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-rw-r--r--fs/ocfs2/dlm/dlmthread.c809
1 files changed, 809 insertions, 0 deletions
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
new file mode 100644
index 0000000000..eedf07ca23
--- /dev/null
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -0,0 +1,809 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * dlmthread.c
+ *
+ * standalone DLM module
+ *
+ * Copyright (C) 2004 Oracle. All rights reserved.
+ */
+
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/highmem.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 <linux/delay.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"
+
+static int dlm_thread(void *data);
+static void dlm_flush_asts(struct dlm_ctxt *dlm);
+
+/* 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|
+ DLM_LOCK_RES_RECOVERY_WAITING))
+ return 0;
+
+ /* Another node has this resource with this node as the master */
+ bit = find_first_bit(res->refmap, O2NM_MAX_NODES);
+ 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);
+}
+
+/*
+ * Do the real purge work:
+ * unhash the lockres, and
+ * clear flag DLM_LOCK_RES_DROPPING_REF.
+ * It requires dlm and lockres spinlock to be taken.
+ */
+void __dlm_do_purge_lockres(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ assert_spin_locked(&dlm->spinlock);
+ assert_spin_locked(&res->spinlock);
+
+ if (!list_empty(&res->purge)) {
+ mlog(0, "%s: Removing res %.*s from purgelist\n",
+ dlm->name, res->lockname.len, res->lockname.name);
+ 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);
+
+ spin_lock(&dlm->track_lock);
+ if (!list_empty(&res->tracking))
+ list_del_init(&res->tracking);
+ else {
+ mlog(ML_ERROR, "%s: Resource %.*s not on the Tracking list\n",
+ dlm->name, res->lockname.len, res->lockname.name);
+ __dlm_print_one_lock_resource(res);
+ }
+ spin_unlock(&dlm->track_lock);
+
+ /*
+ * lockres is not in the hash now. drop the flag and wake up
+ * any processes waiting in dlm_get_lock_resource.
+ */
+ res->state &= ~DLM_LOCK_RES_DROPPING_REF;
+}
+
+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) {
+ if (res->state & DLM_LOCK_RES_DROPPING_REF) {
+ mlog(ML_NOTICE, "%s: res %.*s already in DLM_LOCK_RES_DROPPING_REF state\n",
+ dlm->name, res->lockname.len, res->lockname.name);
+ spin_unlock(&res->spinlock);
+ return;
+ }
+
+ 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 (!master && ret == DLM_DEREF_RESPONSE_INPROG) {
+ mlog(0, "%s: deref %.*s in progress\n",
+ dlm->name, res->lockname.len, res->lockname.name);
+ spin_unlock(&res->spinlock);
+ return;
+ }
+
+ 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);
+
+ spin_lock(&dlm->track_lock);
+ if (!list_empty(&res->tracking))
+ list_del_init(&res->tracking);
+ else {
+ mlog(ML_ERROR, "Resource %.*s not on the Tracking list\n",
+ res->lockname.len, res->lockname.name);
+ __dlm_print_one_lock_resource(res);
+ }
+ spin_unlock(&dlm->track_lock);
+
+ /* 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) ||
+ (lockres->inflight_assert_workers != 0)) {
+ mlog(0, "%s: res %.*s is in use or being remastered, "
+ "used %d, state %d, assert master workers %u\n",
+ dlm->name, lockres->lockname.len,
+ lockres->lockname.name,
+ !unused, lockres->state,
+ lockres->inflight_assert_workers);
+ list_move_tail(&lockres->purge, &dlm->purge_list);
+ 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;
+ 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();
+ }
+ list_for_each_entry(lock, &res->granted, 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;
+ }
+ }
+
+ list_for_each_entry(lock, &res->converting, 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);
+
+ list_for_each_entry(lock, &res->granted, 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;
+ }
+ }
+
+ list_for_each_entry(lock, &res->converting, 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-%s",
+ dlm->name);
+ 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
+
+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 |
+ DLM_LOCK_RES_RECOVERY_WAITING)) {
+ /* 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 22:37:30 +0000