diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2024-10-11 11:00:22 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-11-15 11:34:57 +0100 |
| commit | c374196b2b9f4b803fccd59ed82f0712041e21e1 (patch) | |
| tree | f8ac07aa4e5f901cf554c6207447d514777d1fc0 /include/uapi/linux | |
| parent | 4a530a7c751d27f9dbd70b7fc45670cd11713b13 (diff) | |
fs: name_to_handle_at() support for "explicit connectable" file handles
nfsd encodes "connectable" file handles for the subtree_check feature,
which can be resolved to an open file with a connected path.
So far, userspace nfs server could not make use of this functionality.
Introduce a new flag AT_HANDLE_CONNECTABLE to name_to_handle_at(2).
When used, the encoded file handle is "explicitly connectable".
The "explicitly connectable" file handle sets bits in the high 16bit of
the handle_type field, so open_by_handle_at(2) will know that it needs
to open a file with a connected path.
old kernels will now recognize the handle_type with high bits set,
so "explicitly connectable" file handles cannot be decoded by
open_by_handle_at(2) on old kernels.
The flag AT_HANDLE_CONNECTABLE is not allowed together with either
AT_HANDLE_FID or AT_EMPTY_PATH.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20241011090023.655623-3-amir73il@gmail.com
Fixes: 570df4e9c23f ("ceph: snapshot nfs re-export")
Acked-by:
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/fcntl.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index 87e2dec79fea..56ff2100e021 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -153,6 +153,7 @@ object identity and may not be usable with open_by_handle_at(2). */ #define AT_HANDLE_MNT_ID_UNIQUE 0x001 /* Return the u64 unique mount ID. */ +#define AT_HANDLE_CONNECTABLE 0x002 /* Request a connectable file handle */ #if defined(__KERNEL__) #define AT_GETATTR_NOSEC 0x80000000 |