--- /dev/null
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (C) 2013, Trustees of Indiana University
+ * Author: Joshua Walgenbach <jjw@iu.edu>
+ */
+
+#include <interval_tree.h>
+#include <lustre_net.h>
+#include "nodemap_internal.h"
+
+/*
+ * Range trees
+ *
+ * To classify clients when they connect, build a global range tree
+ * containing all admin defined ranges. Incoming clients can then be
+ * classified into their nodemaps, and the lu_nodemap structure will be
+ * set in the export structure for the connecting client. Pointers to
+ * the lu_nid_range nodes will be added to linked links within the
+ * lu_nodemap structure for reporting purposes. Access to range tree should be
+ * controlled to prevent read access during update operations.
+ */
+
+static struct interval_node *range_interval_root;
+static atomic_t range_highest_id;
+
+void range_init_tree(void)
+{
+ range_interval_root = NULL;
+}
+
+/*
+ * callback for interating over the interval tree
+ *
+ * \param n interval_node matched
+ * \param data void pointer for return
+ *
+ * This dunction stops after a single match. There should be
+ * no intervals containing multiple ranges
+ */
+static enum interval_iter range_cb(struct interval_node *n, void *data)
+{
+ struct lu_nid_range *range = container_of(n, struct lu_nid_range,
+ rn_node);
+ struct lu_nid_range **ret;
+
+ ret = data;
+ *ret = range;
+
+ return INTERVAL_ITER_STOP;
+}
+
+/*
+ * range constructor
+ *
+ * \param min starting nid of the range
+ * \param max ending nid of the range
+ * \param nodemap nodemap that contains this range
+ * \retval lu_nid_range on success, NULL on failure
+ */
+struct lu_nid_range *range_create(lnet_nid_t start_nid, lnet_nid_t end_nid,
+ struct lu_nodemap *nodemap)
+{
+ struct lu_nid_range *range;
+
+ if (LNET_NIDNET(start_nid) != LNET_NIDNET(end_nid) ||
+ LNET_NIDADDR(start_nid) > LNET_NIDADDR(end_nid))
+ return NULL;
+
+ OBD_ALLOC_PTR(range);
+ if (range == NULL) {
+ CERROR("cannot allocate lu_nid_range of size %zu bytes\n",
+ sizeof(*range));
+ return NULL;
+ }
+
+ range->rn_id = atomic_inc_return(&range_highest_id);
+ range->rn_nodemap = nodemap;
+ interval_set(&range->rn_node, start_nid, end_nid);
+ INIT_LIST_HEAD(&range->rn_list);
+
+ return range;
+}
+
+/*
+ * find the exact range
+ *
+ * \param start_nid starting nid
+ * \param end_nid ending nid
+ * \retval matching range or NULL
+ */
+struct lu_nid_range *range_find(lnet_nid_t start_nid, lnet_nid_t end_nid)
+{
+ struct lu_nid_range *range = NULL;
+ struct interval_node *interval = NULL;
+ struct interval_node_extent ext = {
+ .start = start_nid,
+ .end = end_nid
+ };
+
+ interval = interval_find(range_interval_root, &ext);
+
+ if (interval != NULL)
+ range = container_of(interval, struct lu_nid_range,
+ rn_node);
+
+ return range;
+}
+
+/*
+ * range destructor
+ */
+void range_destroy(struct lu_nid_range *range)
+{
+ LASSERT(list_empty(&range->rn_list) == 0);
+ LASSERT(interval_is_intree(&range->rn_node) == 0);
+
+ OBD_FREE_PTR(range);
+}
+
+/*
+ * insert an nid range into the interval tree
+ *
+ * \param range range to insetr
+ * \retval 0 on success
+ *
+ * This function checks that the given nid range
+ * does not overlap so that each nid can belong
+ * to exactly one range
+ */
+int range_insert(struct lu_nid_range *range)
+{
+ struct interval_node_extent ext =
+ range->rn_node.in_extent;
+
+ if (interval_is_overlapped(range_interval_root, &ext) != 0)
+ return -EEXIST;
+
+ interval_insert(&range->rn_node, &range_interval_root);
+
+ return 0;
+}
+
+/*
+ * delete a range from the interval tree and any
+ * associated nodemap references
+ *
+ * \param range range to remove
+ */
+void range_delete(struct lu_nid_range *range)
+{
+ if (range == NULL || interval_is_intree(&range->rn_node) == 0)
+ return;
+ list_del(&range->rn_list);
+ interval_erase(&range->rn_node, &range_interval_root);
+ range_destroy(range);
+}
+
+/*
+ * search the interval tree for an nid within a range
+ *
+ * \param nid nid to search for
+ */
+struct lu_nid_range *range_search(lnet_nid_t nid)
+{
+ struct lu_nid_range *ret = NULL;
+ struct interval_node_extent ext = {
+ .start = nid,
+ .end = nid
+ };
+
+ interval_search(range_interval_root, &ext, range_cb, &ret);
+
+ return ret;
+}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff