1STATFS(2) Linux Programmer's Manual STATFS(2)
2
6 statfs, fstatfs - get file system statistics
7
9 #include <sys/vfs.h> /* or <sys/statfs.h> */
10 int statfs(const char *path, struct statfs *buf);
12 int fstatfs(int fd, struct statfs *buf);
13
15 The function statfs() returns information about a mounted file system.
16 path is the pathname of any file within the mounted file system. buf
17 is a pointer to a statfs structure defined approximately as follows:
18 #if __WORDSIZE == 32 /* System word size */
20 # define __SWORD_TYPE int
21 #else /* __WORDSIZE == 64 */
22 # define __SWORD_TYPE long int
23 #endif
24 struct statfs {
26 __SWORD_TYPE f_type; /* type of file system (see below) */
27 __SWORD_TYPE f_bsize; /* optimal transfer block size */
28 fsblkcnt_t f_blocks; /* total data blocks in file system */
29 fsblkcnt_t f_bfree; /* free blocks in fs */
30 fsblkcnt_t f_bavail; /* free blocks available to
31 unprivileged user */
32 fsfilcnt_t f_files; /* total file nodes in file system */
33 fsfilcnt_t f_ffree; /* free file nodes in fs */
34 fsid_t f_fsid; /* file system id */
35 __SWORD_TYPE f_namelen; /* maximum length of filenames */
36 __SWORD_TYPE f_frsize; /* fragment size (since Linux 2.6) */
37 __SWORD_TYPE f_spare[5];
38 };
39 File system types:
41 ADFS_SUPER_MAGIC 0xadf5
43 AFFS_SUPER_MAGIC 0xADFF
44 BEFS_SUPER_MAGIC 0x42465331
45 BFS_MAGIC 0x1BADFACE
46 CIFS_MAGIC_NUMBER 0xFF534D42
47 CODA_SUPER_MAGIC 0x73757245
48 COH_SUPER_MAGIC 0x012FF7B7
49 CRAMFS_MAGIC 0x28cd3d45
50 DEVFS_SUPER_MAGIC 0x1373
51 EFS_SUPER_MAGIC 0x00414A53
52 EXT_SUPER_MAGIC 0x137D
53 EXT2_OLD_SUPER_MAGIC 0xEF51
54 EXT2_SUPER_MAGIC 0xEF53
55 EXT3_SUPER_MAGIC 0xEF53
56 EXT4_SUPER_MAGIC 0xEF53
57 HFS_SUPER_MAGIC 0x4244
58 HPFS_SUPER_MAGIC 0xF995E849
59 HUGETLBFS_MAGIC 0x958458f6
60 ISOFS_SUPER_MAGIC 0x9660
61 JFFS2_SUPER_MAGIC 0x72b6
62 JFS_SUPER_MAGIC 0x3153464a
63 MINIX_SUPER_MAGIC 0x137F /* orig. minix */
64 MINIX_SUPER_MAGIC2 0x138F /* 30 char minix */
65 MINIX2_SUPER_MAGIC 0x2468 /* minix V2 */
66 MINIX2_SUPER_MAGIC2 0x2478 /* minix V2, 30 char names */
67 MSDOS_SUPER_MAGIC 0x4d44
68 NCP_SUPER_MAGIC 0x564c
69 NFS_SUPER_MAGIC 0x6969
70 NTFS_SB_MAGIC 0x5346544e
71 OPENPROM_SUPER_MAGIC 0x9fa1
72 PROC_SUPER_MAGIC 0x9fa0
73 QNX4_SUPER_MAGIC 0x002f
74 REISERFS_SUPER_MAGIC 0x52654973
75 ROMFS_MAGIC 0x7275
76 SMB_SUPER_MAGIC 0x517B
77 SYSV2_SUPER_MAGIC 0x012FF7B6
78 SYSV4_SUPER_MAGIC 0x012FF7B5
79 TMPFS_MAGIC 0x01021994
80 UDF_SUPER_MAGIC 0x15013346
81 UFS_MAGIC 0x00011954
82 USBDEVICE_SUPER_MAGIC 0x9fa2
83 VXFS_SUPER_MAGIC 0xa501FCF5
84 XENIX_SUPER_MAGIC 0x012FF7B4
85 XFS_SUPER_MAGIC 0x58465342
86 _XIAFS_SUPER_MAGIC 0x012FD16D
87 Nobody knows what f_fsid is supposed to contain (but see below).
89 Fields that are undefined for a particular file system are set to 0.
91 fstatfs() returns the same information about an open file referenced by
92 descriptor fd.
93
95 On success, zero is returned. On error, -1 is returned, and errno is
96 set appropriately.
97
99 EACCES (statfs()) Search permission is denied for a component of the
100 path prefix of path. (See also path_resolution(7).)
101 EBADF (fstatfs()) fd is not a valid open file descriptor.
103 EFAULT buf or path points to an invalid address.
105 EINTR This call was interrupted by a signal.
107 EIO An I/O error occurred while reading from the file system.
109 ELOOP (statfs()) Too many symbolic links were encountered in translat‐
111 ing path.
112 ENAMETOOLONG
114 (statfs()) path is too long.
115 ENOENT (statfs()) The file referred to by path does not exist.
117 ENOMEM Insufficient kernel memory was available.
119 ENOSYS The file system does not support this call.
121 ENOTDIR
123 (statfs()) A component of the path prefix of path is not a
124 directory.
125 EOVERFLOW
127 Some values were too large to be represented in the returned
128 struct.
129
131 Linux-specific. The Linux statfs() was inspired by the 4.4BSD one (but
132 they do not use the same structure).
133
135 The original Linux statfs() and fstatfs() system calls were not
136 designed with extremely large file sizes in mind. Subsequently, Linux
137 2.6 added new statfs64() and fstatfs64() system calls that employ a new
138 structure, statfs64. The new structure contains the same fields as the
139 original statfs structure, but the sizes of various fields are
140 increased, to accommodate large file sizes. The glibc statfs() and
141 fstatfs() wrapper functions transparently deal with the kernel differ‐
142 ences.
143 Some systems only have <sys/vfs.h>, other systems also have
145 <sys/statfs.h>, where the former includes the latter. So it seems
146 including the former is the best choice.
147 LSB has deprecated the library calls statfs() and fstatfs() and tells
149 us to use statvfs(2) and fstatvfs(2) instead.
150 The f_fsid field
152 Solaris, Irix and POSIX have a system call statvfs(2) that returns a
153 struct statvfs (defined in <sys/statvfs.h>) containing an unsigned long
154 f_fsid. Linux, SunOS, HP-UX, 4.4BSD have a system call statfs() that
155 returns a struct statfs (defined in <sys/vfs.h>) containing a fsid_t
156 f_fsid, where fsid_t is defined as struct { int val[2]; }. The same
157 holds for FreeBSD, except that it uses the include file <sys/mount.h>.
158 The general idea is that f_fsid contains some random stuff such that
160 the pair (f_fsid,ino) uniquely determines a file. Some operating sys‐
161 tems use (a variation on) the device number, or the device number com‐
162 bined with the file-system type. Several OSes restrict giving out the
163 f_fsid field to the superuser only (and zero it for unprivileged
164 users), because this field is used in the filehandle of the file system
165 when NFS-exported, and giving it out is a security concern.
166 Under some operating systems the fsid can be used as second argument to
168 the sysfs(2) system call.
169
171 stat(2), statvfs(2), path_resolution(7)
172
174 This page is part of release 3.53 of the Linux man-pages project. A
175 description of the project, and information about reporting bugs, can
176 be found at http://www.kernel.org/doc/man-pages/.
177Linux 2010-11-21 STATFS(2)