File

Underlying type of a file descriptor. More...

Collaboration diagram for File:

Detailed Description

Underlying type of a file descriptor.

A file is the underlying type of a file descriptor. Note that internally the kernel does not use file descriptors, they are simply a per-process handle to a file. The kernel uses files directly.

Data Structures
struct	file_t
	File structure. More...
struct	file_ops_t
	File operations structure. More...
struct	poll_file_t
	Structure for polling multiple files. More...

Functions
file_t *	file_new (const path_t *path, mode_t mode)
	Create a new file structure.
uint64_t	file_generic_seek (file_t *file, int64_t offset, seek_origin_t origin)
	Helper function for basic seeking.

Function Documentation

file_new()

file_t * file_new	(	const path_t *	path,
		mode_t	mode
	)

Create a new file structure.

This does not open the file, instead its used internally by the VFS when opening files.

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

Parameters

path	The path of the file.
mode	The mode with which the file was opened, if no permissions are specified the maximum allowed permissions from the mount are used.

Returns

On success, the new file. On failure, returns NULL and errno is set to:

• EINVAL: Invalid parameters.
• EACCES: The requested mode exceeds the maximum allowed permissions.
• ENOENT: The dentry of the path is negative.
• EISDIR: The dentry of the path is a directory but mode does not specify MODE_DIRECTORY.
• ENOTDIR: The dentry of the path is a file but mode specifies MODE_DIRECTORY.
• ENOMEM: Out of memory.

Definition at line 32 of file file.c.

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file_generic_seek()

uint64_t file_generic_seek	(	file_t *	file,
		int64_t	offset,
		seek_origin_t	origin
	)

Helper function for basic seeking.

This can be used by filesystems that do not have any special requirements for seeking.

Used by setting the file ops seek to this function.

Definition at line 92 of file file.c.