1statvfs(3) Library Functions Manual statvfs(3)
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6 statvfs, fstatvfs - get filesystem statistics
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9 Standard C library (libc, -lc)
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12 #include <sys/statvfs.h>
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14 int statvfs(const char *restrict path, struct statvfs *restrict buf);
15 int fstatvfs(int fd, struct statvfs *buf);
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18 The function statvfs() returns information about a mounted filesystem.
19 path is the pathname of any file within the mounted filesystem. buf is
20 a pointer to a statvfs structure defined approximately as follows:
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22 struct statvfs {
23 unsigned long f_bsize; /* Filesystem block size */
24 unsigned long f_frsize; /* Fragment size */
25 fsblkcnt_t f_blocks; /* Size of fs in f_frsize units */
26 fsblkcnt_t f_bfree; /* Number of free blocks */
27 fsblkcnt_t f_bavail; /* Number of free blocks for
28 unprivileged users */
29 fsfilcnt_t f_files; /* Number of inodes */
30 fsfilcnt_t f_ffree; /* Number of free inodes */
31 fsfilcnt_t f_favail; /* Number of free inodes for
32 unprivileged users */
33 unsigned long f_fsid; /* Filesystem ID */
34 unsigned long f_flag; /* Mount flags */
35 unsigned long f_namemax; /* Maximum filename length */
36 };
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38 Here the types fsblkcnt_t and fsfilcnt_t are defined in <sys/types.h>.
39 Both used to be unsigned long.
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41 The field f_flag is a bit mask indicating various options that were em‐
42 ployed when mounting this filesystem. It contains zero or more of the
43 following flags:
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45 ST_MANDLOCK
46 Mandatory locking is permitted on the filesystem (see fcntl(2)).
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48 ST_NOATIME
49 Do not update access times; see mount(2).
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51 ST_NODEV
52 Disallow access to device special files on this filesystem.
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54 ST_NODIRATIME
55 Do not update directory access times; see mount(2).
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57 ST_NOEXEC
58 Execution of programs is disallowed on this filesystem.
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60 ST_NOSUID
61 The set-user-ID and set-group-ID bits are ignored by exec(3) for
62 executable files on this filesystem
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64 ST_RDONLY
65 This filesystem is mounted read-only.
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67 ST_RELATIME
68 Update atime relative to mtime/ctime; see mount(2).
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70 ST_SYNCHRONOUS
71 Writes are synched to the filesystem immediately (see the de‐
72 scription of O_SYNC in open(2)).
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74 It is unspecified whether all members of the returned struct have mean‐
75 ingful values on all filesystems.
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77 fstatvfs() returns the same information about an open file referenced
78 by descriptor fd.
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81 On success, zero is returned. On error, -1 is returned, and errno is
82 set to indicate the error.
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85 EACCES (statvfs()) Search permission is denied for a component of the
86 path prefix of path. (See also path_resolution(7).)
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88 EBADF (fstatvfs()) fd is not a valid open file descriptor.
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90 EFAULT Buf or path points to an invalid address.
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92 EINTR This call was interrupted by a signal; see signal(7).
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94 EIO An I/O error occurred while reading from the filesystem.
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96 ELOOP (statvfs()) Too many symbolic links were encountered in trans‐
97 lating path.
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99 ENAMETOOLONG
100 (statvfs()) path is too long.
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102 ENOENT (statvfs()) The file referred to by path does not exist.
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104 ENOMEM Insufficient kernel memory was available.
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106 ENOSYS The filesystem does not support this call.
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108 ENOTDIR
109 (statvfs()) A component of the path prefix of path is not a di‐
110 rectory.
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112 EOVERFLOW
113 Some values were too large to be represented in the returned
114 struct.
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117 For an explanation of the terms used in this section, see at‐
118 tributes(7).
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120 ┌────────────────────────────────────────────┬───────────────┬─────────┐
121 │Interface │ Attribute │ Value │
122 ├────────────────────────────────────────────┼───────────────┼─────────┤
123 │statvfs(), fstatvfs() │ Thread safety │ MT-Safe │
124 └────────────────────────────────────────────┴───────────────┴─────────┘
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127 Only the ST_NOSUID and ST_RDONLY flags of the f_flag field are speci‐
128 fied in POSIX.1. To obtain definitions of the remaining flags, one
129 must define _GNU_SOURCE.
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132 The Linux kernel has system calls statfs(2) and fstatfs(2) to support
133 this library call.
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135 The glibc implementations of
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137 pathconf(path, _PC_REC_XFER_ALIGN);
138 pathconf(path, _PC_ALLOC_SIZE_MIN);
139 pathconf(path, _PC_REC_MIN_XFER_SIZE);
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141 respectively use the f_frsize, f_frsize, and f_bsize fields returned by
142 a call to statvfs() with the argument path.
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145 POSIX.1-2008.
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148 POSIX.1-2001.
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150 Before glibc 2.13, statvfs() populated the bits of the f_flag field by
151 scanning the mount options shown in /proc/mounts. However, starting
152 with Linux 2.6.36, the underlying statfs(2) system call provides the
153 necessary information via the f_flags field, and since glibc 2.13, the
154 statvfs() function will use information from that field rather than
155 scanning /proc/mounts.
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158 statfs(2)
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162Linux man-pages 6.04 2023-03-30 statvfs(3)