System calls on files: opening, reading and writing them, their names and attributes, directories, links, mounts and locks. More...

#include "syscalls.h"

Macros
#define	F_OK 0
#define	X_OK 1
#define	W_OK 2
#define	R_OK 4

Functions
static int	at_uio (int dirfd, const char path, struct uio uio)
	Sets up the uio to look up path from the directory that dirfd refers to, or from the working directory for AT_FDCWD.
static int	at_path (int dirfd, const char upath, char path, struct uio uio)
	Copies a path into the kernel (*path, which the caller frees) and sets up the uio to look it up from dirfd, for the calls that take two paths.
static int	at_lookup (int dirfd, const char upath, int flags, struct uio uio, struct vnode **vnode)
	Looks up a path from user memory, from dirfd; with AT_SYMLINK_NOFOLLOW in flags, a final symbolic link isn't followed.
long	sys_close (int fildes)
	Implements close(): frees a descriptor.
long	sys_fstat (int fildes, struct aquila_stat *buf)
	Implements fstat(): an open file's attributes.
long	sys_isatty (int fildes)
	Says whether a descriptor refers to a character device, the only kind of file that can be a terminal.
static int	do_linkat (int olddirfd, const char oldpath, int newdirfd, const char newpath, int flags)
	Makes a link, for link() and linkat().
long	sys_link (const char oldpath, const char newpath)
	Implements link(): a new name for a file.
long	sys_linkat (int olddirfd, const char oldpath, int newdirfd, const char newpath, int flags)
	Implements linkat(): link(), with paths relative to directories.
long	sys_lseek (int fildes, off_t offset, int whence)
	Implements lseek(): moves an open file's offset.
static int	creat_path (const char path, struct uio uio, char **ref)
	Finds what O_CREAT should create for path: if path is a dangling symbolic link, the file it points to, through links to links.
static int	do_openat (int dirfd, const char *upath, int oflags, mode_t mode)
	Opens (or creates) a file on a new descriptor, for open() and openat().
long	sys_open (const char *path, int oflags, mode_t mode)
	Implements open(): opens a file on a new descriptor, creating it with O_CREAT.
long	sys_openat (int dirfd, const char *path, int oflags, mode_t mode)
	Implements openat(): open(), with the path relative to a directory.
long	sys_read (int fildes, void *buf, size_t nbytes)
	Implements read().
static int	do_fstatat (int dirfd, const char path, struct aquila_stat buf, int flags)
	Gets a file's attributes, for the stat() calls.
long	sys_stat (const char path, struct aquila_stat buf)
	Implements stat(): a file's attributes, following a symbolic link.
long	sys_fstatat (int dirfd, const char path, struct aquila_stat buf, int flags)
	Implements fstatat(): stat(), with the path relative to a directory.
static int	do_unlinkat (int dirfd, const char *upath, int flags)
	Removes a name, or a directory with AT_REMOVEDIR, for unlink(), unlinkat() and rmdir().
long	sys_unlink (const char *path)
	Implements unlink(): removes a name of a file (not a directory's).
long	sys_unlinkat (int dirfd, const char *path, int flags)
	Implements unlinkat(): unlink(), or rmdir() with AT_REMOVEDIR, with the path relative to a directory.
long	sys_write (int fd, void *buf, size_t nbytes)
	Implements write().
long	sys_ioctl (int fd, int request, void *argp)
	Implements ioctl(): a device's, a socket's, or a terminal's request.
long	sys_readdir (int fd, struct dirent *dirent)
	Reads a directory's next entry, for the C library's readdir().
long	sys_mount (struct aquila_mount_args *args)
	Implements mount(): mounts a file system on a directory.
static int	do_mknodat (int dirfd, const char *upath, mode_t mode, dev_t dev)
	Makes a file of any type, for mknod(), mknodat() and mkdir().
long	sys_mkdir (const char *path, mode_t mode)
	Implements mkdir(): makes a directory.
long	sys_pipe (int fd[2])
	Implements pipe(): makes a pipe, its read end and its write end open on two new descriptors.
long	sys_fcntl (int fd, int cmd, uintptr_t arg)
	Implements fcntl(): duplicates a descriptor, or reads and sets the descriptor's flags (FD_CLOEXEC) or the open file's status flags.
static int	cwd_set (struct vnode *vnode)
	Makes vnode the working directory, if it is a directory the process may search.
long	sys_chdir (const char *upath)
	Implements chdir(): changes the working directory.
long	sys_getcwd (char *buf, size_t size)
	Implements getcwd(): the working directory's path.
long	sys_mknod (const char *path, uint32_t mode, uint32_t dev)
	Implements mknod(): makes a file, a directory, a FIFO, or (only root) a device file.
long	sys_mknodat (int dirfd, const char *path, uint32_t mode, uint32_t dev)
	Implements mknodat(): mknod(), with the path relative to a directory.
long	sys_lstat (const char path, struct aquila_stat buf)
	Implements lstat(): a file's attributes, a symbolic link's own.
long	sys_ftruncate (int fildes, off_t len)
	Implements ftruncate(): sets an open file's size.
long	sys_umask (mode_t mask)
	Implements umask(): sets the permissions that new files don't get.
static int	do_fchmodat (int dirfd, const char *path, mode_t mode, int flags)
	Changes a file's permissions, for chmod() and fchmodat().
long	sys_chmod (const char *path, mode_t mode)
	Implements chmod(): changes a file's permissions.
long	sys_fchmodat (int dirfd, const char *path, mode_t mode, int flags)
	Implements fchmodat(): chmod(), with the path relative to a directory.
static struct vnode *	fd_vnode (int fd, int *err)
	Returns the vnode of an open file, or NULL with *err set (-EBADF, or -EINVAL for a socket).
long	sys_fchmod (int fd, mode_t mode)
	Implements fchmod(): changes an open file's permissions.
static int	do_faccessat (int dirfd, const char *path, int mode, int flags)
	Checks a file's permissions, for access() and faccessat().
long	sys_access (const char *path, int mode)
	Implements access(): says whether the process may read, write or execute a file.
long	sys_faccessat (int dirfd, const char *path, int mode, int flags)
	Implements faccessat(): access(), with the path relative to a directory.
static int	do_fchownat (int dirfd, const char *path, uid_t owner, gid_t group, int flags)
	Changes a file's owner and group, for the chown() calls.
long	sys_chown (const char *path, uid_t owner, gid_t group)
	Implements chown(): changes a file's owner and group.
long	sys_fchownat (int dirfd, const char *path, uid_t owner, gid_t group, int flags)
	Implements fchownat(): chown(), with the path relative to a directory.
long	sys_fchown (int fd, uid_t owner, gid_t group)
	Implements fchown(): changes an open file's owner and group.
long	sys_lchown (const char *path, uid_t owner, gid_t group)
	Implements lchown(): chown() of a symbolic link itself.
long	sys_utimensat (int dirfd, const char *path, const struct aquila_timespec times[2], int flags)
	Implements utimensat() (and futimens()): sets a file's access and modification times.
long	sys_rmdir (const char *path)
	Implements rmdir(): removes an empty directory.
long	sys_symlinkat (const char utarget, int dirfd, const char upath)
	Implements symlinkat(): makes a symbolic link.
long	sys_readlinkat (int dirfd, const char upath, char buf, size_t size)
	Implements readlinkat(): what a symbolic link points to (not NUL-terminated).
long	sys_renameat (int olddirfd, const char oldpath, int newdirfd, const char newpath)
	Implements renameat() (and rename()): moves a file to another name, replacing what was there.
long	sys_flock (int fd, int op)
	Implements flock(): takes or releases an advisory lock on an open file.
long	sys_sync (void)
	Implements sync(): writes out what the devices' caches hold.
long	sys_fchdir (int fd)
	Implements fchdir(): changes the working directory to an open directory.

Detailed Description

System calls on files: opening, reading and writing them, their names and attributes, directories, links, mounts and locks.

The *at() calls take paths relative to a directory descriptor, and the older calls are the same with AT_FDCWD, the working directory. Paths are copied into the kernel first (upath_get()); the work is the VFS's (fs/).

Definition in file sys_file.c.

Macro Definition Documentation

◆ F_OK

#define F_OK 0

Definition at line 1185 of file sys_file.c.

◆ R_OK

#define R_OK 4

Definition at line 1188 of file sys_file.c.

Referenced by do_faccessat().

◆ W_OK

#define W_OK 2

Definition at line 1187 of file sys_file.c.

Referenced by do_faccessat().

◆ X_OK

#define X_OK 1

Definition at line 1186 of file sys_file.c.

Referenced by do_faccessat().

Function Documentation

◆ at_lookup()

int at_lookup	(	int	dirfd,
		const char *	upath,
		int	flags,
		struct uio *	uio,
		struct vnode **	vnode )

static

Looks up a path from user memory, from dirfd; with AT_SYMLINK_NOFOLLOW in flags, a final symbolic link isn't followed.

Returns 0 or a negative errno.

Definition at line 60 of file sys_file.c.

References at_lookup(), at_uio(), file::flags, uio::flags, kfree(), upath_get(), and vfs_lookup().

Referenced by at_lookup(), do_faccessat(), do_fchmodat(), do_fchownat(), do_fstatat(), and sys_utimensat().

◆ at_path()

int at_path	(	int	dirfd,
		const char *	upath,
		char **	path,
		struct uio *	uio )

static

Copies a path into the kernel (*path, which the caller frees) and sets up the uio to look it up from dirfd, for the calls that take two paths.

Returns 0 or a negative errno.

Definition at line 42 of file sys_file.c.

References at_path(), at_uio(), kfree(), NULL, and upath_get().

Referenced by at_path(), do_linkat(), and sys_renameat().

◆ at_uio()

int at_uio	(	int	dirfd,
		const char *	path,
		struct uio *	uio )

static

Sets up the uio to look up path from the directory that dirfd refers to, or from the working directory for AT_FDCWD.

An absolute path ignores dirfd. Returns 0, -EBADF, or -ENOTDIR.

Definition at line 18 of file sys_file.c.

References at_uio(), curproc, uio::cwd, fd_file(), FILE_SOCKET, file::flags, and PROC_UIO.

Referenced by at_lookup(), at_path(), at_uio(), do_mknodat(), do_openat(), do_unlinkat(), sys_readlinkat(), and sys_symlinkat().

◆ creat_path()

int creat_path	(	const char *	path,
		struct uio *	uio,
		char **	ref )

static

Finds what O_CREAT should create for path: if path is a dangling symbolic link, the file it points to, through links to links.

Sets *ref to that path (which the caller frees), or to NULL for path itself. Returns 0, -EEXIST if path exists, -ELOOP, or another negative errno.

Definition at line 248 of file sys_file.c.

References creat_path(), uio::flags, kfree(), kmalloc(), memcpy(), vnode::mode, NULL, vnode::p, vnode::ref, vfs_close(), vfs_lookup(), and vfs_readlink().

Referenced by creat_path(), and do_openat().

◆ cwd_set()

int cwd_set ( struct vnode * vnode )

static

Makes vnode the working directory, if it is a directory the process may search.

On success, the caller's reference to it becomes the process's. Returns 0, -ENOTDIR or -EACCES.

Definition at line 933 of file sys_file.c.

References curproc, cwd_set(), vnode::mode, PROC_UIO, vfs_access(), vfs_close(), and VFS_X.

Referenced by cwd_set(), sys_chdir(), and sys_fchdir().

◆ do_faccessat()

int do_faccessat	(	int	dirfd,
		const char *	path,
		int	mode,
		int	flags )

static

Checks a file's permissions, for access() and faccessat().

Returns 0 or a negative errno.

Definition at line 1192 of file sys_file.c.

References at_lookup(), do_faccessat(), uio::flags, NULL, R_OK, vfs_access(), vfs_close(), VFS_R, VFS_W, VFS_X, W_OK, and X_OK.

Referenced by do_faccessat(), sys_access(), and sys_faccessat().

◆ do_fchmodat()

int do_fchmodat	(	int	dirfd,
		const char *	path,
		mode_t	mode,
		int	flags )

static

Changes a file's permissions, for chmod() and fchmodat().

Returns 0 or a negative errno.

Definition at line 1101 of file sys_file.c.

References at_lookup(), do_fchmodat(), uio::flags, NULL, vfs_chmod(), and vfs_close().

Referenced by do_fchmodat(), sys_chmod(), and sys_fchmodat().

◆ do_fchownat()

int do_fchownat	(	int	dirfd,
		const char *	path,
		uid_t	owner,
		gid_t	group,
		int	flags )

static

Changes a file's owner and group, for the chown() calls.

Returns 0 or a negative errno.

Definition at line 1244 of file sys_file.c.

References at_lookup(), do_fchownat(), uio::flags, NULL, vfs_chown(), and vfs_close().

Referenced by do_fchownat(), sys_chown(), sys_fchownat(), and sys_lchown().

◆ do_fstatat()

int do_fstatat	(	int	dirfd,
		const char *	path,
		struct aquila_stat *	buf,
		int	flags )

static

Gets a file's attributes, for the stat() calls.

Returns 0 or a negative errno.

Definition at line 477 of file sys_file.c.

References at_lookup(), do_fstatat(), uio::flags, memset(), NULL, vfs_close(), and vfs_stat().

Referenced by do_fstatat(), sys_fstatat(), sys_lstat(), and sys_stat().

◆ do_linkat()

int do_linkat	(	int	olddirfd,
		const char *	oldpath,
		int	newdirfd,
		const char *	newpath,
		int	flags )

static

Makes a link, for link() and linkat().

Returns 0 or a negative errno.

Definition at line 157 of file sys_file.c.

References at_path(), do_linkat(), uio::flags, kfree(), NULL, and vfs_link().

Referenced by do_linkat(), sys_link(), and sys_linkat().

◆ do_mknodat()

int do_mknodat	(	int	dirfd,
		const char *	upath,
		mode_t	mode,
		dev_t	dev )

static

Makes a file of any type, for mknod(), mknodat() and mkdir().

Returns 0 or a negative errno.

Definition at line 754 of file sys_file.c.

References at_uio(), curproc, do_mknodat(), kfree(), NULL, upath_get(), and vfs_mknod().

Referenced by do_mknodat(), sys_mkdir(), sys_mknod(), and sys_mknodat().

◆ do_openat()

int do_openat	(	int	dirfd,
		const char *	upath,
		int	oflags,
		mode_t	mode )

static

Opens (or creates) a file on a new descriptor, for open() and openat().

Returns the descriptor or a negative errno.

Definition at line 311 of file sys_file.c.

References at_uio(), creat_path(), curproc, do_openat(), file_new(), file::flags, uio::flags, kfree(), vnode::mode, NULL, proc_fd_get(), proc_fd_install(), proc_fd_release(), upath_get(), vfs_close(), vfs_creat(), vfs_file_open(), vfs_lookup(), and vfs_perms_check().

Referenced by do_openat(), sys_open(), and sys_openat().

◆ do_unlinkat()

int do_unlinkat	(	int	dirfd,
		const char *	upath,
		int	flags )

static

Removes a name, or a directory with AT_REMOVEDIR, for unlink(), unlinkat() and rmdir().

Returns 0 or a negative errno.

Definition at line 528 of file sys_file.c.

References at_uio(), do_unlinkat(), uio::flags, kfree(), upath_get(), vfs_rmdir(), and vfs_unlink().

Referenced by do_unlinkat(), sys_rmdir(), sys_unlink(), and sys_unlinkat().

◆ fd_vnode()

struct vnode * fd_vnode	(	int	fd,
		int *	err )

static

Returns the vnode of an open file, or NULL with *err set (-EBADF, or -EINVAL for a socket).

Definition at line 1153 of file sys_file.c.

References fd_file(), fd_vnode(), FILE_SOCKET, file::flags, and NULL.

Referenced by fd_vnode(), sys_fchmod(), sys_fchown(), and sys_utimensat().

◆ sys_access()

long sys_access	(	const char *	path,
		int	mode )

Implements access(): says whether the process may read, write or execute a file.

Parameters

path	the file's path
mode	F_OK, or R_OK, W_OK and X_OK together

Returns: 0 if it may, or a negative errno: -EACCES, -ENOENT, ...

Definition at line 1220 of file sys_file.c.

References do_faccessat(), LOG_DEBUG, and sys_access().

Referenced by sys_access().

◆ sys_chdir()

long sys_chdir ( const char * upath )

Implements chdir(): changes the working directory.

Parameters

upath the directory's path

Returns: 0, or a negative errno: -ENOENT, -ENOTDIR, -EACCES, ...

Definition at line 956 of file sys_file.c.

References curproc, cwd_set(), kfree(), LOG_DEBUG, NULL, PROC_UIO, sys_chdir(), upath_get(), vfs_close(), and vfs_lookup().

Referenced by sys_chdir().

◆ sys_chmod()

long sys_chmod	(	const char *	path,
		mode_t	mode )

Implements chmod(): changes a file's permissions.

Parameters

path	the file's path
mode	the new permissions

Returns: 0, or a negative errno: -ENOENT, -EPERM, ...

Definition at line 1129 of file sys_file.c.

References do_fchmodat(), LOG_DEBUG, and sys_chmod().

Referenced by sys_chmod().

◆ sys_chown()

long sys_chown	(	const char *	path,
		uid_t	owner,
		gid_t	group )

Implements chown(): changes a file's owner and group.

Parameters

path	the file's path
owner	the new owner, or -1 to keep it
group	the new group, or -1 to keep it

Returns: 0, or a negative errno: -EPERM, -ENOENT, ...

Definition at line 1269 of file sys_file.c.

References do_fchownat(), LOG_DEBUG, and sys_chown().

Referenced by sys_chown().

◆ sys_close()

long sys_close ( int fildes )

Implements close(): frees a descriptor.

The open file is closed once nothing else refers to it (another descriptor, or a call using it).

Parameters

fildes the descriptor

Returns: 0, -EBADF, or an error from closing the file

Definition at line 86 of file sys_file.c.

References curproc, LOG_DEBUG, proc_fd_close(), and sys_close().

Referenced by sys_close().

◆ sys_faccessat()

long sys_faccessat	(	int	dirfd,
		const char *	path,
		int	mode,
		int	flags )

Implements faccessat(): access(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the file's path
mode	F_OK, or R_OK, W_OK and X_OK together
flags	AT_EACCESS (which changes nothing), AT_SYMLINK_NOFOLLOW

Returns: 0 if it may, or a negative errno

Definition at line 1236 of file sys_file.c.

References do_faccessat(), uio::flags, LOG_DEBUG, and sys_faccessat().

Referenced by sys_faccessat().

◆ sys_fchdir()

long sys_fchdir ( int fd )

Implements fchdir(): changes the working directory to an open directory.

Parameters

fd	the directory's descriptor

Returns: 0, or a negative errno: -EBADF, -ENOTDIR, -EACCES

Definition at line 1523 of file sys_file.c.

References cwd_set(), fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, file::ref, sys_fchdir(), and vfs_close().

Referenced by sys_fchdir().

◆ sys_fchmod()

long sys_fchmod	(	int	fd,
		mode_t	mode )

Implements fchmod(): changes an open file's permissions.

Parameters

fd	the descriptor
mode	the new permissions

Returns: 0, or a negative errno: -EBADF, -EINVAL, -EPERM

Definition at line 1172 of file sys_file.c.

References curproc, fd_vnode(), LOG_DEBUG, vnode::mode, PROC_UIO, sys_fchmod(), and vfs_chmod().

Referenced by sys_fchmod().

◆ sys_fchmodat()

long sys_fchmodat	(	int	dirfd,
		const char *	path,
		mode_t	mode,
		int	flags )

Implements fchmodat(): chmod(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the file's path
mode	the new permissions
flags	0 (AT_SYMLINK_NOFOLLOW isn't supported)

Returns: 0, or a negative errno

Definition at line 1145 of file sys_file.c.

References do_fchmodat(), uio::flags, LOG_DEBUG, and sys_fchmodat().

Referenced by sys_fchmodat().

◆ sys_fchown()

long sys_fchown	(	int	fd,
		uid_t	owner,
		gid_t	group )

Implements fchown(): changes an open file's owner and group.

Parameters

fd	the descriptor
owner	the new owner, or -1
group	the new group, or -1

Returns: 0, or a negative errno: -EBADF, -EINVAL, -EPERM

Definition at line 1301 of file sys_file.c.

References curproc, fd_vnode(), LOG_DEBUG, PROC_UIO, sys_fchown(), and vfs_chown().

Referenced by sys_fchown().

◆ sys_fchownat()

long sys_fchownat	(	int	dirfd,
		const char *	path,
		uid_t	owner,
		gid_t	group,
		int	flags )

Implements fchownat(): chown(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the file's path
owner	the new owner, or -1
group	the new group, or -1
flags	AT_SYMLINK_NOFOLLOW for a symbolic link's own

Returns: 0, or a negative errno

Definition at line 1286 of file sys_file.c.

References do_fchownat(), uio::flags, LOG_DEBUG, and sys_fchownat().

Referenced by sys_fchownat().

◆ sys_fcntl()

long sys_fcntl	(	int	fd,
		int	cmd,
		uintptr_t	arg )

Implements fcntl(): duplicates a descriptor, or reads and sets the descriptor's flags (FD_CLOEXEC) or the open file's status flags.

Parameters

fd	the descriptor
cmd	F_DUPFD, F_DUPFD_CLOEXEC, F_GETFD, F_SETFD, F_GETFL or F_SETFL
arg	the command's argument

Returns: what the command returns, or a negative errno: -EBADF, -EINVAL, -EMFILE

Definition at line 876 of file sys_file.c.

References curproc, fd_file(), FDS_COUNT, file_ref(), FILE_SOCKET, file::flags, LOG_DEBUG, proc_fd_install(), and sys_fcntl().

Referenced by sys_fcntl().

◆ sys_flock()

long sys_flock	(	int	fd,
		int	op )

Implements flock(): takes or releases an advisory lock on an open file.

Parameters

fd	the descriptor
op	LOCK_SH, LOCK_EX or LOCK_UN, with LOCK_NB to not wait

Returns: 0, or a negative errno: -EBADF, -EWOULDBLOCK, -EINTR, ...

Definition at line 1490 of file sys_file.c.

References fd_file(), LOG_DEBUG, sys_flock(), and vfs_file_flock().

Referenced by sys_flock().

◆ sys_fstat()

long sys_fstat	(	int	fildes,
		struct aquila_stat *	buf )

Implements fstat(): an open file's attributes.

A socket only reports its type.

Parameters

fildes	the descriptor
buf	where to put them

Returns: 0, or a negative errno: -EBADF, -EFAULT

Definition at line 103 of file sys_file.c.

References fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, memset(), sys_fstat(), and vfs_stat().

Referenced by sys_fstat().

◆ sys_fstatat()

long sys_fstatat	(	int	dirfd,
		const char *	path,
		struct aquila_stat *	buf,
		int	flags )

Implements fstatat(): stat(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the file's path
buf	where to put its attributes
flags	AT_SYMLINK_NOFOLLOW for a symbolic link's own

Returns: 0, or a negative errno

Definition at line 520 of file sys_file.c.

References do_fstatat(), LOG_DEBUG, and sys_fstatat().

Referenced by sys_fstatat().

◆ sys_ftruncate()

long sys_ftruncate	(	int	fildes,
		off_t	len )

Implements ftruncate(): sets an open file's size.

Parameters

fildes	the descriptor, open for writing
len	the new size

Returns: 0, or a negative errno: -EBADF, -EINVAL, ...

Definition at line 1065 of file sys_file.c.

References fd_file(), file::flags, LOG_DEBUG, sys_ftruncate(), and vfs_file_trunc().

Referenced by sys_ftruncate().

◆ sys_getcwd()

long sys_getcwd	(	char *	buf,
		size_t	size )

Implements getcwd(): the working directory's path.

Parameters

buf	where to put it
size	the room at buf

Returns: 0, or a negative errno: -EINVAL, -ERANGE if it doesn't fit, -ENOMEM, -EFAULT

Definition at line 985 of file sys_file.c.

References curproc, kfree(), kmalloc(), LOG_DEBUG, MIN, NULL, vnode::size, sys_getcwd(), UPATH_MAX, and vfs_vnode_path().

Referenced by sys_getcwd().

◆ sys_ioctl()

long sys_ioctl	(	int	fd,
		int	request,
		void *	argp )

Implements ioctl(): a device's, a socket's, or a terminal's request.

FIONBIO, which sets the descriptor's O_NONBLOCK, works on any file.

Parameters

fd	the descriptor
request	the request
argp	its argument, in user memory

Returns: what the request returns, or a negative errno: -EBADF, -ENOTTY for a request the file doesn't know, -EFAULT

Definition at line 622 of file sys_file.c.

References fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, socket_ioctl(), sys_ioctl(), and vfs_file_ioctl().

Referenced by sys_ioctl().

◆ sys_isatty()

long sys_isatty ( int fildes )

Says whether a descriptor refers to a character device, the only kind of file that can be a terminal.

(The C library's isatty() asks the device with TCGETS instead.)

Parameters

fildes the descriptor

Returns: 1, -ENOTTY, or -EBADF

Definition at line 137 of file sys_file.c.

References fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, and sys_isatty().

Referenced by sys_isatty().

◆ sys_lchown()

long sys_lchown	(	const char *	path,
		uid_t	owner,
		gid_t	group )

Implements lchown(): chown() of a symbolic link itself.

Parameters

path	the link's path
owner	the new owner, or -1
group	the new group, or -1

Returns: 0, or a negative errno

Definition at line 1322 of file sys_file.c.

References do_fchownat(), LOG_DEBUG, and sys_lchown().

Referenced by sys_lchown().

◆ sys_link()

long sys_link	(	const char *	oldpath,
		const char *	newpath )

Implements link(): a new name for a file.

Parameters

oldpath	the file's path
newpath	the new name

Returns: 0, or a negative errno: -ENOENT, -EEXIST, -EPERM, -EXDEV, -EACCES, ...

Definition at line 188 of file sys_file.c.

References do_linkat(), LOG_DEBUG, and sys_link().

Referenced by sys_link().

◆ sys_linkat()

long sys_linkat	(	int	olddirfd,
		const char *	oldpath,
		int	newdirfd,
		const char *	newpath,
		int	flags )

Implements linkat(): link(), with paths relative to directories.

Parameters

olddirfd	the directory oldpath is relative to, or AT_FDCWD
oldpath	the file's path
newdirfd	the directory newpath is relative to, or AT_FDCWD
newpath	the new name
flags	AT_SYMLINK_FOLLOW to link what a symbolic link points to

Returns: 0, or a negative errno

Definition at line 205 of file sys_file.c.

References do_linkat(), uio::flags, LOG_DEBUG, and sys_linkat().

Referenced by sys_linkat().

◆ sys_lseek()

long sys_lseek	(	int	fildes,
		off_t	offset,
		int	whence )

Implements lseek(): moves an open file's offset.

Parameters

fildes	the descriptor
offset	the offset
whence	SEEK_SET, SEEK_CUR or SEEK_END

Returns: the new offset, or a negative errno: -EBADF, -ESPIPE (a socket, a pipe, a terminal), -EINVAL

Definition at line 221 of file sys_file.c.

References fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, file::offset, sys_lseek(), and vfs_file_lseek().

Referenced by sys_lseek().

◆ sys_lstat()

long sys_lstat	(	const char *	path,
		struct aquila_stat *	buf )

Implements lstat(): a file's attributes, a symbolic link's own.

Parameters

path	the file's path
buf	where to put them

Returns: 0, or a negative errno

Definition at line 1052 of file sys_file.c.

References do_fstatat(), LOG_DEBUG, and sys_lstat().

Referenced by sys_lstat().

◆ sys_mkdir()

long sys_mkdir	(	const char *	path,
		mode_t	mode )

Implements mkdir(): makes a directory.

Parameters

path	its path
mode	its permissions (less the umask)

Returns: 0, or a negative errno: -EEXIST, -ENOENT, -EACCES, ...

Definition at line 797 of file sys_file.c.

References do_mknodat(), LOG_DEBUG, and sys_mkdir().

Referenced by sys_mkdir().

◆ sys_mknod()

long sys_mknod	(	const char *	path,
		uint32_t	mode,
		uint32_t	dev )

Implements mknod(): makes a file, a directory, a FIFO, or (only root) a device file.

Parameters

path	its path
mode	its type and permissions
dev	a device file's device number

Returns: 0, or a negative errno: -EEXIST, -EPERM, -EINVAL, ...

Definition at line 1023 of file sys_file.c.

References do_mknodat(), LOG_DEBUG, vnode::mode, and sys_mknod().

Referenced by sys_mknod().

◆ sys_mknodat()

long sys_mknodat	(	int	dirfd,
		const char *	path,
		uint32_t	mode,
		uint32_t	dev )

Implements mknodat(): mknod(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the new file's path
mode	its type and permissions
dev	a device file's device number

Returns: 0, or a negative errno

Definition at line 1039 of file sys_file.c.

References do_mknodat(), LOG_DEBUG, vnode::mode, and sys_mknodat().

Referenced by sys_mknodat().

◆ sys_mount()

long sys_mount ( struct aquila_mount_args * args )

Implements mount(): mounts a file system on a directory.

Only root may.

Parameters

args	the arguments, in user memory: the file system's type, the directory, flags, and the data (the device and the options)

Returns: 0, or a negative errno: -EPERM (not root), -ENOENT, -ENODEV, -EFAULT, ...

Definition at line 706 of file sys_file.c.

References curproc, kfree(), LOG_DEBUG, NULL, PROC_UIO, sys_mount(), upath_get(), and vfs_mount().

Referenced by sys_mount().

◆ sys_open()

long sys_open	(	const char *	path,
		int	oflags,
		mode_t	mode )

Implements open(): opens a file on a new descriptor, creating it with O_CREAT.

Parameters

path	the file's path
oflags	O_* flags
mode	the new file's permissions, with O_CREAT (less the umask)

Returns: the descriptor, or a negative errno: -ENOENT, -EACCES, -EEXIST, -EMFILE, -ENOTDIR, -ELOOP, ...

Definition at line 424 of file sys_file.c.

References do_openat(), LOG_DEBUG, and sys_open().

Referenced by sys_open().

◆ sys_openat()

long sys_openat	(	int	dirfd,
		const char *	path,
		int	oflags,
		mode_t	mode )

Implements openat(): open(), with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the file's path
oflags	O_* flags
mode	the new file's permissions, with O_CREAT

Returns: the descriptor, or a negative errno

Definition at line 439 of file sys_file.c.

References do_openat(), LOG_DEBUG, and sys_openat().

Referenced by sys_openat().

◆ sys_pipe()

long sys_pipe ( int fd[2] )

Implements pipe(): makes a pipe, its read end and its write end open on two new descriptors.

Parameters

fd	where to put the two descriptors

Returns: 0, or a negative errno: -EMFILE, -ENOMEM, -EFAULT

Definition at line 810 of file sys_file.c.

References curproc, file_new(), kfree(), LOG_DEBUG, NULL, pipefs_pipe(), proc_fd_close(), proc_fd_get(), proc_fd_install(), proc_fd_release(), sys_pipe(), and uaccess_check().

Referenced by sys_pipe().

◆ sys_read()

long sys_read	(	int	fildes,
		void *	buf,
		size_t	nbytes )

Implements read().

Parameters

fildes	the descriptor
buf	where to put the data
nbytes	how much to read, at most

Returns: how many bytes were read (0 at the end), or a negative errno: -EBADF, -EFAULT, -EAGAIN, -EINTR, ...

Definition at line 454 of file sys_file.c.

References fd_file(), iobuf_init(), LOG_DEBUG, sys_read(), uaccess_check(), and vfs_file_read().

Referenced by sys_read().

◆ sys_readdir()

long sys_readdir	(	int	fd,
		struct dirent *	dirent )

Reads a directory's next entry, for the C library's readdir().

Parameters

fd	the directory's descriptor
dirent	where to put the entry

Returns: a positive number if there was an entry, 0 at the end, or a negative errno: -EBADF, -ENOTDIR, -EFAULT

Definition at line 667 of file sys_file.c.

References fd_file(), FILE_SOCKET, file::flags, LOG_DEBUG, memset(), sys_readdir(), and vfs_file_readdir().

Referenced by sys_readdir().

◆ sys_readlinkat()

long sys_readlinkat	(	int	dirfd,
		const char *	upath,
		char *	buf,
		size_t	size )

Implements readlinkat(): what a symbolic link points to (not NUL-terminated).

Parameters

dirfd	the directory upath is relative to, or AT_FDCWD
upath	the link's path
buf	where to put the target
size	the room at buf; a longer target is cut

Returns: the target's length, or a negative errno: -EINVAL (not a link), -ENOENT, -EFAULT, ...

Definition at line 1426 of file sys_file.c.

References at_uio(), kfree(), kmalloc(), LOG_DEBUG, MIN, NULL, sys_readlinkat(), uaccess_check(), upath_get(), UPATH_MAX, and vfs_readlink().

Referenced by sys_readlinkat().

◆ sys_renameat()

long sys_renameat	(	int	olddirfd,
		const char *	oldpath,
		int	newdirfd,
		const char *	newpath )

Implements renameat() (and rename()): moves a file to another name, replacing what was there.

Parameters

olddirfd	the directory oldpath is relative to, or AT_FDCWD
oldpath	the file's path
newdirfd	the directory newpath is relative to, or AT_FDCWD
newpath	its new path

Returns: 0, or a negative errno: -ENOENT, -EXDEV, -EISDIR, -ENOTEMPTY, -EINVAL, ...

Definition at line 1464 of file sys_file.c.

References at_path(), kfree(), LOG_DEBUG, NULL, sys_renameat(), and vfs_rename().

Referenced by sys_renameat().

◆ sys_rmdir()

long sys_rmdir ( const char * path )

Implements rmdir(): removes an empty directory.

Parameters

path	the directory's path

Returns: 0, or a negative errno: -ENOTEMPTY, -ENOTDIR, -EBUSY, ...

Definition at line 1383 of file sys_file.c.

References do_unlinkat(), LOG_DEBUG, and sys_rmdir().

Referenced by sys_rmdir().

◆ sys_stat()

long sys_stat	(	const char *	path,
		struct aquila_stat *	buf )

Implements stat(): a file's attributes, following a symbolic link.

Parameters

path	the file's path
buf	where to put them

Returns: 0, or a negative errno: -ENOENT, -EACCES, -EFAULT, ...

Definition at line 504 of file sys_file.c.

References do_fstatat(), LOG_DEBUG, and sys_stat().

Referenced by sys_stat().

◆ sys_symlinkat()

long sys_symlinkat	(	const char *	utarget,
		int	dirfd,
		const char *	upath )

Implements symlinkat(): makes a symbolic link.

Parameters

utarget	what it points to
dirfd	the directory upath is relative to, or AT_FDCWD
upath	the link's path

Returns: 0, or a negative errno: -EEXIST, -ENOENT, -EACCES, ...

Definition at line 1397 of file sys_file.c.

References at_uio(), kfree(), LOG_DEBUG, NULL, sys_symlinkat(), upath_get(), and vfs_symlink().

Referenced by sys_symlinkat().

◆ sys_sync()

long sys_sync ( void )

Implements sync(): writes out what the devices' caches hold.

Returns: 0, or a negative errno from a device

Definition at line 1508 of file sys_file.c.

References kdev_sync(), LOG_DEBUG, and sys_sync().

Referenced by sys_sync().

◆ sys_umask()

long sys_umask ( mode_t mask )

Implements umask(): sets the permissions that new files don't get.

Parameters

mask	the new mask

Returns: the old mask

Definition at line 1089 of file sys_file.c.

References curproc, LOG_DEBUG, and sys_umask().

Referenced by sys_umask().

◆ sys_unlink()

long sys_unlink ( const char * path )

Implements unlink(): removes a name of a file (not a directory's).

Parameters

path the name

Returns: 0, or a negative errno: -ENOENT, -EISDIR, -EACCES, ...

Definition at line 553 of file sys_file.c.

References do_unlinkat(), LOG_DEBUG, and sys_unlink().

Referenced by sys_unlink().

◆ sys_unlinkat()

long sys_unlinkat	(	int	dirfd,
		const char *	path,
		int	flags )

Implements unlinkat(): unlink(), or rmdir() with AT_REMOVEDIR, with the path relative to a directory.

Parameters

dirfd	the directory, or AT_FDCWD
path	the name
flags	AT_REMOVEDIR to remove a directory

Returns: 0, or a negative errno

Definition at line 568 of file sys_file.c.

References do_unlinkat(), uio::flags, LOG_DEBUG, and sys_unlinkat().

Referenced by sys_unlinkat().

◆ sys_utimensat()

long sys_utimensat	(	int	dirfd,
		const char *	path,
		const struct aquila_timespec	times[2],
		int	flags )

Implements utimensat() (and futimens()): sets a file's access and modification times.

Parameters

dirfd	the directory path is relative to, or AT_FDCWD; with a NULL path, the file itself (futimens())
path	the file's path, or NULL
times	the two times, or NULL for now
flags	AT_SYMLINK_NOFOLLOW for a symbolic link's own

Returns: 0, or a negative errno: -EINVAL, -EFAULT, -ENOENT, -EPERM, ...

Definition at line 1340 of file sys_file.c.

References at_lookup(), curproc, fd_vnode(), uio::flags, LOG_DEBUG, NULL, PROC_UIO, sys_utimensat(), vfs_close(), and vfs_utimens().

Referenced by sys_utimensat().

◆ sys_write()

long sys_write	(	int	fd,
		void *	buf,
		size_t	nbytes )

Implements write().

Writing to a pipe that no one reads also raises SIGPIPE.

Parameters

fd	the descriptor
buf	the data
nbytes	how much to write

Returns: how many bytes were written, or a negative errno: -EBADF, -EFAULT, -EPIPE, -EAGAIN, -ENOSPC, ...

Definition at line 584 of file sys_file.c.

References curproc, fd_file(), iobuf_init(), LOG_DEBUG, signal_proc_send(), sys_write(), uaccess_check(), and vfs_file_write().

Referenced by sys_write().

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ F_OK

◆ R_OK

◆ W_OK

◆ X_OK

Function Documentation

◆ at_lookup()

◆ at_path()

◆ at_uio()

◆ creat_path()

◆ cwd_set()

◆ do_faccessat()

◆ do_fchmodat()

◆ do_fchownat()

◆ do_fstatat()

◆ do_linkat()

◆ do_mknodat()

◆ do_openat()

◆ do_unlinkat()

◆ fd_vnode()

◆ sys_access()

◆ sys_chdir()

◆ sys_chmod()

◆ sys_chown()

◆ sys_close()

◆ sys_faccessat()

◆ sys_fchdir()

◆ sys_fchmod()

◆ sys_fchmodat()

◆ sys_fchown()

◆ sys_fchownat()

◆ sys_fcntl()

◆ sys_flock()

◆ sys_fstat()

◆ sys_fstatat()

◆ sys_ftruncate()

◆ sys_getcwd()

◆ sys_ioctl()

◆ sys_isatty()

◆ sys_lchown()

◆ sys_link()

◆ sys_linkat()

◆ sys_lseek()

◆ sys_lstat()

◆ sys_mkdir()

◆ sys_mknod()

◆ sys_mknodat()

◆ sys_mount()

◆ sys_open()

◆ sys_openat()

◆ sys_pipe()

◆ sys_read()

◆ sys_readdir()

◆ sys_readlinkat()

◆ sys_renameat()

◆ sys_rmdir()

◆ sys_stat()

◆ sys_symlinkat()

◆ sys_sync()

◆ sys_umask()

◆ sys_unlink()

◆ sys_unlinkat()

◆ sys_utimensat()

◆ sys_write()