vop_create(9)

NAME

VOP_CREATE, VOP_MKNOD, VOP_MKDIR, VOP_SYMLINK - create a

file, socket,
fifo, device, directory or symlink

SYNOPSIS

#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/namei.h>
int
VOP_CREATE(struct vnode *dvp, struct vnode **vpp,
        struct componentname *cnp, struct vattr *vap);
int
VOP_MKNOD(struct vnode *dvp, struct vnode **vpp,
        struct componentname *cnp, struct vattr *vap);
int
VOP_MKDIR(struct vnode *dvp, struct vnode **vpp,
        struct componentname *cnp, struct vattr *vap);
int
VOP_SYMLINK(struct vnode *dvp, struct vnode **vpp,
        struct  componentname  *cnp, struct vattr *vap, char
*target);

DESCRIPTION

These entry points create a new file, socket, fifo, device,

directory or
symlink in a given directory.

The arguments are:

dvp The locked vnode of the directory.

vpp The address of a variable where the resulting locked

vnode should

be stored.

cnp The pathname component created.

vap The attributes that the new object should be created

with.

target The pathname of the target of the symlink.

These entry points are called after VOP_LOOKUP(9) when an

object is being
created.

LOCKS

The directory, dvp will be locked on entry and must remain

locked on
return. If the call is successful, the new object will be

returned
locked.

RETURN VALUES

If successful, the vnode for the new object is placed in

*vpp and zero is
returned. Otherwise, an appropriate error is returned.

PSEUDOCODE

int
vop_create(struct vnode *dvp,

struct vnode **vpp,
struct componentname *cnp
struct vattr *vap)

{

int mode = MAKEIMODE(vap->va_type, vap->va_mode);
struct vnode *vp;
int error;

*vpp = NULL;
if ((mode & IFMT) == 0)

mode |= IFREG;

error = SOMEFS_VALLOC(dvp, mode, cnp->cn_cred, &vp);
if (error)

return error;

/*

* Update the permissions for the new vnode, including
* copying the group from the directory.
*/

...;

#ifdef QUOTA

/*

* Possibly check quota information.
*/

...;

#endif

/*

* Enter new vnode in directory, taking care that the

vnode
* hits the disk before the directory contents are

changed.
*/

error = ...;

if (error)

goto bad;

*vpp = vp;

return 0;

bad:

/*

* Write error occurred trying to update the inode
* or the directory so must deallocate the inode.
*/

vput(vp);

/*

* Deallocate file system resources for vp.
*/

...;

return error;

}

ERRORS

[ENOSPC] The file system is full.

[EDQUOT] The user's file system space or inode

quota would be

exceeded.

SEE ALSO

vnode(9), VOP_LOOKUP(9)

HISTORY

The function VOP_CREATE appeared in 4.3BSD.

AUTHORS

This manual page was written by Doug Rabson.

BSD July 24, 1996

BSD