Commit Graph

58 Commits

Author SHA1 Message Date
Goldwyn Rodrigues
54a88392cd md-cluster: Fix the remove sequence with the new MD reload code
The remove disk message does not need metadata_update_start(), but
can be an independent message.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:38:42 +11:00
Guoqing Jiang
659b254fa7 md-cluster: remove a disk asynchronously from cluster environment
For cluster raid, if one disk couldn't be reach in one node, then
other nodes would receive the REMOVE message for the disk.

In receiving node, we can't call md_kick_rdev_from_array to remove
the disk from array synchronously since the disk might still be busy
in this node. So let's set a ClusterRemove flag on the disk, then
let the thread to do the removal job eventually.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:38:36 +11:00
Goldwyn Rodrigues
ac277c6a8a md-cluster: Avoid the resync ping-pong
If a RESYNCING message with (0,0) has been sent before, do not send it
again. This avoids a resync ping pong between the nodes. We read
the bitmap lockresource's LVB to figure out the previous value
of the RESYNCING message.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:38:27 +11:00
NeilBrown
30661b49be md-cluster: remove mddev arg from add_resync_info()
The arg isn't used, so its presence is only confusing.

Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24 17:16:18 +11:00
NeilBrown
2e2a7cd96f md-cluster: don't cast void pointers when assigning them.
It is common practice in the kernel to leave out this case.
It isn't needed and adds little if any value.

Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24 17:16:18 +11:00
NeilBrown
823815238f md-cluster: discard unused sb_mutex.
Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24 17:16:18 +11:00
Guoqing Jiang
cf97a348c8 md-cluster: Fix warnings when build with CF=-D__CHECK_ENDIAN__
This patches fixes sparse warnings like incorrect type in assignment
(different base types), cast to restricted __le64.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-24 17:16:18 +11:00
NeilBrown
ba2746b0fa md-cluster: metadata_update_finish: consistently use cmsg.raid_slot as le32
As cmsg.raid_slot is le32, comparing for >0 is not meaningful.

So introduce cpu-endian 'raid_slot' and only assign to cmsg.raid_slot
when we know value is valid.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-16 13:48:35 +11:00
Guoqing Jiang
86b572770e md-cluster: Add 'SUSE' as author for md-cluster.c
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
2015-10-12 11:58:15 -05:00
Guoqing Jiang
aee177ac5a md-cluster: zero cmsg before it was sent
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
2015-10-12 11:58:15 -05:00
Guoqing Jiang
256f5b245a md-cluster: make sure the node do not receive it's own msg
During the past test, the node occasionally received the msg which is
sent from itself, this case should not happen in theory, but it is
better to avoid it in case something wrong happened.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 11:58:14 -05:00
Guoqing Jiang
487cf9142c md-cluster: remove unnecessary setting for slot
Since slot will be set within _sendmsg, we can remove
the redundant code in resync_info_update.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
2015-10-12 11:58:14 -05:00
Guoqing Jiang
faeff83fa4 md-cluster: make other members of cluster_msg is handled by little endian funcs
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
2015-10-12 11:58:14 -05:00
Goldwyn Rodrigues
d216711bed md-cluster: Do not printk() every received message
The receive daemon prints kernel messages for every network message
received. This would fill the kernel message log with unnecessary messages.
Remove the pr_info() messages.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 11:58:00 -05:00
Goldwyn Rodrigues
dbb64f8635 md-cluster: Fix adding of new disk with new reload code
Adding the disk worked incorrectly with the new reload code. Fix it:

 - No operation should be performed on rdev marked as Candidate
 - After a metadata update operation, kick disk if role is 0xfffe
   else clear Candidate bit and continue with the regular change check.
 - Saving the mode of the lock resource to check if token lock is already
   locked, because it can be called twice while adding a disk. However,
   unlock_comm() must be called only once.
 - add_new_disk() is called by the node initiating the --add operation.
   If it needs to be canceled, call add_new_disk_cancel(). The operation
   is completed by md_update_sb() which will write and unlock the
   communication.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 03:35:30 -05:00
Goldwyn Rodrigues
c186b128cd md-cluster: Perform resync/recovery under a DLM lock
Resync or recovery must be performed by only one node at a time.
A DLM lock resource, resync_lockres provides the mutual exclusion
so that only one node performs the recovery/resync at a time.

If a node is unable to get the resync_lockres, because recovery is
being performed by another node, it set MD_RECOVER_NEEDED so as
to schedule recovery in the future.

Remove the debug message in resync_info_update()
used during development.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 03:32:44 -05:00
Goldwyn Rodrigues
70bcecdb15 md-cluster: Improve md_reload_sb to be less error prone
md_reload_sb is too simplistic and it explicitly needs to determine
the changes made by the writing node. However, there are multiple areas
where a simple reload could fail.

Instead, read the superblock of one of the "good" rdevs and update
the necessary information:

- read the superblock into a newly allocated page, by temporarily
  swapping out rdev->sb_page and calling ->load_super.
- if that fails return
- if it succeeds, call check_sb_changes
  1. iterates over list of active devices and checks the matching
   dev_roles[] value.
   	If that is 'faulty', the device must be  marked as faulty
	 - call md_error to mark the device as faulty. Make sure
	   not to set CHANGE_DEVS and wakeup mddev->thread or else
	   it would initiate a resync process, which is the responsibility
	   of the "primary" node.
	 - clear the Blocked bit
	 - Call remove_and_add_spares() to hot remove the device.
	If the device is 'spare':
	 - call remove_and_add_spares() to get the number of spares
	   added in this operation.
	 - Reduce mddev->degraded to mark the array as not degraded.
  2. reset recovery_cp
- read the rest of the rdevs to update recovery_offset. If recovery_offset
  is equal to MaxSector, call spare_active() to set it In_sync

This required that recovery_offset be initialized to MaxSector, as
opposed to zero so as to communicate the end of sync for a rdev.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 01:34:48 -05:00
Goldwyn Rodrigues
b8ca846e45 md-cluster: Wake up suspended process
When the suspended_area is deleted, the suspended processes
must be woken up in order to complete their I/O.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-10-12 01:33:35 -05:00
Guoqing Jiang
099954119d md-cluster: send BITMAP_NEEDS_SYNC when node is leaving cluster
Previously, BITMAP_NEEDS_SYNC message is sent when the resyc
aborts, but it could abort for different reasons, and not all
of reasons require another node to take over the resync ownship.

It is better make BITMAP_NEEDS_SYNC message only be sent when
the node is leaving cluster with dirty bitmap. And we also need
to ensure dlm connection is ok.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-12 01:32:27 -05:00
Goldwyn Rodrigues
c40f341f1e md-cluster: Use a small window for resync
Suspending the entire device for resync could take too long. Resync
in small chunks.

cluster's resync window (32M) is maintained in r1conf as
cluster_sync_low and cluster_sync_high and processed in
raid1's sync_request(). If the current resync is outside the cluster
resync window:

1. Set the cluster_sync_low to curr_resync_completed.
2. Check if the sync will fit in the new window, if not issue a
   wait_barrier() and set cluster_sync_low to sector_nr.
3. Set cluster_sync_high to cluster_sync_low + resync_window.
4. Send a message to all nodes so they may add it in their suspension
   list.

bitmap_cond_end_sync is modified to allow to force a sync inorder
to get the curr_resync_completed uptodate with the sector passed.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-10-12 01:32:05 -05:00
Goldwyn Rodrigues
9ed38ff530 md-cluster: complete all write requests before adding suspend_info
process_suspend_info - which handles the RESYNCING request - must not
reply until all writes which were initiated before the request arrived,
have completed.

As a by-product, all process_* functions now take mddev as their
first arguement making it uniform.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-12 01:29:59 -05:00
NeilBrown
18b9f67962 md-cluster: remove inappropriate try_module_get from join()
md_setup_cluster already calls try_module_get(), so this
try_module_get isn't needed.
Also, there is no matching module_put (except in error patch),
so this leaves an unbalanced module count.

Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:43:17 +02:00
Guoqing Jiang
abb9b22ac9 md-cluster: Read the disk bitmap sb and check if it needs recovery
In gather_all_resync_info, we need to read the disk bitmap sb and
check if it needs recovery.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:42:41 +02:00
Guoqing Jiang
eece075cda md-cluster: only call complete(&cinfo->completion) when node join cluster
Introduce MD_CLUSTER_BEGIN_JOIN_CLUSTER flag to make sure
complete(&cinfo->completion) is only be invoked when node
join cluster. Otherwise node failure could also call the
complete, and it doesn't make sense to do it.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:42:31 +02:00
Guoqing Jiang
6e6d9f2cda md-cluster: add missed lockres_free
We also need to free the lock resource before goto out.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:42:23 +02:00
Guoqing Jiang
b2b9bfff0a md-cluster: remove the unused sb_lock
The sb_lock is not used anywhere, so let's remove it.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:42:14 +02:00
Guoqing Jiang
9e3072e373 md-cluster: init suspend_list and suspend_lock early in join
If the node just join the cluster, and receive the msg from other nodes
before init suspend_list, it will cause kernel crash due to NULL pointer
dereference, so move the initializations early to fix the bug.

md-cluster: Joined cluster 3578507b-e0cb-6d4f-6322-696cd7b1b10c slot 3
BUG: unable to handle kernel NULL pointer dereference at           (null)
... ... ...
Call Trace:
[<ffffffffa0444924>] process_recvd_msg+0x2e4/0x330 [md_cluster]
[<ffffffffa0444a06>] recv_daemon+0x96/0x170 [md_cluster]
[<ffffffffa045189d>] md_thread+0x11d/0x170 [md_mod]
[<ffffffff810768c4>] kthread+0xb4/0xc0
[<ffffffff8151927c>] ret_from_fork+0x7c/0xb0
... ... ...
RIP  [<ffffffffa0443581>] __remove_suspend_info+0x11/0xa0 [md_cluster]

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:42:05 +02:00
Guoqing Jiang
b5ef56789b md-cluster: add the error check if failed to get dlm lock
In complicated cluster environment, it is possible that the
dlm lock couldn't be get/convert on purpose, the related err
info is added for better debug potential issue.

For lockres_free, if the lock is blocking by a lock request or
conversion request, then dlm_unlock just put it back to grant
queue, so need to ensure the lock is free finally.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:41:56 +02:00
Guoqing Jiang
b83d51c078 md-cluster: init completion within lockres_init
We should init completion within lockres_init, otherwise
completion could be initialized more than one time during
it's life cycle.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:41:50 +02:00
Guoqing Jiang
66099bb0ee md-cluster: fix deadlock issue on message lock
There is problem with previous communication mechanism, and we got below
deadlock scenario with cluster which has 3 nodes.

	Sender                	    Receiver        		Receiver

	token(EX)
       message(EX)
      writes message
   downconverts message(CR)
      requests ack(EX)
		                  get message(CR)            gets message(CR)
                		  reads message                reads message
		               requests EX on message    requests EX on message

To fix this problem, we do the following changes:

1. the sender downconverts MESSAGE to CW rather than CR.
2. and the receiver request PR lock not EX lock on message.

And in case we failed to down-convert EX to CW on message, it is better to
unlock message otherthan still hold the lock.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Lidong Zhong <ldzhong@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:41:41 +02:00
Guoqing Jiang
dc737d7c3d md-cluster: transfer the resync ownership to another node
When node A stops an array while the array is doing a resync, we need
to let another node B take over the resync task.

To achieve the goal, we need the A send an explicit BITMAP_NEEDS_SYNC
message to the cluster. And the node B which received that message will
invoke __recover_slot to do resync.

Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:41:12 +02:00
Guoqing Jiang
05cd0e5176 md-cluster: split recover_slot for future code reuse
Make recover_slot as a wraper to __recover_slot, since the
logic of __recover_slot can be reused for the condition
when other nodes need to take over the resync job.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:40:41 +02:00
Guoqing Jiang
b89f704a8d md-cluster: use %pU to print UUIDs
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31 19:40:30 +02:00
Goldwyn Rodrigues
90382ed9af Fix read-balancing during node failure
During a node failure, We need to suspend read balancing so that the
reads are directed to the first device and stale data is not read.
Suspending writes is not required because these would be recorded and
synced eventually.

A new flag MD_CLUSTER_SUSPEND_READ_BALANCING is set in recover_prep().
area_resyncing() will respond true for the entire devices if this
flag is set and the request type is READ. The flag is cleared
in recover_done().

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reported-By: David Teigland <teigland@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-07-24 13:37:59 +10:00
Goldwyn Rodrigues
97f6cd39da md-cluster: re-add capabilities
When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state,
the clustered md:

1. Sends RE_ADD message with the desc_nr. Nodes receiving the message
   clear the Faulty bit in their respective rdev->flags.
2. The node initiating re-add, gathers the bitmaps of all nodes
   and copies them into the local bitmap. It does not clear the bitmap
   from which it is copying.
3. Initiating node schedules a md recovery to sync the devices.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 07:59:39 +10:00
Goldwyn Rodrigues
88bcfef7be md-cluster: remove capabilities
This adds "remove" capabilities for the clustered environment.
When a user initiates removal of a device from the array, a
REMOVE message with disk number in the array is sent to all
the nodes which kick the respective device in their own array.

This facilitates the removal of failed devices.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 07:59:39 +10:00
Guoqing Jiang
8c58f02e24 md-cluster: correct the num for comparison
Since the node num of md-cluster is from zero, and
cinfo->slot_number represents the slot num of dlm,
no need to check for equality.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 07:58:31 +10:00
kbuild test robot
09dd1af2e0 md/cluster: Communication Framework: fix semicolon.cocci warnings
drivers/md/md-cluster.c:328:2-3: Unneeded semicolon

 Removes unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-21 10:33:00 +11:00
kbuild test robot
6dc69c9c46 md: recover_bitmaps() can be static
drivers/md/md-cluster.c:190:6: sparse: symbol 'recover_bitmaps' was not declared. Should it be static?

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-21 10:33:00 +11:00
Goldwyn Rodrigues
fa8259da0e md: Fix stray --cluster-confirm crash
A --cluster-confirm without an --add (by another node) can
crash the kernel.

Fix it by guarding it using a state.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-21 10:33:00 +11:00
Goldwyn Rodrigues
1aee41f637 Add new disk to clustered array
Algorithm:
1. Node 1 issues mdadm --manage /dev/mdX --add /dev/sdYY which issues
   ioctl(ADD_NEW_DISC with disc.state set to MD_DISK_CLUSTER_ADD)
2. Node 1 sends NEWDISK with uuid and slot number
3. Other nodes issue kobject_uevent_env with uuid and slot number
(Steps 4,5 could be a udev rule)
4. In userspace, the node searches for the disk, perhaps
   using blkid -t SUB_UUID=""
5. Other nodes issue either of the following depending on whether the disk
   was found:
   ioctl(ADD_NEW_DISK with disc.state set to MD_DISK_CANDIDATE and
	 disc.number set to slot number)
   ioctl(CLUSTERED_DISK_NACK)
6. Other nodes drop lock on no-new-devs (CR) if device is found
7. Node 1 attempts EX lock on no-new-devs
8. If node 1 gets the lock, it sends METADATA_UPDATED after unmarking the disk
   as SpareLocal
9. If not (get no-new-dev lock), it fails the operation and sends METADATA_UPDATED
10. Other nodes understand if the device is added or not by reading the superblock again after receiving the METADATA_UPDATED message.

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:07 -06:00
Goldwyn Rodrigues
589a1c4916 Suspend writes in RAID1 if within range
If there is a resync going on, all nodes must suspend writes to the
range. This is recorded in the suspend_info/suspend_list.

If there is an I/O within the ranges of any of the suspend_info,
should_suspend will return 1.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:07 -06:00
Goldwyn Rodrigues
e59721ccdc Resync start/Finish actions
When a RESYNC_START message arrives, the node removes the entry
with the current slot number and adds the range to the
suspend_list.

Simlarly, when a RESYNC_FINISHED message is received, node clears
entry with respect to the bitmap number.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:07 -06:00
Goldwyn Rodrigues
965400eb61 Send RESYNCING while performing resync start/stop
When a resync is initiated, RESYNCING message is sent to all active
nodes with the range (lo,hi). When the resync is over, a RESYNCING
message is sent with (0,0). A high sector value of zero indicates
that the resync is over.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
1d7e3e9611 Reload superblock if METADATA_UPDATED is received
Re-reads the devices by invalidating the cache.
Since we don't write to faulty devices, this is detected using
events recorded in the devices. If it is old as compared to the mddev
mark it is faulty.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
293467aa1f metadata_update sends message to other nodes
- request to send a message
   - make changes to superblock
   - send messages telling everyone that the superblock has changed
   - other nodes all read the superblock
   - other nodes all ack the messages
   - updating node release the "I'm sending a message" resource.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
601b515c5d Communication Framework: Sending functions
The sending part is split in two functions to make sure
atomicity of the operations, such as the MD superblock update.

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
4664680c38 Communication Framework: Receiving
1. receive status

   sender                         receiver                   receiver
   ACK:CR                          ACK:CR                     ACK:CR

2. sender get EX of TOKEN
   sender get EX of MESSAGE
   sender                          receiver                   receiver
   TOKEN:EX                         ACK:CR                     ACK:CR
   MESSAGE:EX
   ACK:CR

3. sender write LVB.
   sender down-convert MESSAGE from EX to CR
   sender try to get EX of ACK
   [ wait until all receiver has *processed* the MESSAGE ]

                                     [ triggered by bast of ACK ]
                                     receiver get CR of MESSAGE
                                     receiver read LVB
                                     receiver processes the message
				     [ wait finish ]
                                     receiver release ACK

   sender                         receiver                   receiver
   TOKEN:EX                       MESSAGE:CR                 MESSAGE:CR
   MESSAGE:CR
   ACK:EX

4. sender down-convert ACK from EX to CR
   sender release MESSAGE
   sender release TOKEN
				  receiver upconvert to EX of MESSAGE
                                  receiver get CR of ACK
				  receiver release MESSAGE

   sender                        receiver                   receiver
   ACK:CR                         ACK:CR                     ACK:CR

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
4b26a08af9 Perform resync for cluster node failure
If bitmap_copy_slot returns hi>0, we need to perform resync.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:06 -06:00
Goldwyn Rodrigues
e94987db2e Initiate recovery on node failure
The DLM informs us in case of node failure with the DLM slot number.
cluster_info->recovery_map sets the bit corresponding to the slot number
and wakes up the recovery thread.

The recovery thread:
1. Derives the slot number from the recovery_map
2. Locks the bitmap corresponding to the slot
3. Copies the set bits to the node-local bitmap

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2015-02-23 09:59:05 -06:00