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 <gqj

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>

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md-cluster: make other members of cluster_msg is handled by little endian funcs

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>

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 m

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>

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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 Ca

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>

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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

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>

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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 multi

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>

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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 Rodrigu

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>

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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

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>

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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 r1c

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>

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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 befor

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>

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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_pu

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>

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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: Gol

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>

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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 n

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>

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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 <gqji

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>

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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 <gqji

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>

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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

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>

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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
inf

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>

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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.

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>

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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.

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>

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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.

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>

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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 nod

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>

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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>

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.
Suspend

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>

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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 mes

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>

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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 nu

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>

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