diff options
Diffstat (limited to 'fs/ocfs2/cluster/heartbeat.c')
| -rw-r--r-- | fs/ocfs2/cluster/heartbeat.c | 2553 |
1 files changed, 2553 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c new file mode 100644 index 000000000..12a759060 --- /dev/null +++ b/fs/ocfs2/cluster/heartbeat.c @@ -0,0 +1,2553 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * Copyright (C) 2004, 2005 Oracle. All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/delay.h> +#include <linux/file.h> +#include <linux/kthread.h> +#include <linux/configfs.h> +#include <linux/random.h> +#include <linux/crc32.h> +#include <linux/time.h> +#include <linux/debugfs.h> +#include <linux/slab.h> +#include <linux/bitmap.h> +#include <linux/ktime.h> +#include "heartbeat.h" +#include "tcp.h" +#include "nodemanager.h" +#include "quorum.h" + +#include "masklog.h" + + +/* + * The first heartbeat pass had one global thread that would serialize all hb + * callback calls. This global serializing sem should only be removed once + * we've made sure that all callees can deal with being called concurrently + * from multiple hb region threads. + */ +static DECLARE_RWSEM(o2hb_callback_sem); + +/* + * multiple hb threads are watching multiple regions. A node is live + * whenever any of the threads sees activity from the node in its region. + */ +static DEFINE_SPINLOCK(o2hb_live_lock); +static struct list_head o2hb_live_slots[O2NM_MAX_NODES]; +static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; +static LIST_HEAD(o2hb_node_events); +static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue); + +/* + * In global heartbeat, we maintain a series of region bitmaps. + * - o2hb_region_bitmap allows us to limit the region number to max region. + * - o2hb_live_region_bitmap tracks live regions (seen steady iterations). + * - o2hb_quorum_region_bitmap tracks live regions that have seen all nodes + * heartbeat on it. + * - o2hb_failed_region_bitmap tracks the regions that have seen io timeouts. + */ +static unsigned long o2hb_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)]; +static unsigned long o2hb_live_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)]; +static unsigned long o2hb_quorum_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)]; +static unsigned long o2hb_failed_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)]; + +#define O2HB_DB_TYPE_LIVENODES 0 +#define O2HB_DB_TYPE_LIVEREGIONS 1 +#define O2HB_DB_TYPE_QUORUMREGIONS 2 +#define O2HB_DB_TYPE_FAILEDREGIONS 3 +#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; + int db_len; + void *db_data; +}; + +static struct o2hb_debug_buf *o2hb_db_livenodes; +static struct o2hb_debug_buf *o2hb_db_liveregions; +static struct o2hb_debug_buf *o2hb_db_quorumregions; +static struct o2hb_debug_buf *o2hb_db_failedregions; + +#define O2HB_DEBUG_DIR "o2hb" +#define O2HB_DEBUG_LIVENODES "livenodes" +#define O2HB_DEBUG_LIVEREGIONS "live_regions" +#define O2HB_DEBUG_QUORUMREGIONS "quorum_regions" +#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 LIST_HEAD(o2hb_all_regions); + +static struct o2hb_callback { + struct list_head list; +} o2hb_callbacks[O2HB_NUM_CB]; + +static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type); + +enum o2hb_heartbeat_modes { + O2HB_HEARTBEAT_LOCAL = 0, + O2HB_HEARTBEAT_GLOBAL, + O2HB_HEARTBEAT_NUM_MODES, +}; + +static const char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = { + "local", /* O2HB_HEARTBEAT_LOCAL */ + "global", /* O2HB_HEARTBEAT_GLOBAL */ +}; + +unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD; +static 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. + */ +static 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 + * o2hb_dead_threshold as it can't change once regions are active and + * it's not interesting to anyone until then anyway. */ +static void o2hb_dead_threshold_set(unsigned int threshold) +{ + if (threshold > O2HB_MIN_DEAD_THRESHOLD) { + spin_lock(&o2hb_live_lock); + if (list_empty(&o2hb_all_regions)) + o2hb_dead_threshold = threshold; + spin_unlock(&o2hb_live_lock); + } +} + +static int o2hb_global_heartbeat_mode_set(unsigned int hb_mode) +{ + int ret = -1; + + if (hb_mode < O2HB_HEARTBEAT_NUM_MODES) { + spin_lock(&o2hb_live_lock); + if (list_empty(&o2hb_all_regions)) { + o2hb_heartbeat_mode = hb_mode; + ret = 0; + } + spin_unlock(&o2hb_live_lock); + } + + return ret; +} + +struct o2hb_node_event { + struct list_head hn_item; + enum o2hb_callback_type hn_event_type; + struct o2nm_node *hn_node; + int hn_node_num; +}; + +struct o2hb_disk_slot { + struct o2hb_disk_heartbeat_block *ds_raw_block; + u8 ds_node_num; + u64 ds_last_time; + u64 ds_last_generation; + u16 ds_equal_samples; + u16 ds_changed_samples; + struct list_head ds_live_item; +}; + +/* each thread owns a region.. when we're asked to tear down the region + * we ask the thread to stop, who cleans up the region */ +struct o2hb_region { + struct config_item hr_item; + + struct list_head hr_all_item; + unsigned hr_unclean_stop:1, + hr_aborted_start:1, + hr_item_pinned:1, + hr_item_dropped:1, + hr_node_deleted:1; + + /* protected by the hr_callback_sem */ + struct task_struct *hr_task; + + unsigned int hr_blocks; + unsigned long long hr_start_block; + + unsigned int hr_block_bits; + unsigned int hr_block_bytes; + + unsigned int hr_slots_per_page; + unsigned int hr_num_pages; + + struct page **hr_slot_data; + struct block_device *hr_bdev; + struct o2hb_disk_slot *hr_slots; + + /* live node map of this region */ + unsigned long hr_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; + unsigned int hr_region_num; + + struct dentry *hr_debug_dir; + 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 + * a more complete api that doesn't lead to this sort of fragility. */ + atomic_t hr_steady_iterations; + + /* terminate o2hb thread if it does not reach steady state + * (hr_steady_iterations == 0) within hr_unsteady_iterations */ + atomic_t hr_unsteady_iterations; + + char hr_dev_name[BDEVNAME_SIZE]; + + unsigned int hr_timeout_ms; + + /* randomized as the region goes up and down so that a node + * recognizes a node going up and down in one iteration */ + u64 hr_generation; + + struct delayed_work hr_write_timeout_work; + unsigned long hr_last_timeout_start; + + /* negotiate timer, used to negotiate extending hb timeout. */ + struct delayed_work hr_nego_timeout_work; + unsigned long hr_nego_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; + + /* Used during o2hb_check_slot to hold a copy of the block + * being checked because we temporarily have to zero out the + * crc field. */ + struct o2hb_disk_heartbeat_block *hr_tmp_block; + + /* Message key for negotiate timeout message. */ + unsigned int hr_key; + struct list_head hr_handler_list; + + /* last hb status, 0 for success, other value for error. */ + int hr_last_hb_status; +}; + +struct o2hb_bio_wait_ctxt { + atomic_t wc_num_reqs; + struct completion wc_io_complete; + int wc_error; +}; + +#define O2HB_NEGO_TIMEOUT_MS (O2HB_MAX_WRITE_TIMEOUT_MS/2) + +enum { + O2HB_NEGO_TIMEOUT_MSG = 1, + O2HB_NEGO_APPROVE_MSG = 2, +}; + +struct o2hb_nego_msg { + u8 node_num; +}; + +static void o2hb_write_timeout(struct work_struct *work) +{ + int failed, quorum; + struct o2hb_region *reg = + container_of(work, struct o2hb_region, + hr_write_timeout_work.work); + + mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u " + "milliseconds\n", reg->hr_dev_name, + jiffies_to_msecs(jiffies - reg->hr_last_timeout_start)); + + if (o2hb_global_heartbeat_active()) { + spin_lock(&o2hb_live_lock); + if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap)) + set_bit(reg->hr_region_num, o2hb_failed_region_bitmap); + failed = bitmap_weight(o2hb_failed_region_bitmap, + O2NM_MAX_REGIONS); + quorum = bitmap_weight(o2hb_quorum_region_bitmap, + O2NM_MAX_REGIONS); + spin_unlock(&o2hb_live_lock); + + mlog(ML_HEARTBEAT, "Number of regions %d, failed regions %d\n", + quorum, failed); + + /* + * Fence if the number of failed regions >= half the number + * of quorum regions + */ + if ((failed << 1) < quorum) + return; + } + + o2quo_disk_timeout(); +} + +static void o2hb_arm_timeout(struct o2hb_region *reg) +{ + /* Arm writeout only after thread reaches steady state */ + if (atomic_read(®->hr_steady_iterations) != 0) + return; + + mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n", + O2HB_MAX_WRITE_TIMEOUT_MS); + + if (o2hb_global_heartbeat_active()) { + spin_lock(&o2hb_live_lock); + clear_bit(reg->hr_region_num, o2hb_failed_region_bitmap); + spin_unlock(&o2hb_live_lock); + } + cancel_delayed_work(®->hr_write_timeout_work); + schedule_delayed_work(®->hr_write_timeout_work, + msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS)); + + cancel_delayed_work(®->hr_nego_timeout_work); + /* negotiate timeout must be less than write timeout. */ + schedule_delayed_work(®->hr_nego_timeout_work, + msecs_to_jiffies(O2HB_NEGO_TIMEOUT_MS)); + memset(reg->hr_nego_node_bitmap, 0, sizeof(reg->hr_nego_node_bitmap)); +} + +static void o2hb_disarm_timeout(struct o2hb_region *reg) +{ + cancel_delayed_work_sync(®->hr_write_timeout_work); + cancel_delayed_work_sync(®->hr_nego_timeout_work); +} + +static int o2hb_send_nego_msg(int key, int type, u8 target) +{ + struct o2hb_nego_msg msg; + int status, ret; + + msg.node_num = o2nm_this_node(); +again: + ret = o2net_send_message(type, key, &msg, sizeof(msg), + target, &status); + + if (ret == -EAGAIN || ret == -ENOMEM) { + msleep(100); + goto again; + } + + return ret; +} + +static void o2hb_nego_timeout(struct work_struct *work) +{ + unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; + int master_node, i, ret; + struct o2hb_region *reg; + + reg = container_of(work, struct o2hb_region, hr_nego_timeout_work.work); + /* don't negotiate timeout if last hb failed since it is very + * possible io failed. Should let write timeout fence self. + */ + if (reg->hr_last_hb_status) + return; + + o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap)); + /* lowest node as master node to make negotiate decision. */ + master_node = find_next_bit(live_node_bitmap, O2NM_MAX_NODES, 0); + + if (master_node == o2nm_this_node()) { + if (!test_bit(master_node, reg->hr_nego_node_bitmap)) { + printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s).\n", + o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000, + config_item_name(®->hr_item), reg->hr_dev_name); + set_bit(master_node, reg->hr_nego_node_bitmap); + } + if (memcmp(reg->hr_nego_node_bitmap, live_node_bitmap, + sizeof(reg->hr_nego_node_bitmap))) { + /* check negotiate bitmap every second to do timeout + * approve decision. + */ + schedule_delayed_work(®->hr_nego_timeout_work, + msecs_to_jiffies(1000)); + + return; + } + + printk(KERN_NOTICE "o2hb: all nodes hb write hung, maybe region %s (%s) is down.\n", + config_item_name(®->hr_item), reg->hr_dev_name); + /* approve negotiate timeout request. */ + o2hb_arm_timeout(reg); + + i = -1; + while ((i = find_next_bit(live_node_bitmap, + O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { + if (i == master_node) + continue; + + mlog(ML_HEARTBEAT, "send NEGO_APPROVE msg to node %d\n", i); + ret = o2hb_send_nego_msg(reg->hr_key, + O2HB_NEGO_APPROVE_MSG, i); + if (ret) + mlog(ML_ERROR, "send NEGO_APPROVE msg to node %d fail %d\n", + i, ret); + } + } else { + /* negotiate timeout with master node. */ + printk(KERN_NOTICE "o2hb: node %d hb write hung for %ds on region %s (%s), negotiate timeout with node %d.\n", + o2nm_this_node(), O2HB_NEGO_TIMEOUT_MS/1000, config_item_name(®->hr_item), + reg->hr_dev_name, master_node); + ret = o2hb_send_nego_msg(reg->hr_key, O2HB_NEGO_TIMEOUT_MSG, + master_node); + if (ret) + mlog(ML_ERROR, "send NEGO_TIMEOUT msg to node %d fail %d\n", + master_node, ret); + } +} + +static int o2hb_nego_timeout_handler(struct o2net_msg *msg, u32 len, void *data, + void **ret_data) +{ + struct o2hb_region *reg = data; + struct o2hb_nego_msg *nego_msg; + + nego_msg = (struct o2hb_nego_msg *)msg->buf; + printk(KERN_NOTICE "o2hb: receive negotiate timeout message from node %d on region %s (%s).\n", + nego_msg->node_num, config_item_name(®->hr_item), reg->hr_dev_name); + if (nego_msg->node_num < O2NM_MAX_NODES) + set_bit(nego_msg->node_num, reg->hr_nego_node_bitmap); + else + mlog(ML_ERROR, "got nego timeout message from bad node.\n"); + + return 0; +} + +static int o2hb_nego_approve_handler(struct o2net_msg *msg, u32 len, void *data, + void **ret_data) +{ + struct o2hb_region *reg = data; + + printk(KERN_NOTICE "o2hb: negotiate timeout approved by master node on region %s (%s).\n", + config_item_name(®->hr_item), reg->hr_dev_name); + o2hb_arm_timeout(reg); + return 0; +} + +static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc) +{ + atomic_set(&wc->wc_num_reqs, 1); + init_completion(&wc->wc_io_complete); + wc->wc_error = 0; +} + +/* Used in error paths too */ +static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc, + unsigned int num) +{ + /* sadly atomic_sub_and_test() isn't available on all platforms. The + * good news is that the fast path only completes one at a time */ + while(num--) { + if (atomic_dec_and_test(&wc->wc_num_reqs)) { + BUG_ON(num > 0); + complete(&wc->wc_io_complete); + } + } +} + +static void o2hb_wait_on_io(struct o2hb_bio_wait_ctxt *wc) +{ + o2hb_bio_wait_dec(wc, 1); + wait_for_completion(&wc->wc_io_complete); +} + +static void o2hb_bio_end_io(struct bio *bio) +{ + struct o2hb_bio_wait_ctxt *wc = bio->bi_private; + + if (bio->bi_status) { + mlog(ML_ERROR, "IO Error %d\n", bio->bi_status); + wc->wc_error = blk_status_to_errno(bio->bi_status); + } + + o2hb_bio_wait_dec(wc, 1); + bio_put(bio); +} + +/* Setup a Bio to cover I/O against num_slots slots starting at + * start_slot. */ +static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg, + struct o2hb_bio_wait_ctxt *wc, + unsigned int *current_slot, + unsigned int max_slots, int op, + int op_flags) +{ + int len, current_page; + unsigned int vec_len, vec_start; + unsigned int bits = reg->hr_block_bits; + unsigned int spp = reg->hr_slots_per_page; + unsigned int cs = *current_slot; + struct bio *bio; + struct page *page; + + /* Testing has shown this allocation to take long enough under + * GFP_KERNEL that the local node can get fenced. It would be + * nicest if we could pre-allocate these bios and avoid this + * all together. */ + bio = bio_alloc(GFP_ATOMIC, 16); + if (!bio) { + mlog(ML_ERROR, "Could not alloc slots BIO!\n"); + bio = ERR_PTR(-ENOMEM); + goto bail; + } + + /* Must put everything in 512 byte sectors for the bio... */ + bio->bi_iter.bi_sector = (reg->hr_start_block + cs) << (bits - 9); + bio_set_dev(bio, reg->hr_bdev); + bio->bi_private = wc; + bio->bi_end_io = o2hb_bio_end_io; + bio_set_op_attrs(bio, op, op_flags); + + vec_start = (cs << bits) % PAGE_SIZE; + while(cs < max_slots) { + current_page = cs / spp; + page = reg->hr_slot_data[current_page]; + + vec_len = min(PAGE_SIZE - vec_start, + (max_slots-cs) * (PAGE_SIZE/spp) ); + + mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n", + current_page, vec_len, vec_start); + + len = bio_add_page(bio, page, vec_len, vec_start); + if (len != vec_len) break; + + cs += vec_len / (PAGE_SIZE/spp); + vec_start = 0; + } + +bail: + *current_slot = cs; + return bio; +} + +static int o2hb_read_slots(struct o2hb_region *reg, + unsigned int begin_slot, + unsigned int max_slots) +{ + unsigned int current_slot = begin_slot; + int status; + struct o2hb_bio_wait_ctxt wc; + struct bio *bio; + + o2hb_bio_wait_init(&wc); + + while(current_slot < max_slots) { + bio = o2hb_setup_one_bio(reg, &wc, ¤t_slot, max_slots, + REQ_OP_READ, 0); + if (IS_ERR(bio)) { + status = PTR_ERR(bio); + mlog_errno(status); + goto bail_and_wait; + } + + atomic_inc(&wc.wc_num_reqs); + submit_bio(bio); + } + + status = 0; + +bail_and_wait: + o2hb_wait_on_io(&wc); + if (wc.wc_error && !status) + status = wc.wc_error; + + return status; +} + +static int o2hb_issue_node_write(struct o2hb_region *reg, + struct o2hb_bio_wait_ctxt *write_wc) +{ + int status; + unsigned int slot; + struct bio *bio; + + o2hb_bio_wait_init(write_wc); + + slot = o2nm_this_node(); + + bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1, REQ_OP_WRITE, + REQ_SYNC); + if (IS_ERR(bio)) { + status = PTR_ERR(bio); + mlog_errno(status); + goto bail; + } + + atomic_inc(&write_wc->wc_num_reqs); + submit_bio(bio); + + status = 0; +bail: + return status; +} + +static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg, + struct o2hb_disk_heartbeat_block *hb_block) +{ + __le32 old_cksum; + u32 ret; + + /* We want to compute the block crc with a 0 value in the + * hb_cksum field. Save it off here and replace after the + * crc. */ + old_cksum = hb_block->hb_cksum; + hb_block->hb_cksum = 0; + + ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes); + + hb_block->hb_cksum = old_cksum; + + return ret; +} + +static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block) +{ + mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, " + "cksum = 0x%x, generation 0x%llx\n", + (long long)le64_to_cpu(hb_block->hb_seq), + hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum), + (long long)le64_to_cpu(hb_block->hb_generation)); +} + +static int o2hb_verify_crc(struct o2hb_region *reg, + struct o2hb_disk_heartbeat_block *hb_block) +{ + u32 read, computed; + + read = le32_to_cpu(hb_block->hb_cksum); + computed = o2hb_compute_block_crc_le(reg, hb_block); + + return read == computed; +} + +/* + * Compare the slot data with what we wrote in the last iteration. + * If the match fails, print an appropriate error message. This is to + * detect errors like... another node hearting on the same slot, + * flaky device that is losing writes, etc. + * Returns 1 if check succeeds, 0 otherwise. + */ +static int o2hb_check_own_slot(struct o2hb_region *reg) +{ + struct o2hb_disk_slot *slot; + struct o2hb_disk_heartbeat_block *hb_block; + char *errstr; + + slot = ®->hr_slots[o2nm_this_node()]; + /* Don't check on our 1st timestamp */ + if (!slot->ds_last_time) + return 0; + + hb_block = slot->ds_raw_block; + if (le64_to_cpu(hb_block->hb_seq) == slot->ds_last_time && + le64_to_cpu(hb_block->hb_generation) == slot->ds_last_generation && + hb_block->hb_node == slot->ds_node_num) + return 1; + +#define ERRSTR1 "Another node is heartbeating on device" +#define ERRSTR2 "Heartbeat generation mismatch on device" +#define ERRSTR3 "Heartbeat sequence mismatch on device" + + if (hb_block->hb_node != slot->ds_node_num) + errstr = ERRSTR1; + else if (le64_to_cpu(hb_block->hb_generation) != + slot->ds_last_generation) + errstr = ERRSTR2; + else + errstr = ERRSTR3; + + mlog(ML_ERROR, "%s (%s): expected(%u:0x%llx, 0x%llx), " + "ondisk(%u:0x%llx, 0x%llx)\n", errstr, reg->hr_dev_name, + slot->ds_node_num, (unsigned long long)slot->ds_last_generation, + (unsigned long long)slot->ds_last_time, hb_block->hb_node, + (unsigned long long)le64_to_cpu(hb_block->hb_generation), + (unsigned long long)le64_to_cpu(hb_block->hb_seq)); + + return 0; +} + +static inline void o2hb_prepare_block(struct o2hb_region *reg, + u64 generation) +{ + int node_num; + u64 cputime; + struct o2hb_disk_slot *slot; + struct o2hb_disk_heartbeat_block *hb_block; + + node_num = o2nm_this_node(); + slot = ®->hr_slots[node_num]; + + hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block; + memset(hb_block, 0, reg->hr_block_bytes); + /* TODO: time stuff */ + cputime = ktime_get_real_seconds(); + if (!cputime) + cputime = 1; + + hb_block->hb_seq = cpu_to_le64(cputime); + hb_block->hb_node = node_num; + hb_block->hb_generation = cpu_to_le64(generation); + hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS); + + /* This step must always happen last! */ + hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg, + hb_block)); + + mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n", + (long long)generation, + le32_to_cpu(hb_block->hb_cksum)); +} + +static void o2hb_fire_callbacks(struct o2hb_callback *hbcall, + struct o2nm_node *node, + int idx) +{ + struct o2hb_callback_func *f; + + list_for_each_entry(f, &hbcall->list, hc_item) { + mlog(ML_HEARTBEAT, "calling funcs %p\n", f); + (f->hc_func)(node, idx, f->hc_data); + } +} + +/* Will run the list in order until we process the passed event */ +static void o2hb_run_event_list(struct o2hb_node_event *queued_event) +{ + struct o2hb_callback *hbcall; + struct o2hb_node_event *event; + + /* Holding callback sem assures we don't alter the callback + * lists when doing this, and serializes ourselves with other + * processes wanting callbacks. */ + down_write(&o2hb_callback_sem); + + spin_lock(&o2hb_live_lock); + while (!list_empty(&o2hb_node_events) + && !list_empty(&queued_event->hn_item)) { + event = list_entry(o2hb_node_events.next, + struct o2hb_node_event, + hn_item); + list_del_init(&event->hn_item); + spin_unlock(&o2hb_live_lock); + + mlog(ML_HEARTBEAT, "Node %s event for %d\n", + event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN", + event->hn_node_num); + + hbcall = hbcall_from_type(event->hn_event_type); + + /* We should *never* have gotten on to the list with a + * bad type... This isn't something that we should try + * to recover from. */ + BUG_ON(IS_ERR(hbcall)); + + o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num); + + spin_lock(&o2hb_live_lock); + } + spin_unlock(&o2hb_live_lock); + + up_write(&o2hb_callback_sem); +} + +static void o2hb_queue_node_event(struct o2hb_node_event *event, + enum o2hb_callback_type type, + struct o2nm_node *node, + int node_num) +{ + assert_spin_locked(&o2hb_live_lock); + + BUG_ON((!node) && (type != O2HB_NODE_DOWN_CB)); + + event->hn_event_type = type; + event->hn_node = node; + event->hn_node_num = node_num; + + mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n", + type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num); + + list_add_tail(&event->hn_item, &o2hb_node_events); +} + +static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot) +{ + struct o2hb_node_event event = + { .hn_item = LIST_HEAD_INIT(event.hn_item), }; + struct o2nm_node *node; + int queued = 0; + + node = o2nm_get_node_by_num(slot->ds_node_num); + if (!node) + return; + + spin_lock(&o2hb_live_lock); + if (!list_empty(&slot->ds_live_item)) { + mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n", + slot->ds_node_num); + + list_del_init(&slot->ds_live_item); + + if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { + clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); + + o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, + slot->ds_node_num); + queued = 1; + } + } + spin_unlock(&o2hb_live_lock); + + if (queued) + o2hb_run_event_list(&event); + + o2nm_node_put(node); +} + +static void o2hb_set_quorum_device(struct o2hb_region *reg) +{ + if (!o2hb_global_heartbeat_active()) + return; + + /* Prevent race with o2hb_heartbeat_group_drop_item() */ + if (kthread_should_stop()) + return; + + /* Tag region as quorum only after thread reaches steady state */ + if (atomic_read(®->hr_steady_iterations) != 0) + return; + + spin_lock(&o2hb_live_lock); + + if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap)) + goto unlock; + + /* + * A region can be added to the quorum only when it sees all + * live nodes heartbeat on it. In other words, the region has been + * added to all nodes. + */ + if (memcmp(reg->hr_live_node_bitmap, o2hb_live_node_bitmap, + sizeof(o2hb_live_node_bitmap))) + goto unlock; + + printk(KERN_NOTICE "o2hb: Region %s (%s) is now a quorum device\n", + config_item_name(®->hr_item), reg->hr_dev_name); + + set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap); + + /* + * If global heartbeat active, unpin all regions if the + * region count > CUT_OFF + */ + if (bitmap_weight(o2hb_quorum_region_bitmap, + O2NM_MAX_REGIONS) > O2HB_PIN_CUT_OFF) + o2hb_region_unpin(NULL); +unlock: + spin_unlock(&o2hb_live_lock); +} + +static int o2hb_check_slot(struct o2hb_region *reg, + struct o2hb_disk_slot *slot) +{ + int changed = 0, gen_changed = 0; + struct o2hb_node_event event = + { .hn_item = LIST_HEAD_INIT(event.hn_item), }; + struct o2nm_node *node; + struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block; + u64 cputime; + unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS; + unsigned int slot_dead_ms; + int tmp; + int queued = 0; + + memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes); + + /* + * If a node is no longer configured but is still in the livemap, we + * may need to clear that bit from the livemap. + */ + node = o2nm_get_node_by_num(slot->ds_node_num); + if (!node) { + spin_lock(&o2hb_live_lock); + tmp = test_bit(slot->ds_node_num, o2hb_live_node_bitmap); + spin_unlock(&o2hb_live_lock); + if (!tmp) + return 0; + } + + if (!o2hb_verify_crc(reg, hb_block)) { + /* all paths from here will drop o2hb_live_lock for + * us. */ + spin_lock(&o2hb_live_lock); + + /* Don't print an error on the console in this case - + * a freshly formatted heartbeat area will not have a + * crc set on it. */ + if (list_empty(&slot->ds_live_item)) + goto out; + + /* The node is live but pushed out a bad crc. We + * consider it a transient miss but don't populate any + * other values as they may be junk. */ + mlog(ML_ERROR, "Node %d has written a bad crc to %s\n", + slot->ds_node_num, reg->hr_dev_name); + o2hb_dump_slot(hb_block); + + slot->ds_equal_samples++; + goto fire_callbacks; + } + + /* we don't care if these wrap.. the state transitions below + * clear at the right places */ + cputime = le64_to_cpu(hb_block->hb_seq); + if (slot->ds_last_time != cputime) + slot->ds_changed_samples++; + else + slot->ds_equal_samples++; + slot->ds_last_time = cputime; + + /* The node changed heartbeat generations. We assume this to + * mean it dropped off but came back before we timed out. We + * want to consider it down for the time being but don't want + * to lose any changed_samples state we might build up to + * considering it live again. */ + if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) { + gen_changed = 1; + slot->ds_equal_samples = 0; + mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx " + "to 0x%llx)\n", slot->ds_node_num, + (long long)slot->ds_last_generation, + (long long)le64_to_cpu(hb_block->hb_generation)); + } + + slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); + + mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x " + "seq %llu last %llu changed %u equal %u\n", + slot->ds_node_num, (long long)slot->ds_last_generation, + le32_to_cpu(hb_block->hb_cksum), + (unsigned long long)le64_to_cpu(hb_block->hb_seq), + (unsigned long long)slot->ds_last_time, slot->ds_changed_samples, + slot->ds_equal_samples); + + spin_lock(&o2hb_live_lock); + +fire_callbacks: + /* dead nodes only come to life after some number of + * changes at any time during their dead time */ + if (list_empty(&slot->ds_live_item) && + slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) { + mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n", + slot->ds_node_num, (long long)slot->ds_last_generation); + + set_bit(slot->ds_node_num, reg->hr_live_node_bitmap); + + /* first on the list generates a callback */ + if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { + mlog(ML_HEARTBEAT, "o2hb: Add node %d to live nodes " + "bitmap\n", slot->ds_node_num); + set_bit(slot->ds_node_num, o2hb_live_node_bitmap); + + o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node, + slot->ds_node_num); + + changed = 1; + queued = 1; + } + + list_add_tail(&slot->ds_live_item, + &o2hb_live_slots[slot->ds_node_num]); + + slot->ds_equal_samples = 0; + + /* We want to be sure that all nodes agree on the + * number of milliseconds before a node will be + * considered dead. The self-fencing timeout is + * computed from this value, and a discrepancy might + * result in heartbeat calling a node dead when it + * hasn't self-fenced yet. */ + slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms); + if (slot_dead_ms && slot_dead_ms != dead_ms) { + /* TODO: Perhaps we can fail the region here. */ + mlog(ML_ERROR, "Node %d on device %s has a dead count " + "of %u ms, but our count is %u ms.\n" + "Please double check your configuration values " + "for 'O2CB_HEARTBEAT_THRESHOLD'\n", + slot->ds_node_num, reg->hr_dev_name, slot_dead_ms, + dead_ms); + } + goto out; + } + + /* if the list is dead, we're done.. */ + if (list_empty(&slot->ds_live_item)) + goto out; + + /* live nodes only go dead after enough consequtive missed + * samples.. reset the missed counter whenever we see + * activity */ + if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) { + mlog(ML_HEARTBEAT, "Node %d left my region\n", + slot->ds_node_num); + + clear_bit(slot->ds_node_num, reg->hr_live_node_bitmap); + + /* last off the live_slot generates a callback */ + list_del_init(&slot->ds_live_item); + if (list_empty(&o2hb_live_slots[slot->ds_node_num])) { + mlog(ML_HEARTBEAT, "o2hb: Remove node %d from live " + "nodes bitmap\n", slot->ds_node_num); + clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); + + /* node can be null */ + o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, + node, slot->ds_node_num); + + changed = 1; + queued = 1; + } + + /* We don't clear this because the node is still + * actually writing new blocks. */ + if (!gen_changed) + slot->ds_changed_samples = 0; + goto out; + } + if (slot->ds_changed_samples) { + slot->ds_changed_samples = 0; + slot->ds_equal_samples = 0; + } +out: + spin_unlock(&o2hb_live_lock); + + if (queued) + o2hb_run_event_list(&event); + + if (node) + o2nm_node_put(node); + return changed; +} + +static int o2hb_highest_node(unsigned long *nodes, int numbits) +{ + return find_last_bit(nodes, numbits); +} + +static int o2hb_lowest_node(unsigned long *nodes, int numbits) +{ + return find_first_bit(nodes, numbits); +} + +static int o2hb_do_disk_heartbeat(struct o2hb_region *reg) +{ + int i, ret, highest_node, lowest_node; + int membership_change = 0, own_slot_ok = 0; + unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)]; + unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)]; + struct o2hb_bio_wait_ctxt write_wc; + + ret = o2nm_configured_node_map(configured_nodes, + sizeof(configured_nodes)); + if (ret) { + mlog_errno(ret); + goto bail; + } + + /* + * If a node is not configured but is in the livemap, we still need + * to read the slot so as to be able to remove it from the livemap. + */ + o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap)); + i = -1; + while ((i = find_next_bit(live_node_bitmap, + O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { + set_bit(i, configured_nodes); + } + + highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES); + lowest_node = o2hb_lowest_node(configured_nodes, O2NM_MAX_NODES); + if (highest_node >= O2NM_MAX_NODES || lowest_node >= O2NM_MAX_NODES) { + mlog(ML_NOTICE, "o2hb: No configured nodes found!\n"); + ret = -EINVAL; + goto bail; + } + + /* No sense in reading the slots of nodes that don't exist + * yet. Of course, if the node definitions have holes in them + * then we're reading an empty slot anyway... Consider this + * best-effort. */ + ret = o2hb_read_slots(reg, lowest_node, highest_node + 1); + if (ret < 0) { + mlog_errno(ret); + goto bail; + } + + /* With an up to date view of the slots, we can check that no + * other node has been improperly configured to heartbeat in + * our slot. */ + own_slot_ok = o2hb_check_own_slot(reg); + + /* fill in the proper info for our next heartbeat */ + o2hb_prepare_block(reg, reg->hr_generation); + + ret = o2hb_issue_node_write(reg, &write_wc); + if (ret < 0) { + mlog_errno(ret); + goto bail; + } + + i = -1; + while((i = find_next_bit(configured_nodes, + O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { + membership_change |= o2hb_check_slot(reg, ®->hr_slots[i]); + } + + /* + * We have to be sure we've advertised ourselves on disk + * before we can go to steady state. This ensures that + * people we find in our steady state have seen us. + */ + o2hb_wait_on_io(&write_wc); + if (write_wc.wc_error) { + /* Do not re-arm the write timeout on I/O error - we + * can't be sure that the new block ever made it to + * disk */ + mlog(ML_ERROR, "Write error %d on device \"%s\"\n", + write_wc.wc_error, reg->hr_dev_name); + ret = write_wc.wc_error; + goto bail; + } + + /* Skip disarming the timeout if own slot has stale/bad data */ + if (own_slot_ok) { + o2hb_set_quorum_device(reg); + o2hb_arm_timeout(reg); + reg->hr_last_timeout_start = jiffies; + } + +bail: + /* let the person who launched us know when things are steady */ + if (atomic_read(®->hr_steady_iterations) != 0) { + if (!ret && own_slot_ok && !membership_change) { + if (atomic_dec_and_test(®->hr_steady_iterations)) + wake_up(&o2hb_steady_queue); + } + } + + if (atomic_read(®->hr_steady_iterations) != 0) { + if (atomic_dec_and_test(®->hr_unsteady_iterations)) { + printk(KERN_NOTICE "o2hb: Unable to stabilize " + "heartbeat on region %s (%s)\n", + config_item_name(®->hr_item), + reg->hr_dev_name); + atomic_set(®->hr_steady_iterations, 0); + reg->hr_aborted_start = 1; + wake_up(&o2hb_steady_queue); + ret = -EIO; + } + } + + return ret; +} + +/* + * we ride the region ref that the region dir holds. before the region + * dir is removed and drops it ref it will wait to tear down this + * thread. + */ +static int o2hb_thread(void *data) +{ + int i, ret; + struct o2hb_region *reg = data; + struct o2hb_bio_wait_ctxt write_wc; + ktime_t before_hb, after_hb; + unsigned int elapsed_msec; + + mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n"); + + set_user_nice(current, MIN_NICE); + + /* Pin node */ + ret = o2nm_depend_this_node(); + if (ret) { + mlog(ML_ERROR, "Node has been deleted, ret = %d\n", ret); + reg->hr_node_deleted = 1; + wake_up(&o2hb_steady_queue); + return 0; + } + + while (!kthread_should_stop() && + !reg->hr_unclean_stop && !reg->hr_aborted_start) { + /* We track the time spent inside + * o2hb_do_disk_heartbeat so that we avoid more than + * hr_timeout_ms between disk writes. On busy systems + * this should result in a heartbeat which is less + * likely to time itself out. */ + before_hb = ktime_get_real(); + + ret = o2hb_do_disk_heartbeat(reg); + reg->hr_last_hb_status = ret; + + after_hb = ktime_get_real(); + + elapsed_msec = (unsigned int) + ktime_ms_delta(after_hb, before_hb); + + mlog(ML_HEARTBEAT, + "start = %lld, end = %lld, msec = %u, ret = %d\n", + before_hb, after_hb, elapsed_msec, ret); + + if (!kthread_should_stop() && + elapsed_msec < reg->hr_timeout_ms) { + /* the kthread api has blocked signals for us so no + * need to record the return value. */ + msleep_interruptible(reg->hr_timeout_ms - elapsed_msec); + } + } + + o2hb_disarm_timeout(reg); + + /* unclean stop is only used in very bad situation */ + for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++) + o2hb_shutdown_slot(®->hr_slots[i]); + + /* Explicit down notification - avoid forcing the other nodes + * to timeout on this region when we could just as easily + * write a clear generation - thus indicating to them that + * this node has left this region. + */ + if (!reg->hr_unclean_stop && !reg->hr_aborted_start) { + o2hb_prepare_block(reg, 0); + ret = o2hb_issue_node_write(reg, &write_wc); + if (ret == 0) + o2hb_wait_on_io(&write_wc); + else + mlog_errno(ret); + } + + /* Unpin node */ + o2nm_undepend_this_node(); + + mlog(ML_HEARTBEAT|ML_KTHREAD, "o2hb thread exiting\n"); + + return 0; +} + +#ifdef CONFIG_DEBUG_FS +static int o2hb_debug_open(struct inode *inode, struct file *file) +{ + struct o2hb_debug_buf *db = inode->i_private; + struct o2hb_region *reg; + unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)]; + unsigned long lts; + char *buf = NULL; + int i = -1; + int out = 0; + + /* max_nodes should be the largest bitmap we pass here */ + BUG_ON(sizeof(map) < db->db_size); + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + goto bail; + + switch (db->db_type) { + case O2HB_DB_TYPE_LIVENODES: + case O2HB_DB_TYPE_LIVEREGIONS: + case O2HB_DB_TYPE_QUORUMREGIONS: + case O2HB_DB_TYPE_FAILEDREGIONS: + spin_lock(&o2hb_live_lock); + memcpy(map, db->db_data, db->db_size); + spin_unlock(&o2hb_live_lock); + break; + + case O2HB_DB_TYPE_REGION_LIVENODES: + spin_lock(&o2hb_live_lock); + reg = (struct o2hb_region *)db->db_data; + memcpy(map, reg->hr_live_node_bitmap, db->db_size); + spin_unlock(&o2hb_live_lock); + break; + + case O2HB_DB_TYPE_REGION_NUMBER: + reg = (struct o2hb_region *)db->db_data; + out += scnprintf(buf + out, PAGE_SIZE - out, "%d\n", + reg->hr_region_num); + goto done; + + case O2HB_DB_TYPE_REGION_ELAPSED_TIME: + reg = (struct o2hb_region *)db->db_data; + lts = reg->hr_last_timeout_start; + /* If 0, it has never been set before */ + if (lts) + lts = jiffies_to_msecs(jiffies - lts); + out += scnprintf(buf + out, PAGE_SIZE - out, "%lu\n", lts); + goto done; + + case O2HB_DB_TYPE_REGION_PINNED: + reg = (struct o2hb_region *)db->db_data; + out += scnprintf(buf + out, PAGE_SIZE - out, "%u\n", + !!reg->hr_item_pinned); + goto done; + + default: + goto done; + } + + while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len) + out += scnprintf(buf + out, PAGE_SIZE - out, "%d ", i); + out += scnprintf(buf + out, PAGE_SIZE - out, "\n"); + +done: + i_size_write(inode, out); + + file->private_data = buf; + + return 0; +bail: + return -ENOMEM; +} + +static int o2hb_debug_release(struct inode *inode, struct file *file) +{ + kfree(file->private_data); + return 0; +} + +static ssize_t o2hb_debug_read(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + return simple_read_from_buffer(buf, nbytes, ppos, file->private_data, + i_size_read(file->f_mapping->host)); +} +#else +static int o2hb_debug_open(struct inode *inode, struct file *file) +{ + return 0; +} +static int o2hb_debug_release(struct inode *inode, struct file *file) +{ + return 0; +} +static ssize_t o2hb_debug_read(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + return 0; +} +#endif /* CONFIG_DEBUG_FS */ + +static const struct file_operations o2hb_debug_fops = { + .open = o2hb_debug_open, + .release = o2hb_debug_release, + .read = o2hb_debug_read, + .llseek = generic_file_llseek, +}; + +void o2hb_exit(void) +{ + debugfs_remove_recursive(o2hb_debug_dir); + kfree(o2hb_db_livenodes); + kfree(o2hb_db_liveregions); + kfree(o2hb_db_quorumregions); + kfree(o2hb_db_failedregions); +} + +static void o2hb_debug_create(const char *name, struct dentry *dir, + struct o2hb_debug_buf **db, int db_len, int type, + int size, int len, void *data) +{ + *db = kmalloc(db_len, GFP_KERNEL); + if (!*db) + return; + + (*db)->db_type = type; + (*db)->db_size = size; + (*db)->db_len = len; + (*db)->db_data = data; + + debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db, &o2hb_debug_fops); +} + +static void o2hb_debug_init(void) +{ + o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL); + + o2hb_debug_create(O2HB_DEBUG_LIVENODES, o2hb_debug_dir, + &o2hb_db_livenodes, sizeof(*o2hb_db_livenodes), + O2HB_DB_TYPE_LIVENODES, sizeof(o2hb_live_node_bitmap), + O2NM_MAX_NODES, o2hb_live_node_bitmap); + + o2hb_debug_create(O2HB_DEBUG_LIVEREGIONS, o2hb_debug_dir, + &o2hb_db_liveregions, sizeof(*o2hb_db_liveregions), + O2HB_DB_TYPE_LIVEREGIONS, + sizeof(o2hb_live_region_bitmap), O2NM_MAX_REGIONS, + o2hb_live_region_bitmap); + + o2hb_debug_create(O2HB_DEBUG_QUORUMREGIONS, o2hb_debug_dir, + &o2hb_db_quorumregions, + sizeof(*o2hb_db_quorumregions), + O2HB_DB_TYPE_QUORUMREGIONS, + sizeof(o2hb_quorum_region_bitmap), O2NM_MAX_REGIONS, + o2hb_quorum_region_bitmap); + + o2hb_debug_create(O2HB_DEBUG_FAILEDREGIONS, o2hb_debug_dir, + &o2hb_db_failedregions, + sizeof(*o2hb_db_failedregions), + O2HB_DB_TYPE_FAILEDREGIONS, + sizeof(o2hb_failed_region_bitmap), O2NM_MAX_REGIONS, + o2hb_failed_region_bitmap); +} + +void o2hb_init(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++) + INIT_LIST_HEAD(&o2hb_callbacks[i].list); + + for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++) + INIT_LIST_HEAD(&o2hb_live_slots[i]); + + INIT_LIST_HEAD(&o2hb_node_events); + + memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap)); + memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap)); + memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap)); + 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; + + o2hb_debug_init(); +} + +/* if we're already in a callback then we're already serialized by the sem */ +static void o2hb_fill_node_map_from_callback(unsigned long *map, + unsigned bytes) +{ + BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long))); + + memcpy(map, &o2hb_live_node_bitmap, bytes); +} + +/* + * get a map of all nodes that are heartbeating in any regions + */ +void o2hb_fill_node_map(unsigned long *map, unsigned bytes) +{ + /* callers want to serialize this map and callbacks so that they + * can trust that they don't miss nodes coming to the party */ + down_read(&o2hb_callback_sem); + spin_lock(&o2hb_live_lock); + o2hb_fill_node_map_from_callback(map, bytes); + spin_unlock(&o2hb_live_lock); + up_read(&o2hb_callback_sem); +} +EXPORT_SYMBOL_GPL(o2hb_fill_node_map); + +/* + * heartbeat configfs bits. The heartbeat set is a default set under + * the cluster set in nodemanager.c. + */ + +static struct o2hb_region *to_o2hb_region(struct config_item *item) +{ + return item ? container_of(item, struct o2hb_region, hr_item) : NULL; +} + +/* drop_item only drops its ref after killing the thread, nothing should + * be using the region anymore. this has to clean up any state that + * attributes might have built up. */ +static void o2hb_region_release(struct config_item *item) +{ + int i; + struct page *page; + struct o2hb_region *reg = to_o2hb_region(item); + + mlog(ML_HEARTBEAT, "hb region release (%s)\n", reg->hr_dev_name); + + kfree(reg->hr_tmp_block); + + if (reg->hr_slot_data) { + for (i = 0; i < reg->hr_num_pages; i++) { + page = reg->hr_slot_data[i]; + if (page) + __free_page(page); + } + kfree(reg->hr_slot_data); + } + + if (reg->hr_bdev) + blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE); + + kfree(reg->hr_slots); + + debugfs_remove_recursive(reg->hr_debug_dir); + kfree(reg->hr_db_livenodes); + kfree(reg->hr_db_regnum); + kfree(reg->hr_db_elapsed_time); + kfree(reg->hr_db_pinned); + + spin_lock(&o2hb_live_lock); + list_del(®->hr_all_item); + spin_unlock(&o2hb_live_lock); + + o2net_unregister_handler_list(®->hr_handler_list); + kfree(reg); +} + +static int o2hb_read_block_input(struct o2hb_region *reg, + const char *page, + unsigned long *ret_bytes, + unsigned int *ret_bits) +{ + unsigned long bytes; + char *p = (char *)page; + + bytes = simple_strtoul(p, &p, 0); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + /* Heartbeat and fs min / max block sizes are the same. */ + if (bytes > 4096 || bytes < 512) + return -ERANGE; + if (hweight16(bytes) != 1) + return -EINVAL; + + if (ret_bytes) + *ret_bytes = bytes; + if (ret_bits) + *ret_bits = ffs(bytes) - 1; + + return 0; +} + +static ssize_t o2hb_region_block_bytes_show(struct config_item *item, + char *page) +{ + return sprintf(page, "%u\n", to_o2hb_region(item)->hr_block_bytes); +} + +static ssize_t o2hb_region_block_bytes_store(struct config_item *item, + const char *page, + size_t count) +{ + struct o2hb_region *reg = to_o2hb_region(item); + int status; + unsigned long block_bytes; + unsigned int block_bits; + + if (reg->hr_bdev) + return -EINVAL; + + status = o2hb_read_block_input(reg, page, &block_bytes, + &block_bits); + if (status) + return status; + + reg->hr_block_bytes = (unsigned int)block_bytes; + reg->hr_block_bits = block_bits; + + return count; +} + +static ssize_t o2hb_region_start_block_show(struct config_item *item, + char *page) +{ + return sprintf(page, "%llu\n", to_o2hb_region(item)->hr_start_block); +} + +static ssize_t o2hb_region_start_block_store(struct config_item *item, + const char *page, + size_t count) +{ + struct o2hb_region *reg = to_o2hb_region(item); + unsigned long long tmp; + char *p = (char *)page; + + if (reg->hr_bdev) + return -EINVAL; + + tmp = simple_strtoull(p, &p, 0); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + reg->hr_start_block = tmp; + + return count; +} + +static ssize_t o2hb_region_blocks_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_o2hb_region(item)->hr_blocks); +} + +static ssize_t o2hb_region_blocks_store(struct config_item *item, + const char *page, + size_t count) +{ + struct o2hb_region *reg = to_o2hb_region(item); + unsigned long tmp; + char *p = (char *)page; + + if (reg->hr_bdev) + return -EINVAL; + + tmp = simple_strtoul(p, &p, 0); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > O2NM_MAX_NODES || tmp == 0) + return -ERANGE; + + reg->hr_blocks = (unsigned int)tmp; + + return count; +} + +static ssize_t o2hb_region_dev_show(struct config_item *item, char *page) +{ + unsigned int ret = 0; + + if (to_o2hb_region(item)->hr_bdev) + ret = sprintf(page, "%s\n", to_o2hb_region(item)->hr_dev_name); + + return ret; +} + +static void o2hb_init_region_params(struct o2hb_region *reg) +{ + reg->hr_slots_per_page = PAGE_SIZE >> reg->hr_block_bits; + reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS; + + mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n", + reg->hr_start_block, reg->hr_blocks); + mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n", + reg->hr_block_bytes, reg->hr_block_bits); + mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms); + mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold); +} + +static int o2hb_map_slot_data(struct o2hb_region *reg) +{ + int i, j; + unsigned int last_slot; + unsigned int spp = reg->hr_slots_per_page; + struct page *page; + char *raw; + struct o2hb_disk_slot *slot; + + reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL); + if (reg->hr_tmp_block == NULL) + return -ENOMEM; + + reg->hr_slots = kcalloc(reg->hr_blocks, + sizeof(struct o2hb_disk_slot), GFP_KERNEL); + if (reg->hr_slots == NULL) + return -ENOMEM; + + for(i = 0; i < reg->hr_blocks; i++) { + slot = ®->hr_slots[i]; + slot->ds_node_num = i; + INIT_LIST_HEAD(&slot->ds_live_item); + slot->ds_raw_block = NULL; + } + + reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp; + mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks " + "at %u blocks per page\n", + reg->hr_num_pages, reg->hr_blocks, spp); + + reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *), + GFP_KERNEL); + if (!reg->hr_slot_data) + return -ENOMEM; + + for(i = 0; i < reg->hr_num_pages; i++) { + page = alloc_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + reg->hr_slot_data[i] = page; + + last_slot = i * spp; + raw = page_address(page); + for (j = 0; + (j < spp) && ((j + last_slot) < reg->hr_blocks); + j++) { + BUG_ON((j + last_slot) >= reg->hr_blocks); + + slot = ®->hr_slots[j + last_slot]; + slot->ds_raw_block = + (struct o2hb_disk_heartbeat_block *) raw; + + raw += reg->hr_block_bytes; + } + } + + return 0; +} + +/* Read in all the slots available and populate the tracking + * structures so that we can start with a baseline idea of what's + * there. */ +static int o2hb_populate_slot_data(struct o2hb_region *reg) +{ + int ret, i; + struct o2hb_disk_slot *slot; + struct o2hb_disk_heartbeat_block *hb_block; + + ret = o2hb_read_slots(reg, 0, reg->hr_blocks); + if (ret) + goto out; + + /* We only want to get an idea of the values initially in each + * slot, so we do no verification - o2hb_check_slot will + * actually determine if each configured slot is valid and + * whether any values have changed. */ + for(i = 0; i < reg->hr_blocks; i++) { + slot = ®->hr_slots[i]; + hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block; + + /* Only fill the values that o2hb_check_slot uses to + * determine changing slots */ + slot->ds_last_time = le64_to_cpu(hb_block->hb_seq); + slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation); + } + +out: + return ret; +} + +/* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */ +static ssize_t o2hb_region_dev_store(struct config_item *item, + const char *page, + size_t count) +{ + struct o2hb_region *reg = to_o2hb_region(item); + struct task_struct *hb_task; + long fd; + int sectsize; + char *p = (char *)page; + struct fd f; + ssize_t ret = -EINVAL; + int live_threshold; + + if (reg->hr_bdev) + goto out; + + /* We can't heartbeat without having had our node number + * configured yet. */ + if (o2nm_this_node() == O2NM_MAX_NODES) + goto out; + + fd = simple_strtol(p, &p, 0); + if (!p || (*p && (*p != '\n'))) + goto out; + + if (fd < 0 || fd >= INT_MAX) + goto out; + + f = fdget(fd); + if (f.file == NULL) + goto out; + + if (reg->hr_blocks == 0 || reg->hr_start_block == 0 || + reg->hr_block_bytes == 0) + goto out2; + + if (!S_ISBLK(f.file->f_mapping->host->i_mode)) + goto out2; + + reg->hr_bdev = blkdev_get_by_dev(f.file->f_mapping->host->i_rdev, + FMODE_WRITE | FMODE_READ, NULL); + if (IS_ERR(reg->hr_bdev)) { + ret = PTR_ERR(reg->hr_bdev); + reg->hr_bdev = NULL; + goto out2; + } + + bdevname(reg->hr_bdev, reg->hr_dev_name); + + sectsize = bdev_logical_block_size(reg->hr_bdev); + if (sectsize != reg->hr_block_bytes) { + mlog(ML_ERROR, + "blocksize %u incorrect for device, expected %d", + reg->hr_block_bytes, sectsize); + ret = -EINVAL; + goto out3; + } + + o2hb_init_region_params(reg); + + /* Generation of zero is invalid */ + do { + get_random_bytes(®->hr_generation, + sizeof(reg->hr_generation)); + } while (reg->hr_generation == 0); + + ret = o2hb_map_slot_data(reg); + if (ret) { + mlog_errno(ret); + goto out3; + } + + ret = o2hb_populate_slot_data(reg); + if (ret) { + mlog_errno(ret); + goto out3; + } + + INIT_DELAYED_WORK(®->hr_write_timeout_work, o2hb_write_timeout); + INIT_DELAYED_WORK(®->hr_nego_timeout_work, o2hb_nego_timeout); + + /* + * A node is considered live after it has beat LIVE_THRESHOLD + * times. We're not steady until we've given them a chance + * _after_ our first read. + * The default threshold is bare minimum so as to limit the delay + * during mounts. For global heartbeat, the threshold doubled for the + * first region. + */ + live_threshold = O2HB_LIVE_THRESHOLD; + if (o2hb_global_heartbeat_active()) { + spin_lock(&o2hb_live_lock); + if (bitmap_weight(o2hb_region_bitmap, O2NM_MAX_REGIONS) == 1) + live_threshold <<= 1; + spin_unlock(&o2hb_live_lock); + } + ++live_threshold; + atomic_set(®->hr_steady_iterations, live_threshold); + /* unsteady_iterations is triple the steady_iterations */ + atomic_set(®->hr_unsteady_iterations, (live_threshold * 3)); + + hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s", + reg->hr_item.ci_name); + if (IS_ERR(hb_task)) { + ret = PTR_ERR(hb_task); + mlog_errno(ret); + goto out3; + } + + spin_lock(&o2hb_live_lock); + reg->hr_task = hb_task; + spin_unlock(&o2hb_live_lock); + + ret = wait_event_interruptible(o2hb_steady_queue, + atomic_read(®->hr_steady_iterations) == 0 || + reg->hr_node_deleted); + if (ret) { + atomic_set(®->hr_steady_iterations, 0); + reg->hr_aborted_start = 1; + } + + if (reg->hr_aborted_start) { + ret = -EIO; + goto out3; + } + + if (reg->hr_node_deleted) { + ret = -EINVAL; + goto out3; + } + + /* Ok, we were woken. Make sure it wasn't by drop_item() */ + spin_lock(&o2hb_live_lock); + hb_task = reg->hr_task; + if (o2hb_global_heartbeat_active()) + set_bit(reg->hr_region_num, o2hb_live_region_bitmap); + spin_unlock(&o2hb_live_lock); + + if (hb_task) + ret = count; + else + ret = -EIO; + + if (hb_task && o2hb_global_heartbeat_active()) + printk(KERN_NOTICE "o2hb: Heartbeat started on region %s (%s)\n", + config_item_name(®->hr_item), reg->hr_dev_name); + +out3: + if (ret < 0) { + blkdev_put(reg->hr_bdev, FMODE_READ | FMODE_WRITE); + reg->hr_bdev = NULL; + } +out2: + fdput(f); +out: + return ret; +} + +static ssize_t o2hb_region_pid_show(struct config_item *item, char *page) +{ + struct o2hb_region *reg = to_o2hb_region(item); + pid_t pid = 0; + + spin_lock(&o2hb_live_lock); + if (reg->hr_task) + pid = task_pid_nr(reg->hr_task); + spin_unlock(&o2hb_live_lock); + + if (!pid) + return 0; + + return sprintf(page, "%u\n", pid); +} + +CONFIGFS_ATTR(o2hb_region_, block_bytes); +CONFIGFS_ATTR(o2hb_region_, start_block); +CONFIGFS_ATTR(o2hb_region_, blocks); +CONFIGFS_ATTR(o2hb_region_, dev); +CONFIGFS_ATTR_RO(o2hb_region_, pid); + +static struct configfs_attribute *o2hb_region_attrs[] = { + &o2hb_region_attr_block_bytes, + &o2hb_region_attr_start_block, + &o2hb_region_attr_blocks, + &o2hb_region_attr_dev, + &o2hb_region_attr_pid, + NULL, +}; + +static struct configfs_item_operations o2hb_region_item_ops = { + .release = o2hb_region_release, +}; + +static const struct config_item_type o2hb_region_type = { + .ct_item_ops = &o2hb_region_item_ops, + .ct_attrs = o2hb_region_attrs, + .ct_owner = THIS_MODULE, +}; + +/* heartbeat set */ + +struct o2hb_heartbeat_group { + struct config_group hs_group; + /* some stuff? */ +}; + +static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group) +{ + return group ? + container_of(group, struct o2hb_heartbeat_group, hs_group) + : NULL; +} + +static void o2hb_debug_region_init(struct o2hb_region *reg, + struct dentry *parent) +{ + struct dentry *dir; + + dir = debugfs_create_dir(config_item_name(®->hr_item), parent); + reg->hr_debug_dir = dir; + + o2hb_debug_create(O2HB_DEBUG_LIVENODES, dir, &(reg->hr_db_livenodes), + sizeof(*(reg->hr_db_livenodes)), + O2HB_DB_TYPE_REGION_LIVENODES, + sizeof(reg->hr_live_node_bitmap), O2NM_MAX_NODES, + reg); + + o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER, dir, &(reg->hr_db_regnum), + sizeof(*(reg->hr_db_regnum)), + O2HB_DB_TYPE_REGION_NUMBER, 0, O2NM_MAX_NODES, reg); + + o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME, dir, + &(reg->hr_db_elapsed_time), + sizeof(*(reg->hr_db_elapsed_time)), + O2HB_DB_TYPE_REGION_ELAPSED_TIME, 0, 0, reg); + + o2hb_debug_create(O2HB_DEBUG_REGION_PINNED, dir, &(reg->hr_db_pinned), + sizeof(*(reg->hr_db_pinned)), + O2HB_DB_TYPE_REGION_PINNED, 0, 0, reg); + +} + +static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group, + const char *name) +{ + struct o2hb_region *reg = NULL; + int ret; + + reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL); + if (reg == NULL) + return ERR_PTR(-ENOMEM); + + if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) { + ret = -ENAMETOOLONG; + goto free; + } + + spin_lock(&o2hb_live_lock); + reg->hr_region_num = 0; + if (o2hb_global_heartbeat_active()) { + reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap, + O2NM_MAX_REGIONS); + if (reg->hr_region_num >= O2NM_MAX_REGIONS) { + spin_unlock(&o2hb_live_lock); + ret = -EFBIG; + goto free; + } + set_bit(reg->hr_region_num, o2hb_region_bitmap); + } + list_add_tail(®->hr_all_item, &o2hb_all_regions); + spin_unlock(&o2hb_live_lock); + + config_item_init_type_name(®->hr_item, name, &o2hb_region_type); + + /* this is the same way to generate msg key as dlm, for local heartbeat, + * name is also the same, so make initial crc value different to avoid + * message key conflict. + */ + reg->hr_key = crc32_le(reg->hr_region_num + O2NM_MAX_REGIONS, + name, strlen(name)); + INIT_LIST_HEAD(®->hr_handler_list); + ret = o2net_register_handler(O2HB_NEGO_TIMEOUT_MSG, reg->hr_key, + sizeof(struct o2hb_nego_msg), + o2hb_nego_timeout_handler, + reg, NULL, ®->hr_handler_list); + if (ret) + goto remove_item; + + ret = o2net_register_handler(O2HB_NEGO_APPROVE_MSG, reg->hr_key, + sizeof(struct o2hb_nego_msg), + o2hb_nego_approve_handler, + reg, NULL, ®->hr_handler_list); + if (ret) + goto unregister_handler; + + o2hb_debug_region_init(reg, o2hb_debug_dir); + + return ®->hr_item; + +unregister_handler: + o2net_unregister_handler_list(®->hr_handler_list); +remove_item: + spin_lock(&o2hb_live_lock); + list_del(®->hr_all_item); + if (o2hb_global_heartbeat_active()) + clear_bit(reg->hr_region_num, o2hb_region_bitmap); + spin_unlock(&o2hb_live_lock); +free: + kfree(reg); + return ERR_PTR(ret); +} + +static void o2hb_heartbeat_group_drop_item(struct config_group *group, + struct config_item *item) +{ + 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); + hb_task = reg->hr_task; + reg->hr_task = NULL; + reg->hr_item_dropped = 1; + spin_unlock(&o2hb_live_lock); + + if (hb_task) + kthread_stop(hb_task); + + if (o2hb_global_heartbeat_active()) { + spin_lock(&o2hb_live_lock); + 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); + spin_unlock(&o2hb_live_lock); + printk(KERN_NOTICE "o2hb: Heartbeat %s on region %s (%s)\n", + ((atomic_read(®->hr_steady_iterations) == 0) ? + "stopped" : "start aborted"), config_item_name(item), + reg->hr_dev_name); + } + + /* + * If we're racing a dev_write(), we need to wake them. They will + * check reg->hr_task + */ + if (atomic_read(®->hr_steady_iterations) != 0) { + reg->hr_aborted_start = 1; + atomic_set(®->hr_steady_iterations, 0); + wake_up(&o2hb_steady_queue); + } + + 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 (bitmap_weight(o2hb_quorum_region_bitmap, + O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF) + o2hb_region_pin(NULL); + +unlock: + spin_unlock(&o2hb_live_lock); +} + +static ssize_t o2hb_heartbeat_group_dead_threshold_show(struct config_item *item, + char *page) +{ + return sprintf(page, "%u\n", o2hb_dead_threshold); +} + +static ssize_t o2hb_heartbeat_group_dead_threshold_store(struct config_item *item, + const char *page, size_t count) +{ + unsigned long tmp; + char *p = (char *)page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + /* this will validate ranges for us. */ + o2hb_dead_threshold_set((unsigned int) tmp); + + return count; +} + +static ssize_t o2hb_heartbeat_group_mode_show(struct config_item *item, + char *page) +{ + return sprintf(page, "%s\n", + o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]); +} + +static ssize_t o2hb_heartbeat_group_mode_store(struct config_item *item, + const char *page, size_t count) +{ + unsigned int i; + int ret; + size_t len; + + len = (page[count - 1] == '\n') ? count - 1 : count; + if (!len) + return -EINVAL; + + for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) { + if (strncasecmp(page, o2hb_heartbeat_mode_desc[i], len)) + continue; + + ret = o2hb_global_heartbeat_mode_set(i); + if (!ret) + printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n", + o2hb_heartbeat_mode_desc[i]); + return count; + } + + return -EINVAL; + +} + +CONFIGFS_ATTR(o2hb_heartbeat_group_, dead_threshold); +CONFIGFS_ATTR(o2hb_heartbeat_group_, mode); + +static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = { + &o2hb_heartbeat_group_attr_dead_threshold, + &o2hb_heartbeat_group_attr_mode, + NULL, +}; + +static struct configfs_group_operations o2hb_heartbeat_group_group_ops = { + .make_item = o2hb_heartbeat_group_make_item, + .drop_item = o2hb_heartbeat_group_drop_item, +}; + +static const struct config_item_type o2hb_heartbeat_group_type = { + .ct_group_ops = &o2hb_heartbeat_group_group_ops, + .ct_attrs = o2hb_heartbeat_group_attrs, + .ct_owner = THIS_MODULE, +}; + +/* this is just here to avoid touching group in heartbeat.h which the + * entire damn world #includes */ +struct config_group *o2hb_alloc_hb_set(void) +{ + struct o2hb_heartbeat_group *hs = NULL; + struct config_group *ret = NULL; + + hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL); + if (hs == NULL) + goto out; + + config_group_init_type_name(&hs->hs_group, "heartbeat", + &o2hb_heartbeat_group_type); + + ret = &hs->hs_group; +out: + if (ret == NULL) + kfree(hs); + return ret; +} + +void o2hb_free_hb_set(struct config_group *group) +{ + struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group); + kfree(hs); +} + +/* hb callback registration and issuing */ + +static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type) +{ + if (type == O2HB_NUM_CB) + return ERR_PTR(-EINVAL); + + return &o2hb_callbacks[type]; +} + +void o2hb_setup_callback(struct o2hb_callback_func *hc, + enum o2hb_callback_type type, + o2hb_cb_func *func, + void *data, + int priority) +{ + INIT_LIST_HEAD(&hc->hc_item); + hc->hc_func = func; + hc->hc_data = data; + hc->hc_priority = priority; + hc->hc_type = type; + hc->hc_magic = O2HB_CB_MAGIC; +} +EXPORT_SYMBOL_GPL(o2hb_setup_callback); + +/* + * 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) +{ + int ret = 0, found = 0; + struct o2hb_region *reg; + char *uuid; + + assert_spin_locked(&o2hb_live_lock); + + list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + + 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 ret; +} + +/* + * 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) +{ + struct o2hb_region *reg; + char *uuid; + int found = 0; + + assert_spin_locked(&o2hb_live_lock); + + list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + + uuid = config_item_name(®->hr_item); + if (region_uuid) { + if (strcmp(region_uuid, uuid)) + continue; + found = 1; + } + + 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; + } +} + +static int o2hb_region_inc_user(const char *region_uuid) +{ + int ret = 0; + + spin_lock(&o2hb_live_lock); + + /* 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 (bitmap_weight(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_dec_user(const char *region_uuid) +{ + spin_lock(&o2hb_live_lock); + + /* local heartbeat */ + if (!o2hb_global_heartbeat_active()) { + o2hb_region_unpin(region_uuid); + goto unlock; + } + + /* + * 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); + +unlock: + spin_unlock(&o2hb_live_lock); +} + +int o2hb_register_callback(const char *region_uuid, + struct o2hb_callback_func *hc) +{ + struct o2hb_callback_func *f; + struct o2hb_callback *hbcall; + int ret; + + BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); + BUG_ON(!list_empty(&hc->hc_item)); + + hbcall = hbcall_from_type(hc->hc_type); + if (IS_ERR(hbcall)) { + ret = PTR_ERR(hbcall); + goto out; + } + + if (region_uuid) { + ret = o2hb_region_inc_user(region_uuid); + if (ret) { + mlog_errno(ret); + goto out; + } + } + + down_write(&o2hb_callback_sem); + + list_for_each_entry(f, &hbcall->list, hc_item) { + if (hc->hc_priority < f->hc_priority) { + list_add_tail(&hc->hc_item, &f->hc_item); + break; + } + } + if (list_empty(&hc->hc_item)) + list_add_tail(&hc->hc_item, &hbcall->list); + + up_write(&o2hb_callback_sem); + ret = 0; +out: + mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n", + ret, __builtin_return_address(0), hc); + return ret; +} +EXPORT_SYMBOL_GPL(o2hb_register_callback); + +void o2hb_unregister_callback(const char *region_uuid, + struct o2hb_callback_func *hc) +{ + BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); + + mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n", + __builtin_return_address(0), hc); + + /* XXX Can this happen _with_ a region reference? */ + if (list_empty(&hc->hc_item)) + return; + + if (region_uuid) + o2hb_region_dec_user(region_uuid); + + down_write(&o2hb_callback_sem); + + list_del_init(&hc->hc_item); + + up_write(&o2hb_callback_sem); +} +EXPORT_SYMBOL_GPL(o2hb_unregister_callback); + +int o2hb_check_node_heartbeating_no_sem(u8 node_num) +{ + unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; + + spin_lock(&o2hb_live_lock); + o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map)); + spin_unlock(&o2hb_live_lock); + if (!test_bit(node_num, testing_map)) { + mlog(ML_HEARTBEAT, + "node (%u) does not have heartbeating enabled.\n", + node_num); + return 0; + } + + return 1; +} +EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_no_sem); + +int o2hb_check_node_heartbeating_from_callback(u8 node_num) +{ + unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; + + o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map)); + if (!test_bit(node_num, testing_map)) { + mlog(ML_HEARTBEAT, + "node (%u) does not have heartbeating enabled.\n", + node_num); + return 0; + } + + return 1; +} +EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback); + +/* + * this is just a hack until we get the plumbing which flips file systems + * read only and drops the hb ref instead of killing the node dead. + */ +void o2hb_stop_all_regions(void) +{ + struct o2hb_region *reg; + + mlog(ML_ERROR, "stopping heartbeat on all active regions.\n"); + + spin_lock(&o2hb_live_lock); + + list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) + reg->hr_unclean_stop = 1; + + spin_unlock(&o2hb_live_lock); +} +EXPORT_SYMBOL_GPL(o2hb_stop_all_regions); + +int o2hb_get_all_regions(char *region_uuids, u8 max_regions) +{ + struct o2hb_region *reg; + int numregs = 0; + char *p; + + spin_lock(&o2hb_live_lock); + + p = region_uuids; + list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + + mlog(0, "Region: %s\n", config_item_name(®->hr_item)); + if (numregs < max_regions) { + memcpy(p, config_item_name(®->hr_item), + O2HB_MAX_REGION_NAME_LEN); + p += O2HB_MAX_REGION_NAME_LEN; + } + numregs++; + } + + spin_unlock(&o2hb_live_lock); + + return numregs; +} +EXPORT_SYMBOL_GPL(o2hb_get_all_regions); + +int o2hb_global_heartbeat_active(void) +{ + return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL); +} +EXPORT_SYMBOL(o2hb_global_heartbeat_active); |