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path: root/fs/ocfs2/dlm/dlmthread.c
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Diffstat (limited to 'fs/ocfs2/dlm/dlmthread.c')
-rw-r--r--fs/ocfs2/dlm/dlmthread.c114
1 files changed, 55 insertions, 59 deletions
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 52ec020ea78b..86491f583ea5 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -93,19 +93,27 @@ int __dlm_lockres_has_locks(struct dlm_lock_resource *res)
* truly ready to be freed. */
int __dlm_lockres_unused(struct dlm_lock_resource *res)
{
- if (!__dlm_lockres_has_locks(res) &&
- (list_empty(&res->dirty) && !(res->state & DLM_LOCK_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;
+ int bit;
+
+ if (__dlm_lockres_has_locks(res))
+ return 0;
+
+ if (!list_empty(&res->dirty) || res->state & DLM_LOCK_RES_DIRTY)
+ return 0;
+
+ if (res->state & DLM_LOCK_RES_RECOVERING)
+ return 0;
+
+ bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
+ if (bit < O2NM_MAX_NODES)
+ return 0;
+
+ /*
+ * since the bit for dlm->node_num is not set, inflight_locks better
+ * be zero
+ */
+ BUG_ON(res->inflight_locks != 0);
+ return 1;
}
@@ -153,45 +161,25 @@ void dlm_lockres_calc_usage(struct dlm_ctxt *dlm,
spin_unlock(&dlm->spinlock);
}
-static int dlm_purge_lockres(struct dlm_ctxt *dlm,
+static void dlm_purge_lockres(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res)
{
int master;
int ret = 0;
- spin_lock(&res->spinlock);
- if (!__dlm_lockres_unused(res)) {
- mlog(0, "%s:%.*s: tried to purge but not unused\n",
- dlm->name, res->lockname.len, res->lockname.name);
- __dlm_print_one_lock_resource(res);
- spin_unlock(&res->spinlock);
- BUG();
- }
-
- if (res->state & DLM_LOCK_RES_MIGRATING) {
- mlog(0, "%s:%.*s: Delay dropref as this lockres is "
- "being remastered\n", dlm->name, res->lockname.len,
- res->lockname.name);
- /* Re-add the lockres to the end of the purge list */
- if (!list_empty(&res->purge)) {
- list_del_init(&res->purge);
- list_add_tail(&res->purge, &dlm->purge_list);
- }
- spin_unlock(&res->spinlock);
- return 0;
- }
+ assert_spin_locked(&dlm->spinlock);
+ assert_spin_locked(&res->spinlock);
master = (res->owner == dlm->node_num);
- if (!master)
- res->state |= DLM_LOCK_RES_DROPPING_REF;
- spin_unlock(&res->spinlock);
mlog(0, "purging lockres %.*s, master = %d\n", 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);
@@ -209,31 +197,35 @@ static int dlm_purge_lockres(struct dlm_ctxt *dlm,
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(&res->spinlock);
}
- spin_lock(&res->spinlock);
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);
- spin_unlock(&res->spinlock);
dlm_lockres_put(res);
dlm->purge_count--;
- } else
- spin_unlock(&res->spinlock);
+ }
+
+ if (!__dlm_lockres_unused(res)) {
+ mlog(ML_ERROR, "found lockres %s:%.*s: in use after deref\n",
+ dlm->name, res->lockname.len, res->lockname.name);
+ __dlm_print_one_lock_resource(res);
+ BUG();
+ }
__dlm_unhash_lockres(res);
/* 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);
- }
- return 0;
+ } else
+ spin_unlock(&res->spinlock);
}
static void dlm_run_purge_list(struct dlm_ctxt *dlm,
@@ -252,17 +244,7 @@ static void dlm_run_purge_list(struct dlm_ctxt *dlm,
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);
@@ -274,15 +256,29 @@ static void dlm_run_purge_list(struct dlm_ctxt *dlm,
* 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, "lockres %s:%.*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);
- /* This may drop and reacquire the dlm spinlock if it
- * has to do migration. */
- if (dlm_purge_lockres(dlm, lockres))
- BUG();
+ dlm_purge_lockres(dlm, lockres);
dlm_lockres_put(lockres);