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author | xuejiufei <xuejiufei@huawei.com> | 2016-01-14 15:17:38 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 16:00:49 -0800 |
commit | bef5502de074b6f6fa647b94b73155d675694420 (patch) | |
tree | 3c6c516e6cd7923dfc079e3cbaa27f83b2dc554c /fs | |
parent | 1cce4df04f37d3f7b969e85528fa54f918a06f03 (diff) | |
download | lwn-bef5502de074b6f6fa647b94b73155d675694420.tar.gz lwn-bef5502de074b6f6fa647b94b73155d675694420.zip |
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>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ocfs2/dlm/dlmmaster.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 6f0748122117..8b9d483e94a6 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -2519,6 +2519,11 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm, spin_lock(&dlm->master_lock); ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name, namelen, target, dlm->node_num); + /* get an extra reference on the mle. + * otherwise the assert_master from the new + * master will destroy this. + */ + dlm_get_mle_inuse(mle); spin_unlock(&dlm->master_lock); spin_unlock(&dlm->spinlock); @@ -2554,6 +2559,7 @@ fail: if (mle_added) { dlm_mle_detach_hb_events(dlm, mle); dlm_put_mle(mle); + dlm_put_mle_inuse(mle); } else if (mle) { kmem_cache_free(dlm_mle_cache, mle); mle = NULL; @@ -2571,17 +2577,6 @@ fail: * ensure that all assert_master work is flushed. */ flush_workqueue(dlm->dlm_worker); - /* get an extra reference on the mle. - * otherwise the assert_master from the new - * master will destroy this. - * also, make sure that all callers of dlm_get_mle - * take both dlm->spinlock and dlm->master_lock */ - spin_lock(&dlm->spinlock); - spin_lock(&dlm->master_lock); - dlm_get_mle_inuse(mle); - spin_unlock(&dlm->master_lock); - spin_unlock(&dlm->spinlock); - /* notify new node and send all lock state */ /* call send_one_lockres with migration flag. * this serves as notice to the target node that a @@ -3312,6 +3307,15 @@ top: mle->new_master != dead_node) continue; + if (mle->new_master == dead_node && mle->inuse) { + mlog(ML_NOTICE, "%s: target %u died during " + "migration from %u, the MLE is " + "still keep used, ignore it!\n", + dlm->name, dead_node, + mle->master); + continue; + } + /* If we have reached this point, this mle needs to be * removed from the list and freed. */ dlm_clean_migration_mle(dlm, mle); |