NetBSD/lib/libc/sys/statfs.2

205 lines
6.5 KiB
Groff

.\" $NetBSD: statfs.2,v 1.22 2003/04/16 13:34:57 wiz Exp $
.\"
.\" Copyright (c) 1989, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)statfs.2 8.5 (Berkeley) 5/24/95
.\"
.Dd May 24, 1995
.Dt STATFS 2
.Os
.Sh NAME
.Nm statfs ,
.Nm fstatfs
.Nd get file system statistics
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In sys/mount.h
.Ft int
.Fn statfs "const char *path" "struct statfs *buf"
.Ft int
.Fn fstatfs "int fd" "struct statfs *buf"
.Sh DESCRIPTION
.Fn statfs
returns information about a mounted file system.
.Fa path
is the path name of any file within the mounted file system.
.Fa buf
is a pointer to a
.Nm statfs
structure defined as follows:
.Bd -literal
typedef struct { int32_t val[2]; } fsid_t; /* file system id type */
#define MFSNAMELEN 16 /* length of fs type name, including nul */
#define MNAMELEN 90 /* length of buffer for returned name */
struct statfs {
short f_type; /* type of file system (unused; zero) */
u_short f_oflags; /* deprecated copy of mount flags */
long f_bsize; /* fundamental file system block size */
long f_iosize; /* optimal transfer block size */
long f_blocks; /* total data blocks in file system */
long f_bfree; /* free blocks in fs */
long f_bavail; /* free blocks avail to non-superuser */
long f_files; /* total file nodes in file system */
long f_ffree; /* free file nodes in fs */
fsid_t f_fsid; /* file system id */
uid_t f_owner; /* user that mounted the file system */
long f_flags; /* copy of mount flags */
long f_syncwrites; /* count of sync writes since mount */
long f_asyncwrites; /* count of async writes since mount */
long f_spare[1]; /* spare for later */
char f_fstypename[MFSNAMELEN]; /* fs type name */
char f_mntonname[MNAMELEN]; /* directory on which mounted */
char f_mntfromname[MNAMELEN]; /* mounted file system */
};
.Ed
.Pp
The flags that may be returned include:
.Bl -tag -width MNT_SYNCHRONOUS
.It Dv MNT_RDONLY
The filesystem is mounted read-only;
Even the super-user may not write on it.
.It Dv MNT_NOEXEC
Files may not be executed from the filesystem.
.It Dv MNT_NOSUID
Setuid and setgid bits on files are not honored when they are executed.
.It Dv MNT_NODEV
Special files in the filesystem may not be opened.
.It Dv MNT_SYNCHRONOUS
All I/O to the filesystem is done synchronously.
.It Dv MNT_ASYNC
No filesystem I/O is done synchronously.
.It Dv MNT_UNION
Union with underlying filesystem.
.It Dv MNT_NOCOREDUMP
Don't write core dumps to this file system.
.It Dv MNT_NOATIME
Never update access times.
.It Dv MNT_SYMPERM
Recognize symbolic link permission.
.It Dv MNT_NODEVMTIME
Never update mod. times for device files.
.It Dv MNT_SOFTDEP
Use soft dependencies.
.It Dv MNT_LOCAL
The filesystem resides locally.
.It Dv MNT_QUOTA
The filesystem has quotas enabled on it.
.It Dv MNT_ROOTFS
Identifies the root filesystem.
.It Dv MNT_EXRDONLY
The filesystem is exported read-only.
.It Dv MNT_EXPORTED
The filesystem is exported for both reading and writing.
.It Dv MNT_DEFEXPORTED
The filesystem is exported for both reading and writing to any Internet host.
.It Dv MNT_EXPORTANON
The filesystem maps all remote accesses to the anonymous user.
.It Dv MNT_EXKERB
The filesystem is exported with Kerberos uid mapping.
.It Dv MNT_EXNORESPORT
Don't enforce reserved ports (NFS).
.It Dv MNT_EXPUBLIC
Public export (WebNFS).
.El
.Pp
Fields that are undefined for a particular file system are set to -1.
.Fn fstatfs
returns the same information about an open file referenced by descriptor
.Fa fd .
.Sh RETURN VALUES
Upon successful completion, a value of 0 is returned.
Otherwise, -1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn statfs
fails if one or more of the following are true:
.Bl -tag -width Er
.It Bq Er ENOTDIR
A component of the path prefix of
.Fa path
is not a directory.
.It Bq Er ENAMETOOLONG
The length of a component of
.Fa path
exceeds
.Dv {NAME_MAX}
characters, or the length of
.Fa path
exceeds
.Dv {PATH_MAX}
characters.
.It Bq Er ENOENT
The file referred to by
.Fa path
does not exist.
.It Bq Er EACCES
Search permission is denied for a component of the path prefix of
.Fa path .
.It Bq Er ELOOP
Too many symbolic links were encountered in translating
.Fa path .
.It Bq Er EFAULT
.Fa buf
or
.Fa path
points to an invalid address.
.It Bq Er EIO
An
.Tn I/O
error occurred while reading from or writing to the file system.
.El
.Pp
.Fn fstatfs
fails if one or more of the following are true:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa fd
is not a valid open file descriptor.
.It Bq Er EFAULT
.Fa buf
points to an invalid address.
.It Bq Er EIO
An
.Tn I/O
error occurred while reading from or writing to the file system.
.El
.Sh HISTORY
The
.Fn statfs
function first appeared in
.Bx 4.4 .