diff options
Diffstat (limited to 'fs/ocfs2/dlm/dlmdomain.c')
| -rw-r--r-- | fs/ocfs2/dlm/dlmdomain.c | 1469 |
1 files changed, 1469 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c new file mode 100644 index 00000000000..da3c22045f8 --- /dev/null +++ b/fs/ocfs2/dlm/dlmdomain.c @@ -0,0 +1,1469 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * dlmdomain.c + * + * defines domain join / leave apis + * + * Copyright (C) 2004 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * 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 for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/highmem.h> +#include <linux/utsname.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/delay.h> +#include <linux/err.h> + +#include "cluster/heartbeat.h" +#include "cluster/nodemanager.h" +#include "cluster/tcp.h" + +#include "dlmapi.h" +#include "dlmcommon.h" + +#include "dlmdebug.h" +#include "dlmdomain.h" + +#include "dlmver.h" + +#define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_DOMAIN) +#include "cluster/masklog.h" + +/* + * + * spinlock lock ordering: if multiple locks are needed, obey this ordering: + * dlm_domain_lock + * struct dlm_ctxt->spinlock + * struct dlm_lock_resource->spinlock + * struct dlm_ctxt->master_lock + * struct dlm_ctxt->ast_lock + * dlm_master_list_entry->spinlock + * dlm_lock->spinlock + * + */ + +spinlock_t dlm_domain_lock = SPIN_LOCK_UNLOCKED; +LIST_HEAD(dlm_domains); +static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events); + +#define DLM_DOMAIN_BACKOFF_MS 200 + +static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data); +static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data); +static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data); +static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data); + +static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm); + +void __dlm_unhash_lockres(struct dlm_lock_resource *lockres) +{ + list_del_init(&lockres->list); + dlm_lockres_put(lockres); +} + +void __dlm_insert_lockres(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res) +{ + struct list_head *bucket; + struct qstr *q; + + assert_spin_locked(&dlm->spinlock); + + q = &res->lockname; + q->hash = full_name_hash(q->name, q->len); + bucket = &(dlm->resources[q->hash & DLM_HASH_MASK]); + + /* get a reference for our hashtable */ + dlm_lockres_get(res); + + list_add_tail(&res->list, bucket); +} + +struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm, + const char *name, + unsigned int len) +{ + unsigned int hash; + struct list_head *iter; + struct dlm_lock_resource *tmpres=NULL; + struct list_head *bucket; + + mlog_entry("%.*s\n", len, name); + + assert_spin_locked(&dlm->spinlock); + + hash = full_name_hash(name, len); + + bucket = &(dlm->resources[hash & DLM_HASH_MASK]); + + /* check for pre-existing lock */ + list_for_each(iter, bucket) { + tmpres = list_entry(iter, struct dlm_lock_resource, list); + if (tmpres->lockname.len == len && + memcmp(tmpres->lockname.name, name, len) == 0) { + dlm_lockres_get(tmpres); + break; + } + + tmpres = NULL; + } + return tmpres; +} + +struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm, + const char *name, + unsigned int len) +{ + struct dlm_lock_resource *res; + + spin_lock(&dlm->spinlock); + res = __dlm_lookup_lockres(dlm, name, len); + spin_unlock(&dlm->spinlock); + return res; +} + +static struct dlm_ctxt * __dlm_lookup_domain_full(const char *domain, int len) +{ + struct dlm_ctxt *tmp = NULL; + struct list_head *iter; + + assert_spin_locked(&dlm_domain_lock); + + /* tmp->name here is always NULL terminated, + * but domain may not be! */ + list_for_each(iter, &dlm_domains) { + tmp = list_entry (iter, struct dlm_ctxt, list); + if (strlen(tmp->name) == len && + memcmp(tmp->name, domain, len)==0) + break; + tmp = NULL; + } + + return tmp; +} + +/* For null terminated domain strings ONLY */ +static struct dlm_ctxt * __dlm_lookup_domain(const char *domain) +{ + assert_spin_locked(&dlm_domain_lock); + + return __dlm_lookup_domain_full(domain, strlen(domain)); +} + + +/* returns true on one of two conditions: + * 1) the domain does not exist + * 2) the domain exists and it's state is "joined" */ +static int dlm_wait_on_domain_helper(const char *domain) +{ + int ret = 0; + struct dlm_ctxt *tmp = NULL; + + spin_lock(&dlm_domain_lock); + + tmp = __dlm_lookup_domain(domain); + if (!tmp) + ret = 1; + else if (tmp->dlm_state == DLM_CTXT_JOINED) + ret = 1; + + spin_unlock(&dlm_domain_lock); + return ret; +} + +static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm) +{ + if (dlm->resources) + free_page((unsigned long) dlm->resources); + + if (dlm->name) + kfree(dlm->name); + + kfree(dlm); +} + +/* A little strange - this function will be called while holding + * dlm_domain_lock and is expected to be holding it on the way out. We + * will however drop and reacquire it multiple times */ +static void dlm_ctxt_release(struct kref *kref) +{ + struct dlm_ctxt *dlm; + + dlm = container_of(kref, struct dlm_ctxt, dlm_refs); + + BUG_ON(dlm->num_joins); + BUG_ON(dlm->dlm_state == DLM_CTXT_JOINED); + + /* we may still be in the list if we hit an error during join. */ + list_del_init(&dlm->list); + + spin_unlock(&dlm_domain_lock); + + mlog(0, "freeing memory from domain %s\n", dlm->name); + + wake_up(&dlm_domain_events); + + dlm_free_ctxt_mem(dlm); + + spin_lock(&dlm_domain_lock); +} + +void dlm_put(struct dlm_ctxt *dlm) +{ + spin_lock(&dlm_domain_lock); + kref_put(&dlm->dlm_refs, dlm_ctxt_release); + spin_unlock(&dlm_domain_lock); +} + +static void __dlm_get(struct dlm_ctxt *dlm) +{ + kref_get(&dlm->dlm_refs); +} + +/* given a questionable reference to a dlm object, gets a reference if + * it can find it in the list, otherwise returns NULL in which case + * you shouldn't trust your pointer. */ +struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm) +{ + struct list_head *iter; + struct dlm_ctxt *target = NULL; + + spin_lock(&dlm_domain_lock); + + list_for_each(iter, &dlm_domains) { + target = list_entry (iter, struct dlm_ctxt, list); + + if (target == dlm) { + __dlm_get(target); + break; + } + + target = NULL; + } + + spin_unlock(&dlm_domain_lock); + + return target; +} + +int dlm_domain_fully_joined(struct dlm_ctxt *dlm) +{ + int ret; + + spin_lock(&dlm_domain_lock); + ret = (dlm->dlm_state == DLM_CTXT_JOINED) || + (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN); + spin_unlock(&dlm_domain_lock); + + return ret; +} + +static void dlm_complete_dlm_shutdown(struct dlm_ctxt *dlm) +{ + dlm_unregister_domain_handlers(dlm); + dlm_complete_thread(dlm); + dlm_complete_recovery_thread(dlm); + + /* We've left the domain. Now we can take ourselves out of the + * list and allow the kref stuff to help us free the + * memory. */ + spin_lock(&dlm_domain_lock); + list_del_init(&dlm->list); + spin_unlock(&dlm_domain_lock); + + /* Wake up anyone waiting for us to remove this domain */ + wake_up(&dlm_domain_events); +} + +static void dlm_migrate_all_locks(struct dlm_ctxt *dlm) +{ + int i; + struct dlm_lock_resource *res; + + mlog(0, "Migrating locks from domain %s\n", dlm->name); +restart: + spin_lock(&dlm->spinlock); + for (i=0; i<DLM_HASH_SIZE; i++) { + while (!list_empty(&dlm->resources[i])) { + res = list_entry(dlm->resources[i].next, + struct dlm_lock_resource, list); + /* need reference when manually grabbing lockres */ + dlm_lockres_get(res); + /* this should unhash the lockres + * and exit with dlm->spinlock */ + mlog(0, "purging res=%p\n", res); + if (dlm_lockres_is_dirty(dlm, res)) { + /* HACK! this should absolutely go. + * need to figure out why some empty + * lockreses are still marked dirty */ + mlog(ML_ERROR, "lockres %.*s dirty!\n", + res->lockname.len, res->lockname.name); + + spin_unlock(&dlm->spinlock); + dlm_kick_thread(dlm, res); + wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); + dlm_lockres_put(res); + goto restart; + } + dlm_purge_lockres(dlm, res); + dlm_lockres_put(res); + } + } + spin_unlock(&dlm->spinlock); + + mlog(0, "DONE Migrating locks from domain %s\n", dlm->name); +} + +static int dlm_no_joining_node(struct dlm_ctxt *dlm) +{ + int ret; + + spin_lock(&dlm->spinlock); + ret = dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN; + spin_unlock(&dlm->spinlock); + + return ret; +} + +static void dlm_mark_domain_leaving(struct dlm_ctxt *dlm) +{ + /* Yikes, a double spinlock! I need domain_lock for the dlm + * state and the dlm spinlock for join state... Sorry! */ +again: + spin_lock(&dlm_domain_lock); + spin_lock(&dlm->spinlock); + + if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) { + mlog(0, "Node %d is joining, we wait on it.\n", + dlm->joining_node); + spin_unlock(&dlm->spinlock); + spin_unlock(&dlm_domain_lock); + + wait_event(dlm->dlm_join_events, dlm_no_joining_node(dlm)); + goto again; + } + + dlm->dlm_state = DLM_CTXT_LEAVING; + spin_unlock(&dlm->spinlock); + spin_unlock(&dlm_domain_lock); +} + +static void __dlm_print_nodes(struct dlm_ctxt *dlm) +{ + int node = -1; + + assert_spin_locked(&dlm->spinlock); + + mlog(ML_NOTICE, "Nodes in my domain (\"%s\"):\n", dlm->name); + + while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, + node + 1)) < O2NM_MAX_NODES) { + mlog(ML_NOTICE, " node %d\n", node); + } +} + +static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data) +{ + struct dlm_ctxt *dlm = data; + unsigned int node; + struct dlm_exit_domain *exit_msg = (struct dlm_exit_domain *) msg->buf; + + mlog_entry("%p %u %p", msg, len, data); + + if (!dlm_grab(dlm)) + return 0; + + node = exit_msg->node_idx; + + mlog(0, "Node %u leaves domain %s\n", node, dlm->name); + + spin_lock(&dlm->spinlock); + clear_bit(node, dlm->domain_map); + __dlm_print_nodes(dlm); + + /* notify anything attached to the heartbeat events */ + dlm_hb_event_notify_attached(dlm, node, 0); + + spin_unlock(&dlm->spinlock); + + dlm_put(dlm); + + return 0; +} + +static int dlm_send_one_domain_exit(struct dlm_ctxt *dlm, + unsigned int node) +{ + int status; + struct dlm_exit_domain leave_msg; + + mlog(0, "Asking node %u if we can leave the domain %s me = %u\n", + node, dlm->name, dlm->node_num); + + memset(&leave_msg, 0, sizeof(leave_msg)); + leave_msg.node_idx = dlm->node_num; + + status = o2net_send_message(DLM_EXIT_DOMAIN_MSG, dlm->key, + &leave_msg, sizeof(leave_msg), node, + NULL); + + mlog(0, "status return %d from o2net_send_message\n", status); + + return status; +} + + +static void dlm_leave_domain(struct dlm_ctxt *dlm) +{ + int node, clear_node, status; + + /* At this point we've migrated away all our locks and won't + * accept mastership of new ones. The dlm is responsible for + * almost nothing now. We make sure not to confuse any joining + * nodes and then commence shutdown procedure. */ + + spin_lock(&dlm->spinlock); + /* Clear ourselves from the domain map */ + clear_bit(dlm->node_num, dlm->domain_map); + while ((node = find_next_bit(dlm->domain_map, O2NM_MAX_NODES, + 0)) < O2NM_MAX_NODES) { + /* Drop the dlm spinlock. This is safe wrt the domain_map. + * -nodes cannot be added now as the + * query_join_handlers knows to respond with OK_NO_MAP + * -we catch the right network errors if a node is + * removed from the map while we're sending him the + * exit message. */ + spin_unlock(&dlm->spinlock); + + clear_node = 1; + + status = dlm_send_one_domain_exit(dlm, node); + if (status < 0 && + status != -ENOPROTOOPT && + status != -ENOTCONN) { + mlog(ML_NOTICE, "Error %d sending domain exit message " + "to node %d\n", status, node); + + /* Not sure what to do here but lets sleep for + * a bit in case this was a transient + * error... */ + msleep(DLM_DOMAIN_BACKOFF_MS); + clear_node = 0; + } + + spin_lock(&dlm->spinlock); + /* If we're not clearing the node bit then we intend + * to loop back around to try again. */ + if (clear_node) + clear_bit(node, dlm->domain_map); + } + spin_unlock(&dlm->spinlock); +} + +int dlm_joined(struct dlm_ctxt *dlm) +{ + int ret = 0; + + spin_lock(&dlm_domain_lock); + + if (dlm->dlm_state == DLM_CTXT_JOINED) + ret = 1; + + spin_unlock(&dlm_domain_lock); + + return ret; +} + +int dlm_shutting_down(struct dlm_ctxt *dlm) +{ + int ret = 0; + + spin_lock(&dlm_domain_lock); + + if (dlm->dlm_state == DLM_CTXT_IN_SHUTDOWN) + ret = 1; + + spin_unlock(&dlm_domain_lock); + + return ret; +} + +void dlm_unregister_domain(struct dlm_ctxt *dlm) +{ + int leave = 0; + + spin_lock(&dlm_domain_lock); + BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED); + BUG_ON(!dlm->num_joins); + + dlm->num_joins--; + if (!dlm->num_joins) { + /* We mark it "in shutdown" now so new register + * requests wait until we've completely left the + * domain. Don't use DLM_CTXT_LEAVING yet as we still + * want new domain joins to communicate with us at + * least until we've completed migration of our + * resources. */ + dlm->dlm_state = DLM_CTXT_IN_SHUTDOWN; + leave = 1; + } + spin_unlock(&dlm_domain_lock); + + if (leave) { + mlog(0, "shutting down domain %s\n", dlm->name); + + /* We changed dlm state, notify the thread */ + dlm_kick_thread(dlm, NULL); + + dlm_migrate_all_locks(dlm); + dlm_mark_domain_leaving(dlm); + dlm_leave_domain(dlm); + dlm_complete_dlm_shutdown(dlm); + } + dlm_put(dlm); +} +EXPORT_SYMBOL_GPL(dlm_unregister_domain); + +static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data) +{ + struct dlm_query_join_request *query; + enum dlm_query_join_response response; + struct dlm_ctxt *dlm = NULL; + + query = (struct dlm_query_join_request *) msg->buf; + + mlog(0, "node %u wants to join domain %s\n", query->node_idx, + query->domain); + + /* + * If heartbeat doesn't consider the node live, tell it + * to back off and try again. This gives heartbeat a chance + * to catch up. + */ + if (!o2hb_check_node_heartbeating(query->node_idx)) { + mlog(0, "node %u is not in our live map yet\n", + query->node_idx); + + response = JOIN_DISALLOW; + goto respond; + } + + response = JOIN_OK_NO_MAP; + + spin_lock(&dlm_domain_lock); + dlm = __dlm_lookup_domain_full(query->domain, query->name_len); + /* Once the dlm ctxt is marked as leaving then we don't want + * to be put in someone's domain map. */ + if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) { + spin_lock(&dlm->spinlock); + + if (dlm->dlm_state == DLM_CTXT_NEW && + dlm->joining_node == DLM_LOCK_RES_OWNER_UNKNOWN) { + /*If this is a brand new context and we + * haven't started our join process yet, then + * the other node won the race. */ + response = JOIN_OK_NO_MAP; + } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) { + /* Disallow parallel joins. */ + response = JOIN_DISALLOW; + } else { + /* Alright we're fully a part of this domain + * so we keep some state as to who's joining + * and indicate to him that needs to be fixed + * up. */ + response = JOIN_OK; + __dlm_set_joining_node(dlm, query->node_idx); + } + + spin_unlock(&dlm->spinlock); + } + spin_unlock(&dlm_domain_lock); + +respond: + mlog(0, "We respond with %u\n", response); + + return response; +} + +static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void *data) +{ + struct dlm_assert_joined *assert; + struct dlm_ctxt *dlm = NULL; + + assert = (struct dlm_assert_joined *) msg->buf; + + mlog(0, "node %u asserts join on domain %s\n", assert->node_idx, + assert->domain); + + spin_lock(&dlm_domain_lock); + dlm = __dlm_lookup_domain_full(assert->domain, assert->name_len); + /* XXX should we consider no dlm ctxt an error? */ + if (dlm) { + spin_lock(&dlm->spinlock); + + /* Alright, this node has officially joined our + * domain. Set him in the map and clean up our + * leftover join state. */ + BUG_ON(dlm->joining_node != assert->node_idx); + set_bit(assert->node_idx, dlm->domain_map); + __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); + + __dlm_print_nodes(dlm); + + /* notify anything attached to the heartbeat events */ + dlm_hb_event_notify_attached(dlm, assert->node_idx, 1); + + spin_unlock(&dlm->spinlock); + } + spin_unlock(&dlm_domain_lock); + + return 0; +} + +static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data) +{ + struct dlm_cancel_join *cancel; + struct dlm_ctxt *dlm = NULL; + + cancel = (struct dlm_cancel_join *) msg->buf; + + mlog(0, "node %u cancels join on domain %s\n", cancel->node_idx, + cancel->domain); + + spin_lock(&dlm_domain_lock); + dlm = __dlm_lookup_domain_full(cancel->domain, cancel->name_len); + + if (dlm) { + spin_lock(&dlm->spinlock); + + /* Yikes, this guy wants to cancel his join. No + * problem, we simply cleanup our join state. */ + BUG_ON(dlm->joining_node != cancel->node_idx); + __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); + + spin_unlock(&dlm->spinlock); + } + spin_unlock(&dlm_domain_lock); + + return 0; +} + +static int dlm_send_one_join_cancel(struct dlm_ctxt *dlm, + unsigned int node) +{ + int status; + struct dlm_cancel_join cancel_msg; + + memset(&cancel_msg, 0, sizeof(cancel_msg)); + cancel_msg.node_idx = dlm->node_num; + cancel_msg.name_len = strlen(dlm->name); + memcpy(cancel_msg.domain, dlm->name, cancel_msg.name_len); + + status = o2net_send_message(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY, + &cancel_msg, sizeof(cancel_msg), node, + NULL); + if (status < 0) { + mlog_errno(status); + goto bail; + } + +bail: + return status; +} + +/* map_size should be in bytes. */ +static int dlm_send_join_cancels(struct dlm_ctxt *dlm, + unsigned long *node_map, + unsigned int map_size) +{ + int status, tmpstat; + unsigned int node; + + if (map_size != (BITS_TO_LONGS(O2NM_MAX_NODES) * + sizeof(unsigned long))) { + mlog(ML_ERROR, + "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n", + map_size, BITS_TO_LONGS(O2NM_MAX_NODES)); + return -EINVAL; + } + + status = 0; + node = -1; + while ((node = find_next_bit(node_map, O2NM_MAX_NODES, + node + 1)) < O2NM_MAX_NODES) { + if (node == dlm->node_num) + continue; + + tmpstat = dlm_send_one_join_cancel(dlm, node); + if (tmpstat) { + mlog(ML_ERROR, "Error return %d cancelling join on " + "node %d\n", tmpstat, node); + if (!status) + status = tmpstat; + } + } + + if (status) + mlog_errno(status); + return status; +} + +static int dlm_request_join(struct dlm_ctxt *dlm, + int node, + enum dlm_query_join_response *response) +{ + int status, retval; + struct dlm_query_join_request join_msg; + + mlog(0, "querying node %d\n", node); + + memset(&join_msg, 0, sizeof(join_msg)); + join_msg.node_idx = dlm->node_num; + join_msg.name_len = strlen(dlm->name); + memcpy(join_msg.domain, dlm->name, join_msg.name_len); + + status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg, + sizeof(join_msg), node, &retval); + if (status < 0 && status != -ENOPROTOOPT) { + mlog_errno(status); + goto bail; + } + + /* -ENOPROTOOPT from the net code means the other side isn't + listening for our message type -- that's fine, it means + his dlm isn't up, so we can consider him a 'yes' but not + joined into the domain. */ + if (status == -ENOPROTOOPT) { + status = 0; + *response = JOIN_OK_NO_MAP; + } else if (retval == JOIN_DISALLOW || + retval == JOIN_OK || + retval == JOIN_OK_NO_MAP) { + *response = retval; + } else { + status = -EINVAL; + mlog(ML_ERROR, "invalid response %d from node %u\n", retval, + node); + } + + mlog(0, "status %d, node %d response is %d\n", status, node, + *response); + +bail: + return status; +} + +static int dlm_send_one_join_assert(struct dlm_ctxt *dlm, + unsigned int node) +{ + int status; + struct dlm_assert_joined assert_msg; + + mlog(0, "Sending join assert to node %u\n", node); + + memset(&assert_msg, 0, sizeof(assert_msg)); + assert_msg.node_idx = dlm->node_num; + assert_msg.name_len = strlen(dlm->name); + memcpy(assert_msg.domain, dlm->name, assert_msg.name_len); + + status = o2net_send_message(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY, + &assert_msg, sizeof(assert_msg), node, + NULL); + if (status < 0) + mlog_errno(status); + + return status; +} + +static void dlm_send_join_asserts(struct dlm_ctxt *dlm, + unsigned long *node_map) +{ + int status, node, live; + + status = 0; + node = -1; + while ((node = find_next_bit(node_map, O2NM_MAX_NODES, + node + 1)) < O2NM_MAX_NODES) { + if (node == dlm->node_num) + continue; + + do { + /* It is very important that this message be + * received so we spin until either the node + * has died or it gets the message. */ + status = dlm_send_one_join_assert(dlm, node); + + spin_lock(&dlm->spinlock); + live = test_bit(node, dlm->live_nodes_map); + spin_unlock(&dlm->spinlock); + + if (status) { + mlog(ML_ERROR, "Error return %d asserting " + "join on node %d\n", status, node); + + /* give us some time between errors... */ + if (live) + msleep(DLM_DOMAIN_BACKOFF_MS); + } + } while (status && live); + } +} + +struct domain_join_ctxt { + unsigned long live_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; + unsigned long yes_resp_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; +}; + +static int dlm_should_restart_join(struct dlm_ctxt *dlm, + struct domain_join_ctxt *ctxt, + enum dlm_query_join_response response) +{ + int ret; + + if (response == JOIN_DISALLOW) { + mlog(0, "Latest response of disallow -- should restart\n"); + return 1; + } + + spin_lock(&dlm->spinlock); + /* For now, we restart the process if the node maps have + * changed at all */ + ret = memcmp(ctxt->live_map, dlm->live_nodes_map, + sizeof(dlm->live_nodes_map)); + spin_unlock(&dlm->spinlock); + + if (ret) + mlog(0, "Node maps changed -- should restart\n"); + + return ret; +} + +static int dlm_try_to_join_domain(struct dlm_ctxt *dlm) +{ + int status = 0, tmpstat, node; + struct domain_join_ctxt *ctxt; + enum dlm_query_join_response response; + + mlog_entry("%p", dlm); + + ctxt = kcalloc(1, sizeof(*ctxt), GFP_KERNEL); + if (!ctxt) { + status = -ENOMEM; + mlog_errno(status); + goto bail; + } + + /* group sem locking should work for us here -- we're already + * registered for heartbeat events so filling this should be + * atomic wrt getting those handlers called. */ + o2hb_fill_node_map(dlm->live_nodes_map, sizeof(dlm->live_nodes_map)); + + spin_lock(&dlm->spinlock); + memcpy(ctxt->live_map, dlm->live_nodes_map, sizeof(ctxt->live_map)); + + __dlm_set_joining_node(dlm, dlm->node_num); + + spin_unlock(&dlm->spinlock); + + node = -1; + while ((node = find_next_bit(ctxt->live_map, O2NM_MAX_NODES, + node + 1)) < O2NM_MAX_NODES) { + if (node == dlm->node_num) + continue; + + status = dlm_request_join(dlm, node, &response); + if (status < 0) { + mlog_errno(status); + goto bail; + } + + /* Ok, either we got a response or the node doesn't have a + * dlm up. */ + if (response == JOIN_OK) + set_bit(node, ctxt->yes_resp_map); + + if (dlm_should_restart_join(dlm, ctxt, response)) { + status = -EAGAIN; + goto bail; + } + } + + mlog(0, "Yay, done querying nodes!\n"); + + /* Yay, everyone agree's we can join the domain. My domain is + * comprised of all nodes who were put in the + * yes_resp_map. Copy that into our domain map and send a join + * assert message to clean up everyone elses state. */ + spin_lock(&dlm->spinlock); + memcpy(dlm->domain_map, ctxt->yes_resp_map, + sizeof(ctxt->yes_resp_map)); + set_bit(dlm->node_num, dlm->domain_map); + spin_unlock(&dlm->spinlock); + + dlm_send_join_asserts(dlm, ctxt->yes_resp_map); + + /* Joined state *must* be set before the joining node + * information, otherwise the query_join handler may read no + * current joiner but a state of NEW and tell joining nodes + * we're not in the domain. */ + spin_lock(&dlm_domain_lock); + dlm->dlm_state = DLM_CTXT_JOINED; + dlm->num_joins++; + spin_unlock(&dlm_domain_lock); + +bail: + spin_lock(&dlm->spinlock); + __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN); + if (!status) + __dlm_print_nodes(dlm); + spin_unlock(&dlm->spinlock); + + if (ctxt) { + /* Do we need to send a cancel message to any nodes? */ + if (status < 0) { + tmpstat = dlm_send_join_cancels(dlm, + ctxt->yes_resp_map, + sizeof(ctxt->yes_resp_map)); + if (tmpstat < 0) + mlog_errno(tmpstat); + } + kfree(ctxt); + } + + mlog(0, "returning %d\n", status); + return status; +} + +static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm) +{ + o2hb_unregister_callback(&dlm->dlm_hb_up); + o2hb_unregister_callback(&dlm->dlm_hb_down); + o2net_unregister_handler_list(&dlm->dlm_domain_handlers); +} + +static int dlm_register_domain_handlers(struct dlm_ctxt *dlm) +{ + int status; + + mlog(0, "registering handlers.\n"); + + o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB, + dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI); + status = o2hb_register_callback(&dlm->dlm_hb_down); + if (status) + goto bail; + + o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB, + dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI); + status = o2hb_register_callback(&dlm->dlm_hb_up); + if (status) + goto bail; + + status = o2net_register_handler(DLM_MASTER_REQUEST_MSG, dlm->key, + sizeof(struct dlm_master_request), + dlm_master_request_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_ASSERT_MASTER_MSG, dlm->key, + sizeof(struct dlm_assert_master), + dlm_assert_master_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_CREATE_LOCK_MSG, dlm->key, + sizeof(struct dlm_create_lock), + dlm_create_lock_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_CONVERT_LOCK_MSG, dlm->key, + DLM_CONVERT_LOCK_MAX_LEN, + dlm_convert_lock_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_UNLOCK_LOCK_MSG, dlm->key, + DLM_UNLOCK_LOCK_MAX_LEN, + dlm_unlock_lock_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_PROXY_AST_MSG, dlm->key, + DLM_PROXY_AST_MAX_LEN, + dlm_proxy_ast_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_EXIT_DOMAIN_MSG, dlm->key, + sizeof(struct dlm_exit_domain), + dlm_exit_domain_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_MIGRATE_REQUEST_MSG, dlm->key, + sizeof(struct dlm_migrate_request), + dlm_migrate_request_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_MIG_LOCKRES_MSG, dlm->key, + DLM_MIG_LOCKRES_MAX_LEN, + dlm_mig_lockres_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_MASTER_REQUERY_MSG, dlm->key, + sizeof(struct dlm_master_requery), + dlm_master_requery_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_LOCK_REQUEST_MSG, dlm->key, + sizeof(struct dlm_lock_request), + dlm_request_all_locks_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_RECO_DATA_DONE_MSG, dlm->key, + sizeof(struct dlm_reco_data_done), + dlm_reco_data_done_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_BEGIN_RECO_MSG, dlm->key, + sizeof(struct dlm_begin_reco), + dlm_begin_reco_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_FINALIZE_RECO_MSG, dlm->key, + sizeof(struct dlm_finalize_reco), + dlm_finalize_reco_handler, + dlm, &dlm->dlm_domain_handlers); + if (status) + goto bail; + +bail: + if (status) + dlm_unregister_domain_handlers(dlm); + + return status; +} + +static int dlm_join_domain(struct dlm_ctxt *dlm) +{ + int status; + + BUG_ON(!dlm); + + mlog(0, "Join domain %s\n", dlm->name); + + status = dlm_register_domain_handlers(dlm); + if (status) { + mlog_errno(status); + goto bail; + } + + status = dlm_launch_thread(dlm); + if (status < 0) { + mlog_errno(status); + goto bail; + } + + status = dlm_launch_recovery_thread(dlm); + if (status < 0) { + mlog_errno(status); + goto bail; + } + + do { + unsigned int backoff; + status = dlm_try_to_join_domain(dlm); + + /* If we're racing another node to the join, then we + * need to back off temporarily and let them + * complete. */ + if (status == -EAGAIN) { + if (signal_pending(current)) { + status = -ERESTARTSYS; + goto bail; + } + + /* + * <chip> After you! + * <dale> No, after you! + * <chip> I insist! + * <dale> But you first! + * ... + */ + backoff = (unsigned int)(jiffies & 0x3); + backoff *= DLM_DOMAIN_BACKOFF_MS; + mlog(0, "backoff %d\n", backoff); + msleep(backoff); + } + } while (status == -EAGAIN); + + if (status < 0) { + mlog_errno(status); + goto bail; + } + + status = 0; +bail: + wake_up(&dlm_domain_events); + + if (status) { + dlm_unregister_domain_handlers(dlm); + dlm_complete_thread(dlm); + dlm_complete_recovery_thread(dlm); + } + + return status; +} + +static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain, + u32 key) +{ + int i; + struct dlm_ctxt *dlm = NULL; + + dlm = kcalloc(1, sizeof(*dlm), GFP_KERNEL); + if (!dlm) { + mlog_errno(-ENOMEM); + goto leave; + } + + dlm->name = kmalloc(strlen(domain) + 1, GFP_KERNEL); + if (dlm->name == NULL) { + mlog_errno(-ENOMEM); + kfree(dlm); + dlm = NULL; + goto leave; + } + + dlm->resources = (struct list_head *) __get_free_page(GFP_KERNEL); + if (!dlm->resources) { + mlog_errno(-ENOMEM); + kfree(dlm->name); + kfree(dlm); + dlm = NULL; + goto leave; + } + memset(dlm->resources, 0, PAGE_SIZE); + + for (i=0; i<DLM_HASH_SIZE; i++) + INIT_LIST_HEAD(&dlm->resources[i]); + + strcpy(dlm->name, domain); + dlm->key = key; + dlm->node_num = o2nm_this_node(); + + spin_lock_init(&dlm->spinlock); + spin_lock_init(&dlm->master_lock); + spin_lock_init(&dlm->ast_lock); + INIT_LIST_HEAD(&dlm->list); + INIT_LIST_HEAD(&dlm->dirty_list); + INIT_LIST_HEAD(&dlm->reco.resources); + INIT_LIST_HEAD(&dlm->reco.received); + INIT_LIST_HEAD(&dlm->reco.node_data); + INIT_LIST_HEAD(&dlm->purge_list); + INIT_LIST_HEAD(&dlm->dlm_domain_handlers); + dlm->reco.state = 0; + + INIT_LIST_HEAD(&dlm->pending_asts); + INIT_LIST_HEAD(&dlm->pending_basts); + + mlog(0, "dlm->recovery_map=%p, &(dlm->recovery_map[0])=%p\n", + dlm->recovery_map, &(dlm->recovery_map[0])); + + memset(dlm->recovery_map, 0, sizeof(dlm->recovery_map)); + memset(dlm->live_nodes_map, 0, sizeof(dlm->live_nodes_map)); + memset(dlm->domain_map, 0, sizeof(dlm->domain_map)); + + dlm->dlm_thread_task = NULL; + dlm->dlm_reco_thread_task = NULL; + init_waitqueue_head(&dlm->dlm_thread_wq); + init_waitqueue_head(&dlm->dlm_reco_thread_wq); + init_waitqueue_head(&dlm->reco.event); + init_waitqueue_head(&dlm->ast_wq); + init_waitqueue_head(&dlm->migration_wq); + INIT_LIST_HEAD(&dlm->master_list); + INIT_LIST_HEAD(&dlm->mle_hb_events); + + dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN; + init_waitqueue_head(&dlm->dlm_join_events); + + dlm->reco.new_master = O2NM_INVALID_NODE_NUM; + dlm->reco.dead_node = O2NM_INVALID_NODE_NUM; + atomic_set(&dlm->local_resources, 0); + atomic_set(&dlm->remote_resources, 0); + atomic_set(&dlm->unknown_resources, 0); + + spin_lock_init(&dlm->work_lock); + INIT_LIST_HEAD(&dlm->work_list); + INIT_WORK(&dlm->dispatched_work, dlm_dispatch_work, dlm); + + kref_init(&dlm->dlm_refs); + dlm->dlm_state = DLM_CTXT_NEW; + + INIT_LIST_HEAD(&dlm->dlm_eviction_callbacks); + + mlog(0, "context init: refcount %u\n", + atomic_read(&dlm->dlm_refs.refcount)); + +leave: + return dlm; +} + +/* + * dlm_register_domain: one-time setup per "domain" + */ +struct dlm_ctxt * dlm_register_domain(const char *domain, + u32 key) +{ + int ret; + struct dlm_ctxt *dlm = NULL; + struct dlm_ctxt *new_ctxt = NULL; + + if (strlen(domain) > O2NM_MAX_NAME_LEN) { + ret = -ENAMETOOLONG; + mlog(ML_ERROR, "domain name length too long\n"); + goto leave; + } + + if (!o2hb_check_local_node_heartbeating()) { + mlog(ML_ERROR, "the local node has not been configured, or is " + "not heartbeating\n"); + ret = -EPROTO; + goto leave; + } + + mlog(0, "register called for domain \"%s\"\n", domain); + +retry: + dlm = NULL; + if (signal_pending(current)) { + ret = -ERESTARTSYS; + mlog_errno(ret); + goto leave; + } + + spin_lock(&dlm_domain_lock); + + dlm = __dlm_lookup_domain(domain); + if (dlm) { + if (dlm->dlm_state != DLM_CTXT_JOINED) { + spin_unlock(&dlm_domain_lock); + + mlog(0, "This ctxt is not joined yet!\n"); + wait_event_interruptible(dlm_domain_events, + dlm_wait_on_domain_helper( + domain)); + goto retry; + } + + __dlm_get(dlm); + dlm->num_joins++; + + spin_unlock(&dlm_domain_lock); + + ret = 0; + goto leave; + } + + /* doesn't exist */ + if (!new_ctxt) { + spin_unlock(&dlm_domain_lock); + + new_ctxt = dlm_alloc_ctxt(domain, key); + if (new_ctxt) + goto retry; + + ret = -ENOMEM; + mlog_errno(ret); + goto leave; + } + + /* a little variable switch-a-roo here... */ + dlm = new_ctxt; + new_ctxt = NULL; + + /* add the new domain */ + list_add_tail(&dlm->list, &dlm_domains); + spin_unlock(&dlm_domain_lock); + + ret = dlm_join_domain(dlm); + if (ret) { + mlog_errno(ret); + dlm_put(dlm); + goto leave; + } + + ret = 0; +leave: + if (new_ctxt) + dlm_free_ctxt_mem(new_ctxt); + + if (ret < 0) + dlm = ERR_PTR(ret); + + return dlm; +} +EXPORT_SYMBOL_GPL(dlm_register_domain); + +static LIST_HEAD(dlm_join_handlers); + +static void dlm_unregister_net_handlers(void) +{ + o2net_unregister_handler_list(&dlm_join_handlers); +} + +static int dlm_register_net_handlers(void) +{ + int status = 0; + + status = o2net_register_handler(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, + sizeof(struct dlm_query_join_request), + dlm_query_join_handler, + NULL, &dlm_join_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_ASSERT_JOINED_MSG, DLM_MOD_KEY, + sizeof(struct dlm_assert_joined), + dlm_assert_joined_handler, + NULL, &dlm_join_handlers); + if (status) + goto bail; + + status = o2net_register_handler(DLM_CANCEL_JOIN_MSG, DLM_MOD_KEY, + sizeof(struct dlm_cancel_join), + dlm_cancel_join_handler, + NULL, &dlm_join_handlers); + +bail: + if (status < 0) + dlm_unregister_net_handlers(); + + return status; +} + +/* Domain eviction callback handling. + * + * The file system requires notification of node death *before* the + * dlm completes it's recovery work, otherwise it may be able to + * acquire locks on resources requiring recovery. Since the dlm can + * evict a node from it's domain *before* heartbeat fires, a similar + * mechanism is required. */ + +/* Eviction is not expected to happen often, so a per-domain lock is + * not necessary. Eviction callbacks are allowed to sleep for short + * periods of time. */ +static DECLARE_RWSEM(dlm_callback_sem); + +void dlm_fire_domain_eviction_callbacks(struct dlm_ctxt *dlm, + int node_num) +{ + struct list_head *iter; + struct dlm_eviction_cb *cb; + + down_read(&dlm_callback_sem); + list_for_each(iter, &dlm->dlm_eviction_callbacks) { + cb = list_entry(iter, struct dlm_eviction_cb, ec_item); + + cb->ec_func(node_num, cb->ec_data); + } + up_read(&dlm_callback_sem); +} + +void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb, + dlm_eviction_func *f, + void *data) +{ + INIT_LIST_HEAD(&cb->ec_item); + cb->ec_func = f; + cb->ec_data = data; +} +EXPORT_SYMBOL_GPL(dlm_setup_eviction_cb); + +void dlm_register_eviction_cb(struct dlm_ctxt *dlm, + struct dlm_eviction_cb *cb) +{ + down_write(&dlm_callback_sem); + list_add_tail(&cb->ec_item, &dlm->dlm_eviction_callbacks); + up_write(&dlm_callback_sem); +} +EXPORT_SYMBOL_GPL(dlm_register_eviction_cb); + +void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb) +{ + down_write(&dlm_callback_sem); + list_del_init(&cb->ec_item); + up_write(&dlm_callback_sem); +} +EXPORT_SYMBOL_GPL(dlm_unregister_eviction_cb); + +static int __init dlm_init(void) +{ + int status; + + dlm_print_version(); + + status = dlm_init_mle_cache(); + if (status) + return -1; + + status = dlm_register_net_handlers(); + if (status) { + dlm_destroy_mle_cache(); + return -1; + } + + return 0; +} + +static void __exit dlm_exit (void) +{ + dlm_unregister_net_handlers(); + dlm_destroy_mle_cache(); +} + +MODULE_AUTHOR("Oracle"); +MODULE_LICENSE("GPL"); + +module_init(dlm_init); +module_exit(dlm_exit); |