Comment 28 for bug 879334

Sven Rudolph (rudolph) wrote :

Same here.
NFSv4 mounted home dirs (from a Ubuntu 12.04 LTS NFSv4 server) become very slow. Eventually the client machine freezes completely -> reset button.
Using Opensuse 12.2 as NFSv4 client produces no problems at all.
This is reproducable.

Same on some of our servers with NFSv4 mounted directories. All Ubuntu 12.04 LTS, NFSv4 servers and clients.
Frequent messages in /var/log/syslog:
[...]
Jan 25 11:49:39 xxx kernel: [ 8996.289241] Call Trace:
Jan 25 11:49:39 xxx kernel: [ 8996.289246] [<ffffffff81659ebf>] schedule+0x3f/0x60
Jan 25 11:49:39 xxx kernel: [ 8996.289249] [<ffffffff8165acc7>] __mutex_lock_slowpath+0xd7/0x150
Jan 25 11:49:39 xxx kernel: [ 8996.289253] [<ffffffff8165a8da>] mutex_lock+0x2a/0x50
Jan 25 11:49:39 xxx kernel: [ 8996.289256] [<ffffffff81186404>] do_last+0x2b4/0x730
Jan 25 11:49:39 xxx kernel: [ 8996.289260] [<ffffffff81187c21>] path_openat+0xd1/0x3f0
Jan 25 11:49:39 xxx kernel: [ 8996.289263] [<ffffffff81183565>] ? putname+0x35/0x50
Jan 25 11:49:39 xxx kernel: [ 8996.289266] [<ffffffff81187fc3>] ? user_path_at_empty+0x63/0xa0
Jan 25 11:49:39 xxx kernel: [ 8996.289275] [<ffffffffa01337db>] ? nfs_attribute_cache_expired+0x1b/0x70 [nfs]
Jan 25 11:49:39 xxx kernel: [ 8996.289279] [<ffffffff81188062>] do_filp_open+0x42/0xa0
Jan 25 11:49:39 xxx kernel: [ 8996.289284] [<ffffffff81319c11>] ? strncpy_from_user+0x31/0x40
Jan 25 11:49:39 xxx kernel: [ 8996.289287] [<ffffffff811833aa>] ? do_getname+0x10a/0x180
Jan 25 11:49:39 xxx kernel: [ 8996.289291] [<ffffffff8165bdce>] ? _raw_spin_lock+0xe/0x20
Jan 25 11:49:39 xxx kernel: [ 8996.289294] [<ffffffff81195377>] ? alloc_fd+0xf7/0x150
Jan 25 11:49:39 xxx kernel: [ 8996.289298] [<ffffffff81177688>] do_sys_open+0xf8/0x240
Jan 25 11:49:39 xxx kernel: [ 8996.289301] [<ffffffff811777f0>] sys_open+0x20/0x30
Jan 25 11:49:39 xxx kernel: [ 8996.289304] [<ffffffff816643c2>] system_call_fastpath+0x16/0x1b
[...]

Eventually the servers which act as NFS clients freeze completely -> remote reset. (It's just a test system).
This is reproducable.
Needless to say, that this disqualifies Ubuntu 12.04 LTS as an NFS client.

A fix of this bug would be highly appreciated!