On Tue, 2008-07-15 at 22:30 -0700, Chris Walker wrote: > Thanks for your response. > > In this case, it appears that statsfs triggers the mount, but returns > before the mount completes. stat waits for the automount to complete > before returning.
If statfs really is triggering the mount (not something else you haven't noticed, maybe another command or program system call) then it should wait. If your map doesn't use the "browse" option or the --ghost option then stat and statfs will trigger mounts and wait for them to complete. That's not to say there aren't any races relating to multiple concurrent processes accessing the mount points. I'm working on that right now. But that isn't the situation your describing by the sound of it. So something else is going on that we're not yet aware of. > > I would like statfs() to wait--is there a way to make it? > > Thanks for all your hard work on this critical piece of software. > > From raven [07/15 20:47]: > > > > On Tue, 2008-07-15 at 13:48 -0700, Chris Walker wrote: > > > autofs 5.0.3 > > > linux 2.6.18 What patches have you applied to this kernel. I have a bunch of maintenance and bug fixes that aren't in this kernel. > > > > > > When statfs() is called on an automounted directory, it returns before > > > the automount occurs. This results in output like this initially: > > > > That may be because there are a group of system calls that don't trigger > > a mount because we have to avoid mount storms for map entries that use > > the browse option. In particular stat(2) and calls that use the same > > kernel path lookup flags, such as statfs(2). > > > > Basically, if the mount point directory exists in the autofs file system > > but doesn't currently have a mount for some reason (perhaps it wasn't > > removed at expire or the entry uses the browse option), these calls will > > return the attributes of the autofs directory without performing a > > mount. > > > > > > > > % df /home/XXX > > > Filesystem 1K-blocks Used Available Use% Mounted on > > > - 0 0 0 - /home > > > > > > If df is run a second later, > > > > > > % df /home/XXX > > > Filesystem 1K-blocks Used Available Use% Mounted on > > > XXX:/home/XXX > > > 80634688 77952736 2681952 97% /home/XXX > > > > > > Perhaps there are options of which I'm not aware to mitigate this > > > behavior. > > > > > > Apologies if the answer to my query lies elsewhere in the kernel. > > > > > > _______________________________________________ autofs mailing list [email protected] http://linux.kernel.org/mailman/listinfo/autofs
