xref: /freebsd/lib/libc/gen/statvfs.c (revision cc68614da8232d8baaca0ae0d0dd8f890f06623e)
1 /*
2  * Copyright 2002 Massachusetts Institute of Technology
3  *
4  * Permission to use, copy, modify, and distribute this software and
5  * its documentation for any purpose and without fee is hereby
6  * granted, provided that both the above copyright notice and this
7  * permission notice appear in all copies, that both the above
8  * copyright notice and this permission notice appear in all
9  * supporting documentation, and that the name of M.I.T. not be used
10  * in advertising or publicity pertaining to distribution of the
11  * software without specific, written prior permission.  M.I.T. makes
12  * no representations about the suitability of this software for any
13  * purpose.  It is provided "as is" without express or implied
14  * warranty.
15  *
16  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "namespace.h"
34 #include <sys/param.h>
35 #include <sys/mount.h>
36 #include <sys/statvfs.h>
37 
38 #include <errno.h>
39 #include <limits.h>
40 #include <unistd.h>
41 #include "un-namespace.h"
42 
43 static int	sfs2svfs(const struct statfs *from, struct statvfs *to);
44 
45 int
46 fstatvfs(int fd, struct statvfs *result)
47 {
48 	struct statfs sfs;
49 	int rv;
50 	long pcval;
51 
52 	rv = _fstatfs(fd, &sfs);
53 	if (rv != 0)
54 		return (rv);
55 
56 	rv = sfs2svfs(&sfs, result);
57 	if (rv != 0)
58 		return (rv);
59 
60 	/*
61 	 * Whether pathconf's -1 return means error or unlimited does not
62 	 * make any difference in this best-effort implementation.
63 	 */
64 	pcval = _fpathconf(fd, _PC_NAME_MAX);
65 	if (pcval == -1)
66 		result->f_namemax = ~0UL;
67 	else
68 		result->f_namemax = (unsigned long)pcval;
69 	return (0);
70 }
71 
72 int
73 statvfs(const char * __restrict path, struct statvfs * __restrict result)
74 {
75 	struct statfs sfs;
76 	int rv;
77 	long pcval;
78 
79 	rv = statfs(path, &sfs);
80 	if (rv != 0)
81 		return (rv);
82 
83 	sfs2svfs(&sfs, result);
84 
85 	/*
86 	 * Whether pathconf's -1 return means error or unlimited does not
87 	 * make any difference in this best-effort implementation.
88 	 */
89 	pcval = pathconf(path, _PC_NAME_MAX);
90 	if (pcval == -1)
91 		result->f_namemax = ~0UL;
92 	else
93 		result->f_namemax = (unsigned long)pcval;
94 	return (0);
95 }
96 
97 static int
98 sfs2svfs(const struct statfs *from, struct statvfs *to)
99 {
100 	static const struct statvfs zvfs;
101 
102 	*to = zvfs;
103 
104 	if (from->f_flags & MNT_RDONLY)
105 		to->f_flag |= ST_RDONLY;
106 	if (from->f_flags & MNT_NOSUID)
107 		to->f_flag |= ST_NOSUID;
108 
109 	/* XXX should we clamp negative values? */
110 #define COPY(field) \
111 	do { \
112 		to->field = from->field; \
113 		if (from->field != to->field) { \
114 			errno = EOVERFLOW; \
115 			return (-1); \
116 		} \
117 	} while(0)
118 
119 	COPY(f_bavail);
120 	COPY(f_bfree);
121 	COPY(f_blocks);
122 	COPY(f_ffree);
123 	COPY(f_files);
124 	to->f_bsize = from->f_iosize;
125 	to->f_frsize = from->f_bsize;
126 	to->f_favail = to->f_ffree;
127 	return (0);
128 }
129 
130 #ifdef MAIN
131 #include <err.h>
132 #include <stdint.h>
133 #include <stdio.h>
134 
135 int
136 main(int argc, char **argv)
137 {
138 	struct statvfs buf;
139 
140 	if (statvfs(argv[1], &buf) < 0)
141 		err(1, "statvfs");
142 
143 #define SHOW(field) \
144 	printf(#field ": %ju\n", (uintmax_t)buf.field)
145 
146 	SHOW(f_bavail);
147 	SHOW(f_bfree);
148 	SHOW(f_blocks);
149 	SHOW(f_favail);
150 	SHOW(f_ffree);
151 	SHOW(f_files);
152 	SHOW(f_bsize);
153 	SHOW(f_frsize);
154 	SHOW(f_namemax);
155 	printf("f_flag: %lx\n", (unsigned long)buf.f_flag);
156 
157 	return 0;
158 }
159 
160 #endif /* MAIN */
161