From d04bccd8c19d601232ed3e3c9e248c0040167d47 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 7 Jun 2024 16:55:37 +0200 Subject: listmount: allow listing in reverse order util-linux is about to implement listmount() and statmount() support. Karel requested the ability to scan the mount table in backwards order because that's what libmount currently does in order to get the latest mount first. We currently don't support this in listmount(). Add a new LISTMOUNT_REVERSE flag to allow listing mounts in reverse order. For example, listing all child mounts of /sys without LISTMOUNT_REVERSE gives: /sys/kernel/security @ mnt_id: 4294968369 /sys/fs/cgroup @ mnt_id: 4294968370 /sys/firmware/efi/efivars @ mnt_id: 4294968371 /sys/fs/bpf @ mnt_id: 4294968372 /sys/kernel/tracing @ mnt_id: 4294968373 /sys/kernel/debug @ mnt_id: 4294968374 /sys/fs/fuse/connections @ mnt_id: 4294968375 /sys/kernel/config @ mnt_id: 4294968376 whereas with LISTMOUNT_REVERSE it gives: /sys/kernel/config @ mnt_id: 4294968376 /sys/fs/fuse/connections @ mnt_id: 4294968375 /sys/kernel/debug @ mnt_id: 4294968374 /sys/kernel/tracing @ mnt_id: 4294968373 /sys/fs/bpf @ mnt_id: 4294968372 /sys/firmware/efi/efivars @ mnt_id: 4294968371 /sys/fs/cgroup @ mnt_id: 4294968370 /sys/kernel/security @ mnt_id: 4294968369 Link: https://lore.kernel.org/r/20240607-vfs-listmount-reverse-v1-4-7877a2bfa5e5@kernel.org Reviewed-by: Josef Bacik Signed-off-by: Christian Brauner --- include/uapi/linux/mount.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h index ad5478dbad00..88d78de1519f 100644 --- a/include/uapi/linux/mount.h +++ b/include/uapi/linux/mount.h @@ -207,5 +207,6 @@ struct mnt_id_req { * Special @mnt_id values that can be passed to listmount */ #define LSMT_ROOT 0xffffffffffffffff /* root mount */ +#define LISTMOUNT_REVERSE (1 << 0) /* List later mounts first */ #endif /* _UAPI_LINUX_MOUNT_H */ -- cgit v1.2.3