fops.c File Reference

The operations on open files: each goes to the socket layer, the device's driver, or the vnode's filesystem (its fops). More...

#include <core/system.h>
#include <fs/vfs.h>
#include <fs/posix.h>
#include <fs/pipe.h>
#include <dev/dev.h>
#include <net/socket.h>
#include <aquila/fcntl.h>

Go to the source code of this file.

Functions
int	vfs_file_open (struct file *file)
	Opens a file whose vnode is set: a device's driver, a FIFO's pipe, or the filesystem opens it.
ssize_t	vfs_file_read (struct file *file, struct iobuf *io)
	Reads from an open file, at its offset.
ssize_t	vfs_file_write (struct file *file, struct iobuf *io)
	Writes to an open file, at its offset.
int	vfs_file_ioctl (struct file *file, int request, void *argp)
	Passes an ioctl() request to an open file's device or filesystem.
off_t	vfs_file_lseek (struct file *file, off_t offset, int whence)
	Moves an open file's offset.
ssize_t	vfs_file_readdir (struct file *file, struct dirent *dirent)
	Reads the next entry of an open directory.
ssize_t	vfs_file_close (struct file *file)
	Closes an open file, when its last reference goes: its lock is released, then its socket, device or filesystem closes it.
int	vfs_file_trunc (struct file *file, off_t len)
	Changes the length of an open file.
struct waitq *	vfs_file_wait_queue (struct file *file, int write)
	Finds the wait queue that a reader (or a writer) of an open file sleeps on until it can go on, which poll() and select() wait on too.
int	vfs_file_can_read (struct file *file, size_t size)
	Says whether a read of an open file would go on without waiting, for poll() and select().
int	vfs_file_can_write (struct file *file, size_t size)
	Says whether a write to an open file would go on without waiting, for poll(), select() and non-blocking writes.
int	vfs_file_eof (struct file *file)
	Says whether an open file is at its end, so that a read returns 0 rather than waiting.

Detailed Description

The operations on open files: each goes to the socket layer, the device's driver, or the vnode's filesystem (its fops).

Definition in file fops.c.

Function Documentation

vfs_file_can_read()

int vfs_file_can_read	(	struct file *	file,
		size_t	size )

Says whether a read of an open file would go on without waiting, for poll() and select().

A regular file or a directory never waits.

Parameters

file	the open file
size	how many bytes would be read

Returns

1 if it would, 0 if it would wait, or a negative errno

Definition at line 262 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, kdev_file_can_read(), socket_can_read(), vfs_file_can_read(), and VNODE_DEV.

Referenced by fd_ready(), and vfs_file_can_read().

vfs_file_can_write()

int vfs_file_can_write	(	struct file *	file,
		size_t	size )

Says whether a write to an open file would go on without waiting, for poll(), select() and non-blocking writes.

A regular file never waits.

Parameters

file	the open file
size	how many bytes would be written

Returns

1 if it would, 0 if it would wait, or a negative errno

Definition at line 295 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, kdev_file_can_write(), socket_can_write(), vfs_file_can_write(), and VNODE_DEV.

Referenced by fd_ready(), posix_file_write(), and vfs_file_can_write().

vfs_file_close()

ssize_t vfs_file_close

(

struct file *

file

)

Closes an open file, when its last reference goes: its lock is released, then its socket, device or filesystem closes it.

Parameters

file	the open file

Returns

0, or a negative errno

Definition at line 183 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, kdev_file_close(), posix_file_close(), socket_shutdown(), vfs_file_close(), vfs_file_lock_release(), and VNODE_DEV.

Referenced by file_put(), and vfs_file_close().

vfs_file_eof()

int vfs_file_eof

(

struct file *

file

)

Says whether an open file is at its end, so that a read returns 0 rather than waiting.

Parameters

file	the open file

Returns

1 at the end, 0 otherwise, or a negative errno

Definition at line 325 of file fops.c.

References ISDEV, kdev_file_eof(), vfs_file_eof(), and VNODE_DEV.

Referenced by posix_file_read(), posix_file_write(), and vfs_file_eof().

vfs_file_ioctl()

int vfs_file_ioctl	(	struct file *	file,
		int	request,
		void *	argp )

Passes an ioctl() request to an open file's device or filesystem.

Parameters

file	the open file
request	the request
argp	its argument

Returns

the request's result, or a negative errno

Definition at line 111 of file fops.c.

References ISDEV, kdev_file_ioctl(), vfs_file_ioctl(), and VNODE_DEV.

Referenced by sys_ioctl(), and vfs_file_ioctl().

vfs_file_lseek()

off_t vfs_file_lseek	(	struct file *	file,
		off_t	offset,
		int	whence )

Moves an open file's offset.

Parameters

file	the open file
offset	the offset, or the distance to move it
whence	SEEK_SET, SEEK_CUR or SEEK_END

Returns

the new offset, -ESPIPE for a pipe, or a negative errno

Definition at line 136 of file fops.c.

References ISDEV, kdev_file_lseek(), vfs_file_lseek(), and VNODE_DEV.

Referenced by sys_lseek(), and vfs_file_lseek().

vfs_file_open()

int vfs_file_open

(

struct file *

file

)

Opens a file whose vnode is set: a device's driver, a FIFO's pipe, or the filesystem opens it.

Parameters

file	the file, its vnode and flags set

Returns

0, -EISDIR to write to a directory, -ENOSYS, or the open's error

Definition at line 22 of file fops.c.

References file::flags, ISDEV, kdev_file_open(), pipefs_fifo_open(), vfs_file_open(), and VNODE_DEV.

Referenced by do_openat(), and vfs_file_open().

vfs_file_read()

ssize_t vfs_file_read	(	struct file *	file,
		struct iobuf *	io )

Reads from an open file, at its offset.

Parameters

file	the open file
io	where the data goes, and how much is wanted

Returns

the number of bytes read, 0 at the end, -EISDIR for a directory, or a negative errno

Definition at line 52 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, kdev_file_read(), NULL, socket_recv(), vfs_file_read(), and VNODE_DEV.

Referenced by sys_read(), and vfs_file_read().

vfs_file_readdir()

ssize_t vfs_file_readdir	(	struct file *	file,
		struct dirent *	dirent )

Reads the next entry of an open directory.

Parameters

file	the open directory
dirent	the entry, filled in

Returns

1 if an entry was read, 0 at the end, -ENOTDIR, or a negative errno

Definition at line 162 of file fops.c.

References vfs_file_readdir().

Referenced by sys_readdir(), and vfs_file_readdir().

vfs_file_trunc()

int vfs_file_trunc	(	struct file *	file,
		off_t	len )

Changes the length of an open file.

Parameters

file	the open file
len	the new length, in bytes

Returns

0, -EINVAL for a socket or a device, or a negative errno

Definition at line 213 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, and vfs_file_trunc().

Referenced by posix_file_open(), sys_ftruncate(), and vfs_file_trunc().

vfs_file_wait_queue()

struct waitq * vfs_file_wait_queue	(	struct file *	file,
		int	write )

Finds the wait queue that a reader (or a writer) of an open file sleeps on until it can go on, which poll() and select() wait on too.

A socket says which; a device's and a pipe's are their vnode's (see fs/posix/read.c and write.c).

Parameters

file	the open file
write	whether it's the writers' queue, rather than the readers'

Returns

the wait queue, or NULL if there's none to tell

Definition at line 243 of file fops.c.

References FILE_SOCKET, file::flags, NULL, socket_wait_queue(), and vfs_file_wait_queue().

Referenced by fd_watch(), and vfs_file_wait_queue().

vfs_file_write()

ssize_t vfs_file_write	(	struct file *	file,
		struct iobuf *	io )

Writes to an open file, at its offset.

Parameters

file	the open file
io	the data, and how much of it

Returns

the number of bytes written, or a negative errno

Definition at line 83 of file fops.c.

References FILE_SOCKET, file::flags, ISDEV, kdev_file_write(), NULL, socket_send(), vfs_file_write(), and VNODE_DEV.

Referenced by sys_write(), and vfs_file_write().