求助：samba服务不明不白挂了。。。

[chinaz]

单位服务器ubuntu12.04使用samba做数据中转，数据存储服务器，每天上百人次登录存取文件5年来一直没有问题，近期并没对服务器做管理操作，过了一个周末回来，访问共享突然出问题了。。。求助高手给诊断一下，先谢谢！
现象：
使用nautiius文件管理器可以直接打开共享位置，一级目录中的几个文件也能打开，但是子文件夹无法打开，提示：“无法显示这一位置。找不到“XXX”。也许它最近被删除了。”
使用windows文件管理器也可以打开共享位置，但是子文件夹打开是空白文件夹，不可以建立文件或文件夹。
登录服务器在文件管理器中查看文件和目录结构均未发现异常，在http中访问共享位置也正常。

/var/log/samba/log.smbd
部分log内容如下：
[2017/03/27 11:32:46, 0] smbd/server.c:1072(main)
smbd version 3.6.25 started.
Copyright Andrew Tridgell and the Samba Team 1992-2011
[2017/03/27 11:32:46, 0] param/loadparm.c:6232(lp_bool)
lp_bool(yes wide links = yes): value is not boolean!
[2017/03/27 11:32:46, 2] lib/tallocmsg.c:124(register_msg_pool_usage)
Registered MSG_REQ_POOL_USAGE
[2017/03/27 11:32:46, 2] lib/dmallocmsg.c:78(register_dmalloc_msgs)
Registered MSG_REQ_DMALLOC_MARK and LOG_CHANGED
[2017/03/27 11:32:46.080054, 2] param/loadparm.c:5026(max_open_files)
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
[2017/03/27 11:32:46.080212, 0] param/loadparm.c:6232(lp_bool)
lp_bool(yes wide links = yes): value is not boolean!
[2017/03/27 11:32:46.080248, 2] param/loadparm.c:8379(do_section)
Processing section "[printers]"
[2017/03/27 11:32:46.080319, 2] param/loadparm.c:8379(do_section)
Processing section "[print$]"
[2017/03/27 11:32:46.080372, 2] param/loadparm.c:8379(do_section)
Processing section "[学校共享]"
[2017/03/27 11:32:46.080458, 2] param/loadparm.c:8379(do_section)
Processing section "[net]"
[2017/03/27 11:32:46.080522, 2] param/loadparm.c:8379(do_section)
Processing section "[broadcast]"
[2017/03/27 11:32:46.080863, 2] lib/interface.c:341(add_interface)
added interface eth0 ip=fe80::2e76:8aff:fe5d:86c4%eth0 bcast=fe80::ffff:ffff:ffff:ffff%eth0 netmask=ffff:ffff:ffff:ffff::
[2017/03/27 11:32:46.080954, 2] lib/interface.c:341(add_interface)
added interface eth0 ip=172.20.29.12 bcast=172.20.29.255 netmask=255.255.255.0
[2017/03/27 11:32:46.081027, 0] smbd/server.c:1128(main)
standard input is not a socket, assuming -D option
[2017/03/27 11:32:46.171457, 2] smbd/server.c:861(smbd_parent_loop)
waiting for connections