Inode

Index node. More...

Collaboration diagram for Inode:

Detailed Description

Index node.

A inode 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 inode can appear in multiple dentries due to hardlinks or mounts.

Note

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

Synchronization

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

Todo:

Implement actually writing/syncing dirty inodes, for now inodes should use the notify functions but they will never actually be "cleaned."

Data Structures
struct	inode_t
	Inode structure. More...
struct	inode_ops_t
	Inode operations structure. More...

Enumerations
enum	inode_flags_t { INODE_NONE = 0 }
	Inode flags. More...

Functions
inode_t *	inode_new (superblock_t *superblock, inode_number_t number, inode_type_t type, const inode_ops_t *ops, const file_ops_t *fileOps)
	Create a new inode.
void	inode_notify_access (inode_t *inode)
	Notify the inode that it has been accessed.
void	inode_notify_modify (inode_t *inode)
	Notify the inode that its content has been modified.
void	inode_notify_change (inode_t *inode)
	Notify the inode that its metadata has changed.
void	inode_truncate (inode_t *inode)
	Truncate the inode.

Enumeration Type Documentation

inode_flags_t

enum inode_flags_t

Inode flags.

Enumerator
INODE_NONE	None.

Definition at line 44 of file inode.h.

Function Documentation

inode_new()

inode_t * inode_new	(	superblock_t *	superblock,
		inode_number_t	number,
		inode_type_t	type,
		const inode_ops_t *	ops,
		const file_ops_t *	fileOps
	)

Create a new inode.

This DOES add the inode to the inode cache. It also does not associate the inode with a dentry, that is done when a dentry is made positive with dentry_make_positive().

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

Parameters

superblock	The superblock the inode belongs to.
number	The inode number, for a generic filesystem vfs_id_get() can be used.
type	The inode type.
ops	The inode operations.
fileOps	The file operations for files opened on this inode.

Returns

On success, the new inode. On failure, returns NULL and errno is set.

Definition at line 41 of file inode.c.

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inode_notify_access()

void inode_notify_access

(

inode_t *

inode

)

Notify the inode that it has been accessed.

This updates the access time.

Parameters

inode

The inode to notify.

Definition at line 85 of file inode.c.

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inode_notify_modify()

void inode_notify_modify

(

inode_t *

inode

)

Notify the inode that its content has been modified.

This updates the modify time and change time.

Parameters

inode

The inode to notify.

Definition at line 97 of file inode.c.

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inode_notify_change()

void inode_notify_change

(

inode_t *

inode

)

Notify the inode that its metadata has changed.

This updates the change time.

Parameters

inode

The inode to notify.

Definition at line 109 of file inode.c.

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inode_truncate()

void inode_truncate

(

inode_t *

inode

)

Truncate the inode.

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

Parameters

inode

The inode to truncate.

Definition at line 120 of file inode.c.

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