ocfs2_dlm: fix cluster-wide refcounting of lock resources
This was previously broken and migration of some locks had to be temporarily
disabled. We use a new (and backward-incompatible) set of network messages
to account for all references to a lock resources held across the cluster.
once these are all freed, the master node may then free the lock resource
memory once its local references are dropped.
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 367a11e..d011a2a 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1129,6 +1129,11 @@
if (total_locks == mres_total_locks)
mres->flags |= DLM_MRES_ALL_DONE;
+ mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
+ dlm->name, res->lockname.len, res->lockname.name,
+ orig_flags & DLM_MRES_MIGRATION ? "migrate" : "recovery",
+ send_to);
+
/* send it */
ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
sz, send_to, &status);
@@ -1213,6 +1218,34 @@
return 0;
}
+static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
+ struct dlm_migratable_lockres *mres)
+{
+ struct dlm_lock dummy;
+ memset(&dummy, 0, sizeof(dummy));
+ dummy.ml.cookie = 0;
+ dummy.ml.type = LKM_IVMODE;
+ dummy.ml.convert_type = LKM_IVMODE;
+ dummy.ml.highest_blocked = LKM_IVMODE;
+ dummy.lksb = NULL;
+ dummy.ml.node = dlm->node_num;
+ dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
+}
+
+static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
+ struct dlm_migratable_lock *ml,
+ u8 *nodenum)
+{
+ if (unlikely(ml->cookie == 0 &&
+ ml->type == LKM_IVMODE &&
+ ml->convert_type == LKM_IVMODE &&
+ ml->highest_blocked == LKM_IVMODE &&
+ ml->list == DLM_BLOCKED_LIST)) {
+ *nodenum = ml->node;
+ return 1;
+ }
+ return 0;
+}
int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
struct dlm_migratable_lockres *mres,
@@ -1260,6 +1293,14 @@
goto error;
}
}
+ if (total_locks == 0) {
+ /* send a dummy lock to indicate a mastery reference only */
+ mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
+ dlm->name, res->lockname.len, res->lockname.name,
+ send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
+ "migration");
+ dlm_add_dummy_lock(dlm, mres);
+ }
/* flush any remaining locks */
ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
if (ret < 0)
@@ -1386,13 +1427,16 @@
/* add an extra ref for just-allocated lockres
* otherwise the lockres will be purged immediately */
dlm_lockres_get(res);
-
}
/* at this point we have allocated everything we need,
* and we have a hashed lockres with an extra ref and
* the proper res->state flags. */
ret = 0;
+ spin_lock(&res->spinlock);
+ /* drop this either when master requery finds a different master
+ * or when a lock is added by the recovery worker */
+ dlm_lockres_grab_inflight_ref(dlm, res);
if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
/* migration cannot have an unknown master */
BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
@@ -1400,10 +1444,11 @@
"unknown owner.. will need to requery: "
"%.*s\n", mres->lockname_len, mres->lockname);
} else {
- spin_lock(&res->spinlock);
+ /* take a reference now to pin the lockres, drop it
+ * when locks are added in the worker */
dlm_change_lockres_owner(dlm, res, dlm->node_num);
- spin_unlock(&res->spinlock);
}
+ spin_unlock(&res->spinlock);
/* queue up work for dlm_mig_lockres_worker */
dlm_grab(dlm); /* get an extra ref for the work item */
@@ -1459,6 +1504,9 @@
"this node will take it.\n",
res->lockname.len, res->lockname.name);
} else {
+ spin_lock(&res->spinlock);
+ dlm_lockres_drop_inflight_ref(dlm, res);
+ spin_unlock(&res->spinlock);
mlog(0, "master needs to respond to sender "
"that node %u still owns %.*s\n",
real_master, res->lockname.len,
@@ -1666,10 +1714,25 @@
int i, bad;
struct list_head *iter;
struct dlm_lock *lock = NULL;
+ u8 from = O2NM_MAX_NODES;
+ unsigned int added = 0;
mlog(0, "running %d locks for this lockres\n", mres->num_locks);
for (i=0; i<mres->num_locks; i++) {
ml = &(mres->ml[i]);
+
+ if (dlm_is_dummy_lock(dlm, ml, &from)) {
+ /* placeholder, just need to set the refmap bit */
+ BUG_ON(mres->num_locks != 1);
+ mlog(0, "%s:%.*s: dummy lock for %u\n",
+ dlm->name, mres->lockname_len, mres->lockname,
+ from);
+ spin_lock(&res->spinlock);
+ dlm_lockres_set_refmap_bit(from, res);
+ spin_unlock(&res->spinlock);
+ added++;
+ break;
+ }
BUG_ON(ml->highest_blocked != LKM_IVMODE);
newlock = NULL;
lksb = NULL;
@@ -1711,6 +1774,7 @@
/* do not alter lock refcount. switching lists. */
list_move_tail(&lock->list, queue);
spin_unlock(&res->spinlock);
+ added++;
mlog(0, "just reordered a local lock!\n");
continue;
@@ -1817,12 +1881,24 @@
if (!bad) {
dlm_lock_get(newlock);
list_add_tail(&newlock->list, queue);
+ mlog(0, "%s:%.*s: added lock for node %u, "
+ "setting refmap bit\n", dlm->name,
+ res->lockname.len, res->lockname.name, ml->node);
+ dlm_lockres_set_refmap_bit(ml->node, res);
+ added++;
}
spin_unlock(&res->spinlock);
}
mlog(0, "done running all the locks\n");
leave:
+ /* balance the ref taken when the work was queued */
+ if (added > 0) {
+ spin_lock(&res->spinlock);
+ dlm_lockres_drop_inflight_ref(dlm, res);
+ spin_unlock(&res->spinlock);
+ }
+
if (ret < 0) {
mlog_errno(ret);
if (newlock)
@@ -1935,9 +2011,11 @@
if (res->owner == dead_node) {
list_del_init(&res->recovering);
spin_lock(&res->spinlock);
+ /* new_master has our reference from
+ * the lock state sent during recovery */
dlm_change_lockres_owner(dlm, res, new_master);
res->state &= ~DLM_LOCK_RES_RECOVERING;
- if (!__dlm_lockres_unused(res))
+ if (__dlm_lockres_has_locks(res))
__dlm_dirty_lockres(dlm, res);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
@@ -1977,9 +2055,11 @@
dlm_lockres_put(res);
}
spin_lock(&res->spinlock);
+ /* new_master has our reference from
+ * the lock state sent during recovery */
dlm_change_lockres_owner(dlm, res, new_master);
res->state &= ~DLM_LOCK_RES_RECOVERING;
- if (!__dlm_lockres_unused(res))
+ if (__dlm_lockres_has_locks(res))
__dlm_dirty_lockres(dlm, res);
spin_unlock(&res->spinlock);
wake_up(&res->wq);
@@ -2048,6 +2128,7 @@
{
struct list_head *iter, *tmpiter;
struct dlm_lock *lock;
+ unsigned int freed = 0;
/* this node is the lockres master:
* 1) remove any stale locks for the dead node
@@ -2062,6 +2143,7 @@
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
+ freed++;
}
}
list_for_each_safe(iter, tmpiter, &res->converting) {
@@ -2069,6 +2151,7 @@
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
+ freed++;
}
}
list_for_each_safe(iter, tmpiter, &res->blocked) {
@@ -2076,9 +2159,23 @@
if (lock->ml.node == dead_node) {
list_del_init(&lock->list);
dlm_lock_put(lock);
+ freed++;
}
}
+ if (freed) {
+ mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
+ "dropping ref from lockres\n", dlm->name,
+ res->lockname.len, res->lockname.name, freed, dead_node);
+ BUG_ON(!test_bit(dead_node, res->refmap));
+ dlm_lockres_clear_refmap_bit(dead_node, res);
+ } else if (test_bit(dead_node, res->refmap)) {
+ mlog(0, "%s:%.*s: dead node %u had a ref, but had "
+ "no locks and had not purged before dying\n", dlm->name,
+ res->lockname.len, res->lockname.name, dead_node);
+ dlm_lockres_clear_refmap_bit(dead_node, res);
+ }
+
/* do not kick thread yet */
__dlm_dirty_lockres(dlm, res);
}
@@ -2141,9 +2238,21 @@
spin_lock(&res->spinlock);
/* zero the lvb if necessary */
dlm_revalidate_lvb(dlm, res, dead_node);
- if (res->owner == dead_node)
+ if (res->owner == dead_node) {
+ if (res->state & DLM_LOCK_RES_DROPPING_REF)
+ mlog(0, "%s:%.*s: owned by "
+ "dead node %u, this node was "
+ "dropping its ref when it died. "
+ "continue, dropping the flag.\n",
+ dlm->name, res->lockname.len,
+ res->lockname.name, dead_node);
+
+ /* the wake_up for this will happen when the
+ * RECOVERING flag is dropped later */
+ res->state &= ~DLM_LOCK_RES_DROPPING_REF;
+
dlm_move_lockres_to_recovery_list(dlm, res);
- else if (res->owner == dlm->node_num) {
+ } else if (res->owner == dlm->node_num) {
dlm_free_dead_locks(dlm, res, dead_node);
__dlm_lockres_calc_usage(dlm, res);
}