Virtual nodes

Collaboration diagram for Virtual nodes:

Data Structures
struct	vnode_operations
	Vector table for operations performed on a single virtual node. More...
struct	vnode
	represents a single virtual node More...

Enumerations
enum	vnode_type {   VNODE_FIFO = S_IFIFO , VNODE_CHARDEVICE = S_IFCHR , VNODE_DIRECTORY = S_IFDIR , VNODE_BLOCKDEVICE = S_IFBLK ,   VNODE_FILE = S_IFREG , VNODE_SYMLINK = S_IFLNK , VNODE_SOCKET = S_IFSOCK }
	The different existing types of vnodes. More...

Functions
vnode_t *	vfs_vnode_acquire (vnode_t *, bool *)
	Increment the refcount of a vnode. More...
vnode_t *	vfs_vnode_release (vnode_t *)
	Decrease the refcount of a vnode. More...
bool	vfs_vnode_check_creds (const struct vnode *, const struct user_creds *, int oflags)
	Check if a process has the right to access a vnode based on its credentials. More...

Detailed Description

Enumeration Type Documentation

vnode_type

enum typedef enum vnode_type vnode_type

Enumerator
VNODE_FIFO	FIFO.
VNODE_CHARDEVICE	Character device.
VNODE_DIRECTORY	Regular directory.
VNODE_BLOCKDEVICE	Block device.
VNODE_FILE	Regular file.
VNODE_SYMLINK	Symbolic link.
VNODE_SOCKET	Socket file.

Function Documentation

vfs_vnode_acquire()

vnode_t * vfs_vnode_acquire	(	vnode_t *	node,
		bool *	new
	)

Similarily to any other synchronization mechanism, you must call vfs_vnode_release once you are done using this node

Parameters

	vnode	The referenced vnode
[out]	new	Set to true if a new vnode was created (optional)

Returns

The original vnode, or a newly allocated one if NULL

vfs_vnode_check_creds()

bool vfs_vnode_check_creds	(	const struct vnode *	vnode,
		const struct user_creds *	creds,
		int	oflags
	)

This function should be called while holding both the vnode's and the process' locks.

Parameters

vnode	The vnode to access
creds	The user credentials used by the accessor
oflags	The flag combination used when opening the vnode

Returns

true if the vnode can be accessed.

vfs_vnode_release()

vnode_t * vfs_vnode_release

(

vnode_t *

node

)

Warning

The vnode is free'd if the new refcount is 0

Returns

The original vnode, NULL if the new refcount is 0