[Ocfs2-devel] [PATCH 1/3] ocfs2/dlm: dlm_is_lockres_migrateable() returns boolean
Sunil Mushran
sunil.mushran at oracle.com
Tue Apr 26 16:03:23 PDT 2011
Patch cleans up the gunk added by commit 388c4bcb4e63e88fb1f312a2f5f9eb2623afcf5b.
dlm_is_lockres_migrateable() now returns 1 if lockresource is deemed
migrateable and 0 if not.
Signed-off-by: Sunil Mushran <sunil.mushran at oracle.com>
---
fs/ocfs2/dlm/dlmcommon.h | 12 ++++
fs/ocfs2/dlm/dlmmaster.c | 135 +++++++++++++++++----------------------------
2 files changed, 63 insertions(+), 84 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 4bdf7ba..1aac42a 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -401,6 +401,18 @@ static inline int dlm_lvb_is_empty(char *lvb)
return 1;
}
+static inline char *dlm_list_in_text(enum dlm_lockres_list idx)
+{
+ if (idx == DLM_GRANTED_LIST)
+ return "granted";
+ else if (idx == DLM_CONVERTING_LIST)
+ return "converting";
+ else if (idx == DLM_BLOCKED_LIST)
+ return "blocked";
+ else
+ return "unknown";
+}
+
static inline struct list_head *
dlm_list_idx_to_ptr(struct dlm_lock_resource *res, enum dlm_lockres_list idx)
{
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 9d67610..3e59ff9 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;
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) {
+ nonlocal = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
+ if (nonlocal >= 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;
}
/*
@@ -2416,7 +2406,6 @@ 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))
@@ -2427,19 +2416,13 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
mlog(0, "%s: Migrating %.*s to %u\n", dlm->name, namelen, name, target);
- /*
- * ensure this lockres is a proper candidate for migration
- */
+ /* 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;
- }
+ ret = dlm_is_lockres_migrateable(dlm, res);
spin_unlock(&res->spinlock);
- /* no work to do */
- if (numlocks == 0 && !hasrefs)
+ /* No work to do */
+ if (!ret)
goto leave;
/*
@@ -2655,44 +2638,35 @@ leave:
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 mig, ret;
int lock_dropped = 0;
- int numlocks, hasrefs;
- 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;
- }
+ assert_spin_locked(&dlm->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);
- goto leave;
- }
+ spin_lock(&res->spinlock);
+ mig = dlm_is_lockres_migrateable(dlm, res);
spin_unlock(&res->spinlock);
+ if (!mig)
+ goto leave;
/* Wheee! Migrate lockres here! Will sleep so drop spinlock. */
spin_unlock(&dlm->spinlock);
@@ -2701,15 +2675,8 @@ int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res)
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);
+ mlog(0, "%s: res %.*s, Migrate failed, retrying\n", dlm->name,
+ res->lockname.len, res->lockname.name);
msleep(DLM_MIGRATION_RETRY_MS);
}
spin_lock(&dlm->spinlock);
--
1.7.1
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