Commit Graph

381 Commits

Author SHA1 Message Date
Ingo Molnar
174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Masahiro Yamada
4d39f0ac8e scripts/spelling.txt: add "unneded" pattern and fix typo instances
Fix typos and add the following to the scripts/spelling.txt:

  unneded||unneeded

Link: http://lkml.kernel.org/r/1481573103-11329-15-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-27 18:43:47 -08:00
Peter Zijlstra
2c935bc572 locking/atomic, kref: Add kref_read()
Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:37:18 +01:00
piaojun
28bb5ef485 ocfs2/dlm: clean up deadcode in dlm_master_request_handler()
When 'dispatch_assert' is set, 'response' must be DLM_MASTER_RESP_YES,
and 'res' won't be null, so execution can't reach these two branch.

Link: http://lkml.kernel.org/r/58174C91.3040004@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:06 -08:00
Guozhonghua
aa7b58597f ocfs2: delete redundant code and set the node bit into maybe_map directly
The variable `set_maybe' is redundant when the mle has been found in the
map.  So it is ok to set the node_idx into mle's maybe_map directly.

Link: http://lkml.kernel.org/r/71604351584F6A4EBAE558C676F37CA4A3D490DD@H3CMLB12-EX.srv.huawei-3com.com
Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
Reviewed-by: Mark Fasheh <mfasheh@versity.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:06 -08:00
piaojun
46832b2de5 ocfs2/dlm: clean up useless BUG_ON default case in dlm_finalize_reco_handler()
The value of 'stage' must be between 1 and 2, so the switch can't reach
the default case.

Link: http://lkml.kernel.org/r/57FB5EB2.7050002@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:06 -08:00
Guozhonghua
0cc482ee41 ocfs2: fix memory leak in dlm_migrate_request_handler()
In the dlm_migrate_request_handler(), when `ret' is -EEXIST, the mle
should be freed, otherwise the memory will be leaked.

Link: http://lkml.kernel.org/r/71604351584F6A4EBAE558C676F37CA4A3D3522A@H3CMLB12-EX.srv.huawei-3com.com
Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
Reviewed-by: Mark Fasheh <mfasheh@versity.com>
Cc: Eric Ren <zren@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:30 -07:00
Bhaktipriya Shridhar
055fdcff35 fs/ocfs2/dlm: remove deprecated create_singlethread_workqueue()
The workqueue "dlm_worker" queues a single work item &dlm->dispatched_work
and thus it doesn't require execution ordering.  Hence, alloc_workqueue
has been used to replace the deprecated create_singlethread_workqueue
instance.

The WQ_MEM_RECLAIM flag has been set to ensure forward progress under
memory pressure.

Since there are fixed number of work items, explicit concurrency
limit is unnecessary here.

Link: http://lkml.kernel.org/r/2b5ad8d6688effe1a9ddb2bc2082d26fbbe00302.1472590094.git.bhaktipriya96@gmail.com
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07 18:46:26 -07:00
Joseph Qi
e6f0c6e617 ocfs2/dlm: fix race between convert and migration
Commit ac7cf246df ("ocfs2/dlm: fix race between convert and recovery")
checks if lockres master has changed to identify whether new master has
finished recovery or not.  This will introduce a race that right after
old master does umount ( means master will change), a new convert
request comes.

In this case, it will reset lockres state to DLM_RECOVERING and then
retry convert, and then fail with lockres->l_action being set to
OCFS2_AST_INVALID, which will cause inconsistent lock level between
ocfs2 and dlm, and then finally BUG.

Since dlm recovery will clear lock->convert_pending in
dlm_move_lockres_to_recovery_list, we can use it to correctly identify
the race case between convert and recovery.  So fix it.

Fixes: ac7cf246df ("ocfs2/dlm: fix race between convert and recovery")
Link: http://lkml.kernel.org/r/57CE1569.8010704@huawei.com
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19 15:36:16 -07:00
Linus Torvalds
835c92d43b Merge branch 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull qstr constification updates from Al Viro:
 "Fairly self-contained bunch - surprising lot of places passes struct
  qstr * as an argument when const struct qstr * would suffice; it
  complicates analysis for no good reason.

  I'd prefer to feed that separately from the assorted fixes (those are
  in #for-linus and with somewhat trickier topology)"

* 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  qstr: constify instances in adfs
  qstr: constify instances in lustre
  qstr: constify instances in f2fs
  qstr: constify instances in ext2
  qstr: constify instances in vfat
  qstr: constify instances in procfs
  qstr: constify instances in fuse
  qstr constify instances in fs/dcache.c
  qstr: constify instances in nfs
  qstr: constify instances in ocfs2
  qstr: constify instances in autofs4
  qstr: constify instances in hfs
  qstr: constify instances in hfsplus
  qstr: constify instances in logfs
  qstr: constify dentry_init_security
2016-08-06 09:49:02 -04:00
piaojun
ee8f7fcbe6 ocfs2/dlm: continue to purge recovery lockres when recovery master goes down
We found a dlm-blocked situation caused by continuous breakdown of
recovery masters described below.  To solve this problem, we should
purge recovery lock once detecting recovery master goes down.

N3                      N2                   N1(reco master)
                        go down
                                             pick up recovery lock and
                                             begin recoverying for N2

                                             go down

pick up recovery
lock failed, then
purge it:
dlm_purge_lockres
  ->DROPPING_REF is set

send deref to N1 failed,
recovery lock is not purged

find N1 go down, begin
recoverying for N1, but
blocked in dlm_do_recovery
as DROPPING_REF is set:
dlm_do_recovery
  ->dlm_pick_recovery_master
    ->dlmlock
      ->dlm_get_lock_resource
        ->__dlm_wait_on_lockres_flags(tmpres,
	  	DLM_LOCK_RES_DROPPING_REF);

Fixes: 8c03439681 ("ocfs2/dlm: clear DROPPING_REF flag when the master goes down")
Link: http://lkml.kernel.org/r/578453AF.8030404@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
piaojun
309e91911d ocfs2/dlm: solve a BUG when deref failed in dlm_drop_lockres_ref
We found a BUG situation that lockres is migrated during deref described
below.  To solve the BUG, we could purge lockres directly when other
node says I did not have a ref.  Additionally, we'd better purge lockres
if master goes down, as no one will response deref done.

Node 1                  Node 2(old master)             Node3(new master)
dlm_purge_lockres
send deref to N2

                        leave domain
                        migrate lockres to N3
                                                       finish migration
                                                       send do assert
                                                       master to N1

receive do assert msg
form N3, but can not
find lockres because
DROPPING_REF is set,
so the owner is still
N2.

                        receive deref from N1
                        and response -EINVAL
                        because lockres is migrated

BUG when receive -EINVAL
in dlm_drop_lockres_ref

Fixes: 842b90b624 ("ocfs2/dlm: return in progress if master can not clear the refmap bit right now")

Link: http://lkml.kernel.org/r/57845103.3070406@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
piaojun
86b652b93a ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
We found a BUG situation in which DLM_LOCK_RES_DROPPING_REF is cleared
unexpected that described below.  To solve the bug, we disable the
BUG_ON and purge lockres in dlm_do_local_recovery_cleanup.

Node 1                               Node 2(master)
dlm_purge_lockres
                                     dlm_deref_lockres_handler

                                     DLM_LOCK_RES_SETREF_INPROG is set
                                     response DLM_DEREF_RESPONSE_INPROG

receive DLM_DEREF_RESPONSE_INPROG
stop puring in dlm_purge_lockres
and wait for DLM_DEREF_RESPONSE_DONE

                                     dispatch dlm_deref_lockres_worker
                                     response DLM_DEREF_RESPONSE_DONE

receive DLM_DEREF_RESPONSE_DONE and
prepare to purge lockres

                                     Node 2 goes down

find Node2 down and do local
clean up for Node2:
dlm_do_local_recovery_cleanup
  -> clear DLM_LOCK_RES_DROPPING_REF

when purging lockres, BUG_ON happens
because DLM_LOCK_RES_DROPPING_REF is clear:
dlm_deref_lockres_done_handler
  ->BUG_ON(!(res->state & DLM_LOCK_RES_DROPPING_REF));

[akpm@linux-foundation.org: fix duplicated write to `ret']
Fixes: 60d663cb52 ("ocfs2/dlm: add DEREF_DONE message")
Link: http://lkml.kernel.org/r/57845055.9080702@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Linus Torvalds
554828ee0d Merge branch 'salted-string-hash'
This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.

That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.

It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.

Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.

* merge branch 'salted-string-hash':
  fs/dcache.c: Save one 32-bit multiply in dcache lookup
  vfs: make the string hashes salt the hash
2016-07-28 12:26:31 -07:00
Joseph Qi
8ec7b17a66 ocfs2/dlm: fix memory leak of dlm_debug_ctxt
dlm_debug_ctxt->debug_refcnt is initialized to 1 and then increased to 2
by dlm_debug_get in dlm_debug_init.  But dlm_debug_put is called only
once in dlm_debug_shutdown during unregister dlm, which leads to
dlm_debug_ctxt leaked.

Link: http://lkml.kernel.org/r/577BB755.4030900@huawei.com
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
Al Viro
612645f7cf qstr: constify instances in ocfs2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Linus Torvalds
8387ff2577 vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00
xuejiufei
b73413647e ocfs2/dlm: return zero if deref_done message is successfully handled
dlm_deref_lockres_done_handler() should return zero if the message is
successfully handled.

Fixes: 60d663cb52 ("ocfs2/dlm: add DEREF_DONE message").
Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
xuejiufei
e5054c9aef ocfs2/dlm: move lock to the tail of grant queue while doing in-place convert
We have found a bug when two nodes doing umount one after another.

1) Node 1 migrate a lockres that has 3 locks in grant queue such as
   N2(PR)<->N3(NL)<->N4(PR) to N2.  After migration, lvb of the lock
   N3(NL) and N4(PR) are empty on node 2 because migration target do not
   copy lvb to these two lock.

2) Node 3 want to convert to PR, it can be granted in
   __dlmconvert_master(), and the order of these locks is unchanged.  The
   lvb of the lock N3(PR) on node 2 is copyed from lockres in function
   dlm_update_lvb() while the lvb of lock N4(PR) is still empty.

3) Node 2 want to leave domain, it will migrate this lockres to node 3.
   Then node 2 will trigger the BUG in dlm_prepare_lvb_for_migration()
   when adding the lock N4(PR) to mres with the following message because
   the lvb of mres is already copied from lock N3(PR), but the lvb of lock
   N4(PR) is empty.

"Mismatched lvb in lock cookie=%u:%llu, name=%.*s, node=%u"

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Joseph Qi
be12b299a8 ocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_list
When master handles convert request, it queues ast first and then
returns status.  This may happen that the ast is sent before the request
status because the above two messages are sent by two threads.  And
right after the ast is sent, if master down, it may trigger BUG in
dlm_move_lockres_to_recovery_list in the requested node because ast
handler moves it to grant list without clear lock->convert_pending.  So
remove BUG_ON statement and check if the ast is processed in
dlmconvert_remote.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Joseph Qi
ac7cf246df ocfs2/dlm: fix race between convert and recovery
There is a race window between dlmconvert_remote and
dlm_move_lockres_to_recovery_list, which will cause a lock with
OCFS2_LOCK_BUSY in grant list, thus system hangs.

dlmconvert_remote
{
        spin_lock(&res->spinlock);
        list_move_tail(&lock->list, &res->converting);
        lock->convert_pending = 1;
        spin_unlock(&res->spinlock);

        status = dlm_send_remote_convert_request();
        >>>>>> race window, master has queued ast and return DLM_NORMAL,
               and then down before sending ast.
               this node detects master down and calls
               dlm_move_lockres_to_recovery_list, which will revert the
               lock to grant list.
               Then OCFS2_LOCK_BUSY won't be cleared as new master won't
               send ast any more because it thinks already be authorized.

        spin_lock(&res->spinlock);
        lock->convert_pending = 0;
        if (status != DLM_NORMAL)
                dlm_revert_pending_convert(res, lock);
        spin_unlock(&res->spinlock);
}

In this case, check if res->state has DLM_LOCK_RES_RECOVERING bit set
(res is still in recovering) or res master changed (new master has
finished recovery), reset the status to DLM_RECOVERING, then it will
retry convert.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Jun Piao
8d67d3c244 ocfs2/dlm: fix a variable overflow problem in dlmdomain.c
In dlm_send_join_cancels(), node is defined with type unsigned int, but
initialized with -1, this will lead variable overflow.  Although this
won't cause any runtime problem, the code looks a little uncoordinated.

Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Jiufei Xue
814ce69432 ocfs2: fix a tiny race that leads file system read-only
when o2hb detect a node down, it first set the dead node to recovery map
and create ocfs2rec which will replay journal for dead node.  o2hb
thread then call dlm_do_local_recovery_cleanup() to delete the lock for
dead node.  After the lock of dead node is gone, locks for other nodes
can be granted and may modify the meta data without replaying journal of
the dead node.  The detail is described as follows.

     N1                         N2                   N3(master)
modify the extent tree of
inode, and commit
dirty metadata to journal,
then goes down.
                                                 o2hb thread detects
                                                 N1 goes down, set
                                                 recovery map and
                                                 delete the lock of N1.

                                                 dlm_thread flush ast
                                                 for the lock of N2.
                        do not detect the death
                        of N1, so recovery map is
                        empty.

                        read inode from disk
                        without replaying
                        the journal of N1 and
                        modify the extent tree
                        of the inode that N1
                        had modified.
                                                 ocfs2rec recover the
                                                 journal of N1.
                                                 The modification of N2
                                                 is lost.

The modification of N1 and N2 are not serial, and it will lead to
read-only file system.  We can set recovery_waiting flag to the lock
resource after delete the lock for dead node to prevent other node from
getting the lock before dlm recovery.  After dlm recovery, the recovery
map on N2 is not empty, ocfs2_inode_lock_full_nested() will wait for ocfs2
recovery.

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei
d277f33eda ocfs2/dlm: return EINVAL when the lockres on migration target is in DROPPING_REF state
If master migrate this lock resource to node when it happened to purge
it, a new lock resource will be created and inserted into hash list.  If
then master goes down, the lock resource being purged is recovered, so
there exist two lock resource with different owner.  So return error to
master if the lock resource is in DROPPING state, master will retry to
migrate this lock resource.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei
8c03439681 ocfs2/dlm: clear DROPPING_REF flag when the master goes down
If the master goes down after return in-progress for deref message.  The
lock resource on non-master node can not be purged.  Clear the
DROPPING_REF flag and recovery it.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei
842b90b624 ocfs2/dlm: return in progress if master can not clear the refmap bit right now
Master returns in-progress to non-master node when it can not clear the
refmap bit right now.  And non-master node will not purge the lock
resource until receiving deref done message.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei
60d663cb52 ocfs2/dlm: add DEREF_DONE message
This series of patches is to fix the dis-order issue of setting/clearing
refmap bit described below.

Node 1                               Node 2(master)
dlmlock
dlm_do_master_request
                                dlm_master_request_handler
                                -> dlm_lockres_set_refmap_bit
dlmlock succeed
dlmunlock succeed

dlm_purge_lockres
                                dlm_deref_handler
                                -> find lock resource is in
                                   DLM_LOCK_RES_SETREF_INPROG state,
                                   so dispatch a deref work
dlm_purge_lockres succeed.

call dlmlock again
dlm_do_master_request
                                dlm_master_request_handler
                                -> dlm_lockres_set_refmap_bit

                                deref work trigger, call
                                dlm_lockres_clear_refmap_bit
                                to clear Node 1 from refmap

                                dlm_purge_lockres succeed

dlm_send_remote_lock_request
                                return DLM_IVLOCKID because
                                the lockres is not exist
BUG if the lockres is $RECOVERY

This series of patches add a new message to keep the order of set and
clear.  Other nodes can purge the lock resource only after the refmap bit
on master is cleared.

This patch is to add DEREF_DONE message and corresponding handler.  Node
can purge the lock resource after receiving this message.  As a new
message is added, so increase the minor number of dlm protocol version.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Joseph Qi
39b29af030 ocfs2/dlm: fix a typo in dlmcommon.h
Refer to cluster/tcp.h, NET_MAX_PAYLOAD_BYTES is a typo for
O2NET_MAX_PAYLOAD_BYTES.

Since currently DLM_MIG_LOCKRES_RESERVED is not actually used, it won't
cause any problem.  But we'd better correct it for further use.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
xuejiufei
c95a51807b ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
When recovery master down, dlm_do_local_recovery_cleanup() only remove
the $RECOVERY lock owned by dead node, but do not clear the refmap bit.
Which will make umount thread falling in dead loop migrating $RECOVERY
to the dead node.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05 18:10:40 -08:00
Joseph Qi
3c973b0e71 ocfs2/dlm: cleanup redunant lksb flags in dlmcommon.h
lksb flags are defined both in dlmapi.h and dlmcommon.h.  So clean them
up from dlmcommon.h.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Junxiao Bi
98e141f266 ocfs2: dlm: remove redundant code
Found this when do patch review, remove to make it clear and save a
little cpu time.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
xuejiufei
32e493265b ocfs2/dlm: do not insert a new mle when another process is already migrating
When two processes are migrating the same lockres,
dlm_add_migration_mle() return -EEXIST, but insert a new mle in hash
list.  dlm_migrate_lockres() will detach the old mle and free the new
one which is already in hash list, that will destroy the list.

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
xuejiufei
bef5502de0 ocfs2/dlm: ignore cleaning the migration mle that is inuse
We have found that migration source will trigger a BUG that the refcount
of mle is already zero before put when the target is down during
migration.  The situation is as follows:

dlm_migrate_lockres
  dlm_add_migration_mle
  dlm_mark_lockres_migrating
  dlm_get_mle_inuse
  <<<<<< Now the refcount of the mle is 2.
  dlm_send_one_lockres and wait for the target to become the
  new master.
  <<<<<< o2hb detect the target down and clean the migration
  mle. Now the refcount is 1.

dlm_migrate_lockres woken, and put the mle twice when found the target
goes down which trigger the BUG with the following message:

  "ERROR: bad mle: ".

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Xue jiufei
c372f2193a ocfs2/dlm: return appropriate value when dlm_grab() returns NULL
dlm_grab() may return NULL when the node is doing unmount.  When doing
code review, we found that some dlm handlers may return error to caller
when dlm_grab() returns NULL and make caller BUG or other problems.
Here is an example:

Node 1                                 Node 2
receives migration message
from node 3, and send
migrate request to others
                                     start unmounting

                                     receives migrate request
                                     from node 1 and call
                                     dlm_migrate_request_handler()

                                     unmount thread unregisters
                                     domain handlers and removes
                                     dlm_context from dlm_domains

                                     dlm_migrate_request_handlers()
                                     returns -EINVAL to node 1
Exit migration neither clearing the
migration state nor sending
assert master message to node 3 which
cause node 3 hung.

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
jiangyiwen
b556014338 ocfs2/dlm: wait until DLM_LOCK_RES_SETREF_INPROG is cleared in dlm_deref_lockres_worker
Commit f3f854648d ("ocfs2_dlm: Ensure correct ordering of set/clear
refmap bit on lockres") still exists a race which can't ensure the
ordering is exactly correct.

Node1               Node2                    Node3
umount, migrate
lockres to Node2
                    migrate finished,
                    send migrate request
                    to Node3
                                              received migrate request,
                                              create a migration_mle,
                                              respond to Node2.
                    set DLM_LOCK_RES_SETREF_INPROG
                    and send assert master to
                    Node3
                                              delete migration_mle in
                                              assert_master_handler,
                                              Node3 umount without response
                                              dlm_thread purge
                                              this lockres, send drop
                                              deref message to Node2
                    found the flag of
                    DLM_LOCK_RES_SETREF_INPROG
                    is set, dispatch
                    dlm_deref_lockres_worker to
                    clear refmap, but in function of
                    dlm_deref_lockres_worker,
                    only if node in refmap it wait
                    DLM_LOCK_RES_SETREF_INPROG
                    to be cleared. So worker is
                    done successfully

                                              purge lockres, send
                                              assert master response
                                              to Node1, and finish umount
                    set Node3 in refmap, and it
                    won't be cleared forever, thus
                    lead to umount hung

so wait until DLM_LOCK_RES_SETREF_INPROG is cleared in
dlm_deref_lockres_worker.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Xue jiufei
30bee898f8 ocfs2/dlm: fix a race between purge and migration
We found a race between purge and migration when doing code review.
Node A put lockres to purgelist before receiving the migrate message
from node B which is the master.  Node A call dlm_mig_lockres_handler to
handle this message.

dlm_mig_lockres_handler
  dlm_lookup_lockres
  >>>>>> race window, dlm_run_purge_list may run and send
         deref message to master, waiting the response
  spin_lock(&res->spinlock);
  res->state |= DLM_LOCK_RES_MIGRATING;
  spin_unlock(&res->spinlock);
  dlm_mig_lockres_handler returns

  >>>>>> dlm_thread receives the response from master for the deref
  message and triggers the BUG because the lockres has the state
  DLM_LOCK_RES_MIGRATING with the following message:

dlm_purge_lockres:209 ERROR: 6633EB681FA7474A9C280A4E1A836F0F: res
M0000000000000000030c0300000000 in use after deref

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
xuejiufei
cc28d6d80f ocfs2/dlm: clear migration_pending when migration target goes down
We have found a BUG on res->migration_pending when migrating lock
resources.  The situation is as follows.

dlm_mark_lockres_migration
  res->migration_pending = 1;
  __dlm_lockres_reserve_ast
  dlm_lockres_release_ast returns with res->migration_pending remains
      because other threads reserve asts
  wait dlm_migration_can_proceed returns 1
  >>>>>>> o2hb found that target goes down and remove target
          from domain_map
  dlm_migration_can_proceed returns 1
  dlm_mark_lockres_migrating returns -ESHOTDOWN with
      res->migration_pending still remains.

When reentering dlm_mark_lockres_migrating(), it will trigger the BUG_ON
with res->migration_pending.  So clear migration_pending when target is
down.

Signed-off-by: Jiufei Xue <xuejiufei@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-29 17:45:49 -08:00
Joseph Qi
5afc44e2e9 ocfs2: add uuid to ocfs2 thread name for problem analysis
A node can mount multiple ocfs2 volumes.  And if thread names are same for
each volume/domain, it will bring inconvenience when analyzing problems
because we have to identify which volume/domain the messages belong to.

Since thread name will be printed to messages, so add volume uuid or dlm
name to thread name can benefit problem analysis.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Gang He <ghe@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Joseph Qi
b67de018b3 ocfs2/dlm: unlock lockres spinlock before dlm_lockres_put
dlm_lockres_put will call dlm_lockres_release if it is the last
reference, and then it may call dlm_print_one_lock_resource and
take lockres spinlock.

So unlock lockres spinlock before dlm_lockres_put to avoid deadlock.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-23 17:55:10 +09:00
Joseph Qi
012572d4fc ocfs2/dlm: fix deadlock when dispatch assert master
The order of the following three spinlocks should be:
dlm_domain_lock < dlm_ctxt->spinlock < dlm_lock_resource->spinlock

But dlm_dispatch_assert_master() is called while holding
dlm_ctxt->spinlock and dlm_lock_resource->spinlock, and then it calls
dlm_grab() which will take dlm_domain_lock.

Once another thread (for example, dlm_query_join_handler) has already
taken dlm_domain_lock, and tries to take dlm_ctxt->spinlock deadlock
happens.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: "Junxiao Bi" <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22 15:09:53 -07:00
Andrew Morton
e527b22c3f revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each"
Revert commit f83c7b5e9f ("ocfs2/dlm: use list_for_each_entry instead
of list_for_each").

list_for_each_entry() will dereference its `pos' argument, which can be
NULL in dlm_process_recovery_data().

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-11 15:21:34 -07:00
Yiwen Jiang
f57a22ddec ocfs2: avoid access invalid address when read o2dlm debug messages
The following case will lead to a lockres is freed but is still in use.

cat /sys/kernel/debug/o2dlm/locking_state	dlm_thread
lockres_seq_start
    -> lock dlm->track_lock
    -> get resA
                                                resA->refs decrease to 0,
                                                call dlm_lockres_release,
                                                and wait for "cat" unlock.
Although resA->refs is already set to 0,
increase resA->refs, and then unlock
                                                lock dlm->track_lock
                                                    -> list_del_init()
                                                    -> unlock
                                                    -> free resA

In such a race case, invalid address access may occurs.  So we should
delete list res->tracking before resA->refs decrease to 0.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Norton.Zhu
72f6fe1fe5 ocfs2: optimize error handling in dlm_request_join
Currently error handling in dlm_request_join is a little obscure, so
optimize it to promote readability.

If packet.code is invalid, reset it to JOIN_DISALLOW to keep it
meaningful.  It only influences the log printing.

Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Joseph Qi
f83c7b5e9f ocfs2/dlm: use list_for_each_entry instead of list_for_each
Use list_for_each_entry instead of list_for_each to simplify code.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Joseph Qi
0e3d9eafb8 ocfs2: remove unneeded code in dlm_register_domain_handlers
The last goto statement is unneeded, so remove it.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Joseph Qi
cdd09f49cb ocfs2: fix BUG when o2hb_register_callback fails
In dlm_register_domain_handlers, if o2hb_register_callback fails, it
will call dlm_unregister_domain_handlers to unregister.  This will
trigger the BUG_ON in o2hb_unregister_callback because hc_magic is 0.
So we should call o2hb_setup_callback to initialize hc first.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Joseph Qi
345dc681bd ocfs2/dlm: cleanup unused function __dlm_wait_on_lockres_flags_set
__dlm_wait_on_lockres_flags_set() is declared but not implemented and
used.  So remove it.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:39 -07:00
Junxiao Bi
b1432a2a35 ocfs2: dlm: fix race between purge and get lock resource
There is a race window in dlm_get_lock_resource(), which may return a
lock resource which has been purged.  This will cause the process to
hang forever in dlmlock() as the ast msg can't be handled due to its
lock resource not existing.

    dlm_get_lock_resource {
        ...
        spin_lock(&dlm->spinlock);
        tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash);
        if (tmpres) {
             spin_unlock(&dlm->spinlock);
             >>>>>>>> race window, dlm_run_purge_list() may run and purge
                              the lock resource
             spin_lock(&tmpres->spinlock);
             ...
             spin_unlock(&tmpres->spinlock);
        }
    }

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05 17:10:11 -07:00
Srinivas Eeda
99b8874e79 o2dlm: fix NULL pointer dereference in o2dlm_blocking_ast_wrapper
A tiny race between BAST and unlock message causes the NULL dereference.

A node sends an unlock request to master and receives a response.  Before
processing the response it receives a BAST from the master.  Since both
requests are processed by different threads it creates a race.  While the
BAST is being processed, lock can get freed by unlock code.

This patch makes bast to return immediately if lock is found but unlock is
pending.  The code should handle this race.  We also have to fix master
node to skip sending BAST after receiving unlock message.

Below is the crash stack

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
    IP: o2dlm_blocking_ast_wrapper+0xd/0x16
    dlm_do_local_bast+0x8e/0x97 [ocfs2_dlm]
    dlm_proxy_ast_handler+0x838/0x87e [ocfs2_dlm]
    o2net_process_message+0x395/0x5b8 [ocfs2_nodemanager]
    o2net_rx_until_empty+0x762/0x90d [ocfs2_nodemanager]
    worker_thread+0x14d/0x1ed

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:30 -08:00
Rickard Strandqvist
95671c63d5 ocfs2: dlm: dlmdomain: remove unused function
Remove dlm_joined() that is not used anywhere.

This was partially found by using a static code analysis program called
cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:29 -08:00