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
     _M_o_u_n_t announces to the system that a removable file system
     has been mounted on the block-structured special file _s_p_e_-
     _c_i_a_l; from now on, references to file _n_a_m_e will refer to the
     root file on the newly mounted file system.  _S_p_e_c_i_a_l and
     _n_a_m_e are pointers to null-terminated strings containing the
     appropriate path names.

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

     The following _f_l_a_g_s 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.

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

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





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



     _U_m_o_u_n_t 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
     _M_o_u_n_t 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 _n_a_m_e does not exist.

     [ENODEV]	    A component of _s_p_e_c_i_a_l does not exist.

     [ENOTBLK]	    _S_p_e_c_i_a_l is not a block device.

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

     [ENOTDIR]	    A component of _n_a_m_e is not a directory, or a
		    path prefix of _s_p_e_c_i_a_l 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 _n_a_m_e, or _s_p_e_c_i_a_l 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]	    _S_p_e_c_i_a_l or _n_a_m_e points outside the process's
		    allocated address space.





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



     _U_m_o_u_n_t 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]	    _S_p_e_c_i_a_l does not exist.

     [ENOTBLK]	    _S_p_e_c_i_a_l is not a block device.

     [ENXIO]	    The major device number of _s_p_e_c_i_a_l 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]	    _S_p_e_c_i_a_l 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.



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