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ocfs2/dlm: dlm_is_lockres_migrateable() returns boolean
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Patch cleans up the gunk added by commit 388c4bc.
dlm_is_lockres_migrateable() now returns 1 if lockresource is deemed
migrateable and 0 if not.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
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Sunil Mushran authored and Joel Becker committed May 24, 2011
1 parent 10fca35 commit 9f62e96
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Showing 2 changed files with 63 additions and 84 deletions.
12 changes: 12 additions & 0 deletions fs/ocfs2/dlm/dlmcommon.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down
135 changes: 51 additions & 84 deletions fs/ocfs2/dlm/dlmmaster.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

/*
Expand All @@ -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))
Expand All @@ -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;

/*
Expand Down Expand Up @@ -2658,44 +2641,35 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,

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);
Expand All @@ -2704,15 +2678,8 @@ 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);
Expand Down

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