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path: root/fs/ocfs2/dlm/dlmmaster.c
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Diffstat (limited to 'fs/ocfs2/dlm/dlmmaster.c')
-rw-r--r--fs/ocfs2/dlm/dlmmaster.c255
1 files changed, 90 insertions, 165 deletions
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 84d166328cf7..11eefb8c12e9 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2339,65 +2339,55 @@ static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data)
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.
+/*
+ * A migrateable resource is one that is :
+ * 1. locally mastered, and,
+ * 2. zero local locks, and,
+ * 3. one or more non-local locks, or, one or more references
+ * Returns 1 if yes, 0 if not.
*/
static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
- struct dlm_lock_resource *res,
- int *numlocks,
- int *hasrefs)
+ struct dlm_lock_resource *res)
{
- int ret;
- int i;
- int count = 0;
+ enum dlm_lockres_list idx;
+ int nonlocal = 0, node_ref;
struct list_head *queue;
struct dlm_lock *lock;
+ u64 cookie;
assert_spin_locked(&res->spinlock);
- *numlocks = 0;
- *hasrefs = 0;
-
- 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;
- }
+ if (res->owner != dlm->node_num)
+ return 0;
- ret = 0;
- queue = &res->granted;
- for (i = 0; i < 3; i++) {
+ for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
+ queue = dlm_list_idx_to_ptr(res, idx);
list_for_each_entry(lock, queue, 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;
+ if (lock->ml.node != dlm->node_num) {
+ nonlocal++;
+ continue;
}
+ cookie = be64_to_cpu(lock->ml.cookie);
+ mlog(0, "%s: Not migrateable res %.*s, lock %u:%llu on "
+ "%s list\n", dlm->name, res->lockname.len,
+ res->lockname.name,
+ dlm_get_lock_cookie_node(cookie),
+ dlm_get_lock_cookie_seq(cookie),
+ dlm_list_in_text(idx));
+ return 0;
}
- queue++;
}
- *numlocks = count;
-
- count = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
- if (count < O2NM_MAX_NODES)
- *hasrefs = 1;
+ if (!nonlocal) {
+ node_ref = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
+ if (node_ref >= O2NM_MAX_NODES)
+ return 0;
+ }
- mlog(0, "%s: res %.*s, Migrateable, locks %d, refs %d\n", dlm->name,
- res->lockname.len, res->lockname.name, *numlocks, *hasrefs);
+ mlog(0, "%s: res %.*s, Migrateable\n", dlm->name, res->lockname.len,
+ res->lockname.name);
-leave:
- return ret;
+ return 1;
}
/*
@@ -2406,8 +2396,7 @@ leave:
static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
- struct dlm_lock_resource *res,
- u8 target)
+ struct dlm_lock_resource *res, u8 target)
{
struct dlm_master_list_entry *mle = NULL;
struct dlm_master_list_entry *oldmle = NULL;
@@ -2416,37 +2405,20 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
const char *name;
unsigned int namelen;
int mle_added = 0;
- int numlocks, hasrefs;
int wake = 0;
if (!dlm_grab(dlm))
return -EINVAL;
+ BUG_ON(target == O2NM_MAX_NODES);
+
name = res->lockname.name;
namelen = res->lockname.len;
- mlog(0, "%s: Migrating %.*s to %u\n", dlm->name, namelen, name, target);
-
- /*
- * ensure this lockres is a proper candidate for migration
- */
- spin_lock(&res->spinlock);
- ret = dlm_is_lockres_migrateable(dlm, res, &numlocks, &hasrefs);
- if (ret < 0) {
- spin_unlock(&res->spinlock);
- goto leave;
- }
- spin_unlock(&res->spinlock);
-
- /* no work to do */
- if (numlocks == 0 && !hasrefs)
- goto leave;
-
- /*
- * preallocate up front
- * if this fails, abort
- */
+ mlog(0, "%s: Migrating %.*s to node %u\n", dlm->name, namelen, name,
+ target);
+ /* preallocate up front. if this fails, abort */
ret = -ENOMEM;
mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
if (!mres) {
@@ -2462,35 +2434,10 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
ret = 0;
/*
- * find a node to migrate the lockres to
- */
-
- spin_lock(&dlm->spinlock);
- /* pick a new node */
- if (!test_bit(target, dlm->domain_map) ||
- target >= O2NM_MAX_NODES) {
- target = dlm_pick_migration_target(dlm, res);
- }
- mlog(0, "%s: res %.*s, Node %u chosen for migration\n", dlm->name,
- namelen, name, target);
-
- if (target >= O2NM_MAX_NODES ||
- !test_bit(target, dlm->domain_map)) {
- /* target chosen is not alive */
- ret = -EINVAL;
- }
-
- if (ret) {
- spin_unlock(&dlm->spinlock);
- goto fail;
- }
-
- mlog(0, "continuing with target = %u\n", target);
-
- /*
* clear any existing master requests and
* add the migration mle to the list
*/
+ spin_lock(&dlm->spinlock);
spin_lock(&dlm->master_lock);
ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
namelen, target, dlm->node_num);
@@ -2531,6 +2478,7 @@ fail:
dlm_put_mle(mle);
} else if (mle) {
kmem_cache_free(dlm_mle_cache, mle);
+ mle = NULL;
}
goto leave;
}
@@ -2652,69 +2600,52 @@ leave:
if (wake)
wake_up(&res->wq);
- /* TODO: cleanup */
if (mres)
free_page((unsigned long)mres);
dlm_put(dlm);
- mlog(0, "returning %d\n", ret);
+ mlog(0, "%s: Migrating %.*s to %u, returns %d\n", dlm->name, namelen,
+ name, target, ret);
return ret;
}
#define DLM_MIGRATION_RETRY_MS 100
-/* Should be called only after beginning the domain leave process.
+/*
+ * Should be called only after beginning the domain leave process.
* There should not be any remaining locks on nonlocal lock resources,
* and there should be no local locks left on locally mastered resources.
*
* Called with the dlm spinlock held, may drop it to do migration, but
* will re-acquire before exit.
*
- * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped */
+ * Returns: 1 if dlm->spinlock was dropped/retaken, 0 if never dropped
+ */
int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
{
int ret;
int lock_dropped = 0;
- int numlocks, hasrefs;
+ u8 target = O2NM_MAX_NODES;
+
+ assert_spin_locked(&dlm->spinlock);
spin_lock(&res->spinlock);
- if (res->owner != dlm->node_num) {
- if (!__dlm_lockres_unused(res)) {
- mlog(ML_ERROR, "%s:%.*s: this node is not master, "
- "trying to free this but locks remain\n",
- dlm->name, res->lockname.len, res->lockname.name);
- }
- spin_unlock(&res->spinlock);
- goto leave;
- }
+ if (dlm_is_lockres_migrateable(dlm, res))
+ target = dlm_pick_migration_target(dlm, res);
+ spin_unlock(&res->spinlock);
- /* No need to migrate a lockres having no locks */
- ret = dlm_is_lockres_migrateable(dlm, res, &numlocks, &hasrefs);
- if (ret >= 0 && numlocks == 0 && !hasrefs) {
- spin_unlock(&res->spinlock);
+ if (target == O2NM_MAX_NODES)
goto leave;
- }
- spin_unlock(&res->spinlock);
/* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
spin_unlock(&dlm->spinlock);
lock_dropped = 1;
- while (1) {
- ret = dlm_migrate_lockres(dlm, res, O2NM_MAX_NODES);
- if (ret >= 0)
- break;
- if (ret == -ENOTEMPTY) {
- mlog(ML_ERROR, "lockres %.*s still has local locks!\n",
- res->lockname.len, res->lockname.name);
- BUG();
- }
-
- mlog(0, "lockres %.*s: migrate failed, "
- "retrying\n", res->lockname.len,
- res->lockname.name);
- msleep(DLM_MIGRATION_RETRY_MS);
- }
+ ret = dlm_migrate_lockres(dlm, res, target);
+ if (ret)
+ mlog(0, "%s: res %.*s, Migrate to node %u failed with %d\n",
+ dlm->name, res->lockname.len, res->lockname.name,
+ target, ret);
spin_lock(&dlm->spinlock);
leave:
return lock_dropped;
@@ -2898,61 +2829,55 @@ static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
}
}
-/* for now this is not too intelligent. we will
- * need stats to make this do the right thing.
- * this just finds the first lock on one of the
- * queues and uses that node as the target. */
+/*
+ * Pick a node to migrate the lock resource to. This function selects a
+ * potential target based first on the locks and then on refmap. It skips
+ * nodes that are in the process of exiting the domain.
+ */
static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res)
{
- int i;
+ enum dlm_lockres_list idx;
struct list_head *queue = &res->granted;
struct dlm_lock *lock;
- int nodenum;
+ int noderef;
+ u8 nodenum = O2NM_MAX_NODES;
assert_spin_locked(&dlm->spinlock);
+ assert_spin_locked(&res->spinlock);
- spin_lock(&res->spinlock);
- for (i=0; i<3; i++) {
+ /* Go through all the locks */
+ for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
+ queue = dlm_list_idx_to_ptr(res, idx);
list_for_each_entry(lock, queue, list) {
- /* up to the caller to make sure this node
- * is alive */
- if (lock->ml.node != dlm->node_num) {
- spin_unlock(&res->spinlock);
- return lock->ml.node;
- }
+ if (lock->ml.node == dlm->node_num)
+ continue;
+ if (test_bit(lock->ml.node, dlm->exit_domain_map))
+ continue;
+ nodenum = lock->ml.node;
+ goto bail;
}
- queue++;
- }
-
- nodenum = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
- if (nodenum < O2NM_MAX_NODES) {
- spin_unlock(&res->spinlock);
- return nodenum;
}
- spin_unlock(&res->spinlock);
- mlog(0, "have not found a suitable target yet! checking domain map\n");
- /* ok now we're getting desperate. pick anyone alive. */
- nodenum = -1;
+ /* Go thru the refmap */
+ noderef = -1;
while (1) {
- nodenum = find_next_bit(dlm->domain_map,
- O2NM_MAX_NODES, nodenum+1);
- mlog(0, "found %d in domain map\n", nodenum);
- if (nodenum >= O2NM_MAX_NODES)
+ noderef = find_next_bit(res->refmap, O2NM_MAX_NODES,
+ noderef + 1);
+ if (noderef >= O2NM_MAX_NODES)
break;
- if (nodenum != dlm->node_num) {
- mlog(0, "picking %d\n", nodenum);
- return nodenum;
- }
+ if (noderef == dlm->node_num)
+ continue;
+ if (test_bit(noderef, dlm->exit_domain_map))
+ continue;
+ nodenum = noderef;
+ goto bail;
}
- mlog(0, "giving up. no master to migrate to\n");
- return DLM_LOCK_RES_OWNER_UNKNOWN;
+bail:
+ return nodenum;
}
-
-
/* this is called by the new master once all lockres
* data has been received */
static int dlm_do_migrate_request(struct dlm_ctxt *dlm,