NAME

mount − mount a file system

SYNOPSIS

#include <sys/types.h>
#include <sys/mount.h>

int mount (char ∗spec, char ∗dir, int mflag,
... int fstyp, char ∗dataptr, size_t datalen);

DESCRIPTION

mount requests that a removable file system contained on the block special file identified by spec be mounted on the directory identified by dir. spec and dir are pointers to path names.  fstyp is the file system type number.  If both the MS_DATA and MS_FSS flag bits of mflag are off, the file system type defaults to the root file system type.  Only if either flag is on is fstyp used to indicate the file system type. 

If the MS_DATA flag is set in mflag the system expects the dataptr and datalen arguments to be present.  Together they describe a block of file-system specific data at address dataptr of length datalen.  This is interpreted by file-system specific code within the operating system and its format depends on the file system type.  If a particular file system type does not require this data, dataptr and datalen should both be zero.  Note that MS_FSS is obsolete and is ignored if MS_DATA is also set, but if MS_FSS is set and MS_DATA is not, dataptr and datalen are both assumed to be zero. 

After a successful call to mount, all references to the file dir refer to the root directory on the mounted file system. 

The low-order bit of mflag is used to control write permission on the mounted file system: if 1, writing is forbidden; otherwise writing is permitted according to individual file accessibility. 

mount may be invoked only by the super-user.  It is intended for use only by the mount utility. 

mount fails if one or more of the following are true:

EBUSY dir is currently mounted on, is someone’s current working directory, or is otherwise busy. 

EBUSY The device associated with spec is currently mounted. 

EBUSY There are no more mount table entries. 

EFAULT spec, dir, or datalen points outside the allocated address space of the process. 

EINVAL The super block has an invalid magic number or the fstyp is invalid. 

ELOOP Too many symbolic links were encountered in translating spec or dir. 

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

ENOENT None of the named files exists or is a null pathname. 

ENOTDIR A component of a path prefix is not a directory. 

EPERM The effective user ID is not super-user. 

ENOTBLK spec is not a block special device. 

ENXIO The device associated with spec does not exist. 

ENOTDIR dir is not a directory. 

EROFS spec is write protected and mflag requests write permission.  mflag requests write permission. 

SEE ALSO

umount(2), unmount(2).  mount(1M), fs(4) in the CX/UX Administrator’s Reference Manual. 

DIAGNOSTICS

Upon successful completion a value of 0 is returned.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

CX/UX Programmer’s Reference Manual