On Mon, 11 Jun 2012 08:39:32 -0400 Jeff Layton <jlayton@xxxxxxxxxx> wrote: > On Mon, 11 Jun 2012 08:16:34 -0400 > bfields <bfields@xxxxxxxxxxxx> wrote: > > > On Sun, Jun 10, 2012 at 03:00:42PM +0000, Myklebust, Trond wrote: > > > Cc: linux-nfs@xxxxxxxxxxxxxxx + bfields and changing title to label it > > > as a server regression since that is what the trace appears to imply. > > > > > > On Sun, 2012-06-10 at 12:56 +0200, Joerg Platte wrote: > > > > All 3.4 kernels I tried so far (3.4, 3.4.1 and 3.4.2) suffer from the > > > > same NFS related problem: > > > > > > > > Jun 10 09:23:36 coco kernel: INFO: task kworker/u:1:8 blocked for more > > > > than 120 seconds. > > > > Jun 10 09:23:36 coco kernel: "echo 0 > > > > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > > > Jun 10 09:23:36 coco kernel: kworker/u:1 D 002ba28c 0 8 > > > > 2 0x00000000 > > > > Jun 10 09:23:36 coco kernel: df465ec0 00000046 00000005 002ba28c > > > > 00000000 0000000a 00000282 df465e70 > > > > Jun 10 09:23:36 coco kernel: df465ec0 df44d2b0 ffff6b60 df465e84 > > > > df44d2b0 e33fa6b3 00000282 de764ae0 > > > > Jun 10 09:23:36 coco kernel: ffffffff d78bcfb8 df465e8c c012e0f6 > > > > df465ea4 c013610c 00000000 d78bcf80 > > > > Jun 10 09:23:36 coco kernel: Call Trace: > > > > Jun 10 09:23:36 coco kernel: [<c012e0f6>] ? add_timer+0x11/0x17 > > > > Jun 10 09:23:36 coco kernel: [<c013610c>] ? queue_delayed_work_on+0x74/0xf0 > > > > Jun 10 09:23:36 coco kernel: [<c0136ba4>] ? queue_delayed_work+0x1b/0x28 > > > > Jun 10 09:23:36 coco kernel: [<c0350f5b>] schedule+0x1d/0x4c > > > > Jun 10 09:23:36 coco kernel: [<e0cda5f1>] cld_pipe_upcall+0x4e/0x75 [nfsd] > > > > Jun 10 09:23:36 coco kernel: [<e0cda678>] > > > > nfsd4_cld_grace_done+0x60/0x99 [nfsd] > > > > Jun 10 09:23:36 coco kernel: [<e0cd9cb5>] > > > > nfsd4_record_grace_done+0x10/0x12 [nfsd] > > > > Jun 10 09:23:36 coco kernel: [<e0cd6696>] laundromat_main+0x291/0x2d8 > > > > [nfsd] > > > > Jun 10 09:23:36 coco kernel: [<c0136d2f>] process_one_work+0xff/0x325 > > > > Jun 10 09:23:36 coco kernel: [<c0134bec>] ? start_worker+0x20/0x23 > > > > Jun 10 09:23:36 coco kernel: [<e0cd6405>] ? > > > > nfsd4_process_open1+0x32b/0x32b [nfsd] > > > > Jun 10 09:23:36 coco kernel: [<c013727a>] worker_thread+0xf4/0x39a > > > > Jun 10 09:23:36 coco kernel: [<c0137186>] ? rescuer_thread+0x231/0x231 > > > > Jun 10 09:23:36 coco kernel: [<c013a556>] kthread+0x6c/0x6e > > > > Jun 10 09:23:36 coco kernel: [<c013a4ea>] ? kthreadd+0xe8/0xe8 > > > > Jun 10 09:23:36 coco kernel: [<c035263e>] kernel_thread_helper+0x6/0xd > > > > > > > > A kworker task is stuck in D state and nfs mounts from other clients do > > > > not work at all. This happens only on one machine, another one with the > > > > same kernel (same self compiled Debian package) works. All previous 3.3 > > > > kernels work as well. > > > > > > > > Since this machine is remote it is not that easy to bisect to find the > > > > bad commit. Are there any other things I can try? > > > > If you create a directory named /var/lib/nfs/v4recovery/, does the > > problem go away? > > > > My guess would be that it's trying to upcall to the new reboot-recovery > > state daemon, and you don't have that running. > > > > Before the addition of that upcall state was kept in > > /var/lib/nfs/v4recovery. So we decide whether to use the old method or > > the new one by checking for the existance of that path. > > > > But I'm guessing we were wrong to assume that existing setups that > > people perceived as working would have that path, because the failures > > in the absence of that path were probably less obvious. > > > > --b. > > This sounds like the same problem that Hans reported as well. I've not > been able to reproduce that so far. Here's what I get when I start nfsd > with no v4recoverdir and nfsdcld isn't running: > > [ 109.715080] NFSD: starting 90-second grace period > [ 229.984220] NFSD: Unable to end grace period: -110 > > What I don't quite understand is why the queue_timeout job isn't > getting run here. What should happen is that 30s after upcall, > rpc_timeout_upcall_queue should run. The message will be found to be > still sitting on the , so it should set its status to -ETIMEDOUT > and wake up the caller. > > I can only assume that the queue_timeout job isn't getting run for some > reason, but I'm unclear on why that would be. > Ahh, I think I see the bug. From rpc_timeout_upcall_queue: -----------------------[snip]-------------------------- dentry = dget(pipe->dentry); spin_unlock(&pipe->lock); if (dentry) { rpc_purge_list(&RPC_I(dentry->d_inode)->waitq, &free_list, destroy_msg, -ETIMEDOUT); dput(dentry); } -----------------------[snip]-------------------------- ...when there is no dentry (as there wouldn't be when rpc_pipefs isn't mounted), then the rpc_purge_list won't run. FWIW, you'd probably see similar problems if you attempted a sec=krb5 mount without having rpc_pipefs mounted. I'm still looking at the code to see what the right fix is. For now, making sure you have a /var/lib/nfs/v4recoverydir is probably the easiest workaround. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html