Unverified Commit 230536ff authored by Christian Brauner's avatar Christian Brauner
Browse files

pidfs: support FS_IOC_GETVERSION 

This will allow 32 bit userspace to detect when a given inode number has
been recycled and also to construct a unique 64 bit identifier.

Link: https://lore.kernel.org/r/20241129-work-pidfs-v2-3-61043d66fbce@kernel.org


Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 03c212bf

fs/pidfs.c

+8 −0
Original line number Diff line number Diff line
@@ -271,6 +271,14 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	struct ns_common *ns_common = NULL;

	struct pid_namespace *pid_ns;



	if (cmd == FS_IOC_GETVERSION) {

		if (!arg)

			return -EINVAL;



		__u32 __user *argp = (__u32 __user *)arg;

		return put_user(file_inode(file)->i_generation, argp);

	}



	task = get_pid_task(pid, PIDTYPE_PID);

	if (!task)

		return -ESRCH;