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: Sunil Mushran <sunil.mushran@oracle.com>
Adds new dlm message DLM_QUERY_NODEINFO that sends the attributes of all
registered nodes. This message is sent if the negotiated dlm protocol is
1.1 or higher. If the information of the joining node does not match
that of any existing nodes, the join domain request is rejected.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Adds new dlm message DLM_QUERY_REGION that sends the names of all active
heartbeat regions. This message is only sent in the global heartbeat
mode. If the regions in the joining node do not fully match the ones in
the active nodes, the join domain request is rejected.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
While umounting, a block mle doesn't get freed if dlm is shutdown after
master request is received but before assert master. This results in unclean
shutdown of dlm domain.
This patch frees all mles that lie around after other nodes were notified about
exiting the dlm and marking dlm state as leaving. Only block mles are expected
to be around, so we log ERROR for other mles but still free them.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This patch tries to handle the case in which list 'dlm->tracking_list' is
empty, to avoid accessing an invalid pointer. It fixes the following oops:
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1287
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
O2net: Disallow o2net accept connection request from itself.
ocfs2/dlm: remove potential deadlock -V3
ocfs2/dlm: avoid incorrect bit set in refmap on recovery master
Fix the nested PR lock calling issue in ACL
ocfs2: Count more refcount records in file system fragmentation.
ocfs2 fix o2dlm dlm run purgelist (rev 3)
ocfs2/dlm: fix a dead lock
ocfs2: do not overwrite error codes in ocfs2_init_acl
When we need to take both dlm_domain_lock and dlm->spinlock, we should take
them in order of: dlm_domain_lock then dlm->spinlock.
There is pathes disobey this order. That is calling dlm_lockres_put() with
dlm->spinlock held in dlm_run_purge_list. dlm_lockres_put() calls dlm_put() at
the ref and dlm_put() locks on dlm_domain_lock.
Fix:
Don't grab/put the dlm when the initialising/releasing lockres.
That grab is not required because we don't call dlm_unregister_domain()
based on refcount.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
In the following situation, there remains an incorrect bit in refmap on the
recovery master. Finally the recovery master will fail at purging the lockres
due to the incorrect bit in refmap.
1) node A has no interest on lockres A any longer, so it is purging it.
2) the owner of lockres A is node B, so node A is sending de-ref message
to node B.
3) at this time, node B crashed. node C becomes the recovery master. it recovers
lockres A(because the master is the dead node B).
4) node A migrated lockres A to node C with a refbit there.
5) node A failed to send de-ref message to node B because it crashed. The failure
is ignored. no other action is done for lockres A any more.
For mormal, re-send the deref message to it to recovery master can fix it. Well,
ignoring the failure of deref to the original master and not recovering the lockres
to recovery master has the same effect. And the later is simpler.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Acked-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This patch fixes two problems in dlm_run_purgelist
1. If a lockres is found to be in use, dlm_run_purgelist keeps trying to purge
the same lockres instead of trying the next lockres.
2. When a lockres is found unused, dlm_run_purgelist releases lockres spinlock
before setting DLM_LOCK_RES_DROPPING_REF and calls dlm_purge_lockres.
spinlock is reacquired but in this window lockres can get reused. This leads
to BUG.
This patch modifies dlm_run_purgelist to skip lockres if it's in use and purge
next lockres. It also sets DLM_LOCK_RES_DROPPING_REF before releasing the
lockres spinlock protecting it from getting reused.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Acked-by: Sunil Mushran <sunil.mushran@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
When we have to take both dlm->master_lock and lockres->spinlock,
take them in order
lockres->spinlock and then dlm->master_lock.
The patch fixes a violation of the rule.
We can simply move taking dlm->master_lock to where we have dropped res->spinlock
since when we access res->state and free mle memory we don't need master_lock's
protection.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
For migration, we are waiting for DLM_LOCK_RES_MIGRATING flag to be set
before sending DLM_MIG_LOCKRES_MSG message to the target. We are using
dlm_migration_can_proceed() for that purpose. However, if the node is
down, dlm_migration_can_proceed() will also return "go ahead". In this
rare case, the DLM_LOCK_RES_MIGRATING flag might not be set yet. Remove
the BUG_ON() that trips over this condition.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This function is only called from one place and it's like this:
dlm_register_domain(conn->cc_name, dlm_key, &fs_version);
The "conn->cc_name" is 64 characters long. If strlen(conn->cc_name)
were equal to O2NM_MAX_NAME_LEN (64) that would be a bug because
strlen() doesn't count the NULL character.
In fact, if you look how O2NM_MAX_NAME_LEN is used, it mostly describes
64 character buffers. The only exception is nd_name from struct
o2nm_node.
Anyway I looked into it and in this case the domain string comes from
osb->uuid_str in ocfs2_setup_osb_uuid(). That's 32 characters and NULL
which easily fits into O2NM_MAX_NAME_LEN. This patch doesn't change how
the code works, but I think it makes the code a little cleaner.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
dlm->recovery_map is defined as
unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
We should treat O2NM_MAX_NODES as the bit map size in bits.
This patches fixes a bit operation that takes O2NM_MAX_NODES + 1 as bitmap size.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Add a spin_unlock missing on the error path. Unlock as in the other code
that leads to the leave label.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression E1;
@@
* spin_lock(E1,...);
<+... when != E1
if (...) {
... when != E1
* return ...;
}
...+>
* spin_unlock(E1,...);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (47 commits)
ocfs2: Silence a gcc warning.
ocfs2: Don't retry xattr set in case value extension fails.
ocfs2:dlm: avoid dlm->ast_lock lockres->spinlock dependency break
ocfs2: Reset xattr value size after xa_cleanup_value_truncate().
fs/ocfs2/dlm: Use kstrdup
fs/ocfs2/dlm: Drop memory allocation cast
Ocfs2: Optimize punching-hole code.
Ocfs2: Make ocfs2_find_cpos_for_left_leaf() public.
Ocfs2: Fix hole punching to correctly do CoW during cluster zeroing.
Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.
ocfs2: Block signals for mkdir/link/symlink/O_CREAT.
ocfs2: Wrap signal blocking in void functions.
ocfs2/dlm: Increase o2dlm lockres hash size
ocfs2: Make ocfs2_extend_trans() really extend.
ocfs2/trivial: Code cleanup for allocation reservation.
ocfs2: make ocfs2_adjust_resv_from_alloc simple.
ocfs2: Make nointr a default mount option
ocfs2/dlm: Make o2dlm domain join/leave messages KERN_NOTICE
o2net: log socket state changes
ocfs2: print node # when tcp fails
...
Currently we process a dirty lockres with the lockres->spinlock taken. While
during the process, we may need to lock on dlm->ast_lock. This breaks the
dependency of dlm->ast_lock(lock first) and lockres->spinlock(lock second).
This patch fixes the problem.
Since we can't release lockres->spinlock, we have to take dlm->ast_lock
just before taking the lockres->spinlock and release it after lockres->spinlock
is released. And use __dlm_queue_bast()/__dlm_queue_ast(), the nolock version,
in dlm_shuffle_lists(). There are no too many locks on a lockres, so there is no
performance harm.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Use kstrdup when the goal of an allocation is copy a string into the
allocated region.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to;
expression flag,E1,E2;
statement S;
@@
- to = kmalloc(strlen(from) + 1,flag);
+ to = kstrdup(from, flag);
... when != \(from = E1 \| to = E1 \)
if (to==NULL || ...) S
... when != \(from = E2 \| to = E2 \)
- strcpy(to, from);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Drop cast on the result of kmalloc and similar functions.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
type T;
@@
- (T *)
(\(kmalloc\|kzalloc\|kcalloc\|kmem_cache_alloc\|kmem_cache_zalloc\|
kmem_cache_alloc_node\|kmalloc_node\|kzalloc_node\)(...))
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Lockres hash size of 16KB is far too small for large filesystems (where we
have hundreds of thousands of lock resources stored in the table).
This patch increases it to 128KB.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
o2dlm join and leave messages are more than informational as they are
required for debugging locking issues. This patch changes them from
KERN_INFO to KERN_NOTICE.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Print the node number of a peer node if sending it a message failed.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The checking of lockres owner in dlm_update_lvb() is not inside spinlock
protection. I don't see problem in current call path of dlm_update_lvb().
But just for code robustness.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
In o2dlm, the master of a lock resource keeps a map of all interested
nodes. This prevents the master from purging the resource before an
interested node can create a lock.
A race between the mastery thread and the mastery handler allowed an
interested node to discover who the master is without informing the
master directly. This is easily fixed by holding the dlm spinlock a
little longer in the mastery handler.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
If a node down event happens while dlm shutdown in progress, dlm recovery
should be done before dlm is shutdown. We can't migrate unrecovered locks,
obviously. But dlm_reco_thread only does recovery if the dlm_state is
in DLM_CTXT_JOINED.
dlm_reco_thread should do recovery if dlm_state is in DLM_CTXT_JOINED or
DLM_CTXT_IN_SHUTDOWN.
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We're going to remove the tie between ocfs2_dlmfs and o2dlm.
ocfs2_dlmfs doesn't belong in the fs/ocfs2/dlm directory anymore. Here
we move it to fs/ocfs2/dlmfs.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
o2dlm's userspace filesystem is an easy way to use the DLM from
userspace. It is intentionally simple. For example, it does not allow
for asynchronous behavior or lock conversion. This is intentional to
keep the interface simple.
Because there is no asynchronous notification, there is no way for a
process holding a lock to know another node needs the lock. This is the
number one complaint of ocfs2_dlmfs users. Turns out, we can solve this
very easily. We add poll() support to ocfs2_dlmfs. When a BAST is
received, the lock's file descriptor will receive POLLIN.
This is trivial to implement. Userdlm already has an appropriate
waitqueue, and the lock knows when it is blocked.
We add the "bast" capability to tell userspace this is available.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Over time, dlmfs has added some features that were not part of the
initial ABI. Unfortunately, some of these features are not detectable
via standard usage. For example, Linux's default poll always returns
POLLIN, so there is no way for a caller of poll(2) to know when dlmfs
added poll support. Instead, we provide this list of new capabilities.
Capabilities is a read-only attribute. We do it as a module parameter
so we can discover it whether dlmfs is built in, loaded, or even not
loaded (via modinfo).
The ABI features are local to this machine's dlmfs mount. This is
distinct from the locking protocol, which is concerned with inter-node
interaction.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The debug call printing the name of the lock resource was chopping
off the last character. This patch fixes the problem.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During recovery, the dlm frees the locks for the dead node. If it finds a
lock in a resource for the dead node, it expects that node to also have a
ref in that lock resource. If not, it BUGs.
ossbz#1175 was filed with the above BUG. Now, while it is correct that we
should be expecting the ref, I see no reason why we have to BUG. After all,
we are freeing up the lock and clearing the ref.
This patch replaces the BUG_ON with a printk(). Hopefully, that will give
us more clues next time this happens.
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1175
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Mainline commit aad1b15310 made the
dlm_begin_reco_handler() return -EAGAIN instead of EAGAIN.
As this error is transmitted over the wire, we want the receiver,
dlm_send_begin_reco_message(), to understand both the older EAGAIN and
the newer -EAGAIN, to allow rolling upgrade of the cluster nodes.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
When a lock resource is migrated, the dlm compares the migrated
locks with that that was already existing on the new node. If the
comparison fails, it BUGs. This patch prints more messages when the
comparison fails inorder to help with the root cause analyis.
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1206
This does not fix bz1206. However, if we run into it again, we will
have more information to chew on.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
During lock resource migration, o2dlm fills the packet with a LVB from the
first valid lock. For sanity, it ensures that the other valid locks have the
same LVB. If not, it BUGs.
The valid locks are ones that have granted EX or PR lock levels and are either
on the Granted or Converting lists. Locks in the Blocked list cannot have a
valid LVB.
This patch ensures that we skip the locks in the Blocked list.
Fixes oss bugzilla#1202
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1202
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2/trivial: Use le16_to_cpu for a disk value in xattr.c
ocfs2/trivial: Use proper mask for 2 places in hearbeat.c
Ocfs2: Let ocfs2 support fiemap for symlink and fast symlink.
Ocfs2: Should ocfs2 support fiemap for S_IFDIR inode?
ocfs2: Use FIEMAP_EXTENT_SHARED
fiemap: Add new extent flag FIEMAP_EXTENT_SHARED
ocfs2: replace u8 by __u8 in ocfs2_fs.h
ocfs2: explicit declare uninitialized var in user_cluster_connect()
ocfs2-devel: remove redundant OCFS2_MOUNT_POSIX_ACL check in ocfs2_get_acl_nolock()
ocfs2: return -EAGAIN instead of EAGAIN in dlm
ocfs2/cluster: Make fence method configurable - v2
ocfs2: Set MS_POSIXACL on remount
ocfs2: Make acl use the default
ocfs2: Always include ACL support
We used to return positive EAGAIN to indicate a retry action
is needed in dlm_begin_reco_handler(). Now we return negative
-EAGAIN to erase the confusion caused by this error code.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
* remove asm/atomic.h inclusion from linux/utsname.h --
not needed after kref conversion
* remove linux/utsname.h inclusion from files which do not need it
NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (85 commits)
ocfs2: Use buffer IO if we are appending a file.
ocfs2: add spinlock protection when dealing with lockres->purge.
dlmglue.c: add missed mlog lines
ocfs2: __ocfs2_abort() should not enable panic for local mounts
ocfs2: Add ioctl for reflink.
ocfs2: Enable refcount tree support.
ocfs2: Implement ocfs2_reflink.
ocfs2: Add preserve to reflink.
ocfs2: Create reflinked file in orphan dir.
ocfs2: Use proper parameter for some inode operation.
ocfs2: Make transaction extend more efficient.
ocfs2: Don't merge in 1st refcount ops of reflink.
ocfs2: Modify removing xattr process for refcount.
ocfs2: Add reflink support for xattr.
ocfs2: Create an xattr indexed block if needed.
ocfs2: Call refcount tree remove process properly.
ocfs2: Attach xattr clusters to refcount tree.
ocfs2: Abstract ocfs2 xattr tree extend rec iteration process.
ocfs2: Abstract the creation of xattr block.
ocfs2: Remove inode from ocfs2_xattr_bucket_get_name_value.
...
Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.
This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
when we check/modify lockres->purge, we should with the protection of lockres->spinlock.
in dlm_purge_lockres(), the checking/modifying is not with the protectin.
this patch fixes it.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This enables us to track who does what and print info. Its main use
is catching dirty inodes on the default_backing_dev_info, so we can
fix that up.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In case a downconvert is queued, and a flock receives a signal,
BUG_ON(lockres->l_action != OCFS2_AST_INVALID) is triggered
because a lock cancel triggers a dlmunlock while an AST is
scheduled.
To avoid this, allow a LKM_CANCEL to pass through, and let it
wait on __dlm_wait_on_lockres().
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Acked-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>