xref: /dragonfly/share/man/man9/VOP_OPENCLOSE.9 (revision 31524921)
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27.\" $FreeBSD: src/share/man/man9/VOP_OPENCLOSE.9,v 1.6.2.2 2001/12/17 11:30:18 ru Exp $
28.\"
29.Dd July 24, 1996
30.Dt VOP_OPEN 9
31.Os
32.Sh NAME
33.Nm VOP_OPEN ,
34.Nm VOP_CLOSE
35.Nd open or close a file
36.Sh SYNOPSIS
37.In sys/param.h
38.In sys/vnode.h
39.Ft int
40.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct proc *p"
41.Ft int
42.Fn VOP_CLOSE "struct vnode *vp" "int mode"
43.Sh DESCRIPTION
44The
45.Xr VOP_OPEN 9
46entry point is called before a file is accessed by a process and the
47.Xr VOP_CLOSE 9
48entry point is called after a file is finished with by the process.
49.Pp
50The arguments are:
51.Bl -tag -width mode
52.It Ar vp
53the vnode of the file
54.It Ar mode
55the access mode required by the calling process
56.It Ar p
57the process which is accessing the file
58.El
59.Pp
60The access mode is a set of flags, including
61.Dv FREAD ,
62.Dv FWRITE ,
63.Dv O_NONBLOCK ,
64.Dv O_APPEND .
65.Sh LOCKS
66.Xr VOP_OPEN 9
67expects
68.Fa vp
69to be locked on entry and will leave it locked on return.
70.Pp
71.Xr VOP_CLOSE 9
72expects at least a reference to be associated with the vnode and does not
73care whether the vnode is locked or not.  The lock and reference state is
74left unchanged on return.  Note that
75.Fn vn_close
76expects an unlocked, referenced vnode and will dereference the vnode prior
77to returning.
78.Sh RETURN VALUES
79Zero is returned on success, otherwise an error code is returned.
80.Sh PSEUDOCODE
81.Bd -literal
82int
83vop_open(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
84{
85    /*
86     * Most filesystems don't do much here.
87     */
88    return 0;
89}
90.Ed
91.Sh SEE ALSO
92.Xr vnode 9 ,
93.Xr VOP_OLD_LOOKUP 9
94.Sh AUTHORS
95This man page was written by
96.An Doug Rabson .
97