Detailed Description

Virtual node.

A vnode represents the actual data and metadata of a file. It is referenced by dentries, which represent the name or "location" of the file but a vnode can appear in multiple dentries due to hardlinks or mounts.

Note: Despite the name vnodes are in no way "nodes" in any kind of tree structure, that would be the dentries.

Synchronization

Vnodes have an additional purpose within the Virtual File System (VFS) as they act as the primary means of synchronization. All dentries synchronize upon their vnodes mutex, open files synchronize upon the mutex of the underlying vnode and operations like create, remove, etc synchronize upon the vnode mutex of the parent directory.

Data Structures
struct	vnode_t
	vnode structure. More...

struct	vnode_ops_t
	vnode operations structure. More...

Functions
vnode_t *	vnode_new (superblock_t superblock, vtype_t type, const vnode_ops_t ops, const file_ops_t *fileOps)
	Create a new vnode.

void	vnode_truncate (vnode_t *vnode)
	Truncate the vnode.

Function Documentation

◆ vnode_new()

vnode_t * vnode_new	(	superblock_t *	superblock,
		vtype_t	type,
		const vnode_ops_t *	ops,
		const file_ops_t *	fileOps
	)

Create a new vnode.

Does not associate the vnode with a dentry, that is done when a dentry is made positive with dentry_make_positive().

There is no vnode_free() instead use UNREF().

Parameters

superblock	The superblock the vnode belongs to.
type	The vnode type.
ops	The vnode operations.
fileOps	The file operations for files opened on this vnode.

Returns: On success, the new vnode. On failure, returns NULL and errno is set.

Definition at line 51 of file vnode.c.

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◆ vnode_truncate()

void vnode_truncate ( vnode_t * vnode )

Truncate the vnode.

The filesystem should implement the actual truncation in the vnode ops truncate function, this is just a helper to call it.

Parameters

vnode The vnode to truncate.

Definition at line 75 of file vnode.c.