xref: /openbsd/lib/libc/sys/statfs.2 (revision 097a140d)
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31.\"	@(#)statfs.2	8.3 (Berkeley) 2/11/94
32.\"
33.Dd $Mdocdate: January 3 2021 $
34.Dt STATFS 2
35.Os
36.Sh NAME
37.Nm statfs ,
38.Nm fstatfs
39.Nd get file system statistics
40.Sh SYNOPSIS
41.In sys/types.h
42.In sys/mount.h
43.Ft int
44.Fn statfs "const char *path" "struct statfs *buf"
45.Ft int
46.Fn fstatfs "int fd" "struct statfs *buf"
47.Sh DESCRIPTION
48.Fn statfs
49returns information about a mounted file system.
50.Fa path
51is the pathname of any file within the mounted file system.
52.Fa buf
53is a pointer to a
54.Nm statfs
55structure defined as follows:
56.Bd -literal
57typedef struct { int32_t val[2]; } fsid_t;
58
59#define MFSNAMELEN   16 /* length of fs type name, including nul */
60#define MNAMELEN     90	/* length of buffer for returned name */
61
62struct statfs {
63   u_int32_t       f_flags;        /* copy of mount flags */
64   u_int32_t       f_bsize;        /* file system block size */
65   u_int32_t       f_iosize;       /* optimal transfer block size */
66
67                                   /* unit is f_bsize */
68   u_int64_t       f_blocks;       /* total data blocks in file system */
69   u_int64_t       f_bfree;        /* free blocks in fs */
70   int64_t         f_bavail;       /* free blocks avail to non-superuser */
71
72   u_int64_t       f_files;        /* total file nodes in file system */
73   u_int64_t       f_ffree;        /* free file nodes in fs */
74   int64_t         f_favail;       /* free file nodes avail to non-root */
75
76   u_int64_t       f_syncwrites;   /* count of sync writes since mount */
77   u_int64_t       f_syncreads;    /* count of sync reads since mount */
78   u_int64_t       f_asyncwrites;  /* count of async writes since mount */
79   u_int64_t       f_asyncreads;   /* count of async reads since mount */
80
81   fsid_t          f_fsid;         /* file system id */
82   u_int32_t       f_namemax;      /* maximum filename length */
83   uid_t           f_owner;        /* user that mounted the file system */
84   u_int64_t       f_ctime;        /* last mount [-u] time */
85
86   char f_fstypename[MFSNAMELEN];  /* fs type name */
87   char f_mntonname[MNAMELEN];     /* directory on which mounted */
88   char f_mntfromname[MNAMELEN];   /* mounted file system */
89   char f_mntfromspec[MNAMELEN];   /* special for mount request */
90   union mount_info mount_info;    /* per-filesystem mount options */
91};
92.Ed
93.Pp
94.Fn fstatfs
95returns the same information about an open file referenced by descriptor
96.Fa fd .
97.Pp
98Note that
99.Fa f_fsid
100will be empty unless the user is the superuser.
101.Sh RETURN VALUES
102.Rv -std
103.Sh ERRORS
104.Fn statfs
105fails if one or more of the following are true:
106.Bl -tag -width Er
107.It Bq Er ENOTDIR
108A component of the path prefix of
109.Fa path
110is not a directory.
111.It Bq Er ENAMETOOLONG
112A component of a pathname exceeded
113.Dv NAME_MAX
114characters, or an entire pathname (including the terminating NUL)
115exceeded
116.Dv PATH_MAX
117bytes.
118.It Bq Er ENOENT
119The file referred to by
120.Fa path
121does not exist.
122.It Bq Er EACCES
123Search permission is denied for a component of the path prefix of
124.Fa path .
125.It Bq Er ELOOP
126Too many symbolic links were encountered in translating
127.Fa path .
128.It Bq Er EFAULT
129.Fa buf
130or
131.Fa path
132points to an invalid address.
133.It Bq Er EIO
134An I/O error occurred while reading from or writing to the file system.
135.El
136.Pp
137.Fn fstatfs
138fails if one or more of the following are true:
139.Bl -tag -width Er
140.It Bq Er EBADF
141.Fa fd
142is not a valid open file descriptor.
143.It Bq Er EFAULT
144.Fa buf
145points to an invalid address.
146.It Bq Er EIO
147An I/O error occurred while reading from or writing to the file system.
148.El
149.Sh SEE ALSO
150.Xr df 1 ,
151.Xr getfsstat 2 ,
152.Xr mount 2 ,
153.Xr stat 2
154.Sh HISTORY
155The
156.Fn statfs
157function first appeared in
158.Bx 4.4 .
159