fusedev: add clone_fuse_file method to FuseSession

[loheagn]

This patch adds clone_fuse_file method to FuseSession.

This function obtains a new file descriptor by opening /dev/fuse and associates the file descriptor with the original fuse connection of fuse session using the ioctl FUSE_DEV_IOC_CLONE command.

[loheagn]

I try to use the following code to test this feature:

let dir = TempDir::new().unwrap();
let se = FuseSession::new(dir.as_path(), "foo", "bar", true);
assert!(se.is_ok());
let mut se = se.unwrap();
se.mount().unwrap();

but get CI error:

fusermount3: option allow_other only allowed if 'user_allow_other' is set in /etc/fuse.conf

Should I config the /etc/fuse.conf by modify the ci configuration files?

[bergwolf]

@loheagn Could you explain a bit why you need it?

[loheagn]

@loheagn Could you explain a bit why you need it?

As the comment discussed, clone fuse file can avoid blocking the IO requests when restarting nydusd.

[jiangliu]

let mut se = FuseSession::new(dir.as_path(), "foo", "bar", true).unwrap();?

[loheagn]

fixed

[jiangliu]

user_allow_other

We should do that:)

[loheagn]

user_allow_other

We should do that:)

@jiangliu Should I fix this in this patch?

[jiangliu]

user_allow_other

We should do that:)

@jiangliu Should I fix this in this patch?

Please fix it:)