On Thu, 24 May 2012 10:13:29 +0400 Sergey Urushkin <urushkin@xxxxxxxxx> wrote: > Hi, > > there are issues with cifs share mounted via mount.cifs (with recent > kernels): the first 'ls' on the dir where cifs share is mounted after the > server becomes unavailable 1) hangs (can't be interrupted with ^C) and 2) > lasts about 5 minutes. The first problem appears everywhere I tested > (ubuntu 10.04 with any distributed kernel, ubuntu 12.04, fedora 17), but > with old kernels (tested with ubuntu 10.04 2.6.32 and 2.6.35) 'ls' is > uninterruptable but hangs only for about 25 seconds (which makes this > problem really less complex for old kernels). And with new kernels (ubuntu > 10.04 3.0, ubuntu 12.04 3.2, fedora 17 3.3) I'm facing very long hangs of > 'ls' (the second problem). And many GUI applications (e.g. nautilus, > firefox, gnome-panel,mc) that query that directory for some reason appears > to act the same way as 'ls', so the system becomes unusable for 5(!) > minutes. When the server (tested with samba 3.6, win2003) becomes > unavailable nothing is written on the mounted directory, so I can't > understand why this timeout is so big. Here is how I tested this: > > # mount.cifs //fsrv/home /mnt "-ouser=test,dom=wg,soft" > Password: > # time ls /mnt > Desktop Documents Program Files WINDOWS > > real 0m0.019s > user 0m0.004s > sys 0m0.012s > # iptables -I OUTPUT -d 172.17.0.65 -j DROP > # time ls /mnt # This 'ls' cannot be interrupted > ls: cannot access /mnt: Host is down > > real 4m51.668s > user 0m0.004s > sys 0m0.016s > # time ls /mnt # This 'ls' and all others after can be interrupted > ls: cannot access /mnt: Host is down > > real 0m10.014s > user 0m0.008s > sys 0m0.004s > > I see these messages in syslog: > > kernel: [ 1625.552044] CIFS VFS: Server fsrv has not responded in 300 > seconds. Reconnecting... > kernel: [ 1655.509422] CIFS VFS: Unexpected lookup error -112 > > ... > > And I can not see any timeout options for mount.cifs (except acl timeout). > So, the actual questions are: 1) is there a way to avoid these hangs > (analog of 'intr'?) and 2) how can I reduce this unreachable-host timeout > (analog of 'timeo'?)? Maybe there are some variables in the sources? > > Thanks. > You can try setting the echo_retries kernel module parameter to 1, which should cut down the wait time to 60s. In 3.4, we've removed that parm and it's now set to 1 always. The timeout between echo requests (which is how we detect whether the server is still responding) is not currently tunable. -- Jeff Layton <jlayton@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
