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Diffstat (limited to 'fs/ocfs2/cluster/heartbeat.c')
-rw-r--r--fs/ocfs2/cluster/heartbeat.c216
1 files changed, 178 insertions, 38 deletions
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 9f21dd785364..ad2e41d6879d 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -132,6 +132,33 @@ char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
+/*
+ * o2hb_dependent_users tracks the number of registered callbacks that depend
+ * on heartbeat. o2net and o2dlm are two entities that register this callback.
+ * However only o2dlm depends on the heartbeat. It does not want the heartbeat
+ * to stop while a dlm domain is still active.
+ */
+unsigned int o2hb_dependent_users;
+
+/*
+ * In global heartbeat mode, all regions are pinned if there are one or more
+ * dependent users and the quorum region count is <= O2HB_PIN_CUT_OFF. All
+ * regions are unpinned if the region count exceeds the cut off or the number
+ * of dependent users falls to zero.
+ */
+#define O2HB_PIN_CUT_OFF 3
+
+/*
+ * In local heartbeat mode, we assume the dlm domain name to be the same as
+ * region uuid. This is true for domains created for the file system but not
+ * necessarily true for userdlm domains. This is a known limitation.
+ *
+ * In global heartbeat mode, we pin/unpin all o2hb regions. This solution
+ * works for both file system and userdlm domains.
+ */
+static int o2hb_region_pin(const char *region_uuid);
+static void o2hb_region_unpin(const char *region_uuid);
+
/* Only sets a new threshold if there are no active regions.
*
* No locking or otherwise interesting code is required for reading
@@ -186,7 +213,9 @@ struct o2hb_region {
struct config_item hr_item;
struct list_head hr_all_item;
- unsigned hr_unclean_stop:1;
+ unsigned hr_unclean_stop:1,
+ hr_item_pinned:1,
+ hr_item_dropped:1;
/* protected by the hr_callback_sem */
struct task_struct *hr_task;
@@ -702,6 +731,14 @@ static void o2hb_set_quorum_device(struct o2hb_region *reg,
config_item_name(&reg->hr_item));
set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
+
+ /*
+ * If global heartbeat active, unpin all regions if the
+ * region count > CUT_OFF
+ */
+ if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
+ O2NM_MAX_REGIONS) > O2HB_PIN_CUT_OFF)
+ o2hb_region_unpin(NULL);
}
static int o2hb_check_slot(struct o2hb_region *reg,
@@ -1316,6 +1353,8 @@ int o2hb_init(void)
memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
+ o2hb_dependent_users = 0;
+
return o2hb_debug_init();
}
@@ -2003,16 +2042,20 @@ static void o2hb_heartbeat_group_drop_item(struct config_group *group,
{
struct task_struct *hb_task;
struct o2hb_region *reg = to_o2hb_region(item);
+ int quorum_region = 0;
/* stop the thread when the user removes the region dir */
spin_lock(&o2hb_live_lock);
if (o2hb_global_heartbeat_active()) {
clear_bit(reg->hr_region_num, o2hb_region_bitmap);
clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
+ if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
+ quorum_region = 1;
clear_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
}
hb_task = reg->hr_task;
reg->hr_task = NULL;
+ reg->hr_item_dropped = 1;
spin_unlock(&o2hb_live_lock);
if (hb_task)
@@ -2030,7 +2073,27 @@ static void o2hb_heartbeat_group_drop_item(struct config_group *group,
if (o2hb_global_heartbeat_active())
printk(KERN_NOTICE "o2hb: Heartbeat stopped on region %s\n",
config_item_name(&reg->hr_item));
+
config_item_put(item);
+
+ if (!o2hb_global_heartbeat_active() || !quorum_region)
+ return;
+
+ /*
+ * If global heartbeat active and there are dependent users,
+ * pin all regions if quorum region count <= CUT_OFF
+ */
+ spin_lock(&o2hb_live_lock);
+
+ if (!o2hb_dependent_users)
+ goto unlock;
+
+ if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
+ O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
+ o2hb_region_pin(NULL);
+
+unlock:
+ spin_unlock(&o2hb_live_lock);
}
struct o2hb_heartbeat_group_attribute {
@@ -2216,63 +2279,138 @@ void o2hb_setup_callback(struct o2hb_callback_func *hc,
}
EXPORT_SYMBOL_GPL(o2hb_setup_callback);
-static struct o2hb_region *o2hb_find_region(const char *region_uuid)
+/*
+ * In local heartbeat mode, region_uuid passed matches the dlm domain name.
+ * In global heartbeat mode, region_uuid passed is NULL.
+ *
+ * In local, we only pin the matching region. In global we pin all the active
+ * regions.
+ */
+static int o2hb_region_pin(const char *region_uuid)
{
- struct o2hb_region *p, *reg = NULL;
+ int ret = 0, found = 0;
+ struct o2hb_region *reg;
+ char *uuid;
assert_spin_locked(&o2hb_live_lock);
- list_for_each_entry(p, &o2hb_all_regions, hr_all_item) {
- if (!strcmp(region_uuid, config_item_name(&p->hr_item))) {
- reg = p;
- break;
+ list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
+ uuid = config_item_name(&reg->hr_item);
+
+ /* local heartbeat */
+ if (region_uuid) {
+ if (strcmp(region_uuid, uuid))
+ continue;
+ found = 1;
}
+
+ if (reg->hr_item_pinned || reg->hr_item_dropped)
+ goto skip_pin;
+
+ /* Ignore ENOENT only for local hb (userdlm domain) */
+ ret = o2nm_depend_item(&reg->hr_item);
+ if (!ret) {
+ mlog(ML_CLUSTER, "Pin region %s\n", uuid);
+ reg->hr_item_pinned = 1;
+ } else {
+ if (ret == -ENOENT && found)
+ ret = 0;
+ else {
+ mlog(ML_ERROR, "Pin region %s fails with %d\n",
+ uuid, ret);
+ break;
+ }
+ }
+skip_pin:
+ if (found)
+ break;
}
- return reg;
+ return ret;
}
-static int o2hb_region_get(const char *region_uuid)
+/*
+ * In local heartbeat mode, region_uuid passed matches the dlm domain name.
+ * In global heartbeat mode, region_uuid passed is NULL.
+ *
+ * In local, we only unpin the matching region. In global we unpin all the
+ * active regions.
+ */
+static void o2hb_region_unpin(const char *region_uuid)
{
- int ret = 0;
struct o2hb_region *reg;
+ char *uuid;
+ int found = 0;
- spin_lock(&o2hb_live_lock);
+ assert_spin_locked(&o2hb_live_lock);
- reg = o2hb_find_region(region_uuid);
- if (!reg)
- ret = -ENOENT;
- spin_unlock(&o2hb_live_lock);
+ list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
+ uuid = config_item_name(&reg->hr_item);
+ if (region_uuid) {
+ if (strcmp(region_uuid, uuid))
+ continue;
+ found = 1;
+ }
- if (ret)
- goto out;
+ if (reg->hr_item_pinned) {
+ mlog(ML_CLUSTER, "Unpin region %s\n", uuid);
+ o2nm_undepend_item(&reg->hr_item);
+ reg->hr_item_pinned = 0;
+ }
+ if (found)
+ break;
+ }
+}
- ret = o2nm_depend_this_node();
- if (ret)
- goto out;
+static int o2hb_region_inc_user(const char *region_uuid)
+{
+ int ret = 0;
- ret = o2nm_depend_item(&reg->hr_item);
- if (ret)
- o2nm_undepend_this_node();
+ spin_lock(&o2hb_live_lock);
-out:
+ /* local heartbeat */
+ if (!o2hb_global_heartbeat_active()) {
+ ret = o2hb_region_pin(region_uuid);
+ goto unlock;
+ }
+
+ /*
+ * if global heartbeat active and this is the first dependent user,
+ * pin all regions if quorum region count <= CUT_OFF
+ */
+ o2hb_dependent_users++;
+ if (o2hb_dependent_users > 1)
+ goto unlock;
+
+ if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
+ O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
+ ret = o2hb_region_pin(NULL);
+
+unlock:
+ spin_unlock(&o2hb_live_lock);
return ret;
}
-static void o2hb_region_put(const char *region_uuid)
+void o2hb_region_dec_user(const char *region_uuid)
{
- struct o2hb_region *reg;
-
spin_lock(&o2hb_live_lock);
- reg = o2hb_find_region(region_uuid);
+ /* local heartbeat */
+ if (!o2hb_global_heartbeat_active()) {
+ o2hb_region_unpin(region_uuid);
+ goto unlock;
+ }
- spin_unlock(&o2hb_live_lock);
+ /*
+ * if global heartbeat active and there are no dependent users,
+ * unpin all quorum regions
+ */
+ o2hb_dependent_users--;
+ if (!o2hb_dependent_users)
+ o2hb_region_unpin(NULL);
- if (reg) {
- o2nm_undepend_item(&reg->hr_item);
- o2nm_undepend_this_node();
- }
+unlock:
+ spin_unlock(&o2hb_live_lock);
}
int o2hb_register_callback(const char *region_uuid,
@@ -2293,9 +2431,11 @@ int o2hb_register_callback(const char *region_uuid,
}
if (region_uuid) {
- ret = o2hb_region_get(region_uuid);
- if (ret)
+ ret = o2hb_region_inc_user(region_uuid);
+ if (ret) {
+ mlog_errno(ret);
goto out;
+ }
}
down_write(&o2hb_callback_sem);
@@ -2313,7 +2453,7 @@ int o2hb_register_callback(const char *region_uuid,
up_write(&o2hb_callback_sem);
ret = 0;
out:
- mlog(ML_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n",
+ mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
ret, __builtin_return_address(0), hc);
return ret;
}
@@ -2324,7 +2464,7 @@ void o2hb_unregister_callback(const char *region_uuid,
{
BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
- mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n",
+ mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
__builtin_return_address(0), hc);
/* XXX Can this happen _with_ a region reference? */
@@ -2332,7 +2472,7 @@ void o2hb_unregister_callback(const char *region_uuid,
return;
if (region_uuid)
- o2hb_region_put(region_uuid);
+ o2hb_region_dec_user(region_uuid);
down_write(&o2hb_callback_sem);