MOUNT(S) UNIX System V MOUNT(S)
Name
mount - mount a file system
Syntax
#include <sys/types.h>
#include <sys/mount.h>
int mount (spec, dir, mflag, fstyp, dataptr, datalen)
char *spec, *dir;
int mflag, fstyp;
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(S) system call can be used to determine the file
system type number. Note that if both the MS_DATA and
MS_FSS flag bits of mflag are off, the file system type will
default to the root file system type. Only if either flag
is on will fstyp be 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 upon the file system type. A particular file
system type may not require this data, in which case dataptr
and datalen should both be zero. Note that MS_FSS is
obsolete and will be ignored if MS_DATA is also set, but if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.
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(ADM) utility.
mount will fail if one or more of the following is 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 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to that machine is no longer active.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.
[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 an invalid magic number
or the fstyp is invalid or mflag is not
valid.
See Also
sysfs(S), umount(S), mount(ADM), fs(F)
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.
Standards Conformance
mount is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
and The X/Open Portability Guide II of January 1987.
(printed 6/20/89)