summaryrefslogtreecommitdiffstats
path: root/xlators/experimental/jbr-server/src/all-templates.c
diff options
context:
space:
mode:
Diffstat (limited to 'xlators/experimental/jbr-server/src/all-templates.c')
-rw-r--r--xlators/experimental/jbr-server/src/all-templates.c437
1 files changed, 437 insertions, 0 deletions
diff --git a/xlators/experimental/jbr-server/src/all-templates.c b/xlators/experimental/jbr-server/src/all-templates.c
new file mode 100644
index 00000000000..9b9a3e0be5e
--- /dev/null
+++ b/xlators/experimental/jbr-server/src/all-templates.c
@@ -0,0 +1,437 @@
+/*
+ * 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 = this->private;
+ gf_boolean_t in_recon = _gf_false;
+ int32_t recon_term, recon_index;
+
+ /* 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, EREMOTE,
+ @ERROR_ARGS@);
+ return 0;
+}
+
+/* template-name read-dispatch */
+/* No "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 = this->private;
+ gf_boolean_t result = _gf_false;
+ int op_errno = ENOMEM;
+ int from_leader;
+ int from_recon;
+ uint32_t ti = 0;
+
+ /*
+ * Our first goal here is to avoid "split brain surprise" for users who
+ * specify exactly 50% with two- or three-way replication. That means
+ * either a more-than check against half the total replicas or an
+ * at-least check against half of our peers (one less). Of the two,
+ * only an at-least check supports the intuitive use of 100% to mean
+ * all replicas must be present, because "more than 100%" will never
+ * succeed regardless of which count we use. This leaves us with a
+ * slightly non-traditional definition of quorum ("at least X% of peers
+ * not including ourselves") but one that's useful enough to be worth
+ * it.
+ *
+ * Note that n_children and up_children *do* include the local
+ * subvolume, so we need to subtract one in each case.
+ */
+ if (priv->leader) {
+ result = fop_quorum_check (this, (double)(priv->n_children - 1),
+ (double)(priv->up_children - 1));
+
+ if (result == _gf_false) {
+ /* Emulate the AFR client-side-quorum behavior. */
+ gf_msg (this->name, GF_LOG_ERROR, EROFS,
+ J_MSG_QUORUM_NOT_MET, "Sufficient number of "
+ "subvolumes are not up to meet quorum.");
+ op_errno = EROFS;
+ goto err;
+ }
+ } else {
+ if (xdata) {
+ from_leader = !!dict_get(xdata, JBR_TERM_XATTR);
+ from_recon = !!dict_get(xdata, RECON_TERM_XATTR)
+ && !!dict_get(xdata, RECON_INDEX_XATTR);
+ } else {
+ from_leader = from_recon = _gf_false;
+ }
+
+ /* follower/recon path *
+ * just send it to local node *
+ */
+ if (!from_leader && !from_recon) {
+ op_errno = EREMOTE;
+ goto err;
+ }
+ }
+
+ local = mem_get0(this->local_pool);
+ if (!local) {
+ goto err;
+ }
+#if defined(JBR_CG_NEED_FD)
+ local->fd = fd_ref(fd);
+#else
+ local->fd = NULL;
+#endif
+ INIT_LIST_HEAD(&local->qlinks);
+ frame->local = 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;
+ }
+
+ if (!xdata) {
+ xdata = dict_new();
+ if (!xdata) {
+ gf_msg (this->name, GF_LOG_ERROR, ENOMEM,
+ J_MSG_MEM_ERR, "failed to allocate xdata");
+ goto err;
+ }
+ }
+
+ if (dict_set_int32(xdata, JBR_TERM_XATTR, priv->current_term) != 0) {
+ gf_msg (this->name, GF_LOG_ERROR, 0,
+ J_MSG_DICT_FLR, "failed to set jbr-term");
+ goto err;
+ }
+
+ LOCK(&priv->index_lock);
+ ti = ++(priv->index);
+ UNLOCK(&priv->index_lock);
+ if (dict_set_int32(xdata, JBR_INDEX_XATTR, ti) != 0) {
+ gf_msg (this->name, GF_LOG_ERROR, 0,
+ J_MSG_DICT_FLR, "failed to set index");
+ goto err;
+ }
+
+ local->stub = fop_@NAME@_stub (frame, jbr_@NAME@_continue,
+ @SHORT_ARGS@);
+ if (!local->stub) {
+ goto err;
+ }
+
+
+#if defined(JBR_CG_QUEUE)
+ jbr_inode_ctx_t *ictx = jbr_get_inode_ctx(this, fd->inode);
+
+ if (!ictx) {
+ op_errno = EIO;
+ goto err;
+ }
+ 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 err;
+ }
+ list_add_tail(&local->qlinks, &ictx->pqueue);
+ ++(ictx->pending);
+ UNLOCK(&ictx->lock);
+ return 0;
+ } else {
+ list_add_tail(&local->qlinks, &ictx->aqueue);
+ ++(ictx->active);
+ }
+ UNLOCK(&ictx->lock);
+#endif
+
+ return jbr_@NAME@_dispatch (frame, this, @SHORT_ARGS@);
+
+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-dispatch */
+int32_t
+jbr_@NAME@_dispatch (call_frame_t *frame, xlator_t *this,
+ @LONG_ARGS@)
+{
+ jbr_local_t *local = frame->local;
+ jbr_private_t *priv = this->private;
+ xlator_list_t *trav;
+
+ /*
+ * 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;
+ local->successful_acks = 0;
+ 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 */
+ return 0;
+}
+
+/* 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 = frame->local;
+ uint8_t call_count;
+
+ 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);
+ }
+
+ return 0;
+}
+
+/* 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_private_t *priv = NULL;
+
+ 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.");
+ 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@);
+ }
+
+ ret = 0;
+out:
+ return ret;
+}
+
+/* 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@)
+{
+ gf_boolean_t result = _gf_false;
+ jbr_private_t *priv = this->private;
+
+ jbr_local_t *local = frame->local;
+
+ /* 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)
+ jbr_inode_ctx_t *ictx;
+ jbr_local_t *next;
+
+ if (local->qlinks.next != &local->qlinks) {
+ list_del(&local->qlinks);
+ ictx = jbr_get_inode_ctx(this, local->fd->inode);
+ if (ictx) {
+ LOCK(&ictx->lock);
+ if (ictx->pending) {
+ /*
+ * TBD: dequeue *all* non-conflicting
+ * reqs
+ *
+ * With the stub implementation there
+ * can only be one request active at a
+ * time (zero here) so it's not an
+ * issue. In a real implementation
+ * there might still be other active
+ * requests to check against, and
+ * multiple pending requests that could
+ * continue.
+ */
+ gf_msg_debug (this->name, 0,
+ "unblocking next request");
+ --(ictx->pending);
+ next = list_entry (ictx->pqueue.next,
+ jbr_local_t, qlinks);
+ list_del(&next->qlinks);
+ list_add_tail(&next->qlinks,
+ &ictx->aqueue);
+ call_resume(next->qstub);
+ } else {
+ --(ictx->active);
+ }
+ UNLOCK(&ictx->lock);
+ }
+ }
+#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.");
+ } 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.");
+ }
+ }
+
+ STACK_UNWIND_STRICT (@NAME@, frame, op_ret, op_errno,
+ @SHORT_ARGS@);
+
+
+ return 0;
+
+}
generated by cgit (git 2.34.1) at 2024-11-15 18:22:01 +0000