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1 | .\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl) |
2 | .\" | |
3 | .\" Permission is granted to make and distribute verbatim copies of this | |
4 | .\" manual provided the copyright notice and this permission notice are | |
5 | .\" preserved on all copies. | |
6 | .\" | |
7 | .\" Permission is granted to copy and distribute modified versions of this | |
8 | .\" manual under the conditions for verbatim copying, provided that the | |
9 | .\" entire resulting derived work is distributed under the terms of a | |
10 | .\" permission notice identical to this one. | |
c13182ef | 11 | .\" |
fea681da MK |
12 | .\" Since the Linux kernel and libraries are constantly changing, this |
13 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
14 | .\" responsibility for errors or omissions, or for damages resulting from | |
15 | .\" the use of the information contained herein. The author(s) may not | |
16 | .\" have taken the same level of care in the production of this manual, | |
17 | .\" which is licensed free of charge, as they might when working | |
18 | .\" professionally. | |
c13182ef | 19 | .\" |
fea681da MK |
20 | .\" Formatted or processed versions of this manual, if unaccompanied by |
21 | .\" the source, must acknowledge the copyright and authors of this work. | |
22 | .\" | |
23 | .\" Modified 2003-08-17 by Walter Harms | |
305a0578 | 24 | .\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net> |
fea681da MK |
25 | .\" |
26 | .TH STATFS 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual" | |
27 | .SH NAME | |
28 | statfs, fstatfs \- get file system statistics | |
29 | .SH SYNOPSIS | |
30 | .BR "#include <sys/vfs.h> " "/* or <sys/statfs.h> */" | |
31 | .sp | |
32 | .BI "int statfs(const char *" path ", struct statfs *" buf ); | |
33 | .br | |
34 | .BI "int fstatfs(int " fd ", struct statfs *" buf ); | |
35 | .SH DESCRIPTION | |
36 | The function | |
e511ffb6 | 37 | .BR statfs () |
fea681da MK |
38 | returns information about a mounted file system. |
39 | .I path | |
2d7195b8 | 40 | is the pathname of any file within the mounted filesystem. |
fea681da MK |
41 | .I buf |
42 | is a pointer to a | |
43 | .I statfs | |
44 | structure defined approximately as follows: | |
45 | ||
46 | .RS | |
47 | .nf | |
48 | struct statfs { | |
49 | long f_type; /* type of filesystem (see below) */ | |
50 | long f_bsize; /* optimal transfer block size */ | |
51 | long f_blocks; /* total data blocks in file system */ | |
52 | long f_bfree; /* free blocks in fs */ | |
53 | long f_bavail; /* free blocks avail to non-superuser */ | |
54 | long f_files; /* total file nodes in file system */ | |
55 | long f_ffree; /* free file nodes in fs */ | |
56 | fsid_t f_fsid; /* file system id */ | |
57 | long f_namelen; /* maximum length of filenames */ | |
58 | }; | |
59 | ||
60 | File system types: | |
61 | ||
62 | ADFS_SUPER_MAGIC 0xadf5 | |
63 | AFFS_SUPER_MAGIC 0xADFF | |
64 | BEFS_SUPER_MAGIC 0x42465331 | |
65 | BFS_MAGIC 0x1BADFACE | |
66 | CIFS_MAGIC_NUMBER 0xFF534D42 | |
67 | CODA_SUPER_MAGIC 0x73757245 | |
68 | COH_SUPER_MAGIC 0x012FF7B7 | |
69 | CRAMFS_MAGIC 0x28cd3d45 | |
70 | DEVFS_SUPER_MAGIC 0x1373 | |
71 | EFS_SUPER_MAGIC 0x00414A53 | |
72 | EXT_SUPER_MAGIC 0x137D | |
73 | EXT2_OLD_SUPER_MAGIC 0xEF51 | |
74 | EXT2_SUPER_MAGIC 0xEF53 | |
75 | EXT3_SUPER_MAGIC 0xEF53 | |
76 | HFS_SUPER_MAGIC 0x4244 | |
77 | HPFS_SUPER_MAGIC 0xF995E849 | |
78 | HUGETLBFS_MAGIC 0x958458f6 | |
79 | ISOFS_SUPER_MAGIC 0x9660 | |
80 | JFFS2_SUPER_MAGIC 0x72b6 | |
81 | JFS_SUPER_MAGIC 0x3153464a | |
82 | MINIX_SUPER_MAGIC 0x137F /* orig. minix */ | |
83 | MINIX_SUPER_MAGIC2 0x138F /* 30 char minix */ | |
84 | MINIX2_SUPER_MAGIC 0x2468 /* minix V2 */ | |
85 | MINIX2_SUPER_MAGIC2 0x2478 /* minix V2, 30 char names */ | |
86 | MSDOS_SUPER_MAGIC 0x4d44 | |
87 | NCP_SUPER_MAGIC 0x564c | |
88 | NFS_SUPER_MAGIC 0x6969 | |
89 | NTFS_SB_MAGIC 0x5346544e | |
90 | OPENPROM_SUPER_MAGIC 0x9fa1 | |
91 | PROC_SUPER_MAGIC 0x9fa0 | |
92 | QNX4_SUPER_MAGIC 0x002f | |
93 | REISERFS_SUPER_MAGIC 0x52654973 | |
94 | ROMFS_MAGIC 0x7275 | |
95 | SMB_SUPER_MAGIC 0x517B | |
96 | SYSV2_SUPER_MAGIC 0x012FF7B6 | |
97 | SYSV4_SUPER_MAGIC 0x012FF7B5 | |
98 | TMPFS_MAGIC 0x01021994 | |
99 | UDF_SUPER_MAGIC 0x15013346 | |
100 | UFS_MAGIC 0x00011954 | |
101 | USBDEVICE_SUPER_MAGIC 0x9fa2 | |
102 | VXFS_SUPER_MAGIC 0xa501FCF5 | |
103 | XENIX_SUPER_MAGIC 0x012FF7B4 | |
104 | XFS_SUPER_MAGIC 0x58465342 | |
105 | _XIAFS_SUPER_MAGIC 0x012FD16D | |
106 | .fi | |
107 | .RE | |
108 | .PP | |
109 | Nobody knows what | |
110 | .I f_fsid | |
111 | is supposed to contain (but see below). | |
112 | .PP | |
113 | Fields that are undefined for a particular file system are set to 0. | |
e511ffb6 | 114 | .BR fstatfs () |
fea681da MK |
115 | returns the same information about an open file referenced by descriptor |
116 | .IR fd . | |
117 | .SH "RETURN VALUE" | |
c13182ef MK |
118 | On success, zero is returned. |
119 | On error, \-1 is returned, and | |
fea681da MK |
120 | .I errno |
121 | is set appropriately. | |
122 | .SH ERRORS | |
123 | .TP | |
124 | .B EACCES | |
1e321034 | 125 | .RB ( statfs ()) |
fea681da MK |
126 | Search permission is denied for a component of the path prefix of |
127 | .IR path . | |
128 | (See also | |
129 | .BR path_resolution (2).) | |
130 | .TP | |
131 | .B EBADF | |
1e321034 | 132 | .RB ( fstatfs ()) |
fea681da MK |
133 | .I fd |
134 | is not a valid open file descriptor. | |
135 | .TP | |
136 | .B EFAULT | |
137 | .I buf | |
138 | or | |
139 | .I path | |
140 | points to an invalid address. | |
141 | .TP | |
142 | .B EINTR | |
143 | This call was interrupted by a signal. | |
144 | .TP | |
145 | .B EIO | |
146 | An I/O error occurred while reading from the file system. | |
147 | .TP | |
148 | .B ELOOP | |
1e321034 | 149 | .RB ( statfs ()) |
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150 | Too many symbolic links were encountered in translating |
151 | .IR path . | |
152 | .TP | |
153 | .B ENAMETOOLONG | |
1e321034 | 154 | .RB ( statfs ()) |
fea681da MK |
155 | .I path |
156 | is too long. | |
157 | .TP | |
158 | .B ENOENT | |
1e321034 | 159 | .RB ( statfs ()) |
fea681da MK |
160 | The file referred to by |
161 | .I path | |
162 | does not exist. | |
163 | .TP | |
164 | .B ENOMEM | |
165 | Insufficient kernel memory was available. | |
166 | .TP | |
167 | .B ENOSYS | |
168 | The file system does not support this call. | |
169 | .TP | |
170 | .B ENOTDIR | |
1e321034 | 171 | .RB ( statfs ()) |
fea681da MK |
172 | A component of the path prefix of |
173 | .I path | |
174 | is not a directory. | |
175 | .TP | |
176 | .B EOVERFLOW | |
177 | Some values were too large to be represented in the returned struct. | |
fea681da | 178 | .SH "CONFORMING TO" |
75b48e9d | 179 | Linux specific. |
fea681da | 180 | The Linux |
e511ffb6 | 181 | .BR statfs () |
fea681da MK |
182 | was inspired by the 4.4BSD one |
183 | (but they do not use the same structure). | |
56bbbf8e | 184 | .SH NOTES |
c13182ef MK |
185 | The kernel has system calls |
186 | .BR statfs (), | |
187 | .BR fstatfs (), | |
56bbbf8e MK |
188 | .BR statfs64 (), |
189 | and | |
190 | .BR fstatfs64 () | |
191 | to support this library call. | |
192 | ||
193 | Some systems only have <sys/vfs.h>, other systems also have | |
c13182ef MK |
194 | <sys/statfs.h>, where the former includes the latter. |
195 | So it seems | |
56bbbf8e MK |
196 | including the former is the best choice. |
197 | ||
198 | LSB has deprecated the library calls | |
199 | .BR statfs () | |
200 | and | |
201 | .BR fstatfs () | |
202 | and tells us to use | |
0bfa087b | 203 | .BR statvfs (2) |
56bbbf8e | 204 | and |
0bfa087b | 205 | .BR fstatvfs (2) |
56bbbf8e MK |
206 | instead. |
207 | .SS The f_fsid field | |
fea681da MK |
208 | Solaris, Irix and POSIX have a system call |
209 | .BR statvfs (2) | |
210 | that returns a | |
8478ee02 | 211 | .I "struct statvfs" |
fea681da MK |
212 | (defined in |
213 | .IR "<sys/statvfs.h>" ) | |
214 | containing an | |
9ff08aad | 215 | .I "unsigned long" |
fea681da | 216 | .IR f_fsid . |
97c1eac8 | 217 | Linux, SunOS, HP-UX, 4.4BSD have a system call |
31e9a9ec | 218 | .BR statfs () |
fea681da | 219 | that returns a |
8478ee02 | 220 | .I "struct statfs" |
fea681da MK |
221 | (defined in |
222 | .IR "<sys/vfs.h>" ) | |
223 | containing a | |
9ff08aad | 224 | .I fsid_t |
fea681da MK |
225 | .IR f_fsid , |
226 | where | |
227 | .I fsid_t | |
228 | is defined as | |
8478ee02 | 229 | .IR "struct { int val[2]; }" . |
fea681da MK |
230 | The same holds for FreeBSD, except that it uses the include file |
231 | .IR "<sys/mount.h>" . | |
232 | ||
233 | The general idea is that | |
234 | .I f_fsid | |
235 | contains some random stuff such that the pair | |
236 | .RI ( f_fsid , ino ) | |
237 | uniquely determines a file. | |
238 | Some OSes use (a variation on) the device number, or the device number | |
239 | combined with the filesystem type. | |
240 | Several OSes restrict giving out the | |
241 | .I f_fsid | |
7145b9a9 | 242 | field to the superuser only (and zero it for unprivileged users), |
fea681da MK |
243 | because this field is used in the filehandle of the filesystem |
244 | when NFS-exported, and giving it out is a security concern. | |
245 | .LP | |
246 | Under some OSes the | |
247 | .I fsid | |
248 | can be used as second parameter to the | |
31e9a9ec | 249 | .BR sysfs () |
fea681da | 250 | system call. |
fea681da MK |
251 | .SH "SEE ALSO" |
252 | .BR path_resolution (2), | |
253 | .BR stat (2), | |
254 | .BR statvfs (2) |