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linux-next/fs/ocfs2/cluster/heartbeat.c
Joel Becker a6795e9ebb configfs: Allow ->make_item() and ->make_group() to return detailed errors. 
The configfs operations ->make_item() and ->make_group() currently
return a new item/group.  A return of NULL signifies an error.  Because
of this, -ENOMEM is the only return code bubbled up the stack.

Multiple folks have requested the ability to return specific error codes
when these operations fail.  This patch adds that ability by changing the
->make_item/group() ops to return ERR_PTR() values.  These errors are
bubbled up appropriately.  NULL returns are changed to -ENOMEM for
compatibility.

Also updated are the in-kernel users of configfs.

This is a rework of reverted commit 11c3b79218.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2008-07-17 15:21:29 -07:00

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/* -*- 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 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);
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 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)
{
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));
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(&reg->hr_write_timeout_work);
reg->hr_last_timeout_start = jiffies;
schedule_delayed_work(&reg->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(&reg->hr_write_timeout_work);
flush_scheduled_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)
{
struct address_space *mapping = reg->hr_bdev->bd_inode->i_mapping;
blk_run_address_space(mapping);
o2hb_bio_wait_dec(wc, 1);
wait_for_completion(&wc->wc_io_complete);
}
static void o2hb_bio_end_io(struct bio *bio,
int error)
{
struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
if (error) {
mlog(ML_ERROR, "IO Error %d\n", error);
wc->wc_error = 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_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, &current_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, 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;
}
/* 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 = &reg->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 = &reg->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 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;
unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
unsigned int slot_dead_ms;
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%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);
/* 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;
/* 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);
/* 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 int 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 o2hb_bio_wait_ctxt write_wc;
ret = o2nm_configured_node_map(configured_nodes,
sizeof(configured_nodes));
if (ret) {
mlog_errno(ret);
return ret;
}
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 -EINVAL;
}
/* 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 ret;
}
/* 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_wc);
if (ret < 0) {
mlog_errno(ret);
return ret;
}
i = -1;
while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
change |= o2hb_check_slot(reg, &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);
return write_wc.wc_error;
}
o2hb_arm_write_timeout(reg);
/* let the person who launched us know when things are steady */
if (!change && (atomic_read(&reg->hr_steady_iterations) != 0)) {
if (atomic_dec_and_test(&reg->hr_steady_iterations))
wake_up(&o2hb_steady_queue);
}
return 0;
}
/* 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, -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);
i = 0;
do {
ret = o2hb_do_disk_heartbeat(reg);
} while (ret && ++i < 2);
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, (unsigned long) before_hb.tv_usec,
after_hb.tv_sec, (unsigned long) 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(&reg->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_wc);
if (ret == 0) {
o2hb_wait_on_io(reg, &write_wc);
} 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(&reg->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 = &reg->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 = &reg->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 = &reg->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)
{
struct task_struct *hb_task;
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(&reg->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_DELAYED_WORK(&reg->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.
*/
atomic_set(&reg->hr_steady_iterations, O2HB_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 out;
}
spin_lock(&o2hb_live_lock);
reg->hr_task = hb_task;
spin_unlock(&o2hb_live_lock);
ret = wait_event_interruptible(o2hb_steady_queue,
atomic_read(&reg->hr_steady_iterations) == 0);
if (ret) {
/* We got interrupted (hello ptrace!). Clean up */
spin_lock(&o2hb_live_lock);
hb_task = reg->hr_task;
reg->hr_task = NULL;
spin_unlock(&o2hb_live_lock);
if (hb_task)
kthread_stop(hb_task);
goto out;
}
/* Ok, we were woken. Make sure it wasn't by drop_item() */
spin_lock(&o2hb_live_lock);
hb_task = reg->hr_task;
spin_unlock(&o2hb_live_lock);
if (hb_task)
ret = count;
else
ret = -EIO;
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;
}
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 struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
const char *name)
{
struct o2hb_region *reg = NULL;
reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
if (reg == NULL)
return ERR_PTR(-ENOMEM);
config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
spin_lock(&o2hb_live_lock);
list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
spin_unlock(&o2hb_live_lock);
return &reg->hr_item;
}
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);
/* stop the thread when the user removes the region dir */
spin_lock(&o2hb_live_lock);
hb_task = reg->hr_task;
reg->hr_task = NULL;
spin_unlock(&o2hb_live_lock);
if (hb_task)
kthread_stop(hb_task);
/*
* If we're racing a dev_write(), we need to wake them. They will
* check reg->hr_task
*/
if (atomic_read(&reg->hr_steady_iterations) != 0) {
atomic_set(&reg->hr_steady_iterations, 0);
wake_up(&o2hb_steady_queue);
}
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 = 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 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);
static struct o2hb_region *o2hb_find_region(const char *region_uuid)
{
struct o2hb_region *p, *reg = NULL;
assert_spin_locked(&o2hb_live_lock);
list_for_each_entry(p, &o2hb_all_regions, hr_all_item) {
if (!strcmp(region_uuid, config_item_name(&p->hr_item))) {
reg = p;
break;
}
}
return reg;
}
static int o2hb_region_get(const char *region_uuid)
{
int ret = 0;
struct o2hb_region *reg;
spin_lock(&o2hb_live_lock);
reg = o2hb_find_region(region_uuid);
if (!reg)
ret = -ENOENT;
spin_unlock(&o2hb_live_lock);
if (ret)
goto out;
ret = o2nm_depend_this_node();
if (ret)
goto out;
ret = o2nm_depend_item(&reg->hr_item);
if (ret)
o2nm_undepend_this_node();
out:
return ret;
}
static void o2hb_region_put(const char *region_uuid)
{
struct o2hb_region *reg;
spin_lock(&o2hb_live_lock);
reg = o2hb_find_region(region_uuid);
spin_unlock(&o2hb_live_lock);
if (reg) {
o2nm_undepend_item(&reg->hr_item);
o2nm_undepend_this_node();
}
}
int o2hb_register_callback(const char *region_uuid,
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;
}
if (region_uuid) {
ret = o2hb_region_get(region_uuid);
if (ret)
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);
void o2hb_unregister_callback(const char *region_uuid,
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);
/* XXX Can this happen _with_ a region reference? */
if (list_empty(&hc->hc_item))
return;
if (region_uuid)
o2hb_region_put(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_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);
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