diff options
Diffstat (limited to 'fs/ocfs2/cluster/heartbeat.c')
-rw-r--r-- | fs/ocfs2/cluster/heartbeat.c | 216 |
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(®->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(®->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(®->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, @@ -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); |