man2/statvfs.2

   1 .\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl)
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  23 .\" The pathconf note is from Walter Harms
  24 .\" This is not a system call on Linux
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  26 .\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
  27 .\"
  28 .TH STATVFS 2 2003-08-22 "Linux 2.6.0" "Linux Programmer's Manual"
  29 .SH NAME
  30 statvfs, fstatvfs \- get file system statistics
  31 .SH SYNOPSIS
  32 .B #include <sys/statvfs.h>
  33 .sp
  34 .BI "int statvfs(const char *" path ", struct statvfs *" buf );
  35 .br
  36 .BI "int fstatvfs(int " fd ", struct statvfs *" buf );
  37 .SH DESCRIPTION
  38 The function
  39 .BR statvfs ()
  40 returns information about a mounted file system.
  41 .I path
  42 is the pathname of any file within the mounted filesystem.
  43 .I buf
  44 is a pointer to a
  45 .I statvfs
  46 structure defined approximately as follows:
  47
  48 .nf
  49 struct statvfs {
  50     unsigned long  f_bsize;    /* file system block size */
  51     unsigned long  f_frsize;   /* fragment size */
  52     fsblkcnt_t     f_blocks;   /* size of fs in f_frsize units */
  53     fsblkcnt_t     f_bfree;    /* # free blocks */
  54     fsblkcnt_t     f_bavail;   /* # free blocks for non-root */
  55     fsfilcnt_t     f_files;    /* # inodes */
  56     fsfilcnt_t     f_ffree;    /* # free inodes */
  57     fsfilcnt_t     f_favail;   /* # free inodes for non-root */
  58     unsigned long  f_fsid;     /* file system ID */
  59     unsigned long  f_flag;     /* mount flags */
  60     unsigned long  f_namemax;  /* maximum filename length */
  61 };
  62 .fi
  63
  64 Here the types
  65 .B fsblkcnt_t
  66 and
  67 .B fsfilcnt_t
  68 are defined in
  69 .IR <sys/types.h> .
  70 Both used to be
  71 .IR "unsigned long" .
  72
  73 The field
  74 .I f_flag
  75 is a bit mask (of mount flags, see
  76 .BR mount (8)).
  77 Bits defined by POSIX are
  78 .TP
  79 .B ST_RDONLY
  80 Read-only file system.
  81 .TP
  82 .B ST_NOSUID
  83 Set-user-ID/set-group-ID bits are ignored by
  84 .BR exec (2).
  85 .LP
  86 It is unspecified whether all members of the returned struct
  87 have meaningful values on all filesystems.
  88
  89 .BR fstatvfs ()
  90 returns the same information about an open file referenced by descriptor
  91 .IR fd .
  92 .SH "RETURN VALUE"
  93 On success, zero is returned.  On error, \-1 is returned, and
  94 .I errno
  95 is set appropriately.
  96 .SH ERRORS
  97 .TP
  98 .B EACCES
  99 .RB ( statvfs ())
 100 Search permission is denied for a component of the path prefix of
 101 .IR path .
 102 (See also
 103 .BR path_resolution (2).)
 104 .TP
 105 .B EBADF
 106 .RB ( fstatvfs ())
 107 .I fd
 108 is not a valid open file descriptor.
 109 .TP
 110 .B EFAULT
 111 .I Buf
 112 or
 113 .I path
 114 points to an invalid address.
 115 .TP
 116 .B EINTR
 117 This call was interrupted by a signal.
 118 .TP
 119 .B EIO
 120 An I/O error occurred while reading from the file system.
 121 .TP
 122 .B ELOOP
 123 .RB ( statvfs ())
 124 Too many symbolic links were encountered in translating
 125 .IR path .
 126 .TP
 127 .B ENAMETOOLONG
 128 .RB ( statvfs ())
 129 .I path
 130 is too long.
 131 .TP
 132 .B ENOENT
 133 .RB ( statvfs ())
 134 The file referred to by
 135 .I path
 136 does not exist.
 137 .TP
 138 .B ENOMEM
 139 Insufficient kernel memory was available.
 140 .TP
 141 .B ENOSYS
 142 The file system does not support this call.
 143 .TP
 144 .B ENOTDIR
 145 .RB ( statvfs ())
 146 A component of the path prefix of
 147 .I path
 148 is not a directory.
 149 .TP
 150 .B EOVERFLOW
 151 Some values were too large to be represented in the returned struct.
 152 .SH "CONFORMING TO"
 153 POSIX.1-2001
 154 .SH NOTES
 155 The Linux kernel has system calls
 156 .BR statfs ()
 157 and
 158 .BR fstatfs ()
 159 to support this library call.
 160
 161 The current glibc implementations of
 162 .sp
 163 .nf
 164    pathconf(path, _PC_REC_XFER_ALIGN);
 165    pathconf(path, _PC_ALLOC_SIZE_MIN);
 166    pathconf(path, _PC_REC_MIN_XFER_SIZE);
 167 .fi
 168 .sp
 169 respectively use the
 170 .IR f_frsize ,
 171 .IR f_frsize ,
 172 and
 173 .IR f_bsize
 174 fields of the return value of
 175 .IR "statvfs(path,buf)" .
 176 .SH "SEE ALSO"
 177 .BR statfs (2)