diff options
Diffstat (limited to 'include/linux/exportfs.h')
| -rw-r--r-- | include/linux/exportfs.h | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 262e24d83313..8bcdba28b406 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -200,6 +200,10 @@ struct handle_to_path_ctx { * @get_parent: find the parent of a given directory * @commit_metadata: commit metadata changes to stable storage * + * Methods for open_by_handle(2) syscall with special kernel file systems: + * @permission: custom permission for opening a file by handle + * @open: custom open routine for opening file by handle + * * See Documentation/filesystems/nfs/exporting.rst for details on how to use * this interface correctly and the definition of the flags. * @@ -244,10 +248,14 @@ struct handle_to_path_ctx { * space cannot be allocated, a %ERR_PTR should be returned. * * @permission: - * Allow filesystems to specify a custom permission function. + * Allow filesystems to specify a custom permission function for the + * open_by_handle_at(2) syscall instead of the default permission check. + * This custom permission function is not respected by nfsd. * * @open: - * Allow filesystems to specify a custom open function. + * Allow filesystems to specify a custom open function for the + * open_by_handle_at(2) syscall instead of the default file_open_root(). + * This custom open function is not respected by nfsd. * * @commit_metadata: * @commit_metadata should commit metadata changes to stable storage. @@ -330,6 +338,15 @@ static inline bool exportfs_can_decode_fh(const struct export_operations *nop) return nop && nop->fh_to_dentry; } +static inline bool exportfs_may_export(const struct export_operations *nop) +{ + /* + * Do not allow nfs export for filesystems with custom ->open() or + * ->permission() ops, which nfsd does not respect (e.g. pidfs, nsfs). + */ + return exportfs_can_decode_fh(nop) && !nop->open && !nop->permission; +} + static inline bool exportfs_can_encode_fh(const struct export_operations *nop, int fh_flags) { |