statfs(2) - NetBSD Manual Pages

STATFS(2)                 NetBSD Programmer's Manual                 STATFS(2)


NAME

     statfs, fstatfs - get file system statistics


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <sys/param.h>
     #include <sys/mount.h>

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

     int
     fstatfs(int fd, struct statfs *buf);


DESCRIPTION

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

     typedef struct { int32_t val[2]; } fsid_t;      /* file system id type */

     #define MFSNAMELEN   16 /* length of fs type name, including nul */
     #define MNAMELEN     90 /* length of buffer for returned name */

     struct statfs {
         short   f_type;     /* type of file system (unused; zero) */
         u_short f_oflags;   /* deprecated copy of mount flags */
         long    f_bsize;    /* fundamental file system block size */
         long    f_iosize;   /* 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 */
         uid_t   f_owner;    /* user that mounted the file system */
         long    f_flags;    /* copy of mount flags */
         long    f_syncwrites; /* count of sync writes since mount */
         long    f_asyncwrites; /* count of async writes since mount */
         long    f_spare[1]; /* spare for later */
         char    f_fstypename[MFSNAMELEN]; /* fs type name */
         char    f_mntonname[MNAMELEN];    /* directory on which mounted */
         char    f_mntfromname[MNAMELEN];  /* mounted file system */
     };

     The flags that may be returned include:

     MNT_RDONLY       The filesystem is mounted read-only; Even the super-user
                      may not write on it.

     MNT_NOEXEC       Files may not be executed from the filesystem.

     MNT_NOSUID       Setuid and setgid bits on files are not honored when
                      they are executed.

     MNT_NODEV        Special files in the filesystem may not be opened.

     MNT_SYNCHRONOUS  All I/O to the filesystem is done synchronously.

     MNT_ASYNC        No filesystem I/O is done synchronously.

     MNT_UNION        Union with underlying filesystem.

     MNT_NOCOREDUMP   Don't write core dumps to this file system.

     MNT_NOATIME      Never update access times.

     MNT_SYMPERM      Recognize symbolic link permission.

     MNT_NODEVMTIME   Never update mod. times for device files.

     MNT_SOFTDEP      Use soft dependencies.

     MNT_LOCAL        The filesystem resides locally.

     MNT_QUOTA        The filesystem has quotas enabled on it.

     MNT_ROOTFS       Identifies the root filesystem.

     MNT_EXRDONLY     The filesystem is exported read-only.

     MNT_EXPORTED     The filesystem is exported for both reading and writing.

     MNT_DEFEXPORTED  The filesystem is exported for both reading and writing
                      to any Internet host.

     MNT_EXPORTANON   The filesystem maps all remote accesses to the anonymous
                      user.

     MNT_EXKERB       The filesystem is exported with Kerberos uid mapping.

     MNT_EXNORESPORT  Don't enforce reserved ports (NFS).

     MNT_EXPUBLIC     Public export (WebNFS).

     Fields that are undefined for a particular file system are set to -1.
     fstatfs() returns the same information about an open file referenced by
     descriptor fd.


RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, -1 is
     returned and the global variable errno is set to indicate the error.


ERRORS

     statfs() fails if one or more of the following are true:

     [ENOTDIR]     A component of the path prefix of path is not a directory.

     [ENAMETOOLONG]
                   The length of a component of path exceeds {NAME_MAX} char-
                   acters, or the length of path exceeds {PATH_MAX} charac-
                   ters.

     [ENOENT]      The file referred to by path does not exist.

     [EACCES]      Search permission is denied for a component of the path
                   prefix of path.

     [ELOOP]       Too many symbolic links were encountered in translating
                   path.

     [EFAULT]      buf or path points to an invalid address.

     [EIO]         An I/O error occurred while reading from or writing to the
                   file system.

     fstatfs() fails if one or more of the following are true:

     [EBADF]       fd is not a valid open file descriptor.

     [EFAULT]      buf points to an invalid address.

     [EIO]         An I/O error occurred while reading from or writing to the
                   file system.


HISTORY

     The statfs() function first appeared in 4.4BSD.

NetBSD 1.6                       May 24, 1995                                3