diff options
Diffstat (limited to 'fs/ocfs2/dlm/dlmthread.c')
-rw-r--r-- | fs/ocfs2/dlm/dlmthread.c | 695 |
1 files changed, 695 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c new file mode 100644 index 00000000000..92cd5cd66db --- /dev/null +++ b/fs/ocfs2/dlm/dlmthread.c @@ -0,0 +1,695 @@ +/* -*- 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 <linux/module.h> +#include <linux/fs.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/highmem.h> +#include <linux/utsname.h> +#include <linux/init.h> +#include <linux/sysctl.h> +#include <linux/random.h> +#include <linux/blkdev.h> +#include <linux/socket.h> +#include <linux/inet.h> +#include <linux/timer.h> +#include <linux/kthread.h> + + +#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" + +extern spinlock_t dlm_domain_lock; +extern struct list_head dlm_domains; + +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); + current->state = TASK_RUNNING; +} + + +static int __dlm_lockres_unused(struct dlm_lock_resource *res) +{ + if (list_empty(&res->granted) && + list_empty(&res->converting) && + list_empty(&res->blocked) && + list_empty(&res->dirty)) + return 1; + return 0; +} + + +/* 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) +{ + mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); + + assert_spin_locked(&dlm->spinlock); + assert_spin_locked(&res->spinlock); + + if (__dlm_lockres_unused(res)){ + if (list_empty(&res->purge)) { + mlog(0, "putting lockres %.*s from purge list\n", + res->lockname.len, res->lockname.name); + + res->last_used = jiffies; + list_add_tail(&res->purge, &dlm->purge_list); + dlm->purge_count++; + } + } else if (!list_empty(&res->purge)) { + mlog(0, "removing lockres %.*s from purge list\n", + res->lockname.len, res->lockname.name); + + list_del_init(&res->purge); + dlm->purge_count--; + } +} + +void dlm_lockres_calc_usage(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res) +{ + mlog_entry("%.*s\n", res->lockname.len, res->lockname.name); + spin_lock(&dlm->spinlock); + spin_lock(&res->spinlock); + + __dlm_lockres_calc_usage(dlm, res); + + spin_unlock(&res->spinlock); + spin_unlock(&dlm->spinlock); +} + +/* TODO: Eventual API: Called with the dlm spinlock held, may drop it + * to do migration, but will re-acquire before exit. */ +void dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *lockres) +{ + int master; + int ret; + + spin_lock(&lockres->spinlock); + master = lockres->owner == dlm->node_num; + spin_unlock(&lockres->spinlock); + + mlog(0, "purging lockres %.*s, master = %d\n", lockres->lockname.len, + lockres->lockname.name, master); + + /* Non master is the easy case -- no migration required, just + * quit. */ + if (!master) + goto finish; + + /* Wheee! Migrate lockres here! */ + spin_unlock(&dlm->spinlock); +again: + + ret = dlm_migrate_lockres(dlm, lockres, O2NM_MAX_NODES); + if (ret == -ENOTEMPTY) { + mlog(ML_ERROR, "lockres %.*s still has local locks!\n", + lockres->lockname.len, lockres->lockname.name); + + BUG(); + } else if (ret < 0) { + mlog(ML_NOTICE, "lockres %.*s: migrate failed, retrying\n", + lockres->lockname.len, lockres->lockname.name); + goto again; + } + + spin_lock(&dlm->spinlock); + +finish: + if (!list_empty(&lockres->purge)) { + list_del_init(&lockres->purge); + dlm->purge_count--; + } + __dlm_unhash_lockres(lockres); +} + +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); + + /* 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 -- there's no need to keep the lockres + * spinlock. */ + spin_lock(&lockres->spinlock); + unused = __dlm_lockres_unused(lockres); + spin_unlock(&lockres->spinlock); + + if (!unused) + continue; + + 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 */ + break; + } + + list_del_init(&lockres->purge); + dlm->purge_count--; + + /* This may drop and reacquire the dlm spinlock if it + * has to do migration. */ + mlog(0, "calling dlm_purge_lockres!\n"); + dlm_purge_lockres(dlm, lockres); + mlog(0, "DONE calling dlm_purge_lockres!\n"); + + /* 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; + + //mlog(0, "res->lockname.len=%d\n", res->lockname.len); + //mlog(0, "res->lockname.name=%p\n", res->lockname.name); + //mlog(0, "shuffle res %.*s\n", res->lockname.len, + // res->lockname.name); + + /* 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(&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, "res %.*s has locks on a convert queue\n", 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: converting a lock with no " + "convert_type!\n", 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, "calling ast for converting lock: %.*s, have: %d, " + "granting: %d, node: %u\n", res->lockname.len, + res->lockname.name, target->ml.type, + target->ml.convert_type, target->ml.node); + + target->ml.type = target->ml.convert_type; + target->ml.convert_type = LKM_IVMODE; + list_del_init(&target->list); + list_add_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, "calling ast for blocked lock: %.*s, granting: %d, " + "node: %u\n", res->lockname.len, res->lockname.name, + target->ml.type, target->ml.node); + + // target->ml.type is already correct + list_del_init(&target->list); + list_add_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) +{ + mlog_entry("dlm=%p, res=%p\n", dlm, 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) +{ + mlog_entry("dlm=%p, res=%p\n", dlm, res); + + assert_spin_locked(&dlm->spinlock); + assert_spin_locked(&res->spinlock); + + /* don't shuffle secondary queues */ + if ((res->owner == dlm->node_num) && + !(res->state & DLM_LOCK_RES_DIRTY)) { + list_add_tail(&res->dirty, &dlm->dirty_list); + res->state |= DLM_LOCK_RES_DIRTY; + } +} + + +/* 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, "delivering an ast for this lockres\n"); + + 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, "aha another ast got queued while " + "we were finishing the last one. will " + "keep the ast_pending flag set.\n"); + } 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, "delivering a bast for this lockres " + "(blocked = %d\n", hi); + + 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, "aha another bast got queued while " + "we were finishing the last one. will " + "keep the bast_pending flag set.\n"); + } 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); + res->state &= ~DLM_LOCK_RES_DIRTY; + list_del_init(&res->dirty); + spin_unlock(&res->spinlock); + spin_unlock(&dlm->spinlock); + + /* lockres can be re-dirtied/re-added to the + * dirty_list in this gap, but that is ok */ + + spin_lock(&res->spinlock); + if (res->owner != dlm->node_num) { + __dlm_print_one_lock_resource(res); + mlog(ML_ERROR, "inprog:%s, mig:%s, reco:%s, dirty:%s\n", + res->state & DLM_LOCK_RES_IN_PROGRESS ? "yes" : "no", + res->state & DLM_LOCK_RES_MIGRATING ? "yes" : "no", + res->state & DLM_LOCK_RES_RECOVERING ? "yes" : "no", + res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no"); + } + 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. */ + if (res->state & (DLM_LOCK_RES_IN_PROGRESS | + DLM_LOCK_RES_MIGRATING | + DLM_LOCK_RES_RECOVERING)) { + /* move it to the tail and keep going */ + spin_unlock(&res->spinlock); + mlog(0, "delaying list shuffling for in-" + "progress lockres %.*s, state=%d\n", + 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. */ + + mlog(0, "calling dlm_shuffle_lists with dlm=%p, " + "res=%p\n", dlm, res); + + /* called while holding lockres lock */ + dlm_shuffle_lists(dlm, res); + spin_unlock(&res->spinlock); + + 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); + list_add_tail(&res->dirty, &dlm->dirty_list); + res->state |= DLM_LOCK_RES_DIRTY; + spin_unlock(&res->spinlock); + } + dlm_lockres_put(res); + + /* unlikely, but we may need to give time to + * other tasks */ + if (!--n) { + mlog(0, "throttling dlm_thread\n"); + break; + } + } + + spin_unlock(&dlm->spinlock); + dlm_flush_asts(dlm); + + /* yield and continue right away if there is more work to do */ + if (!n) { + yield(); + 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; +} |