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VOP_CREATE(9)		 BSD Kernel Developer's	Manual		 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 re-
     turn.  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
     VOP_LOOKUP(9)

HISTORY
     The function VOP_CREATE appeared in 4.3BSD.

SEE ALSO
     vnode(9)

AUTHORS
     This man page was written by Doug Rabson.

BSD				 July 24, 1996				   BSD
NAME | SYNOPSIS | DESCRIPTION | LOCKS | RETURN VALUES | PSEUDOCODE | ERRORS | SEE ALSO | HISTORY | SEE ALSO | AUTHORS

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