Commit graph

71 commits

Author SHA1 Message Date
Wei Yongjun
0f6187dbe5 md-cluster: fix error return code in join()
Fix to return error code -ENOMEM from the lockres_init() error
handling case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-08-24 10:21:51 -07:00
Guoqing Jiang
1fa9a1ad0a md-cluster: check the return value of process_recvd_msg
We don't need to run the full path of recv_daemon
if process_recvd_msg doesn't return 0.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-09 09:24:04 -07:00
Guoqing Jiang
51e453aecb md-cluster: gather resync infos and enable recv_thread after bitmap is ready
The in-memory bitmap is not ready when node joins cluster,
so it doesn't make sense to make gather_all_resync_info()
called so earlier, we need to call it after the node's
bitmap is setup. Also, recv_thread could be wake up after
node joins cluster, but it could cause problem if node
receives RESYNCING message without persionality since
mddev->pers->quiesce is called in process_suspend_info.

This commit introduces a new cluster interface load_bitmaps
to fix above problems, load_bitmaps is called in bitmap_load
where bitmap and persionality are ready, and load_bitmaps
does the following tasks:

1. call gather_all_resync_info to load all the node's
   bitmap info.
2. set MD_CLUSTER_ALREADY_IN_CLUSTER bit to recv_thread
   could be wake up, and wake up recv_thread if there is
   pending recv event.

Then ack_bast only wakes up recv_thread after IN_CLUSTER
bit is ready otherwise MD_CLUSTER_PENDING_RESYNC_EVENT is
set.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-09 09:24:03 -07:00
Guoqing Jiang
18c9ff7f48 md-cluster: sync bitmap when node received RESYNCING msg
If the node received RESYNCING message which means
another node will perform resync with the area, then
we don't want to do it again in another node.

Let's set RESYNC_MASK and clear NEEDED_MASK for the
region from old-low to new-low which has finished
syncing, and the region from old-hi to new-hi is about
to syncing, bitmap_sync_with_cluste is introduced for
the purpose.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-04 12:39:35 -07:00
Guoqing Jiang
1535212c54 md-cluster: fix locking when node joins cluster during message broadcast
If a node joins the cluster while a message broadcast
is under way, a lock issue could happen as follows.

For a cluster which included two nodes, if node A is
calling __sendmsg before up-convert CR to EX on ack,
and node B released CR on ack. But if a new node C
joins the cluster and it doesn't receive the message
which A sent before, so it could hold CR on ack before
A up-convert CR to EX on ack.

So a node joining the cluster should get an EX lock on
the "token" first to ensure no broadcast is ongoing,
then release it after held CR on ack.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-04 12:39:35 -07:00
Guoqing Jiang
5b0fb33e8a md-cluster: unregister thread if err happened
The two threads need to be unregistered if a node
can't join cluster successfully.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-04 12:39:35 -07:00
Guoqing Jiang
eb315cd093 md-cluster: wake up thread to continue recovery
In recovery case, we need to set MD_RECOVERY_NEEDED
and wake up thread only if recover is not finished.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-04 12:39:35 -07:00
Guoqing Jiang
41a9a0dcf8 md-cluster: change resync lock from asynchronous to synchronous
If multiple nodes choose to attempt do resync at the same time
they need to be serialized so they don't duplicate effort. This
serialization is done by locking the 'resync' DLM lock.

Currently if a node cannot get the lock immediately it doesn't
request notification when the lock becomes available (i.e.
DLM_LKF_NOQUEUE is set), so it may not reliably find out when it
is safe to try again.

Rather than trying to arrange an async wake-up when the lock
becomes available, switch to using synchronous locking - this is
a lot easier to think about.  As it is not permitted to block in
the 'raid1d' thread, move the locking to the resync thread.  So
the rsync thread is forked immediately, but it blocks until the
resync lock is available. Once the lock is locked it checks again
if any resync action is needed.

A particular symptom of the current problem is that a node can
get stuck with "resync=pending" indefinitely.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-05-04 12:39:35 -07:00
Shaohua Li
4ac7a65f80 md-cluster: fix missing memory free
There are several places we allocate dlm_lock_resource, but not free it.

leave() need free a lock resource too (from Guoqing)
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Guoqing Jiang <gqjiang@suse.com>
Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
2016-01-24 18:13:18 -08:00
Guoqing Jiang
e19508fa4d md-cluster: update comments for MD_CLUSTER_SEND_LOCKED_ALREADY
1. fix unbalanced parentheses.
2. add more description about that MD_CLUSTER_SEND_LOCKED_ALREADY
   will be cleared after set it in add_new_disk.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:39:21 +11:00
Guoqing Jiang
8b9277c814 md-cluster: Protect communication with mutexes
Communication can happen through multiple threads. It is possible that
one thread steps over another threads sequence. So, we use mutexes to
protect both the send and receive sequences.

Send communication is locked through state bit, MD_CLUSTER_SEND_LOCK.
Communication is locked with bit manipulation in order to allow
"lock and hold" for the add operation. In case of an add operation,
if the lock is held, MD_CLUSTER_SEND_LOCKED_ALREADY is set.
When md_update_sb() calls metadata_update_start(), it checks
(in a single statement to avoid races), if the communication
is already locked. If yes, it merely returns zero, else it
locks the token lockresource.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:39:17 +11:00
Guoqing Jiang
15858fa5b0 md-cluster: Defer MD reloading to mddev->thread
Reloading of superblock must be performed under reconfig_mutex. However,
this cannot be done with md_reload_sb because it would deadlock with
the message DLM lock. So, we defer it in md_check_recovery() which is
executed by mddev->thread.

This introduces a new flag, MD_RELOAD_SB, which if set, will reload the
superblock. And good_device_nr is also added to 'struct mddev' which is
used to get the num of the good device within cluster raid.

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 11:39:10 +11:00
Guoqing Jiang
f6a2dc64ee md-cluster: append some actions when change bitmap from clustered to none
For clustered raid, we need to do extra actions when change
bitmap to none.

1. check if all the bitmap lock could be get or not, if yes then
   we can continue the change since cluster raid is only active
   in current node. Otherwise return fail and unlock the related
   bitmap locks
2. set nodes to 0 and then leave cluster environment.
3. release other nodes's bitmap lock.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2016-01-06 11:38:57 +11:00
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