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.Dd March 30, 2020 29.Dt GETFSSTAT 2 30.Os 31.Sh NAME 32.Nm getfsstat 33.Nd get list of all mounted file systems 34.Sh LIBRARY 35.Lb libc 36.Sh SYNOPSIS 37.In sys/param.h 38.In sys/ucred.h 39.In sys/mount.h 40.Ft int 41.Fn getfsstat "struct statfs *buf" "long bufsize" "int mode" 42.Sh DESCRIPTION 43The 44.Fn getfsstat 45system call 46returns information about all mounted file systems. 47The 48.Fa buf 49argument 50is a pointer to 51.Vt statfs 52structures, as described in 53.Xr statfs 2 . 54.Pp 55Fields that are undefined for a particular file system are set to -1. 56The buffer is filled with an array of 57.Fa statfs 58structures, one for each mounted file system 59up to the byte count specified by 60.Fa bufsize . 61Note, the 62.Fa bufsize 63argument is the number of bytes that 64.Fa buf 65can hold, not the count of statfs structures it will hold. 66.Pp 67If 68.Fa buf 69is given as NULL, 70.Fn getfsstat 71returns just the number of mounted file systems. 72.Pp 73Normally 74.Fa mode 75should be specified as 76.Dv MNT_WAIT . 77If 78.Fa mode 79is set to 80.Dv MNT_NOWAIT , 81.Fn getfsstat 82will return the information it has available without requesting 83an update from each file system. 84Thus, some of the information will be out of date, but 85.Fn getfsstat 86will not block waiting for information from a file system that is 87unable to respond. 88It will also skip any file system that is in the process of being 89unmounted, even if the unmount would eventually fail. 90.Sh RETURN VALUES 91Upon successful completion, the number of 92.Fa statfs 93structures is returned. 94Otherwise, -1 is returned and the global variable 95.Va errno 96is set to indicate the error. 97.Sh ERRORS 98The 99.Fn getfsstat 100system call 101fails if one or more of the following are true: 102.Bl -tag -width Er 103.It Bq Er EFAULT 104The 105.Fa buf 106argument 107points to an invalid address. 108.It Bq Er EINVAL 109.Fa mode 110is set to a value other than 111.Dv MNT_WAIT 112or 113.Dv MNT_NOWAIT . 114.It Bq Er EIO 115An 116.Tn I/O 117error occurred while reading from or writing to the file system. 118.It Bq Er EINTEGRITY 119Corrupted data was detected while reading from the file system. 120.El 121.Sh SEE ALSO 122.Xr statfs 2 , 123.Xr fstab 5 , 124.Xr mount 8 125.Sh HISTORY 126The 127.Fn getfsstat 128system call first appeared in 129.Bx 4.4 . 130