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ocfs2_dlm: fix cluster-wide refcounting of lock resources

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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>
This commit is contained in:
Kurt Hackel
2006-12-01 14:47:20 -08:00
committed by Mark Fasheh
parent 5331be0905
commit ba2bf21851
8 changed files with 727 additions and 172 deletions
Download Patch File Download Diff File Expand all files Collapse all files

167
fs/ocfs2/dlm/dlmthread.c
View File

@ -54,9 +54,6 @@
#include "cluster/masklog.h"
static int dlm_thread(void *data);
static void dlm_purge_lockres_now(struct dlm_ctxt *dlm,
struct dlm_lock_resource *lockres);
static void dlm_flush_asts(struct dlm_ctxt *dlm);
#define dlm_lock_is_remote(dlm, lock) ((lock)->ml.node != (dlm)->node_num)
@ -82,14 +79,33 @@ repeat:
current->state = TASK_RUNNING;
}
int __dlm_lockres_unused(struct dlm_lock_resource *res)
int __dlm_lockres_has_locks(struct dlm_lock_resource *res)
{
if (list_empty(&res->granted) &&
list_empty(&res->converting) &&
list_empty(&res->blocked) &&
list_empty(&res->dirty))
return 1;
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)
{
if (!__dlm_lockres_has_locks(res) &&
list_empty(&res->dirty)) {
/* try not to scan the bitmap unless the first two
* conditions are already true */
int bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
if (bit >= O2NM_MAX_NODES) {
/* since the bit for dlm->node_num is not
* set, inflight_locks better be zero */
BUG_ON(res->inflight_locks != 0);
return 1;
}
}
return 0;
}
@ -106,46 +122,21 @@ void __dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
assert_spin_locked(&res->spinlock);
if (__dlm_lockres_unused(res)){
/* For now, just keep any resource we master */
if (res->owner == dlm->node_num)
{
if (!list_empty(&res->purge)) {
mlog(0, "we master %s:%.*s, but it is on "
"the purge list. Removing\n",
dlm->name, res->lockname.len,
res->lockname.name);
list_del_init(&res->purge);
dlm->purge_count--;
}
return;
}
if (list_empty(&res->purge)) {
mlog(0, "putting lockres %.*s from purge list\n",
res->lockname.len, res->lockname.name);
mlog(0, "putting lockres %.*s:%p onto purge list\n",
res->lockname.len, res->lockname.name, res);
res->last_used = jiffies;
dlm_lockres_get(res);
list_add_tail(&res->purge, &dlm->purge_list);
dlm->purge_count++;
/* if this node is not the owner, there is
* no way to keep track of who the owner could be.
* unhash it to avoid serious problems. */
if (res->owner != dlm->node_num) {
mlog(0, "%s:%.*s: doing immediate "
"purge of lockres owned by %u\n",
dlm->name, res->lockname.len,
res->lockname.name, res->owner);
dlm_purge_lockres_now(dlm, res);
}
}
} else if (!list_empty(&res->purge)) {
mlog(0, "removing lockres %.*s from purge list, "
"owner=%u\n", res->lockname.len, res->lockname.name,
res->owner);
mlog(0, "removing lockres %.*s:%p from purge list, owner=%u\n",
res->lockname.len, res->lockname.name, res, res->owner);
list_del_init(&res->purge);
dlm_lockres_put(res);
dlm->purge_count--;
}
}
@ -163,68 +154,60 @@ void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
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 dlm_purge_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
{
int master;
int ret;
int ret = 0;
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. */
spin_lock(&res->spinlock);
if (!__dlm_lockres_unused(res)) {
spin_unlock(&res->spinlock);
mlog(0, "%s:%.*s: tried to purge but not unused\n",
dlm->name, res->lockname.len, res->lockname.name);
return -ENOTEMPTY;
}
master = (res->owner == dlm->node_num);
if (!master)
goto finish;
res->state |= DLM_LOCK_RES_DROPPING_REF;
spin_unlock(&res->spinlock);
/* Wheee! Migrate lockres here! */
spin_unlock(&dlm->spinlock);
again:
mlog(0, "purging lockres %.*s, master = %d\n", res->lockname.len,
res->lockname.name, master);
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);
msleep(100);
goto again;
if (!master) {
/* drop spinlock to do messaging, retake below */
spin_unlock(&dlm->spinlock);
/* clear our bit from the master's refmap, ignore errors */
ret = dlm_drop_lockres_ref(dlm, res);
if (ret < 0) {
mlog_errno(ret);
if (!dlm_is_host_down(ret))
BUG();
}
mlog(0, "%s:%.*s: dlm_deref_lockres returned %d\n",
dlm->name, res->lockname.len, res->lockname.name, ret);
spin_lock(&dlm->spinlock);
}
spin_lock(&dlm->spinlock);
finish:
if (!list_empty(&lockres->purge)) {
list_del_init(&lockres->purge);
if (!list_empty(&res->purge)) {
mlog(0, "removing lockres %.*s:%p from purgelist, "
"master = %d\n", res->lockname.len, res->lockname.name,
res, master);
list_del_init(&res->purge);
dlm_lockres_put(res);
dlm->purge_count--;
}
__dlm_unhash_lockres(lockres);
}
__dlm_unhash_lockres(res);
/* make an unused lockres go away immediately.
* as soon as the dlm spinlock is dropped, this lockres
* will not be found. kfree still happens on last put. */
static void dlm_purge_lockres_now(struct dlm_ctxt *dlm,
struct dlm_lock_resource *lockres)
{
assert_spin_locked(&dlm->spinlock);
assert_spin_locked(&lockres->spinlock);
BUG_ON(!__dlm_lockres_unused(lockres));
if (!list_empty(&lockres->purge)) {
list_del_init(&lockres->purge);
dlm->purge_count--;
/* lockres is not in the hash now. drop the flag and wake up
* any processes waiting in dlm_get_lock_resource. */
if (!master) {
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_DROPPING_REF;
spin_unlock(&res->spinlock);
wake_up(&res->wq);
}
__dlm_unhash_lockres(lockres);
return 0;
}
static void dlm_run_purge_list(struct dlm_ctxt *dlm,
@ -268,13 +251,17 @@ static void dlm_run_purge_list(struct dlm_ctxt *dlm,
break;
}
mlog(0, "removing lockres %.*s:%p from purgelist\n",
lockres->lockname.len, lockres->lockname.name, lockres);
list_del_init(&lockres->purge);
dlm_lockres_put(lockres);
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);
if (dlm_purge_lockres(dlm, lockres))
BUG();
mlog(0, "DONE calling dlm_purge_lockres!\n");
/* Avoid adding any scheduling latencies */