Inode

Index node. More...

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

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.

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 note that a inode can appear in multiple dentries due to hardlinks or becouse of mountpoints.

So despite the name they are in no way "nodes" in some kind of tree structure, this confused me for a long time when first learning about filesystems.

Enumeration Type Documentation

inode_flags_t

enum inode_flags_t

Inode flags.

Enumerator
INODE_NONE	None.

Definition at line 42 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 DEREF().

Parameters

superblock	The superblock the inode belongs to.
number	The inode number.
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 42 of file inode.c.

References inode_t::accessTime, superblock_ops_t::allocInode, inode_t::blocks, inode_t::changeTime, inode_t::createTime, DEREF, EINVAL, ERR, errno, inode_t::fileOps, fileOps, inode_t::flags, inode_free(), INODE_NONE, inode_t::linkCount, malloc(), map_entry_init(), inode_t::mapEntry, inode_t::modifyTime, inode_t::mutex, mutex_init(), NULL, inode_t::number, inode_t::ops, superblock_t::ops, ops, inode_t::private, inode_t::ref, REF, ref_init(), inode_t::size, inode_t::superblock, timer_unix_epoch(), inode_t::type, and vfs_add_inode().

Referenced by ramfs_inode_new(), sysfs_dir_new(), sysfs_file_new(), sysfs_mount(), and sysfs_mount_new().

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 93 of file inode.c.

References inode_t::accessTime, inode_t::mutex, MUTEX_SCOPE, NULL, and timer_unix_epoch().

Referenced by vfs_getdents(), vfs_ioctl(), vfs_mmap(), vfs_open(), vfs_open2(), and vfs_read().

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 119 of file inode.c.

References inode_t::changeTime, inode_t::mutex, MUTEX_SCOPE, NULL, and timer_unix_epoch().

Referenced by vfs_link(), and vfs_remove().

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 106 of file inode.c.

References inode_t::changeTime, inode_t::modifyTime, inode_t::mutex, MUTEX_SCOPE, NULL, and timer_unix_epoch().

Referenced by vfs_link(), and vfs_write().

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 131 of file inode.c.

References assert, inode_t::mutex, MUTEX_SCOPE, NULL, inode_t::ops, RFLAGS_INTERRUPT_ENABLE, rflags_read(), and inode_ops_t::truncate.

Referenced by vfs_open(), and vfs_open2().