" function needed for @NAME@ */

/* template-name read-continue */
/* No "continue" function needed for @NAME@ */

/* template-name read-complete */
/* No "complete" function needed for @NAME@ */

/* template-name write-fop */
int32_t
jbr_@NAME@ (call_frame_t *frame, xlator_t *this,
            @LONG_ARGS@)
{
        jbr_local_t     *local         = NULL;
        jbr_private_t   *priv          = NULL;
        int32_t          ret           = -1;
        int              op_errno      = ENOMEM;

        GF_VALIDATE_OR_GOTO ("jbr", this, err);
        priv = this->private;
        GF_VALIDATE_OR_GOTO (this->name, priv, err);
        GF_VALIDATE_OR_GOTO (this->name, frame, err);

#if defined(JBR_CG_NEED_FD)
        ret = jbr_leader_checks_and_init (frame, this, &op_errno, xdata, fd);
#else
        ret = jbr_leader_checks_and_init (frame, this, &op_errno, xdata, NULL);
#endif
        if (ret)
                goto err;

        local = frame->local;

        /*
         * If we let it through despite not being the leader, then we just want
         * to pass it on down without all of the additional xattrs, queuing, and
         * so on.  However, jbr_*_complete does depend on the initialization
         * immediately above this.
         */
        if (!priv->leader) {
                STACK_WIND (frame, jbr_@NAME@_complete,
                            FIRST_CHILD(this), FIRST_CHILD(this)->fops->@NAME@,
                            @SHORT_ARGS@);
                return 0;
        }

        ret = jbr_initialize_xdata_set_attrs (this, &xdata);
        if (ret)
                goto err;

        local->xdata = dict_ref(xdata);
        local->stub = fop_@NAME@_stub (frame, jbr_@NAME@_continue,
                                       @SHORT_ARGS@);
        if (!local->stub) {
                goto err;
        }

        /*
         * Can be used to just call_dispatch or be customised per fop to *
         * perform ops specific to that particular fop.                  *
         */
        ret = jbr_@NAME@_perform_local_op (frame, this, &op_errno,
                                           @SHORT_ARGS@);
        if (ret)
                goto err;

        return ret;
err:
        if (local) {
                if (local->stub) {
                        call_stub_destroy(local->stub);
                }
                if (local->qstub) {
                        call_stub_destroy(local->qstub);
                }
                if (local->fd) {
                        fd_unref(local->fd);
                }
                mem_put(local);
        }
        STACK_UNWIND_STRICT (@NAME@, frame, -1, op_errno,
                             @ERROR_ARGS@);
        return 0;
}

/* template-name write-perform_local_op */
int32_t
jbr_@NAME@_perform_local_op (call_frame_t *frame, xlator_t *this, int *op_errno,
                             @LONG_ARGS@)
{
        int32_t          ret    = -1;

        GF_VALIDATE_OR_GOTO ("jbr", this, out);
        GF_VALIDATE_OR_GOTO (this->name, frame, out);
        GF_VALIDATE_OR_GOTO (this->name, op_errno, out);

        ret = jbr_@NAME@_call_dispatch (frame, this, op_errno,
                                        @SHORT_ARGS@);

out:
        return ret;
}

/* template-name write-call_dispatch */
int32_t
jbr_@NAME@_call_dispatch (call_frame_t *frame, xlator_t *this, int *op_errno,
                          @LONG_ARGS@)
{
        jbr_local_t     *local  = NULL;
        jbr_private_t   *priv   = NULL;
        int32_t          ret    = -1;

        GF_VALIDATE_OR_GOTO ("jbr", this, out);
        priv = this->private;
        GF_VALIDATE_OR_GOTO (this->name, priv, out);
        GF_VALIDATE_OR_GOTO (this->name, frame, out);
        local = frame->local;
        GF_VALIDATE_OR_GOTO (this->name, local, out);
        GF_VALIDATE_OR_GOTO (this->name, op_errno, out);

#if defined(JBR_CG_QUEUE)
        jbr_inode_ctx_t  *ictx  = jbr_get_inode_ctx(this, fd->inode);
        if (!ictx) {
                *op_errno = EIO;
                goto out;
        }

        LOCK(&ictx->lock);
                if (ictx->active) {
                        gf_msg_debug (this->name, 0,
                                      "queuing request due to conflict");
                        /*
                         * TBD: enqueue only for real conflict
                         *
                         * Currently we just act like all writes are in
                         * conflict with one another.  What we should really do
                         * is check the active/pending queues and defer only if
                         * there's a conflict there.
                         *
                         * It's important to check the pending queue because we
                         * might have an active request X which conflicts with
                         * a pending request Y, and this request Z might
                         * conflict with Y but not X.  If we checked only the
                         * active queue then Z could jump ahead of Y, which
                         * would be incorrect.
                         */
                        local->qstub = fop_@NAME@_stub (frame,
                                                        jbr_@NAME@_dispatch,
                                                        @SHORT_ARGS@);
                        if (!local->qstub) {
                                UNLOCK(&ictx->lock);
                                goto out;
                        }
                        list_add_tail(&local->qlinks, &ictx->pqueue);
                        ++(ictx->pending);
                        UNLOCK(&ictx->lock);
                        ret = 0;
                        goto out;
                } else {
                        list_add_tail(&local->qlinks, &ictx->aqueue);
                        ++(ictx->active);
                }
        UNLOCK(&ictx->lock);
#endif
        ret = jbr_@NAME@_dispatch (frame, this, @SHORT_ARGS@);

out:
        return ret;
}

/* template-name write-dispatch */
int32_t
jbr_@NAME@_dispatch (call_frame_t *frame, xlator_t *this,
                     @LONG_ARGS@)
{
        jbr_local_t     *local  = NULL;
        jbr_private_t   *priv   = NULL;
        int32_t          ret    = -1;
        xlator_list_t   *trav;

        GF_VALIDATE_OR_GOTO ("jbr", this, out);
        priv = this->private;
        GF_VALIDATE_OR_GOTO (this->name, priv, out);
        GF_VALIDATE_OR_GOTO (this->name, frame, out);
        local = frame->local;
        GF_VALIDATE_OR_GOTO (this->name, local, out);

        /*
         * TBD: unblock pending request(s) if we fail after this point but
         * before we get to jbr_@NAME@_complete (where that code currently
         * resides).
         */

        local->call_count = priv->n_children - 1;
        for (trav = this->children->next; trav; trav = trav->next) {
                STACK_WIND (frame, jbr_@NAME@_fan_in,
                            trav->xlator, trav->xlator->fops->@NAME@,
                            @SHORT_ARGS@);
        }

        /* TBD: variable Issue count */
        ret = 0;
out:
        return ret;
}

/* template-name write-fan-in */
int32_t
jbr_@NAME@_fan_in (call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno,
                   @LONG_ARGS@)
{
        jbr_local_t   *local  = NULL;
        int32_t        ret    = -1;
        uint8_t        call_count;

        GF_VALIDATE_OR_GOTO ("jbr", this, out);
        GF_VALIDATE_OR_GOTO (this->name, frame, out);
        local = frame->local;
        GF_VALIDATE_OR_GOTO (this->name, local, out);

        gf_msg_trace (this->name, 0, "op_ret = %d, op_errno = %d\n",
                      op_ret, op_errno);

        LOCK(&frame->lock);
        call_count = --(local->call_count);
        if (op_ret != -1) {
                /* Increment the number of successful acks *
                 * received for the operation.             *
                 */
                (local->successful_acks)++;
                local->successful_op_ret = op_ret;
        }
        gf_msg_debug (this->name, 0, "succ_acks = %d, op_ret = %d, op_errno = %d\n",
                      op_ret, op_errno, local->successful_acks);
        UNLOCK(&frame->lock);

        /* TBD: variable Completion count */
        if (call_count == 0) {
                call_resume(local->stub);
        }

        ret = 0;
out:
        return ret;
}

/* template-name write-continue */
int32_t
jbr_@NAME@_continue (call_frame_t *frame, xlator_t *this,
                     @LONG_ARGS@)
{
        int32_t          ret       = -1;
        gf_boolean_t     result    = _gf_false;
        jbr_local_t     *local     = NULL;
        jbr_local_t     *new_local = NULL;
        jbr_private_t   *priv      = NULL;
        int32_t          op_errno  = 0;

        GF_VALIDATE_OR_GOTO ("jbr", this, out);
        GF_VALIDATE_OR_GOTO (this->name, frame, out);
        priv = this->private;
        local = frame->local;
        GF_VALIDATE_OR_GOTO (this->name, priv, out);
        GF_VALIDATE_OR_GOTO (this->name, local, out);

        /* Perform quorum check to see if the leader needs     *
         * to perform the operation. If the operation will not *
         * meet quorum irrespective of the leader's result     *
         * there is no point in the leader performing the fop  *
         */
        result = fop_quorum_check (this, (double)priv->n_children,
                                   (double)local->successful_acks + 1);
        if (result == _gf_false) {
                gf_msg (this->name, GF_LOG_ERROR, EROFS,
                        J_MSG_QUORUM_NOT_MET, "Didn't receive enough acks "
                        "to meet quorum. Failing the operation without trying "
                        "it on the leader.");

#if defined(JBR_CG_QUEUE)
                /*
                 * In case of a fop failure, before unwinding need to *
                 * remove it from queue                               *
                 */
                ret = jbr_remove_from_queue (frame, this);
                if (ret) {
                        gf_msg (this->name, GF_LOG_ERROR, 0,
                                J_MSG_GENERIC, "Failed to remove from queue.");
                }
#endif

                /*
                 * In this case, the quorum is not met on the followers  *
                 * So the operation will not be performed on the leader  *
                 * and a rollback will be sent via GF_FOP_IPC to all the *
                 * followers, where this particular fop's term and index *
                 * numbers will be journaled, and later used to rollback *
                 */
                call_frame_t    *new_frame;

                new_frame = copy_frame (frame);

                if (new_frame) {
                        new_local = mem_get0(this->local_pool);
                        if (new_local) {
                                INIT_LIST_HEAD(&new_local->qlinks);
                                ret = dict_set_int32 (local->xdata,
                                                      "rollback-fop",
                                                      GF_FOP_@UPNAME@);
                                if (ret) {
                                        gf_msg (this->name, GF_LOG_ERROR, 0,
                                                J_MSG_DICT_FLR,
                                                "failed to set rollback-fop");
                                } else {
                                        new_local->xdata = dict_ref(local->xdata);
                                        new_frame->local = new_local;
                                        jbr_ipc_call_dispatch (new_frame,
                                                               this, &op_errno,
                                                               FDL_IPC_JBR_SERVER_ROLLBACK,
                                                               new_local->xdata);
                                }
                        } else {
                                gf_log (this->name, GF_LOG_WARNING,
                                        "Could not create local for new_frame");
                        }
                } else {
                        gf_log (this->name, GF_LOG_WARNING,
                                "Could not send rollback ipc");
                }

                STACK_UNWIND_STRICT (@NAME@, frame, -1, EROFS,
                                     @ERROR_ARGS@);
        } else {
                STACK_WIND (frame, jbr_@NAME@_complete,
                            FIRST_CHILD(this), FIRST_CHILD(this)->fops->@NAME@,
                            @SHORT_ARGS@);
        }

out:
        return 0;
}

/* template-name write-complete */
int32_t
jbr_@NAME@_complete (call_frame_t *frame, void *cookie, xlator_t *this,
                     int32_t op_ret, int32_t op_errno,
                     @LONG_ARGS@)
{
        int32_t          ret       = -1;
        gf_boolean_t     result    = _gf_false;
        jbr_private_t   *priv      = NULL;
        jbr_local_t     *local     = NULL;
        jbr_local_t     *new_local = NULL;

        GF_VALIDATE_OR_GOTO ("jbr", this, err);
        GF_VALIDATE_OR_GOTO (this->name, frame, err);
        priv = this->private;
        local = frame->local;
        GF_VALIDATE_OR_GOTO (this->name, priv, err);
        GF_VALIDATE_OR_GOTO (this->name, local, err);

        /* If the fop failed on the leader, then reduce one succesful ack
         * before calculating the fop quorum
         */
        LOCK(&frame->lock);
        if (op_ret == -1)
                (local->successful_acks)--;
        UNLOCK(&frame->lock);

#if defined(JBR_CG_QUEUE)
        ret = jbr_remove_from_queue (frame, this);
        if (ret)
                goto err;
#endif

#if defined(JBR_CG_FSYNC)
        jbr_mark_fd_dirty(this, local);
#endif

#if defined(JBR_CG_NEED_FD)
        fd_unref(local->fd);
#endif

        /* After the leader completes the fop, a quorum check is      *
         * performed, taking into account the outcome of the fop      *
         * on the leader. Irrespective of the fop being successful    *
         * or failing on the leader, the result of the quorum will    *
         * determine if the overall fop is successful or not. For     *
         * example, a fop might have succeeded on every node except   *
         * the leader, in which case as quorum is being met, the fop  *
         * will be treated as a successful fop, even though it failed *
         * on the leader. On follower nodes, no quorum check should   *
         * be done, and the result is returned to the leader as is.   *
         */
        if (priv->leader) {
                result = fop_quorum_check (this, (double)priv->n_children,
                                           (double)local->successful_acks + 1);
                if (result == _gf_false) {
                        op_ret = -1;
                        op_errno = EROFS;
                        gf_msg (this->name, GF_LOG_ERROR, EROFS,
                                J_MSG_QUORUM_NOT_MET, "Quorum is not met. "
                                "The operation has failed.");
                        /*
                         * In this case, the quorum is not met after the      *
                         * operation is performed on the leader. Hence a      *
                         * rollback will be sent via GF_FOP_IPC to the leader *
                         * where this particular fop's term and index numbers *
                         * will be journaled, and later used to rollback.     *
                         * The same will be done on all the followers         *
                         */
                        call_frame_t    *new_frame;

                        new_frame = copy_frame (frame);
                        if (new_frame) {
                                new_local = mem_get0(this->local_pool);
                                if (new_local) {
                                        INIT_LIST_HEAD(&new_local->qlinks);
                                        gf_msg (this->name, GF_LOG_ERROR, 0,
                                                J_MSG_DICT_FLR, "op = %d",
                                                new_frame->op);
                                        ret = dict_set_int32 (local->xdata,
                                                              "rollback-fop",
                                                              GF_FOP_@UPNAME@);
                                        if (ret) {
                                                gf_msg (this->name,
                                                        GF_LOG_ERROR, 0,
                                                        J_MSG_DICT_FLR,
                                                        "failed to set "
                                                        "rollback-fop");
                                        } else {
                                                new_local->xdata = dict_ref (local->xdata);
                                                new_frame->local = new_local;
                                                /*
                                                 * Calling STACK_WIND instead *
                                                 * of jbr_ipc as it will not  *
                                                 * unwind to the previous     *
                                                 * translators like it will   *
                                                 * in case of jbr_ipc.        *
                                                 */
                                                STACK_WIND (new_frame,
                                                            jbr_ipc_complete,
                                                            FIRST_CHILD(this),
                                                            FIRST_CHILD(this)->fops->ipc,
                                                            FDL_IPC_JBR_SERVER_ROLLBACK,
                                                            new_local->xdata);
                                        }
                                } else {
                                        gf_log (this->name, GF_LOG_WARNING,
                                                "Could not create local "
                                                "for new_frame");
                                }
                        } else {
                                gf_log (this->name, GF_LOG_WARNING,
                                        "Could not send rollback ipc");
                        }
                } else {
#if defined(JBR_CG_NEED_FD)
                        op_ret = local->successful_op_ret;
#else
                        op_ret = 0;
#endif
                        op_errno = 0;
                        gf_msg_debug (this->name, 0,
                                      "Quorum has met. The operation has succeeded.");
                }
        }

        /*
         * Unrefing the reference taken in jbr_@NAME@ () *
         */
        dict_unref (local->xdata);

        STACK_UNWIND_STRICT (@NAME@, frame, op_ret, op_errno,
                             @SHORT_ARGS@);


        return 0;

err:
        STACK_UNWIND_STRICT (@NAME@, frame, -1, 0,
                             @SHORT_ARGS@);

        return 0;
}