From: "Yan, Zheng" <[email protected]> Migrator::export_dir() only check if it can lock the export lock set but not take the lock set. So someone else can change the path to the exporting dir and confuse Migrator::handle_export_discover().
Signed-off-by: Yan, Zheng <[email protected]> --- src/mds/Migrator.cc | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/mds/Migrator.cc b/src/mds/Migrator.cc index c157279..5db21cd 100644 --- a/src/mds/Migrator.cc +++ b/src/mds/Migrator.cc @@ -236,6 +236,8 @@ void Migrator::handle_mds_failure_or_stop(int who) dir->unfreeze_tree(); // cancel the freeze dir->auth_unpin(this); export_state.erase(dir); // clean up + export_unlock(dir); + export_locks.erase(dir); dir->state_clear(CDir::STATE_EXPORTING); if (export_peer[dir] != who) // tell them. mds->send_message_mds(new MExportDirCancel(dir->dirfrag()), export_peer[dir]); @@ -663,6 +665,8 @@ void Migrator::export_dir(CDir *dir, int dest) dout(7) << "export_dir can't rdlock needed locks, failing." << dendl; return; } + mds->locker->rdlock_take_set(locks); + export_locks[dir].swap(locks); // ok. assert(export_state.count(dir) == 0); @@ -705,6 +709,9 @@ void Migrator::handle_export_discover_ack(MExportDirDiscoverAck *m) export_peer[dir] != m->get_source().num()) { dout(7) << "must have aborted" << dendl; } else { + // release locks to avoid deadlock + export_unlock(dir); + export_locks.erase(dir); // freeze the subtree export_state[dir] = EXPORT_FREEZING; dir->auth_unpin(this); -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
