unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (SunOS-5.10)
Page:
Section:
Apropos / Subsearch:
optional field

umount(2)                        System Calls                        umount(2)



NAME
       umount, umount2 - unmount a file system

SYNOPSIS
       #include <sys/mount.h>

       int umount(const char *file);

       int umount2(const char *file, int mflag);

DESCRIPTION
       The  umount()   function requests that a previously mounted file system
       contained on a block special device or  directory  be  unmounted.   The
       file  argument is a pointer to the absolute pathname of the file system
       to be unmounted. After unmounting the file system, the  directory  upon
       which  the  file system was mounted reverts to its ordinary interpreta-
       tion.

       The umount2()  function is identical to umount(), with  the  additional
       capability  of  unmounting  file  systems  even if there are open files
       active. The mflag argument must contain one of the following values:

       0               Perform  a  normal  unmount  that  is   equivalent   to
                       umount().  The  umount2()  function   returns  EBUSY if
                       there are open files active within the file  system  to
                       be unmounted.



       MS_FORCE        Unmount  the  file system, even if there are open files
                       active. A forced unmount can result in loss of data, so
                       it should be used only when a regular unmount is unsuc-
                       cessful. The umount2() function  returns ENOTSUP if the
                       specified  file systems does not support MS_FORCE. Cur-
                       rently only nfs-  and  ufs-type  file  systems  support
                       MS_FORCE.



RETURN VALUES
       Upon  successful  completion,  0 is returned. Otherwise, -1 is returned
       and errno is set to indicate the error.

ERRORS
       The umount() and umount2() functions will fail if:

       EACCES                  The permission bits of the mount point  do  not
                               permit  read/write  access or search permission
                               is denied on a component of the path prefix.

                               The calling process is not  the  owner  of  the
                               mountpoint.

                               The  mountpoint  is  not  a  regular  file or a
                               directory and the  caller  does  not  have  all
                               privileges available in a its zone.

                               The  special device device does not permit read
                               access in the case of read-only mounts or read-
                               write access in the case of read/write mounts.



       EBUSY                   A file on file is busy.



       EFAULT                  The  file pointed to by file points to an ille-
                               gal address.



       EINVAL                  The file pointed to by file is not mounted.



       ELOOP                   Too many symbolic  links  were  encountered  in
                               translating the path pointed to by file.



       ENAMETOOLONG            The   length   of  the  file  argument  exceeds
                               PATH_MAX, or the length of  a   file  component
                               exceeds  NAME_MAX  while  _POSIX_NO_TRUNC is in
                               effect.



       ENOENT                  The file pointed to by file does not  exist  or
                               is not an absolute path.



       ENOLINK                 The  file  pointed  to  by  file is on a remote
                               machine and the link  to  that  machine  is  no
                               longer active.



       ENOTBLK                 The file pointed to by file is not a block spe-
                               cial device.



       EPERM                   The {PRIV_SYS_MOUNT} privilege is not  asserted
                               in the effective set of the calling process.



       EREMOTE                 The file pointed to by file is remote.



       The umount2() function will fail if:

       ENOTSUP                 The  file  pointed  to by file does not support
                               this operation.



USAGE
       The umount() and umount2() functions can be invoked only by  a  process
       that has the {PRIV_SYS_MOUNT} privilege asserted in its effective set.

       Because  it  provides  greater functionality, the umount2() function is
       preferred.

SEE ALSO
       mount(2), privileges(5)



SunOS 5.10                        22 Mar 2004                        umount(2)