1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getfsstat.2 8.3 (Berkeley) 5/25/95 29.\" $FreeBSD$ 30.\" 31.Dd December 27, 2016 32.Dt GETFSSTAT 2 33.Os 34.Sh NAME 35.Nm getfsstat 36.Nd get list of all mounted file systems 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In sys/param.h 41.In sys/ucred.h 42.In sys/mount.h 43.Ft int 44.Fn getfsstat "struct statfs *buf" "long bufsize" "int mode" 45.Sh DESCRIPTION 46The 47.Fn getfsstat 48system call 49returns information about all mounted file systems. 50The 51.Fa buf 52argument 53is a pointer to 54.Vt statfs 55structures, as described in 56.Xr statfs 2 . 57.Pp 58Fields that are undefined for a particular file system are set to -1. 59The buffer is filled with an array of 60.Fa statfs 61structures, one for each mounted file system 62up to the byte count specified by 63.Fa bufsize . 64Note, the 65.Fa bufsize 66argument is the number of bytes that 67.Fa buf 68can hold, not the count of statfs structures it will hold. 69.Pp 70If 71.Fa buf 72is given as NULL, 73.Fn getfsstat 74returns just the number of mounted file systems. 75.Pp 76Normally 77.Fa mode 78should be specified as 79.Dv MNT_WAIT . 80If 81.Fa mode 82is set to 83.Dv MNT_NOWAIT , 84.Fn getfsstat 85will return the information it has available without requesting 86an update from each file system. 87Thus, some of the information will be out of date, but 88.Fn getfsstat 89will not block waiting for information from a file system that is 90unable to respond. 91It will also skip any file system that is in the process of being 92unmounted, even if the unmount would eventually fail. 93.Sh RETURN VALUES 94Upon successful completion, the number of 95.Fa statfs 96structures is returned. 97Otherwise, -1 is returned and the global variable 98.Va errno 99is set to indicate the error. 100.Sh ERRORS 101The 102.Fn getfsstat 103system call 104fails if one or more of the following are true: 105.Bl -tag -width Er 106.It Bq Er EFAULT 107The 108.Fa buf 109argument 110points to an invalid address. 111.It Bq Er EINVAL 112.Fa mode 113is set to a value other than 114.Dv MNT_WAIT 115or 116.Dv MNT_NOWAIT . 117.It Bq Er EIO 118An 119.Tn I/O 120error occurred while reading from or writing to the file system. 121.El 122.Sh SEE ALSO 123.Xr statfs 2 , 124.Xr fstab 5 , 125.Xr mount 8 126.Sh HISTORY 127The 128.Fn getfsstat 129system call first appeared in 130.Bx 4.4 . 131