2.11BSD#431 - /usr/man/cat2/umount.0

MOUNT(2)	    UNIX Programmer's Manual		 MOUNT(2)


NAME
     mount, umount - mount or remove file system

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

     umount(special)
     char *special;

DESCRIPTION
     Mount announces to the system that a removable file system
     has been mounted on the block-structured special file spe-
     cial; from now on, references 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 following flags may be specified to suppress default
     semantics which affect filesystem access.

     MNT_RDONLY          The filesystem should be treated as
			 read-only; Even the super-user may not
			 write on it.

     MNT_NOEXEC          Do not allow files to be executed from
			 the filesystem.

     MNT_NOSUID          Do not honor setuid or setgid bits on
			 files when executing them.

     MNT_NODEV		 Do not interpret special files on the
			 filesystem.

     MNT_SYNCHRONOUS	 All I/O to the filesystem should be done
			 synchronously.

     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.


Printed 11/26/99	January 25, 1996			1


MOUNT(2)	    UNIX Programmer's Manual		 MOUNT(2)


     Umount returns 0 if the action occurred; -1 if if the spe-
     cial 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 number 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 sys-
		    tem.

     [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.


Printed 11/26/99	January 25, 1996			2


MOUNT(2)	    UNIX Programmer's Manual		 MOUNT(2)


     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 char-
		    acters, 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 informa-
		    tion.

     [EFAULT]	    Special points outside the process's allo-
		    cated address space.

SEE ALSO
     mount(8), umount(8)

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

     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.

     MNT_SYNCHRONOUS is not currently implemented in the kernel
     but may be specified because the kernel ignores it.


Printed 11/26/99	January 25, 1996			3