From 2d769c3bc5aab3e4ef4fea37d7871311f6f21b88 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:52 +0200 Subject: [PATCH] nsfs: support exhaustive file handles Pidfd file handles are exhaustive meaning they don't require a handle on another pidfd to pass to open_by_handle_at() so it can derive the filesystem to decode in. Instead it can be derived from the file handle itself. The same is possible for namespace file handles. Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- include/uapi/linux/fcntl.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index 59cbae1..3b401f2 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -111,6 +111,7 @@ #define PIDFD_SELF_THREAD_GROUP -10001 /* Current thread group leader. */ #define FD_PIDFS_ROOT -10002 /* Root of the pidfs filesystem */ +#define FD_NSFS_ROOT -10003 /* Root of the nsfs filesystem */ #define FD_INVALID -10009 /* Invalid file descriptor: -10000 - EBADF = -10009 */ /* Generic flags for the *at(2) family of syscalls. */