2016-11-24 10:10 GMT+01:00 Miklos Szeredi <miklos@xxxxxxxxxx>: > On Thu, Nov 24, 2016 at 12:11 AM, Nikolaus Rath <Nikolaus@xxxxxxxx> wrote: >> Hello, >> >> Currently, both a call to umount(2) and writing "1" to >> /sys/fs/fuse/connections/NNN/abort will put the /dev/fuse fd into the >> same state: reading from it returns ENODEV, and polling on it returns >> POLLERR. >> >> This causes problems for filesystems that want to ensure that the >> mountpoint is free when they exit. If accessing the device fd gives the >> above errors, they have to do an additional check to determine if they >> still need to unmount the mountpoint. This is difficult to do without >> race conditions (think of someone unmounting and immediately re-starting >> a new filesystem instance). A filesystem should check the mountpouint is already mounted when starting right? So when it's mounted already do not start and return a proper return value. I'm currently working with the order of unmounting. When the userspace filesystem detects the VFS has disconnected the filedescriptor (event occurs but reading from it gives zero size when using recv). This happens when terminating with kill. I do not know this also happens when aborting. I must say with my filesystems I've got the fd added to epoll which watches it constantly, and when doing so it reports the event when the VFS closes the fd. What is the right order for the userspace daemon in this case? I think the userspace daemon has to test the mountpoint is still mounted and umount if it is? Stef -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
