dlm_request_all_locks() should deal with the status sent from target node
if DLM_LOCK_REQUEST_MSG is sent successfully, or recovery master will fall
into endless loop, waiting for other nodes to send locks and
DLM_RECO_DATA_DONE_MSG to me.

        NodeA                                  NodeB
                                     selected as recovery master
                                     dlm_remaster_locks()
                                     ->dlm_request_all_locks()
                                     send DLM_LOCK_REQUEST_MSG to nodeA

It happened that NodeA cannot alloc memory when it processes this
message.  dlm_request_all_locks_handler() do not queue
dlm_request_all_locks_worker and returns -ENOMEM.  It will never send
locks and DLM_RECO_DATA_DONE_MSG to NodeB.

                                    NodeB do not deal with the status
                                    sent from nodeA, and will fall in
                                    endless loop waiting for the
                                    recovery state of NodeA to be
                                    changed.
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Jeff Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dlmlock_master() returns DLM_RECOVERING/DLM_MIGRATING/ DLM_FORWAR after
adding lock to blocked list if lockres has the state
DLM_LOCK_RES_RECOVERING/DLM_LOCK_RES_MIGRATING/ DLM_LOCK_RES_IN_PROGRESS.
so it will retry in dlmlock().  And this may cause dlm_thread fall into an
infinite loop

	Thread1                                  dlm_thread

  calls dlm_lock->dlmlock_master,
  if lockresA is in state
  DLM_LOCK_RES_RECOVERING, calls
  __dlm_wait_on_lockres() and waits
  until others threads clear this
  state;

  If cannot grant this lock,
  adding lock to blocked list,
  and return DLM_RECOVERING;

                                        Grant this lock and move it to
                                        grant list;

  After a while, retry and
  calls list_add_tail(), adding lock
  to blocked list again.

Granted and blocked list of this lockres will become the following
conditions:

    lock_res->granted.next = dlm_lock->list_head;
    lock_res->blocked.next = dlm_lock->list_head;
    dlm_lock->list_head.next = dlm_lock_resource->blocked;

When dlm_thread traverses the granted list, it will fall into an endless
loop, checking dlm_lock.list_head, dlm_lock->list_head.next
(i.e.lock_res->blocked), lock_res->blocked.next(i.e.dlm_lock.list_head
again) .....
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Reviewed-by: Njensen <shencanquan@huawei.com>
Cc: Jeff Liu <jeff.liu@oracle.com>
Acked-by: NSunil Mushran <sunil.mushran@gmail.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dlm_begin_reco_handler() returns without putting dlm when dlm recovery
state is DLM_RECO_STATE_FINALIZE.
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Reviewed-by: NJie Liu <jeff.liu@oracle.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In dlm_request_all_locks, ret is type enum.  But o2net_send_message
returns a type int value.  Then it will never run into the following
error branch.  So we should change the ret type from enum to int.
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NSunil Mushran <sunil.mushran@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Below 3 functions have already been declared in dlmcommon.h, so we have
no need to declare them again in dlmrecovery.c:

  dlm_complete_recovery_thread
  dlm_launch_recovery_thread
  dlm_kick_recovery_thread
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NSunil Mushran <sunil.mushran@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dlm_mig_lockres_handler() is missing a dlm_lockres_put() on an error path.
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Reviewed-by: Nshencanquan <shencanquan@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kfree on a NULL pointer is a no-op.  Remove the redundant null pointer
check.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NMark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

My static checker complains that this is called with a spin_lock held
in dlm_master_requery_handler() from dlmrecovery.c.  Probably the reason
we have not received any bug reports about this is that recovery is not
a common operation.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

smatch analysis indicates a number of redundant NULL checks before
calling kfree(), eg:

  fs/ocfs2/alloc.c:6138 ocfs2_begin_truncate_log_recovery() info:
   redundant null check on *tl_copy calling kfree()

  fs/ocfs2/alloc.c:6755 ocfs2_zero_range_for_truncate() info:
   redundant null check on pages calling kfree()

etc....

[akpm@linux-foundation.org: revert dubious change in ocfs2_begin_truncate_log_recovery()]
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Memory allocated using kmem_cache_zalloc should be freed using
kmem_cache_free, not kfree.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,e,e1,e2;
@@

x = kmem_cache_zalloc(e1,e2)
... when != x = e
?-kfree(x)
+kmem_cache_free(e1,x)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

These files were getting <linux/module.h> via an implicit include
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason.  Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

The cluster up check only checks to see if the node is heartbeating or not.
If yes it continues assuming that the node is connected to all the nodes. But
if that is not the case, the cluster join aborts with a stack of errors that
are not easy to comprehend.

This patch adds the network connect check upfront and prints the nodes that
the node is not yet connected to, before aborting.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

In dlmlock_remote(), we wait for the resource to stop being active before
setting the inprogress flag. Active includes recovery, migration, etc.

The problem here is that if the resource was being recovered or migrated, the
new owner could very well be that node itself (and thus not a remote node).
This problem was observed in Oracle bug#12583620. The error messages observed
were as follows:

dlm_send_remote_lock_request:337 ERROR: Error -40 (ELOOP) when sending message 503 (key 0xd6d8c7) to node 2
dlmlock_remote:271 ERROR: dlm status = DLM_BADARGS
dlmlock:751 ERROR: dlm status = DLM_BADARGS
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

The inflight reference count, in the lock resource, is taken to pin the resource
in memory. We take it when a new resource is created and release it after a
lock is attached to it. We do this to prevent the resource from getting purged
prematurely.

Earlier this reference count was being taken for locally mastered resources
only. This patch extends the same functionality for remotely mastered ones.

We are doing this because the same premature purging could occur for remotely
mastered resources if the remote node were to die before completion of the
create lock.

Fix for Oracle bug#12405575.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

dlm_wait_for_node_death() and dlm_wait_for_node_recovery() needed a facelift.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

Add mlog to trace adding and removing the resource from/to the hash table.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

Patch cleans up helpers that set/clear refmap bits and grab/drop inflight lock
ref counts.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

dlm_finish_local_lockres_recovery() needed a facelift.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

o2dlm messages needed a facelift.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>

During dlm domain shutdown, o2dlm has to free all the lock resources. Ones that
have no locks and references are freed. Ones that have locks and/or references
are migrated to another node.

The first task in migration is finding a target. Currently we scan the lock
resource and find one node that either has a lock or a reference. This is not
very efficient in a parallel umount case as we might end up migrating the
lock resource to a node which itself may have to migrate it to a third node.

The patch scans the dlm->exit_domain_map to ensure the target node is not
leaving the domain. If no valid target node is found, o2dlm does not migrate
the resource but instead waits for the unlock and deref messages that will
allow it to free the resource.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

This patch adds a new dlm message DLM_BEGIN_EXIT_DOMAIN_MSG and ups the dlm
protocol to 1.2.

o2dlm sends this new message in dlm_unregister_domain() to mark the beginning
of the exit domain. This message is sent to all nodes in the domain.

Currently o2dlm has no way of informing other nodes of its impending exit.
This information is useful as the other nodes could disregard the exiting
node in certain operations. For example, in resource migration. If two or
more nodes were umounting in parallel, it would be more efficient if o2dlm
were to choose a non-exiting node to be the new master node rather than an
exiting one.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Reviewed-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Patch cleans up the gunk added by commit 388c4bcb.
dlm_is_lockres_migrateable() now returns 1 if lockresource is deemed
migrateable and 0 if not.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

During resource migration, if the target node were to die, the thread doing
the migration spins until the target node is not removed from the domain map.
This patch slows the spin by making the thread wait for the recovery to kick in.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Patch fixes a bug in the o2dlm protocol negotiation in that it is using
the builtin version rather than the negotiated version during the domain
join. This causes join errors when a node having kernel >= 2.6.37 joins
a cluster with nodes having kernels < 2.6.37.

This only affects the o2cb cluster stack.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Reported-by: NJacek Stepniewski <Jacek.Stepniewski@agora.pl>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Replace EXTRA_CFLAGS with ccflags-y. And change ntfs-objs to ntfs-y
for cleaner conditional inclusion.
Signed-off-by: Nmatt mooney <mfm@muteddisk.com>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

In dlm_query_region_handler(), move the kmalloc outside the spinlock.
This allows us to use GFP_KERNEL instead of GFP_ATOMIC.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <jlbec@evilplan.org>

mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
   Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
   mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

ENTRY is used to record the entry of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

So for mlog_entry_void, we just remove it.
for mlog_entry(...), we replace it with mlog(0,...), and they
will be replace by trace event later.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>

In o2dlm, the enumerated message values are part of the protocol.
The patch hard codes each value so as to reduce the chance of an editing
error causing a protocol mismatch.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Patch makes use of task_pid_nr(). Also removes the null check before calling
debugfs_remove().
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Remove struct debug_buffer in dlmdebug.c/h.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

This patch adds support for pinning o2hb regions in configfs. Pinning disallows
a region to be cleanly stopped as long as it has an active dependent user
(read o2dlm).

In local heartbeat mode, the region uuid matching the domain name is pinned as
long as the o2dlm domain is active.

In global heartbeat mode, all regions are pinned as long as there is atleast
one dependent user and the region count is 3 or less. All regions are unpinned
if the number of dependent users is zero or region count is greater than 3.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Make existing convertion precedent over new lock. It makes o2dlm locking more
like fair locking.
Signed-off-by: NWengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

Add the domain name and the resource name in the mlogs.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

o2dlm was not migrating resources with zero locks because it assumed that that
resource would get purged by dlm_thread. However, some usage patterns involve
creating and dropping locks at a high rate leading to the migrate thread seeing
zero locks but the purge thread seeing an active reference. When this happens,
the dlm_thread cannot purge the resource and the migrate thread sees no reason
to migrate that resource. The spell is broken when the migrate thread catches
the resource with a lock.

The fix is to make the migrate thread also consider the reference map.

This usage pattern can be triggered by userspace on userdlm locks and flocks.
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

coccinelle check scripts/coccinelle/locks/call_kern.cocci found that
in fs/ocfs2/dlm/dlmdomain.c an allocation with GFP_KERNEL is done
with locks held:

dlm_query_region_handler
  spin_lock(dlm_domain_lock)
    dlm_match_regions
      kmalloc(GFP_KERNEL)

Change it to GFP_ATOMIC.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
CC: Joel Becker <joel.becker@oracle.com>
CC: Mark Fasheh <mfasheh@suse.com>
CC: ocfs2-devel@oss.oracle.com

--
Exists in v2.6.37-rc1 and current linux-next.
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

dlm protocol 1.1. activates messages DLM_QUERY_REGION and DLM_QUERY_NODEINFO
that are a must for global heartbeat.

It also activates o2hb_global_heartbeat_active().
Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>