On 20/7/23 00:19, Robert Vasek wrote:
Dear autofs mailing list, When stat()-ing mountpoints under autofs, the info it returns is stale, and takes about 3min to for it to reflect up-to-date data after it's changed. I suspect this is related to some caching and timeout settings, but I'm having trouble finding the right config options to set the refresh interval to something shorter. Is there a way to configure this? What I mean by stale info: in my setup, the mounts under autofs are backed by a FUSE-based driver. If the driver process goes down (for any reason; crashing, exiting without first unmounting, being killed...), stat()-ing the mountpoint should normally fail with ENOTCONN. I need to detect these situations and reconcile. When the mounts are managed by autofs however, once the FUSE process is down, it takes around 3min for it to go from returning the old stat info until it gives me ENOTCONN.
It's necessary to understand what's happening to work out if there's anything that can be done. Without information about what's going on once the mount is mounted by autofs then there's very little autofs can do other than check if the mount should be expired and attempt to umount it if it thinks it has timed out. It sounds to me like the case you are describing is similar to the mount becoming unresponsive such as like when an NFS server stops responding. Mostly autofs doesn't know about situations like this and if it tries to umount the mount it will often take a long time to timeout when the mount isn't responsive. A lot of time has been put into dealing with NFS mounts that become unresponsive and they are still a problem at times. To implement a server monitoring system is problematic too, for example, how does autofs know how to check the fuse mounts here, even that's not straight forward and could be different for different file system types. Ian
# automount --version Linux automount version 5.1.7-36.el9 Directories: config dir: /etc/sysconfig maps dir: /etc modules dir: /usr/lib64/autofs Compile options: DISABLE_MOUNT_LOCKING ENABLE_FORCED_SHUTDOWN ENABLE_IGNORE_BUSY_MOUNTS WITH_SYSTEMD WITH_LDAP WITH_SASL LIBXML2_WORKAROUND WITH_LIBTIRPC # uname -srvmpio Linux 5.19.9-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Sep 15 09:49:52 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux Contents of /etc/auto.master.d/eos.autofs map: /eos /etc/auto.eos Contents of /etc/auto.eos: ams -fstype=eosx,fsname=ams :eosxd atlas -fstype=eosx,fsname=atlas :eosxd cms -fstype=eosx,fsname=cms :eosxd experiment -fstype=eosx,fsname=experiment :eosxd geant4 -fstype=eosx,fsname=geant4 :eosxd lhcb -fstype=eosx,fsname=lhcb :eosxd ... The automount daemon is set to run with a timeout of 300 seconds. # stat /eos/atlas File: /eos/atlas Size: 4096 Blocks: 8 IO Block: 4096 directory Device: 100033h/1048627d Inode: 26193792 Links: 2 Access: (0700/drwx------) Uid: (110701/ UNKNOWN) Gid: ( 2763/ UNKNOWN) Access: 2023-07-11 15:29:03.528901692 +0200 Modify: 2023-07-11 15:29:03.528901692 +0200 Change: 2023-07-11 15:29:03.528901692 +0200 Birth: - # kill <PID> (stat keeps showing the same output) (... ~3 minutes later ...) # stat /eos/atlas stat: cannot statx '/eos/atlas': Transport endpoint is not connected Thanks! Cheers, Robert
