STATFS(2)		   Linux Programmers Manual		    STATFS(2)



NAME
       statfs, fstatfs - get file system statistics

SYNOPSIS
       #include     /* or  */

       int statfs(const char *path, struct statfs *buf);
       int fstatfs(int fd, struct statfs *buf);

DESCRIPTION
       The  function statfs() returns information about a mounted file system.
       path is the pathname of any file within the mounted file  system.   buf
       is a pointer to a statfs structure defined approximately as follows:

	   struct statfs {
	      long    f_type;	  /* type of file system (see below) */
	      long    f_bsize;	  /* optimal transfer block size */
	      long    f_blocks;   /* total data blocks in file system */
	      long    f_bfree;	  /* free blocks in fs */
	      long    f_bavail;   /* free blocks avail to non-superuser */
	      long    f_files;	  /* total file nodes in file system */
	      long    f_ffree;	  /* free file nodes in fs */
	      fsid_t  f_fsid;	  /* file system id */
	      long    f_namelen;  /* maximum length of filenames */
	   };

	   File system types:

	      ADFS_SUPER_MAGIC	    0xadf5
	      AFFS_SUPER_MAGIC	    0xADFF
	      BEFS_SUPER_MAGIC	    0x42465331
	      BFS_MAGIC 	    0x1BADFACE
	      CIFS_MAGIC_NUMBER     0xFF534D42
	      CODA_SUPER_MAGIC	    0x73757245
	      COH_SUPER_MAGIC	    0x012FF7B7
	      CRAMFS_MAGIC	    0x28cd3d45
	      DEVFS_SUPER_MAGIC     0x1373
	      EFS_SUPER_MAGIC	    0x00414A53
	      EXT_SUPER_MAGIC	    0x137D
	      EXT2_OLD_SUPER_MAGIC  0xEF51
	      EXT2_SUPER_MAGIC	    0xEF53
	      EXT3_SUPER_MAGIC	    0xEF53
	      HFS_SUPER_MAGIC	    0x4244
	      HPFS_SUPER_MAGIC	    0xF995E849
	      HUGETLBFS_MAGIC	    0x958458f6
	      ISOFS_SUPER_MAGIC     0x9660
	      JFFS2_SUPER_MAGIC     0x72b6
	      JFS_SUPER_MAGIC	    0x3153464a
	      MINIX_SUPER_MAGIC     0x137F /* orig. minix */
	      MINIX_SUPER_MAGIC2    0x138F /* 30 char minix */
	      MINIX2_SUPER_MAGIC    0x2468 /* minix V2 */
	      MINIX2_SUPER_MAGIC2   0x2478 /* minix V2, 30 char names */
	      MSDOS_SUPER_MAGIC     0x4d44
	      NCP_SUPER_MAGIC	    0x564c
	      NFS_SUPER_MAGIC	    0x6969
	      NTFS_SB_MAGIC	    0x5346544e
	      OPENPROM_SUPER_MAGIC  0x9fa1
	      PROC_SUPER_MAGIC	    0x9fa0
	      QNX4_SUPER_MAGIC	    0x002f
	      REISERFS_SUPER_MAGIC  0x52654973
	      ROMFS_MAGIC	    0x7275
	      SMB_SUPER_MAGIC	    0x517B
	      SYSV2_SUPER_MAGIC     0x012FF7B6
	      SYSV4_SUPER_MAGIC     0x012FF7B5
	      TMPFS_MAGIC	    0x01021994
	      UDF_SUPER_MAGIC	    0x15013346
	      UFS_MAGIC 	    0x00011954
	      USBDEVICE_SUPER_MAGIC 0x9fa2
	      VXFS_SUPER_MAGIC	    0xa501FCF5
	      XENIX_SUPER_MAGIC     0x012FF7B4
	      XFS_SUPER_MAGIC	    0x58465342
	      _XIAFS_SUPER_MAGIC    0x012FD16D

       Nobody knows what f_fsid is supposed to contain (but see below).

       Fields  that  are  undefined for a particular file system are set to 0.
       fstatfs() returns the same information about an open file referenced by
       descriptor fd.

RETURN VALUE
       On  success,  zero is returned.	On error, -1 is returned, and errno is
       set appropriately.

ERRORS
       EACCES (statfs()) Search permission is denied for a  component  of  the
	      path prefix of path.  (See also path_resolution(7).)

       EBADF  (fstatfs()) fd is not a valid open file descriptor.

       EFAULT buf or path points to an invalid address.

       EINTR  This call was interrupted by a signal.

       EIO    An I/O error occurred while reading from the file system.

       ELOOP  (statfs()) Too many symbolic links were encountered in translat
	      ing path.

       ENAMETOOLONG
	      (statfs()) path is too long.

       ENOENT (statfs()) The file referred to by path does not exist.

       ENOMEM Insufficient kernel memory was available.

       ENOSYS The file system does not support this call.

       ENOTDIR
	      (statfs()) A component of the path  prefix  of  path  is	not  a
	      directory.

       EOVERFLOW
	      Some  values  were  too  large to be represented in the returned
	      struct.

CONFORMING TO
       Linux-specific.	The Linux statfs() was inspired by the 4.4BSD one (but
       they do not use the same structure).

NOTES
       The  kernel  has  system  calls	statfs(),  fstatfs(),  statfs64(), and
       fstatfs64() to support this library call.

       Some  systems  only  have  ,	 other	 systems   also   have
       ,	where  the  former  includes  the latter.  So it seems
       including the former is the best choice.

       LSB has deprecated the library calls statfs() and fstatfs()  and  tells
       us to use statvfs(2) and fstatvfs(2) instead.

   The f_fsid field
       Solaris,  Irix  and  POSIX have a system call statvfs(2) that returns a
       struct statvfs (defined in ) containing an unsigned long
       f_fsid.	 Linux,  SunOS, HP-UX, 4.4BSD have a system call statfs() that
       returns a struct statfs (defined in )  containing  a	fsid_t
       f_fsid,	where  fsid_t  is defined as struct { int val[2]; }.  The same
       holds for FreeBSD, except that it uses the include file	.

       The  general  idea  is that f_fsid contains some random stuff such that
       the pair (f_fsid,ino) uniquely determines a file.   Some  OSes  use  (a
       variation on) the device number, or the device number combined with the
       file-system type.  Several OSes restrict giving out the f_fsid field to
       the  superuser  only (and zero it for unprivileged users), because this
       field is used in the filehandle of the file system  when  NFS-exported,
       and giving it out is a security concern.

       Under  some OSes the fsid can be used as second argument to the sysfs()
       system call.

SEE ALSO
       stat(2), statvfs(2), path_resolution(7)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2004-06-23			     STATFS(2)