DragonFly On-Line Manual Pages

VOP_OPEN(9)           DragonFly Kernel Developer's Manual          VOP_OPEN(9)

NAME
     VOP_OPEN, VOP_CLOSE -- open or close a file

SYNOPSIS
     #include <sys/param.h>
     #include <sys/vnode.h>

     int
     VOP_OPEN(struct vnode *vp, int mode, struct ucred *cred, struct proc *p);

     int
     VOP_CLOSE(struct vnode *vp, int mode);

DESCRIPTION
     The VOP_OPEN(9) entry point is called before a file is accessed by a
     process and the VOP_CLOSE(9) entry point is called after a file is
     finished with by the process.

     The arguments are:

     vp    the vnode of the file

     mode  the access mode required by the calling process

     p     the process which is accessing the file

     The access mode is a set of flags, including FREAD, FWRITE, O_NONBLOCK,
     O_APPEND.

LOCKS
     VOP_OPEN(9) expects vp to be locked on entry and will leave it locked on
     return.

     VOP_CLOSE(9) expects at least a reference to be associated with the vnode
     and does not care whether the vnode is locked or not.  The lock and
     reference state is left unchanged on return.  Note that vn_close()
     expects an unlocked, referenced vnode and will dereference the vnode
     prior to returning.

RETURN VALUES
     Zero is returned on success, otherwise an error code is returned.

PSEUDOCODE
     int
     vop_open(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
     {
         /*
          * Most filesystems don't do much here.
          */
         return 0;
     }

SEE ALSO
     vnode(9), VOP_OLD_LOOKUP(9)

AUTHORS
     This man page was written by Doug Rabson.

DragonFly 3.9                    July 24, 1996                   DragonFly 3.9