1STATVFS(3)                 Linux Programmer's Manual                STATVFS(3)
2
3
4

NAME

6       statvfs, fstatvfs - get filesystem statistics
7

SYNOPSIS

9       #include <sys/statvfs.h>
10
11       int statvfs(const char *restrict path, struct statvfs *restrict buf);
12       int fstatvfs(int fd, struct statvfs *buf);
13

DESCRIPTION

15       The  function statvfs() returns information about a mounted filesystem.
16       path is the pathname of any file within the mounted filesystem.  buf is
17       a pointer to a statvfs structure defined approximately as follows:
18
19           struct statvfs {
20               unsigned long  f_bsize;    /* Filesystem block size */
21               unsigned long  f_frsize;   /* Fragment size */
22               fsblkcnt_t     f_blocks;   /* Size of fs in f_frsize units */
23               fsblkcnt_t     f_bfree;    /* Number of free blocks */
24               fsblkcnt_t     f_bavail;   /* Number of free blocks for
25                                             unprivileged users */
26               fsfilcnt_t     f_files;    /* Number of inodes */
27               fsfilcnt_t     f_ffree;    /* Number of free inodes */
28               fsfilcnt_t     f_favail;   /* Number of free inodes for
29                                             unprivileged users */
30               unsigned long  f_fsid;     /* Filesystem ID */
31               unsigned long  f_flag;     /* Mount flags */
32               unsigned long  f_namemax;  /* Maximum filename length */
33           };
34
35       Here  the types fsblkcnt_t and fsfilcnt_t are defined in <sys/types.h>.
36       Both used to be unsigned long.
37
38       The field f_flag is a bit mask indicating various options that were em‐
39       ployed  when mounting this filesystem.  It contains zero or more of the
40       following flags:
41
42       ST_MANDLOCK
43              Mandatory locking is permitted on the filesystem (see fcntl(2)).
44
45       ST_NOATIME
46              Do not update access times; see mount(2).
47
48       ST_NODEV
49              Disallow access to device special files on this filesystem.
50
51       ST_NODIRATIME
52              Do not update directory access times; see mount(2).
53
54       ST_NOEXEC
55              Execution of programs is disallowed on this filesystem.
56
57       ST_NOSUID
58              The set-user-ID and set-group-ID bits are ignored by exec(3) for
59              executable files on this filesystem
60
61       ST_RDONLY
62              This filesystem is mounted read-only.
63
64       ST_RELATIME
65              Update atime relative to mtime/ctime; see mount(2).
66
67       ST_SYNCHRONOUS
68              Writes  are  synched  to the filesystem immediately (see the de‐
69              scription of O_SYNC in open(2)).
70
71       It is unspecified whether all members of the returned struct have mean‐
72       ingful values on all filesystems.
73
74       fstatvfs()  returns  the same information about an open file referenced
75       by descriptor fd.
76

RETURN VALUE

78       On success, zero is returned.  On error, -1 is returned, and  errno  is
79       set to indicate the error.
80

ERRORS

82       EACCES (statvfs())  Search  permission is denied for a component of the
83              path prefix of path.  (See also path_resolution(7).)
84
85       EBADF  (fstatvfs()) fd is not a valid open file descriptor.
86
87       EFAULT Buf or path points to an invalid address.
88
89       EINTR  This call was interrupted by a signal; see signal(7).
90
91       EIO    An I/O error occurred while reading from the filesystem.
92
93       ELOOP  (statvfs()) Too many symbolic links were encountered  in  trans‐
94              lating path.
95
96       ENAMETOOLONG
97              (statvfs()) path is too long.
98
99       ENOENT (statvfs()) The file referred to by path does not exist.
100
101       ENOMEM Insufficient kernel memory was available.
102
103       ENOSYS The filesystem does not support this call.
104
105       ENOTDIR
106              (statvfs())  A component of the path prefix of path is not a di‐
107              rectory.
108
109       EOVERFLOW
110              Some values were too large to be  represented  in  the  returned
111              struct.
112

ATTRIBUTES

114       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
115       tributes(7).
116
117       ┌────────────────────────────────────────────┬───────────────┬─────────┐
118Interface                                   Attribute     Value   
119       ├────────────────────────────────────────────┼───────────────┼─────────┤
120statvfs(), fstatvfs()                       │ Thread safety │ MT-Safe │
121       └────────────────────────────────────────────┴───────────────┴─────────┘
122

CONFORMING TO

124       POSIX.1-2001, POSIX.1-2008.
125
126       Only the ST_NOSUID and ST_RDONLY flags of the f_flag field  are  speci‐
127       fied  in  POSIX.1.   To  obtain definitions of the remaining flags, one
128       must define _GNU_SOURCE.
129

NOTES

131       The Linux kernel has system calls statfs(2) and fstatfs(2)  to  support
132       this library call.
133
134       In  glibc  versions  before  2.13,  statvfs() populated the bits of the
135       f_flag field by scanning the mount options shown in /proc/mounts.  How‐
136       ever,  starting with Linux 2.6.36, the underlying statfs(2) system call
137       provides the necessary information via the  f_flags  field,  and  since
138       glibc  version  2.13,  the statvfs() function will use information from
139       that field rather than scanning /proc/mounts.
140
141       The glibc implementations of
142
143           pathconf(path, _PC_REC_XFER_ALIGN);
144           pathconf(path, _PC_ALLOC_SIZE_MIN);
145           pathconf(path, _PC_REC_MIN_XFER_SIZE);
146
147       respectively use the f_frsize, f_frsize, and f_bsize fields returned by
148       a call to statvfs() with the argument path.
149

SEE ALSO

151       statfs(2)
152

COLOPHON

154       This  page  is  part of release 5.13 of the Linux man-pages project.  A
155       description of the project, information about reporting bugs,  and  the
156       latest     version     of     this    page,    can    be    found    at
157       https://www.kernel.org/doc/man-pages/.
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161Linux                             2021-03-22                        STATVFS(3)
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