1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __SCCSID("@(#)getmntinfo.c 8.1 (Berkeley) 6/4/93"); 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/ucred.h> 38 #include <sys/mount.h> 39 #include <stdlib.h> 40 41 #define MAX_TRIES 3 42 #define SCALING_FACTOR 2 43 44 /* 45 * Return information about mounted filesystems. 46 */ 47 int 48 getmntinfo(struct statfs **mntbufp, int mode) 49 { 50 static struct statfs *mntbuf; 51 static int mntsize; 52 static long bufsize; 53 unsigned tries = 0; 54 55 if (mntsize <= 0 && (mntsize = getfsstat(0, 0, MNT_NOWAIT)) < 0) 56 return (0); 57 if (bufsize > 0 && (mntsize = getfsstat(mntbuf, bufsize, mode)) < 0) 58 return (0); 59 while (tries++ < MAX_TRIES && bufsize <= mntsize * sizeof(*mntbuf)) { 60 bufsize = (mntsize * SCALING_FACTOR) * sizeof(*mntbuf); 61 if ((mntbuf = reallocf(mntbuf, bufsize)) == NULL) 62 return (0); 63 if ((mntsize = getfsstat(mntbuf, bufsize, mode)) < 0) 64 return (0); 65 } 66 *mntbufp = mntbuf; 67 if (mntsize > (bufsize / sizeof(*mntbuf))) 68 return (bufsize / sizeof(*mntbuf)); 69 return (mntsize); 70 } 71