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VOP_CREATE.9freebsd

BSD mandoc

NAME

VOP_CREATE VOP_MKNOD VOP_MKDIR VOP_SYMLINK - create a file, socket, fifo, device, directory or symlink

SYNOPSIS

In sys/param.h In sys/vnode.h In sys/namei.h Ft int Fn VOP_CREATE struct vnode *dvp struct vnode **vpp struct componentname *cnp struct vattr *vap Ft int Fn VOP_MKNOD struct vnode *dvp struct vnode **vpp struct componentname *cnp struct vattr *vap Ft int Fn VOP_MKDIR struct vnode *dvp struct vnode **vpp struct componentname *cnp struct vattr *vap Ft int Fn 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:

Fa dvp

The locked vnode of the directory.

Fa vpp

The address of a variable where the resulting locked vnode should be stored.

Fa cnp

The pathname component created.

Fa vap

The attributes that the new object should be created with.

Fa target

The pathname of the target of the symlink.

These entry points are called after VOP_LOOKUP9 when an object is being created.

LOCKS

The directory, Fa 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 Fa *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

Bq Er ENOSPC

The file system is full.

Bq Er EDQUOT

The user's file system space or inode quota would be exceeded.

SEE ALSO

vnode(9), VOP_LOOKUP9

HISTORY

The function appeared in BSD 4.3

AUTHORS

This manual page was written by An Doug Rabson .