mount(2)                                                              mount(2)



NAME
     mount - mount a file system

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

     int mount (const char *spec, const char *dir, int mflag,
          .../* char *fstyp, const char *dataptr, int 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.  The sysfs(2) system call can be used to determine the file
     system type number.  If both the MSDATA and MSFSS 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 MSDATA 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     Note that MSFSS is obsolete and is ignored if MSDATA is also set, but
     if MSFSS is set and MSDATA 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 a process with the super-user privilege.  It
     is intended for use only by the mount utility.

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

     EACCES              Search permission is denied on a component of dir or
                         spec.

     EPERM               The calling process does not have the super-user
                         privilege.

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






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mount(2)                                                              mount(2)



     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 {PATHMAX},
                         or the length of a path component exceeds {NAMEMAX}
                         while POSIXNOTRUNC 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.

     EREMOTE             spec is remote and cannot be mounted.

     ENOLINK             path points to a remote machine and the link to that
                         machine is no longer active.

     EMULTIHOP           Components of path require hopping to multiple remote
                         machines and the file system type does not allow it.

     ETIMEDOUT           A component of path is located on a remote file
                         system which is not available [see intro(2)].

     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.

     ENOSPC              The file system state in the super-block is not
                         FsOKAY and mflag requests write permission.

     E2BIG               The file system's size parameters are larger than the
                         size of special device spec. Either mkfs(1M) was run
                         on a different overlapping device or the device has
                         been changed with fx(1M) since mkfs was run.

     EFSCORRUPTED        The filesystem has a corruption forcing failure of
                         the mount.




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mount(2)                                                              mount(2)



     EWRONGFS            The wrong filesystem type was supplied in fstyp, or
                         there is no filesystem on spec.

NOTES
     It is the responsibility of the caller to assure that the block size of
     the device corresponds to the blocksize of the filesystem being mounted.
     This is particularly important with CDROM devices, as the default block
     size of the device can vary between 512 bytes and 2048 bytes.  The
     mount(1M) command manages this for filesystems via dks(7M) DIOCSELFLAGS
     and DIOCSELECT ioctls.

SEE ALSO
     fx(1M), mkfs(1M), mount(1M), sysfs(2), umount(2), dks(7M),fs(4), xfs(4)

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.






































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