diff options
Diffstat (limited to 'fs/ocfs2/cluster/heartbeat.c')
| -rw-r--r-- | fs/ocfs2/cluster/heartbeat.c | 1797 |
1 files changed, 1797 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c new file mode 100644 index 00000000000..7307ba52891 --- /dev/null +++ b/fs/ocfs2/cluster/heartbeat.c @@ -0,0 +1,1797 @@ +/* -*- 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 "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 spinlock_t o2hb_live_lock = SPIN_LOCK_UNLOCKED; +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); + +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 + +unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD; + +/* 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); + } +} + +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; + + /* 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; + + /* 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; + + 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 work_struct 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; +}; + +static void o2hb_write_timeout(void *arg) +{ + struct o2hb_region *reg = arg; + + 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)); + o2quo_disk_timeout(); +} + +static void o2hb_arm_write_timeout(struct o2hb_region *reg) +{ + mlog(0, "Queue write timeout for %u ms\n", O2HB_MAX_WRITE_TIMEOUT_MS); + + 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(®->hr_write_timeout_work); + flush_scheduled_work(); +} + +static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc, + unsigned int num_ios) +{ + atomic_set(&wc->wc_num_reqs, num_ios); + init_completion(&wc->wc_io_complete); +} + +/* 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) +{ + struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping; + + blk_run_address_space(mapping); + + wait_for_completion(&wc->wc_io_complete); +} + +static int o2hb_bio_end_io(struct bio *bio, + unsigned int bytes_done, + int error) +{ + struct o2hb_bio_wait_ctxt *wc = bio->bi_private; + + if (error) + mlog(ML_ERROR, "IO Error %d\n", error); + + if (bio->bi_size) + return 1; + + o2hb_bio_wait_dec(wc, 1); + return 0; +} + +/* 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 start_slot, + unsigned int num_slots) +{ + int i, nr_vecs, len, first_page, last_page; + unsigned int vec_len, vec_start; + unsigned int bits = reg->hr_block_bits; + unsigned int spp = reg->hr_slots_per_page; + struct bio *bio; + struct page *page; + + nr_vecs = (num_slots + spp - 1) / spp; + + /* 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, nr_vecs); + 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_sector = (reg->hr_start_block + start_slot) << (bits - 9); + bio->bi_bdev = reg->hr_bdev; + bio->bi_private = wc; + bio->bi_end_io = o2hb_bio_end_io; + + first_page = start_slot / spp; + last_page = first_page + nr_vecs; + vec_start = (start_slot << bits) % PAGE_CACHE_SIZE; + for(i = first_page; i < last_page; i++) { + page = reg->hr_slot_data[i]; + + vec_len = PAGE_CACHE_SIZE; + /* last page might be short */ + if (((i + 1) * spp) > (start_slot + num_slots)) + vec_len = ((num_slots + start_slot) % spp) << bits; + vec_len -= vec_start; + + mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n", + i, vec_len, vec_start); + + len = bio_add_page(bio, page, vec_len, vec_start); + if (len != vec_len) { + bio_put(bio); + bio = ERR_PTR(-EIO); + + mlog(ML_ERROR, "Error adding page to bio i = %d, " + "vec_len = %u, len = %d\n, start = %u\n", + i, vec_len, len, vec_start); + goto bail; + } + + vec_start = 0; + } + +bail: + return bio; +} + +/* + * Compute the maximum number of sectors the bdev can handle in one bio, + * as a power of two. + * + * Stolen from oracleasm, thanks Joel! + */ +static int compute_max_sectors(struct block_device *bdev) +{ + int max_pages, max_sectors, pow_two_sectors; + + struct request_queue *q; + + q = bdev_get_queue(bdev); + max_pages = q->max_sectors >> (PAGE_SHIFT - 9); + if (max_pages > BIO_MAX_PAGES) + max_pages = BIO_MAX_PAGES; + if (max_pages > q->max_phys_segments) + max_pages = q->max_phys_segments; + if (max_pages > q->max_hw_segments) + max_pages = q->max_hw_segments; + max_pages--; /* Handle I/Os that straddle a page */ + + max_sectors = max_pages << (PAGE_SHIFT - 9); + + /* Why is fls() 1-based???? */ + pow_two_sectors = 1 << (fls(max_sectors) - 1); + + return pow_two_sectors; +} + +static inline void o2hb_compute_request_limits(struct o2hb_region *reg, + unsigned int num_slots, + unsigned int *num_bios, + unsigned int *slots_per_bio) +{ + unsigned int max_sectors, io_sectors; + + max_sectors = compute_max_sectors(reg->hr_bdev); + + io_sectors = num_slots << (reg->hr_block_bits - 9); + + *num_bios = (io_sectors + max_sectors - 1) / max_sectors; + *slots_per_bio = max_sectors >> (reg->hr_block_bits - 9); + + mlog(ML_HB_BIO, "My io size is %u sectors for %u slots. This " + "device can handle %u sectors of I/O\n", io_sectors, num_slots, + max_sectors); + mlog(ML_HB_BIO, "Will need %u bios holding %u slots each\n", + *num_bios, *slots_per_bio); +} + +static int o2hb_read_slots(struct o2hb_region *reg, + unsigned int max_slots) +{ + unsigned int num_bios, slots_per_bio, start_slot, num_slots; + int i, status; + struct o2hb_bio_wait_ctxt wc; + struct bio **bios; + struct bio *bio; + + o2hb_compute_request_limits(reg, max_slots, &num_bios, &slots_per_bio); + + bios = kcalloc(num_bios, sizeof(struct bio *), GFP_KERNEL); + if (!bios) { + status = -ENOMEM; + mlog_errno(status); + return status; + } + + o2hb_bio_wait_init(&wc, num_bios); + + num_slots = slots_per_bio; + for(i = 0; i < num_bios; i++) { + start_slot = i * slots_per_bio; + + /* adjust num_slots at last bio */ + if (max_slots < (start_slot + num_slots)) + num_slots = max_slots - start_slot; + + bio = o2hb_setup_one_bio(reg, &wc, start_slot, num_slots); + if (IS_ERR(bio)) { + o2hb_bio_wait_dec(&wc, num_bios - i); + + status = PTR_ERR(bio); + mlog_errno(status); + goto bail_and_wait; + } + bios[i] = bio; + + submit_bio(READ, bio); + } + + status = 0; + +bail_and_wait: + o2hb_wait_on_io(reg, &wc); + + if (bios) { + for(i = 0; i < num_bios; i++) + if (bios[i]) + bio_put(bios[i]); + kfree(bios); + } + + return status; +} + +static int o2hb_issue_node_write(struct o2hb_region *reg, + struct bio **write_bio, + struct o2hb_bio_wait_ctxt *write_wc) +{ + int status; + unsigned int slot; + struct bio *bio; + + o2hb_bio_wait_init(write_wc, 1); + + slot = o2nm_this_node(); + + bio = o2hb_setup_one_bio(reg, write_wc, slot, 1); + if (IS_ERR(bio)) { + status = PTR_ERR(bio); + mlog_errno(status); + goto bail; + } + + submit_bio(WRITE, bio); + + *write_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%"MLFx64", node = %u, " + "cksum = 0x%x, generation 0x%"MLFx64"\n", + le64_to_cpu(hb_block->hb_seq), hb_block->hb_node, + le32_to_cpu(hb_block->hb_cksum), + 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; +} + +/* We want to make sure that nobody is heartbeating on top of us -- + * this will help detect an invalid configuration. */ +static int o2hb_check_last_timestamp(struct o2hb_region *reg) +{ + int node_num, ret; + struct o2hb_disk_slot *slot; + struct o2hb_disk_heartbeat_block *hb_block; + + node_num = o2nm_this_node(); + + ret = 1; + slot = ®->hr_slots[node_num]; + /* Don't check on our 1st timestamp */ + if (slot->ds_last_time) { + hb_block = slot->ds_raw_block; + + if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time) + ret = 0; + } + + return ret; +} + +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); + + /* 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%"MLFx64", cksum = 0x%x\n", + cpu_to_le64(generation), le32_to_cpu(hb_block->hb_cksum)); +} + +static void o2hb_fire_callbacks(struct o2hb_callback *hbcall, + struct o2nm_node *node, + int idx) +{ + struct list_head *iter; + struct o2hb_callback_func *f; + + list_for_each(iter, &hbcall->list) { + f = list_entry(iter, struct o2hb_callback_func, 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) +{ + int empty; + struct o2hb_callback *hbcall; + struct o2hb_node_event *event; + + spin_lock(&o2hb_live_lock); + empty = list_empty(&queued_event->hn_item); + spin_unlock(&o2hb_live_lock); + if (empty) + return; + + /* 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); + + 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; + + 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); + } + } + spin_unlock(&o2hb_live_lock); + + o2hb_run_event_list(&event); + + o2nm_node_put(node); +} + +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; + + memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes); + + /* Is this correct? Do we assume that the node doesn't exist + * if we're not configured for him? */ + node = o2nm_get_node_by_num(slot->ds_node_num); + if (!node) + 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%"MLFx64" " + "to 0x%"MLFx64")\n", slot->ds_node_num, + slot->ds_last_generation, + 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%"MLFx64" cksum 0x%x " + "seq %"MLFu64" last %"MLFu64" changed %u equal %u\n", + slot->ds_node_num, slot->ds_last_generation, + le32_to_cpu(hb_block->hb_cksum), le64_to_cpu(hb_block->hb_seq), + 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%"MLFx64") joined my " + "region\n", slot->ds_node_num, slot->ds_last_generation); + + /* first on the list generates a callback */ + if (list_empty(&o2hb_live_slots[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; + } + + list_add_tail(&slot->ds_live_item, + &o2hb_live_slots[slot->ds_node_num]); + + slot->ds_equal_samples = 0; + 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); + + /* 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])) { + clear_bit(slot->ds_node_num, o2hb_live_node_bitmap); + + o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node, + slot->ds_node_num); + + changed = 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); + + o2hb_run_event_list(&event); + + o2nm_node_put(node); + return changed; +} + +/* This could be faster if we just implmented a find_last_bit, but I + * don't think the circumstances warrant it. */ +static int o2hb_highest_node(unsigned long *nodes, + int numbits) +{ + int highest, node; + + highest = numbits; + node = -1; + while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) { + if (node >= numbits) + break; + + highest = node; + } + + return highest; +} + +static void o2hb_do_disk_heartbeat(struct o2hb_region *reg) +{ + int i, ret, highest_node, change = 0; + unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)]; + struct bio *write_bio; + struct o2hb_bio_wait_ctxt write_wc; + + if (o2nm_configured_node_map(configured_nodes, sizeof(configured_nodes))) + return; + + highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES); + if (highest_node >= O2NM_MAX_NODES) { + mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n"); + return; + } + + /* 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); + return; + } + + /* 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. */ + if (!o2hb_check_last_timestamp(reg)) + mlog(ML_ERROR, "Device \"%s\": another node is heartbeating " + "in our slot!\n", reg->hr_dev_name); + + /* fill in the proper info for our next heartbeat */ + o2hb_prepare_block(reg, reg->hr_generation); + + /* And fire off the write. Note that we don't wait on this I/O + * until later. */ + ret = o2hb_issue_node_write(reg, &write_bio, &write_wc); + if (ret < 0) { + mlog_errno(ret); + return; + } + + i = -1; + while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) { + + 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); + bio_put(write_bio); + o2hb_arm_write_timeout(reg); + + /* let the person who launched us know when things are steady */ + if (!change && (atomic_read(®->hr_steady_iterations) != 0)) { + if (atomic_dec_and_test(®->hr_steady_iterations)) + wake_up(&o2hb_steady_queue); + } +} + +/* 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 bio *write_bio; + 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, -20); + + while (!kthread_should_stop() && !reg->hr_unclean_stop) { + /* We track the time spent inside + * o2hb_do_disk_heartbeat so that we avoid more then + * 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); + + o2hb_do_disk_heartbeat(reg); + + do_gettimeofday(&after_hb); + elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb); + + mlog(0, "start = %lu.%lu, end = %lu.%lu, msec = %u\n", + before_hb.tv_sec, before_hb.tv_usec, + after_hb.tv_sec, after_hb.tv_usec, elapsed_msec); + + if (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. + * + * XXX: Should we skip this on unclean_stop? */ + o2hb_prepare_block(reg, 0); + ret = o2hb_issue_node_write(reg, &write_bio, &write_wc); + if (ret == 0) { + o2hb_wait_on_io(reg, &write_wc); + bio_put(write_bio); + } else { + mlog_errno(ret); + } + + mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n"); + + return 0; +} + +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)); +} + +/* 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); + + if (reg->hr_tmp_block) + 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); + + if (reg->hr_slots) + kfree(reg->hr_slots); + + 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; + + mlog_entry_void(); + + 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: + mlog_exit(ret); + 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) +{ + long fd; + int sectsize; + char *p = (char *)page; + struct file *filp = NULL; + struct inode *inode = NULL; + ssize_t ret = -EINVAL; + + 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; + + filp = fget(fd); + if (filp == NULL) + goto out; + + if (reg->hr_blocks == 0 || reg->hr_start_block == 0 || + reg->hr_block_bytes == 0) + goto out; + + inode = igrab(filp->f_mapping->host); + if (inode == NULL) + goto out; + + if (!S_ISBLK(inode->i_mode)) + goto out; + + reg->hr_bdev = I_BDEV(filp->f_mapping->host); + ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, 0); + if (ret) { + reg->hr_bdev = NULL; + goto out; + } + inode = NULL; + + bdevname(reg->hr_bdev, reg->hr_dev_name); + + sectsize = bdev_hardsect_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 out; + } + + 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 out; + } + + ret = o2hb_populate_slot_data(reg); + if (ret) { + mlog_errno(ret); + goto out; + } + + INIT_WORK(®->hr_write_timeout_work, o2hb_write_timeout, reg); + + /* + * 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. + */ + atomic_set(®->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1); + + reg->hr_task = kthread_run(o2hb_thread, reg, "o2hb-%s", + reg->hr_item.ci_name); + if (IS_ERR(reg->hr_task)) { + ret = PTR_ERR(reg->hr_task); + mlog_errno(ret); + reg->hr_task = NULL; + goto out; + } + + ret = wait_event_interruptible(o2hb_steady_queue, + atomic_read(®->hr_steady_iterations) == 0); + if (ret) { + kthread_stop(reg->hr_task); + reg->hr_task = NULL; + goto out; + } + + ret = count; +out: + if (filp) + fput(filp); + if (inode) + iput(inode); + if (ret < 0) { + if (reg->hr_bdev) { + blkdev_put(reg->hr_bdev); + reg->hr_bdev = NULL; + } + } + return ret; +} + +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 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, + 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 struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group, + const char *name) +{ + struct o2hb_region *reg = NULL; + struct config_item *ret = NULL; + + reg = kcalloc(1, sizeof(struct o2hb_region), GFP_KERNEL); + if (reg == NULL) + goto out; /* ENOMEM */ + + config_item_init_type_name(®->hr_item, name, &o2hb_region_type); + + ret = ®->hr_item; + + spin_lock(&o2hb_live_lock); + list_add_tail(®->hr_all_item, &o2hb_all_regions); + spin_unlock(&o2hb_live_lock); +out: + if (ret == NULL) + kfree(reg); + + return ret; +} + +static void o2hb_heartbeat_group_drop_item(struct config_group *group, + struct config_item *item) +{ + struct o2hb_region *reg = to_o2hb_region(item); + + /* stop the thread when the user removes the region dir */ + if (reg->hr_task) { + kthread_stop(reg->hr_task); + reg->hr_task = NULL; + } + + config_item_put(item); +} + +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 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 configfs_attribute *o2hb_heartbeat_group_attrs[] = { + &o2hb_heartbeat_group_attr_threshold.attr, + NULL, +}; + +static struct configfs_item_operations o2hb_hearbeat_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_hearbeat_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 = kcalloc(1, 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 issueing */ + +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); + +int o2hb_register_callback(struct o2hb_callback_func *hc) +{ + struct o2hb_callback_func *tmp; + struct list_head *iter; + 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; + } + + down_write(&o2hb_callback_sem); + + list_for_each(iter, &hbcall->list) { + tmp = list_entry(iter, struct o2hb_callback_func, hc_item); + if (hc->hc_priority < tmp->hc_priority) { + list_add_tail(&hc->hc_item, iter); + 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_HEARTBEAT, "returning %d on behalf of %p for funcs %p\n", + ret, __builtin_return_address(0), hc); + return ret; +} +EXPORT_SYMBOL_GPL(o2hb_register_callback); + +int o2hb_unregister_callback(struct o2hb_callback_func *hc) +{ + BUG_ON(hc->hc_magic != O2HB_CB_MAGIC); + + mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n", + __builtin_return_address(0), hc); + + if (list_empty(&hc->hc_item)) + return 0; + + down_write(&o2hb_callback_sem); + + list_del_init(&hc->hc_item); + + up_write(&o2hb_callback_sem); + + return 0; +} +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_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); |