NAME

mount − mount a file system

SYNOPSIS

#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(2) system call can be used to determine the file system type number.  Note that if the MS_FSS flag bit of mflag is off, the file system type defaults to the 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 the MS_DATA flag is off or if either dataptr or datalenis zero, there is no additional data.  In the normal case of a local mount, dataptr should be null. 

Upon successful completion, 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(1M) utility. 

mount fails 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 cannot be mounted. 

­[ENOLINK] Pathname points to a remote machine and the link to that machine is no longer active.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

mount(1M), sysfs(2), umount(2), fs(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. 

September 02, 1992