xref: /freebsd/share/man/man9/VOP_OPENCLOSE.9 (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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3.\" Copyright (c) 1996 Doug Rabson
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29.\" $FreeBSD$
30.\"
31.Dd December 2, 2009
32.Dt VOP_OPEN 9
33.Os
34.Sh NAME
35.Nm VOP_OPEN ,
36.Nm VOP_CLOSE
37.Nd open or close a file
38.Sh SYNOPSIS
39.In sys/param.h
40.In sys/vnode.h
41.Ft int
42.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" "struct file *fp"
43.Ft int
44.Fn VOP_CLOSE "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td"
45.Sh DESCRIPTION
46The
47.Fn VOP_OPEN
48entry point is called before a file is accessed by a process and the
49.Fn VOP_CLOSE
50entry point is called after a file is finished with by the process.
51.Pp
52The arguments are:
53.Bl -tag -width mode
54.It Fa vp
55The vnode of the file.
56.It Fa mode
57The access mode required by the calling process.
58.It Fa cred
59The caller's credentials.
60.It Fa td
61The thread which is accessing the file.
62.It Fa fp
63The file being opened.
64.El
65.Pp
66Pointer to the file
67.Fa fp
68is useful for file systems which require such information, e.g.,
69.Xr fdescfs 5 .
70Use
71.Ql NULL
72as
73.Fa fp
74argument to
75.Fn VOP_OPEN
76for in-kernel opens.
77.Pp
78The access mode is a set of flags, including
79.Dv FREAD ,
80.Dv FWRITE ,
81.Dv O_NONBLOCK ,
82.Dv O_APPEND .
83.Sh LOCKS
84.Fn VOP_OPEN
85expects
86.Fa vp
87to be locked on entry and will leave it locked on return.
88.Pp
89.Fn VOP_CLOSE
90expects at least a reference to be associated with the vnode and does not
91care whether the vnode is locked or not.
92The lock and reference state is left unchanged on return.
93Note that
94.Fa vn_close
95expects an unlocked, referenced vnode and will dereference the vnode prior
96to returning.
97.Sh RETURN VALUES
98Zero is returned on success, otherwise an error code is returned.
99.Sh SEE ALSO
100.Xr vnode 9 ,
101.Xr VOP_LOOKUP 9
102.Sh AUTHORS
103This manual page was written by
104.An Doug Rabson .
105