xref: /freebsd/lib/libc/gen/statvfs.c (revision 1db64f89363c97858961c4df0b7d02f3223723cf)
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 "namespace.h"
31 #include <sys/param.h>
32 #include <sys/mount.h>
33 #include <sys/statvfs.h>
34 
35 #include <errno.h>
36 #include <limits.h>
37 #include <unistd.h>
38 #include "un-namespace.h"
39 
40 static int	sfs2svfs(const struct statfs *from, struct statvfs *to);
41 
42 int
43 fstatvfs(int fd, struct statvfs *result)
44 {
45 	struct statfs sfs;
46 	int rv;
47 	long pcval;
48 
49 	rv = _fstatfs(fd, &sfs);
50 	if (rv != 0)
51 		return (rv);
52 
53 	rv = sfs2svfs(&sfs, result);
54 	if (rv != 0)
55 		return (rv);
56 
57 	/*
58 	 * Whether pathconf's -1 return means error or unlimited does not
59 	 * make any difference in this best-effort implementation.
60 	 */
61 	pcval = _fpathconf(fd, _PC_NAME_MAX);
62 	if (pcval == -1)
63 		result->f_namemax = ~0UL;
64 	else
65 		result->f_namemax = (unsigned long)pcval;
66 	return (0);
67 }
68 
69 int
70 statvfs(const char * __restrict path, struct statvfs * __restrict result)
71 {
72 	struct statfs sfs;
73 	int rv;
74 	long pcval;
75 
76 	rv = statfs(path, &sfs);
77 	if (rv != 0)
78 		return (rv);
79 
80 	sfs2svfs(&sfs, result);
81 
82 	/*
83 	 * Whether pathconf's -1 return means error or unlimited does not
84 	 * make any difference in this best-effort implementation.
85 	 */
86 	pcval = pathconf(path, _PC_NAME_MAX);
87 	if (pcval == -1)
88 		result->f_namemax = ~0UL;
89 	else
90 		result->f_namemax = (unsigned long)pcval;
91 	return (0);
92 }
93 
94 static int
95 sfs2svfs(const struct statfs *from, struct statvfs *to)
96 {
97 	static const struct statvfs zvfs;
98 
99 	*to = zvfs;
100 
101 	if (from->f_flags & MNT_RDONLY)
102 		to->f_flag |= ST_RDONLY;
103 	if (from->f_flags & MNT_NOSUID)
104 		to->f_flag |= ST_NOSUID;
105 
106 	/* XXX should we clamp negative values? */
107 #define COPY(field) \
108 	do { \
109 		to->field = from->field; \
110 		if (from->field != to->field) { \
111 			errno = EOVERFLOW; \
112 			return (-1); \
113 		} \
114 	} while(0)
115 
116 	COPY(f_bavail);
117 	COPY(f_bfree);
118 	COPY(f_blocks);
119 	COPY(f_ffree);
120 	COPY(f_files);
121 	to->f_bsize = from->f_iosize;
122 	to->f_frsize = from->f_bsize;
123 	to->f_favail = to->f_ffree;
124 	return (0);
125 }
126 
127 #ifdef MAIN
128 #include <err.h>
129 #include <stdint.h>
130 #include <stdio.h>
131 
132 int
133 main(int argc, char **argv)
134 {
135 	struct statvfs buf;
136 
137 	if (statvfs(argv[1], &buf) < 0)
138 		err(1, "statvfs");
139 
140 #define SHOW(field) \
141 	printf(#field ": %ju\n", (uintmax_t)buf.field)
142 
143 	SHOW(f_bavail);
144 	SHOW(f_bfree);
145 	SHOW(f_blocks);
146 	SHOW(f_favail);
147 	SHOW(f_ffree);
148 	SHOW(f_files);
149 	SHOW(f_bsize);
150 	SHOW(f_frsize);
151 	SHOW(f_namemax);
152 	printf("f_flag: %lx\n", (unsigned long)buf.f_flag);
153 
154 	return 0;
155 }
156 
157 #endif /* MAIN */
158