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.\" 30.Dd March 30, 2020 31.Dt GETFSSTAT 2 32.Os 33.Sh NAME 34.Nm getfsstat 35.Nd get list of all mounted file systems 36.Sh LIBRARY 37.Lb libc 38.Sh SYNOPSIS 39.In sys/param.h 40.In sys/ucred.h 41.In sys/mount.h 42.Ft int 43.Fn getfsstat "struct statfs *buf" "long bufsize" "int mode" 44.Sh DESCRIPTION 45The 46.Fn getfsstat 47system call 48returns information about all mounted file systems. 49The 50.Fa buf 51argument 52is a pointer to 53.Vt statfs 54structures, as described in 55.Xr statfs 2 . 56.Pp 57Fields that are undefined for a particular file system are set to -1. 58The buffer is filled with an array of 59.Fa statfs 60structures, one for each mounted file system 61up to the byte count specified by 62.Fa bufsize . 63Note, the 64.Fa bufsize 65argument is the number of bytes that 66.Fa buf 67can hold, not the count of statfs structures it will hold. 68.Pp 69If 70.Fa buf 71is given as NULL, 72.Fn getfsstat 73returns just the number of mounted file systems. 74.Pp 75Normally 76.Fa mode 77should be specified as 78.Dv MNT_WAIT . 79If 80.Fa mode 81is set to 82.Dv MNT_NOWAIT , 83.Fn getfsstat 84will return the information it has available without requesting 85an update from each file system. 86Thus, some of the information will be out of date, but 87.Fn getfsstat 88will not block waiting for information from a file system that is 89unable to respond. 90It will also skip any file system that is in the process of being 91unmounted, even if the unmount would eventually fail. 92.Sh RETURN VALUES 93Upon successful completion, the number of 94.Fa statfs 95structures is returned. 96Otherwise, -1 is returned and the global variable 97.Va errno 98is set to indicate the error. 99.Sh ERRORS 100The 101.Fn getfsstat 102system call 103fails if one or more of the following are true: 104.Bl -tag -width Er 105.It Bq Er EFAULT 106The 107.Fa buf 108argument 109points to an invalid address. 110.It Bq Er EINVAL 111.Fa mode 112is set to a value other than 113.Dv MNT_WAIT 114or 115.Dv MNT_NOWAIT . 116.It Bq Er EIO 117An 118.Tn I/O 119error occurred while reading from or writing to the file system. 120.It Bq Er EINTEGRITY 121Corrupted data was detected while reading from the file system. 122.El 123.Sh SEE ALSO 124.Xr statfs 2 , 125.Xr fstab 5 , 126.Xr mount 8 127.Sh HISTORY 128The 129.Fn getfsstat 130system call first appeared in 131.Bx 4.4 . 132