statvfs

STATVFS(3)                 Linux Programmer's Manual                STATVFS(3)



NAME
       statvfs, fstatvfs - get filesystem statistics

SYNOPSIS
       #include <sys/statvfs.h>

       int statvfs(const char *path, struct statvfs *buf);
       int fstatvfs(int fd, struct statvfs *buf);

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

           struct statvfs {
               unsigned long  f_bsize;    /* Filesystem block size */
               unsigned long  f_frsize;   /* Fragment size */
               fsblkcnt_t     f_blocks;   /* Size of fs in f_frsize units */
               fsblkcnt_t     f_bfree;    /* Number of free blocks */
               fsblkcnt_t     f_bavail;   /* Number of free blocks for
                                             unprivileged users */
               fsfilcnt_t     f_files;    /* Number of inodes */
               fsfilcnt_t     f_ffree;    /* Number of free inodes */
               fsfilcnt_t     f_favail;   /* Number of free inodes for
                                             unprivileged users */
               unsigned long  f_fsid;     /* Filesystem ID */
               unsigned long  f_flag;     /* Mount flags */
               unsigned long  f_namemax;  /* Maximum filename length */
           };

       Here the types fsblkcnt_t and fsfilcnt_t are defined in <sys/types.h>.
       Both used to be unsigned long.

       The field f_flag is a bit mask indicating various options that were
       employed when mounting this filesystem.  It contains zero or more of
       the following flags:

       ST_MANDLOCK
              Mandatory locking is permitted on the filesystem (see fcntl(2)).

       ST_NOATIME
              Do not update access times; see mount(2).

       ST_NODEV
              Disallow access to device special files on this filesystem.

       ST_NODIRATIME
              Do not update directory access times; see mount(2).

       ST_NOEXEC
              Execution of programs is disallowed on this filesystem.

       ST_NOSUID
              The set-user-ID and set-group-ID bits are ignored by exec(3) for
              executable files on this filesystem

       ST_RDONLY
              This filesystem is mounted read-only.

       ST_RELATIME
              Update atime relative to mtime/ctime; see mount(2).

       ST_SYNCHRONOUS
              Writes are synched to the filesystem immediately (see the
              description of O_SYNC in open(2)).

       It is unspecified whether all members of the returned struct have
       meaningful values on all filesystems.

       fstatvfs() 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 (statvfs()) Search permission is denied for a component of the
              path prefix of path.  (See also path_resolution(7).)

       EBADF  (fstatvfs()) 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; see signal(7).

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

       ELOOP  (statvfs()) Too many symbolic links were encountered in
              translating path.

       ENAMETOOLONG
              (statvfs()) path is too long.

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

       ENOMEM Insufficient kernel memory was available.

       ENOSYS The filesystem does not support this call.

       ENOTDIR
              (statvfs()) 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.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────────────────┬───────────────┬─────────┐
       │Interface             Attribute     Value   │
       ├──────────────────────┼───────────────┼─────────┤
       │statvfs(), fstatvfs() │ Thread safety │ MT-Safe │
       └──────────────────────┴───────────────┴─────────┘
CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

       Only the ST_NOSUID and ST_RDONLY flags of the f_flag field are
       specified in POSIX.1.  To obtain definitions of the remaining flags,
       one must define _GNU_SOURCE.

NOTES
       The Linux kernel has system calls statfs(2) and fstatfs(2) to support
       this library call.

       In glibc versions before 2.13, statvfs() populated the bits of the
       f_flag field by scanning the mount options shown in /proc/mounts.
       However, starting with Linux 2.6.36, the underlying statfs(2) system
       call provides the necessary information via the f_flags field, and
       since glibc version 2.13, the statvfs() function will use information
       from that field rather than scanning /proc/mounts.

       The glibc implementations of

           pathconf(path, _PC_REC_XFER_ALIGN);
           pathconf(path, _PC_ALLOC_SIZE_MIN);
           pathconf(path, _PC_REC_MIN_XFER_SIZE);

       respectively use the f_frsize, f_frsize, and f_bsize fields returned by
       a call to statvfs() with the argument path.

SEE ALSO
       statfs(2)

COLOPHON
       This page is part of release 5.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux                             2017-09-15                        STATVFS(3)