Date: Thu, 11 Feb 2021 15:06:57 -0700 From: Alan Somers <asomers@freebsd.org> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: freebsd-fs <freebsd-fs@freebsd.org> Subject: Re: NFS delegations don't expire after unmounting client Message-ID: <CAOtMX2jXC-h8kuKn2tqYyY1VnDmZd9Yy%2BjHQNwgmVBC8nHtYQQ@mail.gmail.com> In-Reply-To: <YQXPR0101MB09684A4372F120C3B3FE5BE5DD8C9@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM> References: <CAOtMX2h_2zCNpyzOs=SzuohRvLgga=Eip-LJ-7QjJBvwmueLXg@mail.gmail.com> <YQXPR0101MB09684A4372F120C3B3FE5BE5DD8C9@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Feb 11, 2021 at 2:54 PM Rick Macklem <rmacklem@uoguelph.ca> wrote: > Alan Somers wrote: > >I have several Linux 5.9.15 clients mounting NFS 4.1 served from a FreeBSD > >12.2-RELEASE server. Today, most of those clients' mounts hung, and their > >dmesg displayed "nfs: server XXX not responding, still trying". > Usually these messages indicate a networking layer problem. > Next time (or if it still happening), check basic network connectivity. > Also, if any net interface does not handle TSO correctly for an RPC > message near 64Kbytes in size (the nasty one is where the NFS RPC is > less than 64K by less than 14bytes, so when the MAC layer header is > prepended, the total exceed 64K), you can get "stuck" TCP connections. > Most FreeBSD net chip drivers should be fixed for this, but I wouldn't be > surprised if there are some broken ones out there. > --> Disabling TSO fixes the problem in this case. In fact it is still happening. Basic network connectivity works. But tcpdump shows almost no network activity. Just a few keepalive packets of length 0-1. Based on the fact that unmount and even lsof hang on the client, I'm suspecting a Linux bug somewhere. -Alan
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOtMX2jXC-h8kuKn2tqYyY1VnDmZd9Yy%2BjHQNwgmVBC8nHtYQQ>