Hi Linus,
These two fixes are for ocfs2 dlm regressions introduced during the
merge window.
Please pull from 'upstream-linus' branch of
git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2.git upstream-linus
to receive the following updates:
fs/ocfs2/dlm/dlmdomain.c | 8 ++-
fs/ocfs2/dlm/dlmmaster.c | 99 ++++++++++++++++++++++++++++++-----------------
fs/ocfs2/dlm/dlmthread.c | 10 ----
3 files changed, 73 insertions(+), 44 deletions(-)
Sunil Mushran:
ocfs2_dlm: Fix lockres ref counting bug
ocfs2_dlm: Check for migrateable lockres in dlm_empty_lockres()
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 6087c47..c558442 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -138,8 +138,10 @@ static void dlm_unregister_domain_handle
void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
{
- hlist_del_init(&lockres->hash_node);
- dlm_lockres_put(lockres);
+ if (!hlist_unhashed(&lockres->hash_node)) {
+ hlist_del_init(&lockres->hash_node);
+ dlm_lockres_put(lockres);
+ }
}
void __dlm_insert_lockres(struct dlm_ctxt *dlm,
@@ -655,6 +657,8 @@ void dlm_unregister_domain(struct dlm_ct
dlm_kick_thread(dlm, NULL);
while (dlm_migrate_all_locks(dlm)) {
+ /* Give dlm_thread time to purge the lockres' */
+ msleep(500);
mlog(0, "%s: more migration to do\n", dlm->name);
}
dlm_mark_domain_leaving(dlm);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 9229e04..6edffca 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2424,6 +2424,57 @@ static void dlm_deref_lockres_worker(str
dlm_lockres_put(res);
}
+/* Checks whether the lockres can be migrated. Returns 0 if yes, < 0
+ * if not. If 0, numlocks is set to the number of locks in the lockres.
+ */
+static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res,
+ int *numlocks)
+{
+ int ret;
+ int i;
+ int count = 0;
+ struct list_head *queue, *iter;
+ struct dlm_lock *lock;
+
+ assert_spin_locked(&res->spinlock);
+
+ ret = -EINVAL;
+ if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
+ mlog(0, "cannot migrate lockres with unknown owner!\n");
+ goto leave;
+ }
+
+ if (res->owner != dlm->node_num) {
+ mlog(0, "cannot migrate lockres this node doesn't own!\n");
+ goto leave;
+ }
+
+ ret = 0;
+ queue = &res->granted;
+ for (i = 0; i < 3; i++) {
+ list_for_each(iter, queue) {
+ lock = list_entry(iter, struct dlm_lock, list);
+ ++count;
+ if (lock->ml.node == dlm->node_num) {
+ mlog(0, "found a lock owned by this node still "
+ "on the %s queue! will not migrate this "
+ "lockres\n", (i == 0 ? "granted" :
+ (i == 1 ? "converting" :
+ "blocked")));
+ ret = -ENOTEMPTY;
+ goto leave;
+ }
+ }
+ queue++;
+ }
+
+ *numlocks = count;
+ mlog(0, "migrateable lockres having %d locks\n", *numlocks);
+
+leave:
+ return ret;
+}
/*
* DLM_MIGRATE_LOCKRES
@@ -2437,14 +2488,12 @@ static int dlm_migrate_lockres(struct dl
struct dlm_master_list_entry *mle = NULL;
struct dlm_master_list_entry *oldmle = NULL;
struct dlm_migratable_lockres *mres = NULL;
- int ret = -EINVAL;
+ int ret = 0;
const char *name;
unsigned int namelen;
int mle_added = 0;
- struct list_head *queue, *iter;
- int i;
- struct dlm_lock *lock;
- int empty = 1, wake = 0;
+ int numlocks;
+ int wake = 0;
if (!dlm_grab(dlm))
return -EINVAL;
@@ -2458,42 +2507,16 @@ static int dlm_migrate_lockres(struct dl
* ensure this lockres is a proper candidate for migration
*/
spin_lock(&res->spinlock);
- if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
- mlog(0, "cannot migrate lockres with unknown owner!\n");
- spin_unlock(&res->spinlock);
- goto leave;
- }
- if (res->owner != dlm->node_num) {
- mlog(0, "cannot migrate lockres this node doesn't own!\n");
+ ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
+ if (ret < 0) {
spin_unlock(&res->spinlock);
goto leave;
}
- mlog(0, "checking queues...\n");
- queue = &res->granted;
- for (i=0; i<3; i++) {
- list_for_each(iter, queue) {
- lock = list_entry (iter, struct dlm_lock, list);
- empty = 0;
- if (lock->ml.node == dlm->node_num) {
- mlog(0, "found a lock owned by this node "
- "still on the %s queue! will not "
- "migrate this lockres\n",
- i==0 ? "granted" :
- (i==1 ? "converting" : "blocked"));
- spin_unlock(&res->spinlock);
- ret = -ENOTEMPTY;
- goto leave;
- }
- }
- queue++;
- }
- mlog(0, "all locks on this lockres are nonlocal. continuing\n");
spin_unlock(&res->spinlock);
/* no work to do */
- if (empty) {
+ if (numlocks == 0) {
mlog(0, "no locks were found on this lockres! done!\n");
- ret = 0;
goto leave;
}
@@ -2729,6 +2752,7 @@ int dlm_empty_lockres(struct dlm_ctxt *d
{
int ret;
int lock_dropped = 0;
+ int numlocks;
spin_lock(&res->spinlock);
if (res->owner != dlm->node_num) {
@@ -2740,6 +2764,13 @@ int dlm_empty_lockres(struct dlm_ctxt *d
spin_unlock(&res->spinlock);
goto leave;
}
+
+ /* No need to migrate a lockres having no locks */
+ ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);
+ if (ret >= 0 && numlocks == 0) {
+ spin_unlock(&res->spinlock);
+ goto leave;
+ }
spin_unlock(&res->spinlock);
/* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 6421a8f..2b264c6 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -256,20 +256,14 @@ static void dlm_run_purge_list(struct dl
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--;
+ dlm_lockres_get(lockres);
/* This may drop and reacquire the dlm spinlock if it
* has to do migration. */
- mlog(0, "calling dlm_purge_lockres!\n");
- dlm_lockres_get(lockres);
if (dlm_purge_lockres(dlm, lockres))
BUG();
+
dlm_lockres_put(lockres);
- mlog(0, "DONE calling dlm_purge_lockres!\n");
/* Avoid adding any scheduling latencies */
cond_resched_lock(&dlm->spinlock);