/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * dlmthread.c * * standalone DLM module * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include "cluster/heartbeat.h" #include "cluster/nodemanager.h" #include "cluster/tcp.h" #include "dlmapi.h" #include "dlmcommon.h" #include "dlmdomain.h" #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_THREAD) #include "cluster/masklog.h" static int dlm_thread(void *data); static void dlm_flush_asts(struct dlm_ctxt *dlm); #define dlm_lock_is_remote(dlm, lock) ((lock)->ml.node != (dlm)->node_num) /* will exit holding res->spinlock, but may drop in function */ /* waits until flags are cleared on res->state */ void __dlm_wait_on_lockres_flags(struct dlm_lock_resource *res, int flags) { DECLARE_WAITQUEUE(wait, current); assert_spin_locked(&res->spinlock); add_wait_queue(&res->wq, &wait); repeat: set_current_state(TASK_UNINTERRUPTIBLE); if (res->state & flags) { spin_unlock(&res->spinlock); schedule(); spin_lock(&res->spinlock); goto repeat; } remove_wait_queue(&res->wq, &wait); __set_current_state(TASK_RUNNING); } int __dlm_lockres_has_locks(struct dlm_lock_resource *res) { if (list_empty(&res->granted) && list_empty(&res->converting) && list_empty(&res->blocked)) return 0; return 1; } /* "unused": the lockres has no locks, is not on the dirty list, * has no inflight locks (in the gap between mastery and acquiring * the first lock), and has no bits in its refmap. * truly ready to be freed. */ int __dlm_lockres_unused(struct dlm_lock_resource *res) { int bit; assert_spin_locked(&res->spinlock); if (__dlm_lockres_has_locks(res)) return 0; /* Locks are in the process of being created */ if (res->inflight_locks) return 0; if (!list_empty(&res->dirty) || res->state & DLM_LOCK_RES_DIRTY) return 0; if (res->state & DLM_LOCK_RES_RECOVERING) return 0; /* Another node has this resource with this node as the master */ bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0); if (bit < O2NM_MAX_NODES) return 0; return 1; } /* Call whenever you may have added or deleted something from one of * the lockres queue's. This will figure out whether it belongs on the * unused list or not and does the appropriate thing. */ void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { assert_spin_locked(&dlm->spinlock); assert_spin_locked(&res->spinlock); if (__dlm_lockres_unused(res)){ if (list_empty(&res->purge)) { mlog(0, "%s: Adding res %.*s to purge list\n", dlm->name, res->lockname.len, res->lockname.name); res->last_used = jiffies; dlm_lockres_get(res); list_add_tail(&res->purge, &dlm->purge_list); dlm->purge_count++; } } else if (!list_empty(&res->purge)) { mlog(0, "%s: Removing res %.*s from purge list\n", dlm->name, res->lockname.len, res->lockname.name); list_del_init(&res->purge); dlm_lockres_put(res); dlm->purge_count--; } } void dlm_lockres_calc_usage(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { spin_lock(&dlm->spinlock); spin_lock(&res->spinlock); __dlm_lockres_calc_usage(dlm, res); spin_unlock(&res->spinlock); spin_unlock(&dlm->spinlock); } static void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { int master; int ret = 0; assert_spin_locked(&dlm->spinlock); assert_spin_locked(&res->spinlock); master = (res->owner == dlm->node_num); mlog(0, "%s: Purging res %.*s, master %d\n", dlm->name, res->lockname.len, res->lockname.name, master); if (!master) { res->state |= DLM_LOCK_RES_DROPPING_REF; /* drop spinlock... retake below */ spin_unlock(&res->spinlock); spin_unlock(&dlm->spinlock); spin_lock(&res->spinlock); /* This ensures that clear refmap is sent after the set */ __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_SETREF_INPROG); spin_unlock(&res->spinlock); /* clear our bit from the master's refmap, ignore errors */ ret = dlm_drop_lockres_ref(dlm, res); if (ret < 0) { if (!dlm_is_host_down(ret)) BUG(); } spin_lock(&dlm->spinlock); spin_lock(&res->spinlock); } if (!list_empty(&res->purge)) { mlog(0, "%s: Removing res %.*s from purgelist, master %d\n", dlm->name, res->lockname.len, res->lockname.name, master); list_del_init(&res->purge); dlm_lockres_put(res); dlm->purge_count--; } if (!__dlm_lockres_unused(res)) { mlog(ML_ERROR, "%s: res %.*s in use after deref\n", dlm->name, res->lockname.len, res->lockname.name); __dlm_print_one_lock_resource(res); BUG(); } __dlm_unhash_lockres(dlm, res); /* lockres is not in the hash now. drop the flag and wake up * any processes waiting in dlm_get_lock_resource. */ if (!master) { res->state &= ~DLM_LOCK_RES_DROPPING_REF; spin_unlock(&res->spinlock); wake_up(&res->wq); } else spin_unlock(&res->spinlock); } static void dlm_run_purge_list(struct dlm_ctxt *dlm, int purge_now) { unsigned int run_max, unused; unsigned long purge_jiffies; struct dlm_lock_resource *lockres; spin_lock(&dlm->spinlock); run_max = dlm->purge_count; while(run_max && !list_empty(&dlm->purge_list)) { run_max--; lockres = list_entry(dlm->purge_list.next, struct dlm_lock_resource, purge); spin_lock(&lockres->spinlock); purge_jiffies = lockres->last_used + msecs_to_jiffies(DLM_PURGE_INTERVAL_MS); /* Make sure that we want to be processing this guy at * this time. */ if (!purge_now && time_after(purge_jiffies, jiffies)) { /* Since resources are added to the purge list * in tail order, we can stop at the first * unpurgable resource -- anyone added after * him will have a greater last_used value */ spin_unlock(&lockres->spinlock); break; } /* Status of the lockres *might* change so double * check. If the lockres is unused, holding the dlm * spinlock will prevent people from getting and more * refs on it. */ unused = __dlm_lockres_unused(lockres); if (!unused || (lockres->state & DLM_LOCK_RES_MIGRATING)) { mlog(0, "%s: res %.*s is in use or being remastered, " "used %d, state %d\n", dlm->name, lockres->lockname.len, lockres->lockname.name, !unused, lockres->state); list_move_tail(&dlm->purge_list, &lockres->purge); spin_unlock(&lockres->spinlock); continue; } dlm_lockres_get(lockres); dlm_purge_lockres(dlm, lockres); dlm_lockres_put(lockres); /* Avoid adding any scheduling latencies */ cond_resched_lock(&dlm->spinlock); } spin_unlock(&dlm->spinlock); } static void dlm_shuffle_lists(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { struct dlm_lock *lock, *target; struct list_head *iter; struct list_head *head; int can_grant = 1; /* * Because this function is called with the lockres * spinlock, and because we know that it is not migrating/ * recovering/in-progress, it is fine to reserve asts and * basts right before queueing them all throughout */ assert_spin_locked(&dlm->ast_lock); assert_spin_locked(&res->spinlock); BUG_ON((res->state & (DLM_LOCK_RES_MIGRATING| DLM_LOCK_RES_RECOVERING| DLM_LOCK_RES_IN_PROGRESS))); converting: if (list_empty(&res->converting)) goto blocked; mlog(0, "%s: res %.*s has locks on the convert queue\n", dlm->name, res->lockname.len, res->lockname.name); target = list_entry(res->converting.next, struct dlm_lock, list); if (target->ml.convert_type == LKM_IVMODE) { mlog(ML_ERROR, "%s: res %.*s converting lock to invalid mode\n", dlm->name, res->lockname.len, res->lockname.name); BUG(); } head = &res->granted; list_for_each(iter, head) { lock = list_entry(iter, struct dlm_lock, list); if (lock==target) continue; if (!dlm_lock_compatible(lock->ml.type, target->ml.convert_type)) { can_grant = 0; /* queue the BAST if not already */ if (lock->ml.highest_blocked == LKM_IVMODE) { __dlm_lockres_reserve_ast(res); __dlm_queue_bast(dlm, lock); } /* update the highest_blocked if needed */ if (lock->ml.highest_blocked < target->ml.convert_type) lock->ml.highest_blocked = target->ml.convert_type; } } head = &res->converting; list_for_each(iter, head) { lock = list_entry(iter, struct dlm_lock, list); if (lock==target) continue; if (!dlm_lock_compatible(lock->ml.type, target->ml.convert_type)) { can_grant = 0; if (lock->ml.highest_blocked == LKM_IVMODE) { __dlm_lockres_reserve_ast(res); __dlm_queue_bast(dlm, lock); } if (lock->ml.highest_blocked < target->ml.convert_type) lock->ml.highest_blocked = target->ml.convert_type; } } /* we can convert the lock */ if (can_grant) { spin_lock(&target->spinlock); BUG_ON(target->ml.highest_blocked != LKM_IVMODE); mlog(0, "%s: res %.*s, AST for Converting lock %u:%llu, type " "%d => %d, node %u\n", dlm->name, res->lockname.len, res->lockname.name, dlm_get_lock_cookie_node(be64_to_cpu(target->ml.cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(target->ml.cookie)), target->ml.type, target->ml.convert_type, target->ml.node); target->ml.type = target->ml.convert_type; target->ml.convert_type = LKM_IVMODE; list_move_tail(&target->list, &res->granted); BUG_ON(!target->lksb); target->lksb->status = DLM_NORMAL; spin_unlock(&target->spinlock); __dlm_lockres_reserve_ast(res); __dlm_queue_ast(dlm, target); /* go back and check for more */ goto converting; } blocked: if (list_empty(&res->blocked)) goto leave; target = list_entry(res->blocked.next, struct dlm_lock, list); head = &res->granted; list_for_each(iter, head) { lock = list_entry(iter, struct dlm_lock, list); if (lock==target) continue; if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { can_grant = 0; if (lock->ml.highest_blocked == LKM_IVMODE) { __dlm_lockres_reserve_ast(res); __dlm_queue_bast(dlm, lock); } if (lock->ml.highest_blocked < target->ml.type) lock->ml.highest_blocked = target->ml.type; } } head = &res->converting; list_for_each(iter, head) { lock = list_entry(iter, struct dlm_lock, list); if (lock==target) continue; if (!dlm_lock_compatible(lock->ml.type, target->ml.type)) { can_grant = 0; if (lock->ml.highest_blocked == LKM_IVMODE) { __dlm_lockres_reserve_ast(res); __dlm_queue_bast(dlm, lock); } if (lock->ml.highest_blocked < target->ml.type) lock->ml.highest_blocked = target->ml.type; } } /* we can grant the blocked lock (only * possible if converting list empty) */ if (can_grant) { spin_lock(&target->spinlock); BUG_ON(target->ml.highest_blocked != LKM_IVMODE); mlog(0, "%s: res %.*s, AST for Blocked lock %u:%llu, type %d, " "node %u\n", dlm->name, res->lockname.len, res->lockname.name, dlm_get_lock_cookie_node(be64_to_cpu(target->ml.cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(target->ml.cookie)), target->ml.type, target->ml.node); /* target->ml.type is already correct */ list_move_tail(&target->list, &res->granted); BUG_ON(!target->lksb); target->lksb->status = DLM_NORMAL; spin_unlock(&target->spinlock); __dlm_lockres_reserve_ast(res); __dlm_queue_ast(dlm, target); /* go back and check for more */ goto converting; } leave: return; } /* must have NO locks when calling this with res !=NULL * */ void dlm_kick_thread(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { if (res) { spin_lock(&dlm->spinlock); spin_lock(&res->spinlock); __dlm_dirty_lockres(dlm, res); spin_unlock(&res->spinlock); spin_unlock(&dlm->spinlock); } wake_up(&dlm->dlm_thread_wq); } void __dlm_dirty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { assert_spin_locked(&dlm->spinlock); assert_spin_locked(&res->spinlock); /* don't shuffle secondary queues */ if ((res->owner == dlm->node_num)) { if (res->state & (DLM_LOCK_RES_MIGRATING | DLM_LOCK_RES_BLOCK_DIRTY)) return; if (list_empty(&res->dirty)) { /* ref for dirty_list */ dlm_lockres_get(res); list_add_tail(&res->dirty, &dlm->dirty_list); res->state |= DLM_LOCK_RES_DIRTY; } } mlog(0, "%s: res %.*s\n", dlm->name, res->lockname.len, res->lockname.name); } /* Launch the NM thread for the mounted volume */ int dlm_launch_thread(struct dlm_ctxt *dlm) { mlog(0, "Starting dlm_thread...\n"); dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread"); if (IS_ERR(dlm->dlm_thread_task)) { mlog_errno(PTR_ERR(dlm->dlm_thread_task)); dlm->dlm_thread_task = NULL; return -EINVAL; } return 0; } void dlm_complete_thread(struct dlm_ctxt *dlm) { if (dlm->dlm_thread_task) { mlog(ML_KTHREAD, "Waiting for dlm thread to exit\n"); kthread_stop(dlm->dlm_thread_task); dlm->dlm_thread_task = NULL; } } static int dlm_dirty_list_empty(struct dlm_ctxt *dlm) { int empty; spin_lock(&dlm->spinlock); empty = list_empty(&dlm->dirty_list); spin_unlock(&dlm->spinlock); return empty; } static void dlm_flush_asts(struct dlm_ctxt *dlm) { int ret; struct dlm_lock *lock; struct dlm_lock_resource *res; u8 hi; spin_lock(&dlm->ast_lock); while (!list_empty(&dlm->pending_asts)) { lock = list_entry(dlm->pending_asts.next, struct dlm_lock, ast_list); /* get an extra ref on lock */ dlm_lock_get(lock); res = lock->lockres; mlog(0, "%s: res %.*s, Flush AST for lock %u:%llu, type %d, " "node %u\n", dlm->name, res->lockname.len, res->lockname.name, dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), lock->ml.type, lock->ml.node); BUG_ON(!lock->ast_pending); /* remove from list (including ref) */ list_del_init(&lock->ast_list); dlm_lock_put(lock); spin_unlock(&dlm->ast_lock); if (lock->ml.node != dlm->node_num) { ret = dlm_do_remote_ast(dlm, res, lock); if (ret < 0) mlog_errno(ret); } else dlm_do_local_ast(dlm, res, lock); spin_lock(&dlm->ast_lock); /* possible that another ast was queued while * we were delivering the last one */ if (!list_empty(&lock->ast_list)) { mlog(0, "%s: res %.*s, AST queued while flushing last " "one\n", dlm->name, res->lockname.len, res->lockname.name); } else lock->ast_pending = 0; /* drop the extra ref. * this may drop it completely. */ dlm_lock_put(lock); dlm_lockres_release_ast(dlm, res); } while (!list_empty(&dlm->pending_basts)) { lock = list_entry(dlm->pending_basts.next, struct dlm_lock, bast_list); /* get an extra ref on lock */ dlm_lock_get(lock); res = lock->lockres; BUG_ON(!lock->bast_pending); /* get the highest blocked lock, and reset */ spin_lock(&lock->spinlock); BUG_ON(lock->ml.highest_blocked <= LKM_IVMODE); hi = lock->ml.highest_blocked; lock->ml.highest_blocked = LKM_IVMODE; spin_unlock(&lock->spinlock); /* remove from list (including ref) */ list_del_init(&lock->bast_list); dlm_lock_put(lock); spin_unlock(&dlm->ast_lock); mlog(0, "%s: res %.*s, Flush BAST for lock %u:%llu, " "blocked %d, node %u\n", dlm->name, res->lockname.len, res->lockname.name, dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)), dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)), hi, lock->ml.node); if (lock->ml.node != dlm->node_num) { ret = dlm_send_proxy_bast(dlm, res, lock, hi); if (ret < 0) mlog_errno(ret); } else dlm_do_local_bast(dlm, res, lock, hi); spin_lock(&dlm->ast_lock); /* possible that another bast was queued while * we were delivering the last one */ if (!list_empty(&lock->bast_list)) { mlog(0, "%s: res %.*s, BAST queued while flushing last " "one\n", dlm->name, res->lockname.len, res->lockname.name); } else lock->bast_pending = 0; /* drop the extra ref. * this may drop it completely. */ dlm_lock_put(lock); dlm_lockres_release_ast(dlm, res); } wake_up(&dlm->ast_wq); spin_unlock(&dlm->ast_lock); } #define DLM_THREAD_TIMEOUT_MS (4 * 1000) #define DLM_THREAD_MAX_DIRTY 100 #define DLM_THREAD_MAX_ASTS 10 static int dlm_thread(void *data) { struct dlm_lock_resource *res; struct dlm_ctxt *dlm = data; unsigned long timeout = msecs_to_jiffies(DLM_THREAD_TIMEOUT_MS); mlog(0, "dlm thread running for %s...\n", dlm->name); while (!kthread_should_stop()) { int n = DLM_THREAD_MAX_DIRTY; /* dlm_shutting_down is very point-in-time, but that * doesn't matter as we'll just loop back around if we * get false on the leading edge of a state * transition. */ dlm_run_purge_list(dlm, dlm_shutting_down(dlm)); /* We really don't want to hold dlm->spinlock while * calling dlm_shuffle_lists on each lockres that * needs to have its queues adjusted and AST/BASTs * run. So let's pull each entry off the dirty_list * and drop dlm->spinlock ASAP. Once off the list, * res->spinlock needs to be taken again to protect * the queues while calling dlm_shuffle_lists. */ spin_lock(&dlm->spinlock); while (!list_empty(&dlm->dirty_list)) { int delay = 0; res = list_entry(dlm->dirty_list.next, struct dlm_lock_resource, dirty); /* peel a lockres off, remove it from the list, * unset the dirty flag and drop the dlm lock */ BUG_ON(!res); dlm_lockres_get(res); spin_lock(&res->spinlock); /* We clear the DLM_LOCK_RES_DIRTY state once we shuffle lists below */ list_del_init(&res->dirty); spin_unlock(&res->spinlock); spin_unlock(&dlm->spinlock); /* Drop dirty_list ref */ dlm_lockres_put(res); /* lockres can be re-dirtied/re-added to the * dirty_list in this gap, but that is ok */ spin_lock(&dlm->ast_lock); spin_lock(&res->spinlock); if (res->owner != dlm->node_num) { __dlm_print_one_lock_resource(res); mlog(ML_ERROR, "%s: inprog %d, mig %d, reco %d," " dirty %d\n", dlm->name, !!(res->state & DLM_LOCK_RES_IN_PROGRESS), !!(res->state & DLM_LOCK_RES_MIGRATING), !!(res->state & DLM_LOCK_RES_RECOVERING), !!(res->state & DLM_LOCK_RES_DIRTY)); } BUG_ON(res->owner != dlm->node_num); /* it is now ok to move lockreses in these states * to the dirty list, assuming that they will only be * dirty for a short while. */ BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); if (res->state & (DLM_LOCK_RES_IN_PROGRESS | DLM_LOCK_RES_RECOVERING)) { /* move it to the tail and keep going */ res->state &= ~DLM_LOCK_RES_DIRTY; spin_unlock(&res->spinlock); spin_unlock(&dlm->ast_lock); mlog(0, "%s: res %.*s, inprogress, delay list " "shuffle, state %d\n", dlm->name, res->lockname.len, res->lockname.name, res->state); delay = 1; goto in_progress; } /* at this point the lockres is not migrating/ * recovering/in-progress. we have the lockres * spinlock and do NOT have the dlm lock. * safe to reserve/queue asts and run the lists. */ /* called while holding lockres lock */ dlm_shuffle_lists(dlm, res); res->state &= ~DLM_LOCK_RES_DIRTY; spin_unlock(&res->spinlock); spin_unlock(&dlm->ast_lock); dlm_lockres_calc_usage(dlm, res); in_progress: spin_lock(&dlm->spinlock); /* if the lock was in-progress, stick * it on the back of the list */ if (delay) { spin_lock(&res->spinlock); __dlm_dirty_lockres(dlm, res); spin_unlock(&res->spinlock); } dlm_lockres_put(res); /* unlikely, but we may need to give time to * other tasks */ if (!--n) { mlog(0, "%s: Throttling dlm thread\n", dlm->name); break; } } spin_unlock(&dlm->spinlock); dlm_flush_asts(dlm); /* yield and continue right away if there is more work to do */ if (!n) { cond_resched(); continue; } wait_event_interruptible_timeout(dlm->dlm_thread_wq, !dlm_dirty_list_empty(dlm) || kthread_should_stop(), timeout); } mlog(0, "quitting DLM thread\n"); return 0; }