#define O2HB_DB_TYPE_REGION_LIVENODES 4
#define O2HB_DB_TYPE_REGION_NUMBER 5
#define O2HB_DB_TYPE_REGION_ELAPSED_TIME 6
+#define O2HB_DB_TYPE_REGION_PINNED 7
struct o2hb_debug_buf {
int db_type;
int db_size;
#define O2HB_DEBUG_FAILEDREGIONS "failed_regions"
#define O2HB_DEBUG_REGION_NUMBER "num"
#define O2HB_DEBUG_REGION_ELAPSED_TIME "elapsed_time_in_ms"
+#define O2HB_DEBUG_REGION_PINNED "pinned"
static struct dentry *o2hb_debug_dir;
static struct dentry *o2hb_debug_livenodes;
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
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;
struct dentry *hr_debug_livenodes;
struct dentry *hr_debug_regnum;
struct dentry *hr_debug_elapsed_time;
+ struct dentry *hr_debug_pinned;
struct o2hb_debug_buf *hr_db_livenodes;
struct o2hb_debug_buf *hr_db_regnum;
struct o2hb_debug_buf *hr_db_elapsed_time;
+ struct o2hb_debug_buf *hr_db_pinned;
/* let the person setting up hb wait for it to return until it
* has reached a 'steady' state. This will be fixed when we have
static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
{
- cancel_delayed_work(®->hr_write_timeout_work);
- flush_scheduled_work();
+ cancel_delayed_work_sync(®->hr_write_timeout_work);
}
static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
config_item_name(®->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,
set_user_nice(current, -20);
+ /* Pin node */
+ o2nm_depend_this_node();
+
while (!kthread_should_stop() && !reg->hr_unclean_stop) {
/* We track the time spent inside
* o2hb_do_disk_heartbeat so that we avoid more than
mlog_errno(ret);
}
+ /* Unpin node */
+ o2nm_undepend_this_node();
+
mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n");
return 0;
reg->hr_last_timeout_start));
goto done;
+ case O2HB_DB_TYPE_REGION_PINNED:
+ reg = (struct o2hb_region *)db->db_data;
+ out += snprintf(buf + out, PAGE_SIZE - out, "%u\n",
+ !!reg->hr_item_pinned);
+ goto done;
+
default:
goto done;
}
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();
}
debugfs_remove(reg->hr_debug_livenodes);
debugfs_remove(reg->hr_debug_regnum);
debugfs_remove(reg->hr_debug_elapsed_time);
+ debugfs_remove(reg->hr_debug_pinned);
debugfs_remove(reg->hr_debug_dir);
spin_lock(&o2hb_live_lock);
goto bail;
}
+ reg->hr_debug_pinned =
+ o2hb_debug_create(O2HB_DEBUG_REGION_PINNED,
+ reg->hr_debug_dir,
+ &(reg->hr_db_pinned),
+ sizeof(*(reg->hr_db_pinned)),
+ O2HB_DB_TYPE_REGION_PINNED,
+ 0, 0, reg);
+ if (!reg->hr_debug_pinned) {
+ mlog_errno(ret);
+ goto bail;
+ }
+
ret = 0;
bail:
return ret;
{
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)
if (o2hb_global_heartbeat_active())
printk(KERN_NOTICE "o2hb: Heartbeat stopped on region %s\n",
config_item_name(®->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 {
}
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(®->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(®->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(®->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(®->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(®->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(®->hr_item);
- o2nm_undepend_this_node();
- }
+unlock:
+ spin_unlock(&o2hb_live_lock);
}
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);
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;
}
{
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? */
return;
if (region_uuid)
- o2hb_region_put(region_uuid);
+ o2hb_region_dec_user(region_uuid);
down_write(&o2hb_callback_sem);
git.openpandora.org / pandora-kernel.git / blobdiff