Godeps/_workspace/src/gopkg.in/mgo.v2/session.go
func (s *Session) FsyncLock() error {
	return s.Run(bson.D{{"fsync", 1}, {"lock", true}}, nil)
}
func (s *Session) FsyncLock() error {
	return s.Run(bson.D{{"fsync", 1}, {"lock", true}}, nil)
}
func ( s * Session ) FsyncLock ( ) error { return s . Run ( bson . D { { " " , 1 } , { " " , true } } , nil ) }
// FsyncLock locks all writes in the specific server the session is
// established with and returns. Any writes attempted to the server
// after it is successfully locked will block until FsyncUnlock is
// called for the same server.
//
// This method works on secondaries as well, preventing the oplog from
// being flushed while the server is locked, but since only the server
// connected to is locked, for locking specific secondaries it may be
// necessary to establish a connection directly to the secondary (see
// Dial's connect=direct option).
//
// As an important caveat, note that once a write is attempted and
// blocks, follow up reads will block as well due to the way the
// lock is internally implemented in the server. More details at:
//
//     https://jira.mongodb.org/browse/SERVER-4243
//
// FsyncLock is often used for performing consistent backups of
// the database files on disk.
//
// Relevant documentation:
//
//     http://www.mongodb.org/display/DOCS/fsync+Command
//     http://www.mongodb.org/display/DOCS/Backups
//
FsyncLock locks all writes in the specific server the session is established with and returns . Any writes attempted to the server after it is successfully locked will block until FsyncUnlock is called for the same server . This method works on secondaries as well preventing the oplog from being flushed while the server is locked but since only the server connected to is locked for locking specific secondaries it may be necessary to establish a connection directly to the secondary ( see Dial s connect = direct option ) . As an important caveat note that once a write is attempted and blocks follow up reads will block as well due to the way the lock is internally implemented in the server . More details at : https : // jira . mongodb . org / browse / SERVER - 4243 FsyncLock is often used for performing consistent backups of the database files on disk . Relevant documentation : http : // www . mongodb . org / display / DOCS / fsync + Command http : // www . mongodb . org / display / DOCS / Backups