| /* -*- mode: c; c-basic-offset: 8; -*- |
| * vim: noexpandtab sw=8 ts=8 sts=0: |
| * |
| * Copyright (C) 2004, 2005 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| |
| #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 "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 struct dentry *o2hb_debug_livenodes; |
| static struct dentry *o2hb_debug_liveregions; |
| static struct dentry *o2hb_debug_quorumregions; |
| static struct dentry *o2hb_debug_failedregions; |
| |
| 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); |
| |
| #define O2HB_DEFAULT_BLOCK_BITS 9 |
| |
| enum o2hb_heartbeat_modes { |
| O2HB_HEARTBEAT_LOCAL = 0, |
| O2HB_HEARTBEAT_GLOBAL, |
| O2HB_HEARTBEAT_NUM_MODES, |
| }; |
| |
| 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; |
| 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 |
| * 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; |
| |
| /* 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 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 |
| * 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; |
| |
| /* 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; |
| }; |
| |
| struct o2hb_bio_wait_ctxt { |
| atomic_t wc_num_reqs; |
| struct completion wc_io_complete; |
| int wc_error; |
| }; |
| |
| static void o2hb_write_timeout(struct work_struct *work) |
| { |
| int failed, quorum; |
| unsigned long flags; |
| 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_irqsave(&o2hb_live_lock, flags); |
| 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_irqrestore(&o2hb_live_lock, flags); |
| |
| 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_write_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); |
| reg->hr_last_timeout_start = jiffies; |
| schedule_delayed_work(®->hr_write_timeout_work, |
| msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS)); |
| } |
| |
| static void o2hb_disarm_write_timeout(struct o2hb_region *reg) |
| { |
| cancel_delayed_work_sync(®->hr_write_timeout_work); |
| } |
| |
| 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_region *reg, |
| 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_error) { |
| mlog(ML_ERROR, "IO Error %d\n", bio->bi_error); |
| wc->wc_error = bio->bi_error; |
| } |
| |
| 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 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->bi_bdev = reg->hr_bdev; |
| bio->bi_private = wc; |
| bio->bi_end_io = o2hb_bio_end_io; |
| |
| vec_start = (cs << bits) % PAGE_CACHE_SIZE; |
| while(cs < max_slots) { |
| current_page = cs / spp; |
| page = reg->hr_slot_data[current_page]; |
| |
| vec_len = min(PAGE_CACHE_SIZE - vec_start, |
| (max_slots-cs) * (PAGE_CACHE_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_CACHE_SIZE/spp); |
| vec_start = 0; |
| } |
| |
| bail: |
| *current_slot = cs; |
| return bio; |
| } |
| |
| static int o2hb_read_slots(struct o2hb_region *reg, |
| unsigned int max_slots) |
| { |
| unsigned int current_slot=0; |
| 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); |
| if (IS_ERR(bio)) { |
| status = PTR_ERR(bio); |
| mlog_errno(status); |
| goto bail_and_wait; |
| } |
| |
| atomic_inc(&wc.wc_num_reqs); |
| submit_bio(READ, bio); |
| } |
| |
| status = 0; |
| |
| bail_and_wait: |
| o2hb_wait_on_io(reg, &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); |
| if (IS_ERR(bio)) { |
| status = PTR_ERR(bio); |
| mlog_errno(status); |
| goto bail; |
| } |
| |
| atomic_inc(&write_wc->wc_num_reqs); |
| submit_bio(WRITE_SYNC, 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 = CURRENT_TIME.tv_sec; |
| 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_do_disk_heartbeat(struct o2hb_region *reg) |
| { |
| int i, ret, highest_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); |
| if (highest_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, 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(reg, &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_write_timeout(reg); |
| } |
| |
| 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 " |
| "heartbeart 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; |
| } |
| |
| /* Subtract b from a, storing the result in a. a *must* have a larger |
| * value than b. */ |
| static void o2hb_tv_subtract(struct timeval *a, |
| struct timeval *b) |
| { |
| /* just return 0 when a is after b */ |
| if (a->tv_sec < b->tv_sec || |
| (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) { |
| a->tv_sec = 0; |
| a->tv_usec = 0; |
| return; |
| } |
| |
| a->tv_sec -= b->tv_sec; |
| a->tv_usec -= b->tv_usec; |
| while ( a->tv_usec < 0 ) { |
| a->tv_sec--; |
| a->tv_usec += 1000000; |
| } |
| } |
| |
| static unsigned int o2hb_elapsed_msecs(struct timeval *start, |
| struct timeval *end) |
| { |
| struct timeval res = *end; |
| |
| o2hb_tv_subtract(&res, start); |
| |
| return res.tv_sec * 1000 + res.tv_usec / 1000; |
| } |
| |
| /* |
| * 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; |
| struct timeval 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 */ |
| o2nm_depend_this_node(); |
| |
| 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. */ |
| do_gettimeofday(&before_hb); |
| |
| ret = o2hb_do_disk_heartbeat(reg); |
| |
| do_gettimeofday(&after_hb); |
| elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb); |
| |
| mlog(ML_HEARTBEAT, |
| "start = %lu.%lu, end = %lu.%lu, msec = %u, ret = %d\n", |
| before_hb.tv_sec, (unsigned long) before_hb.tv_usec, |
| after_hb.tv_sec, (unsigned long) after_hb.tv_usec, |
| 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_write_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(reg, &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 += snprintf(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 += snprintf(buf + out, PAGE_SIZE - out, "%lu\n", lts); |
| 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; |
| } |
| |
| while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len) |
| out += snprintf(buf + out, PAGE_SIZE - out, "%d ", i); |
| out += snprintf(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) |
| { |
| kfree(o2hb_db_livenodes); |
| kfree(o2hb_db_liveregions); |
| kfree(o2hb_db_quorumregions); |
| kfree(o2hb_db_failedregions); |
| debugfs_remove(o2hb_debug_failedregions); |
| debugfs_remove(o2hb_debug_quorumregions); |
| debugfs_remove(o2hb_debug_liveregions); |
| debugfs_remove(o2hb_debug_livenodes); |
| debugfs_remove(o2hb_debug_dir); |
| } |
| |
| static struct dentry *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 NULL; |
| |
| (*db)->db_type = type; |
| (*db)->db_size = size; |
| (*db)->db_len = len; |
| (*db)->db_data = data; |
| |
| return debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db, |
| &o2hb_debug_fops); |
| } |
| |
| static int o2hb_debug_init(void) |
| { |
| int ret = -ENOMEM; |
| |
| o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL); |
| if (!o2hb_debug_dir) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| o2hb_debug_livenodes = 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); |
| if (!o2hb_debug_livenodes) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| o2hb_debug_liveregions = 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); |
| if (!o2hb_debug_liveregions) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| o2hb_debug_quorumregions = |
| 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); |
| if (!o2hb_debug_quorumregions) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| o2hb_debug_failedregions = |
| 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); |
| if (!o2hb_debug_failedregions) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| ret = 0; |
| bail: |
| if (ret) |
| o2hb_exit(); |
| |
| return ret; |
| } |
| |
| int 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; |
| |
| return 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); |
| |
| kfree(reg->hr_db_regnum); |
| kfree(reg->hr_db_livenodes); |
| 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); |
| list_del(®->hr_all_item); |
| spin_unlock(&o2hb_live_lock); |
| |
| kfree(reg); |
| } |
| |
| static int o2hb_read_block_input(struct o2hb_region *reg, |
| const char *page, |
| size_t count, |
| 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_read(struct o2hb_region *reg, |
| char *page) |
| { |
| return sprintf(page, "%u\n", reg->hr_block_bytes); |
| } |
| |
| static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg, |
| const char *page, |
| size_t count) |
| { |
| int status; |
| unsigned long block_bytes; |
| unsigned int block_bits; |
| |
| if (reg->hr_bdev) |
| return -EINVAL; |
| |
| status = o2hb_read_block_input(reg, page, count, |
| &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_read(struct o2hb_region *reg, |
| char *page) |
| { |
| return sprintf(page, "%llu\n", reg->hr_start_block); |
| } |
| |
| static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg, |
| const char *page, |
| size_t count) |
| { |
| 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_read(struct o2hb_region *reg, |
| char *page) |
| { |
| return sprintf(page, "%d\n", reg->hr_blocks); |
| } |
| |
| static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg, |
| const char *page, |
| size_t count) |
| { |
| 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_read(struct o2hb_region *reg, |
| char *page) |
| { |
| unsigned int ret = 0; |
| |
| if (reg->hr_bdev) |
| ret = sprintf(page, "%s\n", reg->hr_dev_name); |
| |
| return ret; |
| } |
| |
| static void o2hb_init_region_params(struct o2hb_region *reg) |
| { |
| reg->hr_slots_per_page = PAGE_CACHE_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) { |
| mlog_errno(-ENOMEM); |
| return -ENOMEM; |
| } |
| |
| reg->hr_slots = kcalloc(reg->hr_blocks, |
| sizeof(struct o2hb_disk_slot), GFP_KERNEL); |
| if (reg->hr_slots == NULL) { |
| mlog_errno(-ENOMEM); |
| 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) { |
| mlog_errno(-ENOMEM); |
| return -ENOMEM; |
| } |
| |
| for(i = 0; i < reg->hr_num_pages; i++) { |
| page = alloc_page(GFP_KERNEL); |
| if (!page) { |
| mlog_errno(-ENOMEM); |
| 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, reg->hr_blocks); |
| if (ret) { |
| mlog_errno(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_write(struct o2hb_region *reg, |
| const char *page, |
| size_t count) |
| { |
| struct task_struct *hb_task; |
| long fd; |
| int sectsize; |
| char *p = (char *)page; |
| struct fd f; |
| struct inode *inode; |
| 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; |
| |
| inode = igrab(f.file->f_mapping->host); |
| if (inode == NULL) |
| goto out2; |
| |
| if (!S_ISBLK(inode->i_mode)) |
| goto out3; |
| |
| reg->hr_bdev = I_BDEV(f.file->f_mapping->host); |
| ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL); |
| if (ret) { |
| reg->hr_bdev = NULL; |
| goto out3; |
| } |
| inode = NULL; |
| |
| 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); |
| |
| /* |
| * 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 double the steady_iterations */ |
| atomic_set(®->hr_unsteady_iterations, (live_threshold << 1)); |
| |
| 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); |
| if (ret) { |
| atomic_set(®->hr_steady_iterations, 0); |
| reg->hr_aborted_start = 1; |
| } |
| |
| if (reg->hr_aborted_start) { |
| ret = -EIO; |
| 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: |
| iput(inode); |
| out2: |
| fdput(f); |
| out: |
| if (ret < 0) { |
| if (reg->hr_bdev) { |
| blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE); |
| reg->hr_bdev = NULL; |
| } |
| } |
| return ret; |
| } |
| |
| static ssize_t o2hb_region_pid_read(struct o2hb_region *reg, |
| char *page) |
| { |
| 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); |
| } |
| |
| struct o2hb_region_attribute { |
| struct configfs_attribute attr; |
| ssize_t (*show)(struct o2hb_region *, char *); |
| ssize_t (*store)(struct o2hb_region *, const char *, size_t); |
| }; |
| |
| static struct o2hb_region_attribute o2hb_region_attr_block_bytes = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "block_bytes", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_region_block_bytes_read, |
| .store = o2hb_region_block_bytes_write, |
| }; |
| |
| static struct o2hb_region_attribute o2hb_region_attr_start_block = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "start_block", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_region_start_block_read, |
| .store = o2hb_region_start_block_write, |
| }; |
| |
| static struct o2hb_region_attribute o2hb_region_attr_blocks = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "blocks", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_region_blocks_read, |
| .store = o2hb_region_blocks_write, |
| }; |
| |
| static struct o2hb_region_attribute o2hb_region_attr_dev = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "dev", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_region_dev_read, |
| .store = o2hb_region_dev_write, |
| }; |
| |
| static struct o2hb_region_attribute o2hb_region_attr_pid = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "pid", |
| .ca_mode = S_IRUGO | S_IRUSR }, |
| .show = o2hb_region_pid_read, |
| }; |
| |
| static struct configfs_attribute *o2hb_region_attrs[] = { |
| &o2hb_region_attr_block_bytes.attr, |
| &o2hb_region_attr_start_block.attr, |
| &o2hb_region_attr_blocks.attr, |
| &o2hb_region_attr_dev.attr, |
| &o2hb_region_attr_pid.attr, |
| NULL, |
| }; |
| |
| static ssize_t o2hb_region_show(struct config_item *item, |
| struct configfs_attribute *attr, |
| char *page) |
| { |
| struct o2hb_region *reg = to_o2hb_region(item); |
| struct o2hb_region_attribute *o2hb_region_attr = |
| container_of(attr, struct o2hb_region_attribute, attr); |
| ssize_t ret = 0; |
| |
| if (o2hb_region_attr->show) |
| ret = o2hb_region_attr->show(reg, page); |
| return ret; |
| } |
| |
| static ssize_t o2hb_region_store(struct config_item *item, |
| struct configfs_attribute *attr, |
| const char *page, size_t count) |
| { |
| struct o2hb_region *reg = to_o2hb_region(item); |
| struct o2hb_region_attribute *o2hb_region_attr = |
| container_of(attr, struct o2hb_region_attribute, attr); |
| ssize_t ret = -EINVAL; |
| |
| if (o2hb_region_attr->store) |
| ret = o2hb_region_attr->store(reg, page, count); |
| return ret; |
| } |
| |
| static struct configfs_item_operations o2hb_region_item_ops = { |
| .release = o2hb_region_release, |
| .show_attribute = o2hb_region_show, |
| .store_attribute = o2hb_region_store, |
| }; |
| |
| static 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 int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) |
| { |
| int ret = -ENOMEM; |
| |
| reg->hr_debug_dir = |
| debugfs_create_dir(config_item_name(®->hr_item), dir); |
| if (!reg->hr_debug_dir) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| reg->hr_debug_livenodes = |
| o2hb_debug_create(O2HB_DEBUG_LIVENODES, |
| reg->hr_debug_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); |
| if (!reg->hr_debug_livenodes) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| reg->hr_debug_regnum = |
| o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER, |
| reg->hr_debug_dir, |
| &(reg->hr_db_regnum), |
| sizeof(*(reg->hr_db_regnum)), |
| O2HB_DB_TYPE_REGION_NUMBER, |
| 0, O2NM_MAX_NODES, reg); |
| if (!reg->hr_debug_regnum) { |
| mlog_errno(ret); |
| goto bail; |
| } |
| |
| reg->hr_debug_elapsed_time = |
| o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME, |
| reg->hr_debug_dir, |
| &(reg->hr_db_elapsed_time), |
| sizeof(*(reg->hr_db_elapsed_time)), |
| O2HB_DB_TYPE_REGION_ELAPSED_TIME, |
| 0, 0, reg); |
| if (!reg->hr_debug_elapsed_time) { |
| mlog_errno(ret); |
| 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; |
| } |
| |
| 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); |
| |
| ret = o2hb_debug_region_init(reg, o2hb_debug_dir); |
| if (ret) { |
| config_item_put(®->hr_item); |
| goto free; |
| } |
| |
| return ®->hr_item; |
| 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); |
| } |
| |
| struct o2hb_heartbeat_group_attribute { |
| struct configfs_attribute attr; |
| ssize_t (*show)(struct o2hb_heartbeat_group *, char *); |
| ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t); |
| }; |
| |
| static ssize_t o2hb_heartbeat_group_show(struct config_item *item, |
| struct configfs_attribute *attr, |
| char *page) |
| { |
| struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); |
| struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = |
| container_of(attr, struct o2hb_heartbeat_group_attribute, attr); |
| ssize_t ret = 0; |
| |
| if (o2hb_heartbeat_group_attr->show) |
| ret = o2hb_heartbeat_group_attr->show(reg, page); |
| return ret; |
| } |
| |
| static ssize_t o2hb_heartbeat_group_store(struct config_item *item, |
| struct configfs_attribute *attr, |
| const char *page, size_t count) |
| { |
| struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item)); |
| struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr = |
| container_of(attr, struct o2hb_heartbeat_group_attribute, attr); |
| ssize_t ret = -EINVAL; |
| |
| if (o2hb_heartbeat_group_attr->store) |
| ret = o2hb_heartbeat_group_attr->store(reg, page, count); |
| return ret; |
| } |
| |
| static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group, |
| char *page) |
| { |
| return sprintf(page, "%u\n", o2hb_dead_threshold); |
| } |
| |
| static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group, |
| 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 o2hb_heartbeat_group *group, |
| char *page) |
| { |
| return sprintf(page, "%s\n", |
| o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]); |
| } |
| |
| static |
| ssize_t o2hb_heartbeat_group_mode_store(struct o2hb_heartbeat_group *group, |
| 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; |
| |
| } |
| |
| static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "dead_threshold", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_heartbeat_group_threshold_show, |
| .store = o2hb_heartbeat_group_threshold_store, |
| }; |
| |
| static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_mode = { |
| .attr = { .ca_owner = THIS_MODULE, |
| .ca_name = "mode", |
| .ca_mode = S_IRUGO | S_IWUSR }, |
| .show = o2hb_heartbeat_group_mode_show, |
| .store = o2hb_heartbeat_group_mode_store, |
| }; |
| |
| static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = { |
| &o2hb_heartbeat_group_attr_threshold.attr, |
| &o2hb_heartbeat_group_attr_mode.attr, |
| NULL, |
| }; |
| |
| static struct configfs_item_operations o2hb_heartbeat_group_item_ops = { |
| .show_attribute = o2hb_heartbeat_group_show, |
| .store_attribute = o2hb_heartbeat_group_store, |
| }; |
| |
| 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 struct config_item_type o2hb_heartbeat_group_type = { |
| .ct_group_ops = &o2hb_heartbeat_group_group_ops, |
| .ct_item_ops = &o2hb_heartbeat_group_item_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; |
| } |
| |
| 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(u8 node_num) |
| { |
| unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
| |
| o2hb_fill_node_map(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); |
| |
| int o2hb_check_node_heartbeating_no_sem(u8 node_num) |
| { |
| unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&o2hb_live_lock, flags); |
| o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map)); |
| spin_unlock_irqrestore(&o2hb_live_lock, flags); |
| 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); |
| |
| /* Makes sure our local node is configured with a node number, and is |
| * heartbeating. */ |
| int o2hb_check_local_node_heartbeating(void) |
| { |
| u8 node_num; |
| |
| /* if this node was set then we have networking */ |
| node_num = o2nm_this_node(); |
| if (node_num == O2NM_MAX_NODES) { |
| mlog(ML_HEARTBEAT, "this node has not been configured.\n"); |
| return 0; |
| } |
| |
| return o2hb_check_node_heartbeating(node_num); |
| } |
| EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating); |
| |
| /* |
| * 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); |