diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2023-10-25 16:01:59 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-11-18 14:56:16 +0100 |
| commit | 98d2b43081972abeb5bb5a087bc3e3197531c46e (patch) | |
| tree | b56d8e448127d642c39b6fad6f14a5166666d3f1 /include/uapi | |
| parent | b85ea95d086471afb4ad062012a4d73cd328fa86 (diff) | |
add unique mount ID
If a mount is released then its mnt_id can immediately be reused. This is
bad news for user interfaces that want to uniquely identify a mount.
Implementing a unique mount ID is trivial (use a 64bit counter).
Unfortunately userspace assumes 32bit size and would overflow after the
counter reaches 2^32.
Introduce a new 64bit ID alongside the old one. Initialize the counter to
2^32, this guarantees that the old and new IDs are never mixed up.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://lore.kernel.org/r/20231025140205.3586473-2-mszeredi@redhat.com
Reviewed-by: Ian Kent <raven@themaw.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/stat.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 7cab2c65d3d7..2f2ee82d5517 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -154,6 +154,7 @@ struct statx { #define STATX_BTIME 0x00000800U /* Want/got stx_btime */ #define STATX_MNT_ID 0x00001000U /* Got stx_mnt_id */ #define STATX_DIOALIGN 0x00002000U /* Want/got direct I/O alignment info */ +#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */ #define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */ |