MOUNT(NS) UNIX System V
Name
mount - Mount a file system
Syntax
#include <sys/types.h>
#include <sys/mount.h>
int mount (spec, dir, mflag, fstyp,
char *spec, *dir;
int mflag, fstyp;
caddrt 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(S) system call can be used to determine the file
system type number. If the MS_FSS flag bit of mflag is off,
the file system type will default to root file system type.
If the bit is on, then fstyp is used to indicate the file
system type. Additionally, if the MS_DATA flag is on in
mflag then dataptr and datalen are used to pass mount
parameters to the system. If MS_DATA is off, or if either
of dataptr and datalen is zero, it means that there is no
additional data. In the normal case of a local mount,
dataptr should be NULL. When mounting an NFS file system,
dataptr should point to a structure that describes the NFS
mount options.
Upon successful completion, references to the file dir will
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(NADM) utility.
mount will fail if one or more of the following are true:
[EPERM]
The effective user ID is not super-user.
[ENOENT]
Any of the named files does not exist.
[ENOTDIR]
A component of a path prefix is not a
directory.
[EREMOTE]
spec is remote and can not 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to that machine is no longer active.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.
[ENOTBLK]
spec is not a block special device.
[ENXIO]
The device associated with spec does not
exist.
[ENOTDIR]
dir is not a directory.
[EFAULT]
spec or dir points outside the allocated
address space of the process.
[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.
[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.
[EINVAL]
The super block has a bad magic number or the
fstyp is invalid or mflag is not valid.
See Also
sysfs(S), fs(F), mount(NADM)
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.
(printed 8/17/89) MOUNT(NS)