diff options
Diffstat (limited to 'include/linux/kernfs.h')
| -rw-r--r-- | include/linux/kernfs.h | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index a9b11b8d06f2..ab25c8b6d9e3 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -69,6 +69,12 @@ enum kernfs_root_flag { * following flag enables that behavior. */ KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK = 0x0002, + + /* + * The filesystem supports exportfs operation, so userspace can use + * fhandle to access nodes of the fs. + */ + KERNFS_ROOT_SUPPORT_EXPORTOP = 0x0004, }; /* type-specific structures for kernfs_node union members */ @@ -95,6 +101,21 @@ struct kernfs_elem_attr { struct kernfs_node *notify_next; /* for kernfs_notify() */ }; +/* represent a kernfs node */ +union kernfs_node_id { + struct { + /* + * blktrace will export this struct as a simplified 'struct + * fid' (which is a big data struction), so userspace can use + * it to find kernfs node. The layout must match the first two + * fields of 'struct fid' exactly. + */ + u32 ino; + u32 generation; + }; + u64 id; +}; + /* * kernfs_node - the building block of kernfs hierarchy. Each and every * kernfs node is represented by single kernfs_node. Most fields are @@ -131,9 +152,9 @@ struct kernfs_node { void *priv; + union kernfs_node_id id; unsigned short flags; umode_t mode; - unsigned int ino; struct kernfs_iattrs *iattr; }; @@ -163,7 +184,8 @@ struct kernfs_root { unsigned int flags; /* KERNFS_ROOT_* flags */ /* private fields, do not use outside kernfs proper */ - struct ida ino_ida; + struct idr ino_idr; + u32 next_generation; struct kernfs_syscall_ops *syscall_ops; /* list of kernfs_super_info of this root, protected by kernfs_mutex */ @@ -336,6 +358,8 @@ struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns); void kernfs_init(void); +struct kernfs_node *kernfs_get_node_by_id(struct kernfs_root *root, + const union kernfs_node_id *id); #else /* CONFIG_KERNFS */ static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn) |