4.3BSD - /usr/man/cat2/umount.0

MOUNT(2)                                                              MOUNT(2)


NAME
       mount, umount - mount or remove file system

SYNOPSIS
       mount(special, name, rwflag)
       char *special, *name;
       int rwflag;

       umount(special)
       char *special;

DESCRIPTION
       Mount  announces  to  the  system that a removable file system has been
       mounted on the block-structured special file special; from now on, ref‐
       erences  to  file name will refer to the root file on the newly mounted
       file system.  Special and name are pointers to null-terminated  strings
       containing the appropriate path names.

       Name  must  exist already.  Name must be a directory.  Its old contents
       are inaccessible while the file system is mounted.

       The rwflag argument determines whether the file system can  be  written
       on;  if  it  is  0  writing is allowed, if non-zero no writing is done.
       Physically write-protected and  magnetic  tape  file  systems  must  be
       mounted  read-only  or errors will occur when access times are updated,
       whether or not any explicit write is attempted.

       Umount announces to the system that the special file is  no  longer  to
       contain  a  removable  file system.  The associated file reverts to its
       ordinary interpretation.

RETURN VALUE
       Mount returns 0 if the action occurred, -1 if special  is  inaccessible
       or  not  an  appropriate  file,  if  name does not exist, if special is
       already mounted, if name is in use, or if there are  already  too  many
       file systems mounted.

       Umount  returns  0 if the action occurred; -1 if if the special file is
       inaccessible or does not have a mounted file system, or  if  there  are
       active files in the mounted file system.

ERRORS
       Mount will fail when one of the following occurs:

       [ENAMETOOLONG] A  component of either pathname exceeded 255 characters,
                      or the entire length of either path name  exceeded  1023
                      characters.

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

       [EPERM]        The caller is not the super-user.

       [ENOENT]       A component of name does not exist.

       [ENODEV]       A component of special does not exist.

       [ENOTBLK]      Special is not a block device.

       [ENXIO]        The major device number of special is out of range (this
                      indicates  no  device  driver  exists for the associated
                      hardware).

       [ENOTDIR]      A component of name is not a directory, or a path prefix
                      of special is not a directory.

       [EINVAL]       Either pathname contains a character with the high-order
                      bit set.

       [EINVAL]       The super block for the file system had a bad magic num‐
                      ber or an out of range block size.

       [EBUSY]        Another  process currently holds a reference to name, or
                      special is already mounted.

       [EMFILE]       No space remains in the mount table.

       [ENOMEM]       Not enough memory was available  to  read  the  cylinder
                      group information for the file system.

       [EIO]          An  I/O  error occurred while reading the super block or
                      cylinder group information.

       [EFAULT]       Special or name points outside the  process’s  allocated
                      address space.

       Umount may fail with one of the following errors:

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

       [EINVAL]       The  pathname  contains  a character with the high-order
                      bit set.

       [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an
                      entire path name exceeded 1023 characters.

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

       [EPERM]        The caller is not the super-user.

       [ENODEV]       Special does not exist.

       [ENOTBLK]      Special is not a block device.

       [ENXIO]        The major device number of special is out of range (this
                      indicates  no  device  driver  exists for the associated
                      hardware).

       [EINVAL]       The requested device is not in the mount table.

       [EBUSY]        A process is holding a reference to a  file  located  on
                      the file system.

       [EIO]          An  I/O  error occurred while writing the super block or
                      other cached file system information.

       [EFAULT]       Special points outside the process’s  allocated  address
                      space.

SEE ALSO
       mount(8), umount(8)

BUGS
       Some of the error codes need translation to more obvious messages.


4th Berkeley Distribution       August 26, 1985                       MOUNT(2)