[apple/xnu.git] / bsd / man / man2 / getfsstat.2

.\"	$NetBSD: getfsstat.2,v 1.6 1995/06/29 11:40:44 cgd 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.
.\"
.\"	@(#)getfsstat.2	8.1 (Berkeley) 6/9/93
.\"
.Dd June 9, 1993
.Dt GETFSSTAT 2
.Os
.Sh NAME
.Nm getfsstat
.Nd get list of all mounted file systems
.Sh SYNOPSIS
.Fd #include <sys/param.h>
.Fd #include <sys/ucred.h>
.Fd #include <sys/mount.h>
.Ft int
.Fn getfsstat "struct statfs *buf" "int bufsize" "int flags"
.Sh DESCRIPTION
.Fn Getfsstat
returns information about all mounted file systems.
.Fa Buf
is a pointer to an array of
.Xr statfs
structures defined as follows:
.Bd -literal
typedef struct { int32_t val[2]; } fsid_t;

#define MFSNAMELEN   15 /* length of fs type name, not inc. nul */
#define MNAMELEN     90	/* length of buffer for returned name */

struct statfs {
    short   f_otype;	/* type of file system (reserved: zero) */
    short   f_oflags;	/* copy of mount flags (reserved: zero) */
    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 (super-user only) */
    uid_t   f_owner;	/* user that mounted the file system */
    short   f_reserved1;	/* reserved for future use */
    short   f_type;	/* type of file system (reserved) */
    long    f_flags;	/* copy of mount flags (reserved) */
    long    f_reserved2[2];	/* reserved for future use */
    char    f_fstypename[MFSNAMELEN]; /* fs type name */
    char    f_mntonname[MNAMELEN];    /* directory on which mounted */
    char    f_mntfromname[MNAMELEN];  /* mounted file system */
    char    f_reserved3;	/* reserved for future use */
    long    f_reserved4[4];	/* reserved for future use */
};
.Ed
.Pp
Fields that are undefined for a particular file system are set to -1.
The buffer is filled with an array of
.Fa statfs
structures, one for each mounted file system
up to the size specified by
.Fa bufsize .
.Pp
If
.Fa buf
is given as NULL,
.Fn getfsstat
returns just the number of mounted file systems.
.Pp
If
.Fa flags
is set to
.Dv MNT_NOWAIT ,
.Fn getfsstat
will directly return the information retained in the kernel
to avoid delays caused by waiting for updated information from
a file system that is perhaps temporarily unable to respond.
Some of the information returned may be out of date, however; if
.Fa flags
is set to
.Dv MNT_WAIT
instead,
.Fn getfsstat
will request updated information from each mounted filesystem before
returning.
.Sh RETURN VALUES
Upon successful completion, the number of 
.Fa statfs
structures is returned.
Otherwise, -1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
.Fn Getfsstat
fails if one or more of the following are true:
.Bl -tag -width Er
.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 SEE ALSO
.Xr statfs 2 ,
.Xr fstab 5 ,
.Xr mount 8
.Sh HISTORY
The
.Fn getfsstat
function first appeared in 4.4BSD.
Commit	Line	Data
9bccf70c A	1	.\" $NetBSD: getfsstat.2,v 1.6 1995/06/29 11:40:44 cgd Exp $
	2	.\"
	3	.\" Copyright (c) 1989, 1991, 1993
	4	.\" The Regents of the University of California. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\" 3. All advertising materials mentioning features or use of this software
	15	.\" must display the following acknowledgement:
	16	.\" This product includes software developed by the University of
	17	.\" California, Berkeley and its contributors.
	18	.\" 4. Neither the name of the University nor the names of its contributors
	19	.\" may be used to endorse or promote products derived from this software
	20	.\" without specific prior written permission.
	21	.\"
	22	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	.\" SUCH DAMAGE.
	33	.\"
	34	.\" @(#)getfsstat.2 8.1 (Berkeley) 6/9/93
	35	.\"
	36	.Dd June 9, 1993
	37	.Dt GETFSSTAT 2
	38	.Os
	39	.Sh NAME
	40	.Nm getfsstat
	41	.Nd get list of all mounted file systems
	42	.Sh SYNOPSIS
	43	.Fd #include <sys/param.h>
	44	.Fd #include <sys/ucred.h>
	45	.Fd #include <sys/mount.h>
	46	.Ft int
91447636	47	.Fn getfsstat "struct statfs *buf" "int bufsize" "int flags"
9bccf70c A	48	.Sh DESCRIPTION
	49	.Fn Getfsstat
	50	returns information about all mounted file systems.
	51	.Fa Buf
	52	is a pointer to an array of
	53	.Xr statfs
	54	structures defined as follows:
	55	.Bd -literal
	56	typedef struct { int32_t val[2]; } fsid_t;
	57
55e303ae A	58	#define MFSNAMELEN 15 /* length of fs type name, not inc. nul */
55e303ae A	59	#define MNAMELEN 90 /* length of buffer for returned name */
9bccf70c A	60
9bccf70c A	61	struct statfs {
55e303ae A	62	short f_otype; /* type of file system (reserved: zero) */
55e303ae A	63	short f_oflags; /* copy of mount flags (reserved: zero) */
9bccf70c A	64	long f_bsize; /* fundamental file system block size */
	65	long f_iosize; /* optimal transfer block size */
	66	long f_blocks; /* total data blocks in file system */
	67	long f_bfree; /* free blocks in fs */
	68	long f_bavail; /* free blocks avail to non-superuser */
	69	long f_files; /* total file nodes in file system */
	70	long f_ffree; /* free file nodes in fs */
55e303ae	71	fsid_t f_fsid; /* file system id (super-user only) */
9bccf70c	72	uid_t f_owner; /* user that mounted the file system */
55e303ae A	73	short f_reserved1; /* reserved for future use */
	74	short f_type; /* type of file system (reserved) */
	75	long f_flags; /* copy of mount flags (reserved) */
	76	long f_reserved2[2]; /* reserved for future use */
9bccf70c A	77	char f_fstypename[MFSNAMELEN]; /* fs type name */
	78	char f_mntonname[MNAMELEN]; /* directory on which mounted */
	79	char f_mntfromname[MNAMELEN]; /* mounted file system */
55e303ae A	80	char f_reserved3; /* reserved for future use */
55e303ae A	81	long f_reserved4[4]; /* reserved for future use */
9bccf70c A	82	};
	83	.Ed
	84	.Pp
	85	Fields that are undefined for a particular file system are set to -1.
	86	The buffer is filled with an array of
	87	.Fa statfs
	88	structures, one for each mounted file system
	89	up to the size specified by
	90	.Fa bufsize .
	91	.Pp
	92	If
	93	.Fa buf
	94	is given as NULL,
	95	.Fn getfsstat
	96	returns just the number of mounted file systems.
	97	.Pp
9bccf70c A	98	If
	99	.Fa flags
	100	is set to
	101	.Dv MNT_NOWAIT ,
	102	.Fn getfsstat
91447636 A	103	will directly return the information retained in the kernel
	104	to avoid delays caused by waiting for updated information from
	105	a file system that is perhaps temporarily unable to respond.
	106	Some of the information returned may be out of date, however; if
	107	.Fa flags
	108	is set to
	109	.Dv MNT_WAIT
	110	instead,
9bccf70c	111	.Fn getfsstat
91447636 A	112	will request updated information from each mounted filesystem before
91447636 A	113	returning.
9bccf70c A	114	.Sh RETURN VALUES
	115	Upon successful completion, the number of
	116	.Fa statfs
	117	structures is returned.
	118	Otherwise, -1 is returned and the global variable
	119	.Va errno
	120	is set to indicate the error.
	121	.Sh ERRORS
	122	.Fn Getfsstat
	123	fails if one or more of the following are true:
	124	.Bl -tag -width Er
	125	.It Bq Er EFAULT
	126	.Fa Buf
	127	points to an invalid address.
	128	.It Bq Er EIO
	129	An
	130	.Tn I/O
	131	error occurred while reading from or writing to the file system.
	132	.El
	133	.Sh SEE ALSO
	134	.Xr statfs 2 ,
	135	.Xr fstab 5 ,
	136	.Xr mount 8
	137	.Sh HISTORY
	138	The
	139	.Fn getfsstat
	140	function first appeared in 4.4BSD.