Copyright (c) 1980 Regents of the University of California.
All rights reserved. The Berkeley software License Agreement
specifies the terms and conditions for redistribution.

@(#)mount.2 4.1 (Berkeley) 05/09/85

C 4 mount, umount - mount or remove file system

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

 umount(special)  char *special; 

Mount announces to the system that a removable file system has been mounted on the block-structured special file special; 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 (unless the root of the mounted file system is not 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.

mount(8) 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.

If a file containing holes (unallocated blocks) is read, even on a file system mounted read-only, the system will attempt to fill in the holes by writing on the device. (mount = 21.)

sys mount; special; name; rwflag

(umount = 22.)

sys umount; special