[Ocfs2-devel] [patch 19/25] ocfs2: o2hb: add negotiate timer
jiangyiwen
jiangyiwen at huawei.com
Fri Mar 25 19:54:01 PDT 2016
On 2016/3/24 10:50, Junxiao Bi wrote:
> This is v1 version, I sent out V2 patch set before to fix all code style
> issue.
>
> On 03/24/2016 04:12 AM, akpm at linux-foundation.org wrote:
>> From: Junxiao Bi <junxiao.bi at oracle.com>
>> Subject: ocfs2: o2hb: add negotiate timer
>>
>> This series of patches is to fix the issue that when storage down, all
>> nodes will fence self due to write timeout.
>>
>> With this patch set, all nodes will keep going until storage back online,
>> except if the following issue happens, then all nodes will do as before to
>> fence self.
>>
>> 1. io error got
>> 2. network between nodes down
>> 3. nodes panic
>>
>>
>> This patch (of 6):
>>
>> When storage down, all nodes will fence self due to write timeout. The
>> negotiate timer is designed to avoid this, with it node will wait until
>> storage up again.
>>
>> Negotiate timer working in the following way:
>>
>> 1. The timer expires before write timeout timer, its timeout is half
>> of write timeout now. It is re-queued along with write timeout timer.
>> If expires, it will send NEGO_TIMEOUT message to master node(node with
>> lowest node number). This message does nothing but marks a bit in a
>> bitmap recording which nodes are negotiating timeout on master node.
>>
>> 2. If storage down, nodes will send this message to master node, then
>> when master node finds its bitmap including all online nodes, it sends
>> NEGO_APPROVL message to all nodes one by one, this message will
>> re-queue write timeout timer and negotiate timer. For any node doesn't
>> receive this message or meets some issue when handling this message, it
>> will be fenced. If storage up at any time, o2hb_thread will run and
>> re-queue all the timer, nothing will be affected by these two steps.
>>
>> Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>
>> Reviewed-by: Ryan Ding <ryan.ding at oracle.com>
>> Cc: Gang He <ghe at suse.com>
>> Cc: rwxybh <rwxybh at 126.com>
>> Cc: Mark Fasheh <mfasheh at suse.de>
>> Cc: Joel Becker <jlbec at evilplan.org>
>> Cc: Joseph Qi <joseph.qi at huawei.com>
>> Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
>> ---
>>
>> fs/ocfs2/cluster/heartbeat.c | 52 ++++++++++++++++++++++++++++++---
>> 1 file changed, 48 insertions(+), 4 deletions(-)
>>
>> diff -puN fs/ocfs2/cluster/heartbeat.c~ocfs2-o2hb-add-negotiate-timer fs/ocfs2/cluster/heartbeat.c
>> --- a/fs/ocfs2/cluster/heartbeat.c~ocfs2-o2hb-add-negotiate-timer
>> +++ a/fs/ocfs2/cluster/heartbeat.c
>> @@ -272,6 +272,10 @@ struct o2hb_region {
>> struct delayed_work hr_write_timeout_work;
>> unsigned long hr_last_timeout_start;
>>
>> + /* negotiate timer, used to negotiate extending hb timeout. */
>> + struct delayed_work hr_nego_timeout_work;
>> + unsigned long hr_nego_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
>> +
>> /* Used during o2hb_check_slot to hold a copy of the block
>> * being checked because we temporarily have to zero out the
>> * crc field. */
>> @@ -319,7 +323,7 @@ static void o2hb_write_timeout(struct wo
>> o2quo_disk_timeout();
>> }
>>
>> -static void o2hb_arm_write_timeout(struct o2hb_region *reg)
>> +static void o2hb_arm_timeout(struct o2hb_region *reg)
>> {
>> /* Arm writeout only after thread reaches steady state */
>> if (atomic_read(®->hr_steady_iterations) != 0)
>> @@ -337,11 +341,50 @@ static void o2hb_arm_write_timeout(struc
>> reg->hr_last_timeout_start = jiffies;
>> schedule_delayed_work(®->hr_write_timeout_work,
>> msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
>> +
>> + cancel_delayed_work(®->hr_nego_timeout_work);
>> + /* negotiate timeout must be less than write timeout. */
>> + schedule_delayed_work(®->hr_nego_timeout_work,
>> + msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS)/2);
>> + memset(reg->hr_nego_node_bitmap, 0, sizeof(reg->hr_nego_node_bitmap));
>> }
>>
>> -static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
>> +static void o2hb_disarm_timeout(struct o2hb_region *reg)
>> {
>> cancel_delayed_work_sync(®->hr_write_timeout_work);
>> + cancel_delayed_work_sync(®->hr_nego_timeout_work);
>> +}
>> +
>> +static void o2hb_nego_timeout(struct work_struct *work)
>> +{
>> + struct o2hb_region *reg =
>> + container_of(work, struct o2hb_region,
>> + hr_nego_timeout_work.work);
>> + unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
>> + int master_node;
>> +
>> + o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
>> + /* lowest node as master node to make negotiate decision. */
>> + master_node = find_next_bit(live_node_bitmap, O2NM_MAX_NODES, 0);
>> +
>> + if (master_node == o2nm_this_node()) {
>> + set_bit(master_node, reg->hr_nego_node_bitmap);
>> + if (memcmp(reg->hr_nego_node_bitmap, live_node_bitmap,
>> + sizeof(reg->hr_nego_node_bitmap))) {
>> + /* check negotiate bitmap every second to do timeout
>> + * approve decision.
>> + */
>> + schedule_delayed_work(®->hr_nego_timeout_work,
>> + msecs_to_jiffies(1000));
>> +
>> + return;
>> + }
>> +
>> + /* approve negotiate timeout request. */
>> + } else {
>> + /* negotiate timeout with master node. */
>> + }
>> +
>> }
>>
>> static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
>> @@ -1032,7 +1075,7 @@ static int o2hb_do_disk_heartbeat(struct
>> /* Skip disarming the timeout if own slot has stale/bad data */
>> if (own_slot_ok) {
>> o2hb_set_quorum_device(reg);
>> - o2hb_arm_write_timeout(reg);
>> + o2hb_arm_timeout(reg);
>> }
>>
>> bail:
>> @@ -1114,7 +1157,7 @@ static int o2hb_thread(void *data)
>> }
>> }
>>
>> - o2hb_disarm_write_timeout(reg);
>> + o2hb_disarm_timeout(reg);
>>
>> /* unclean stop is only used in very bad situation */
>> for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
>> @@ -1763,6 +1806,7 @@ static ssize_t o2hb_region_dev_store(str
>> }
>>
>> INIT_DELAYED_WORK(®->hr_write_timeout_work, o2hb_write_timeout);
>> + INIT_DELAYED_WORK(®->hr_nego_timeout_work, o2hb_nego_timeout);
>>
>> /*
>> * A node is considered live after it has beat LIVE_THRESHOLD
>> _
>>
>
>
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> .
>
Hi, Junxiao
This patch may have a problem. That is journal of every nodes become
abort when storage down, and then when storage up, because journal
has become abort, all of operations of metadata will fail. So how to
restore environment? panic or reset? how to trigger?
Thanks,
Yiwen Jiang.
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