mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-28 11:57:28 +00:00
126 lines
4.0 KiB
Groff
126 lines
4.0 KiB
Groff
.\"
|
|
.\" Copyright (c) 2003 Robert N. M. Watson.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice(s), this list of conditions and the following disclaimer as
|
|
.\" the first lines of this file unmodified other than the possible
|
|
.\" addition of one or more copyright notices.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice(s), this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
|
|
.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
|
|
.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
|
|
.\" DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 11, 2004
|
|
.Dt VN_FULLPATH 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm vn_fullpath
|
|
.Nd "convert a vnode reference to a full pathname, given a process context"
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In sys/vnode.h
|
|
.Ft int
|
|
.Fo vn_fullpath
|
|
.Fa "struct thread *td" "struct vnode *vp" "char **retbuf" "char **freebuf"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn vn_fullpath
|
|
function makes a
|
|
.Dq "best effort"
|
|
attempt to generate a string pathname for
|
|
the passed (locked) vnode; the resulting path, if any, will be relative to
|
|
the root directory of the process associated with the passed thread pointer.
|
|
The
|
|
.Fn vn_fullpath
|
|
function
|
|
is implemented by inspecting the VFS name cache, and attempting to
|
|
reconstruct a path from the process root to the object.
|
|
.Pp
|
|
This process is necessarily unreliable for several reasons: intermediate
|
|
entries in the path may not be found in the cache; files may have more
|
|
than one name (hard links), not all file systems use the name cache
|
|
(specifically, most synthetic file systems do not); a single name may
|
|
be used for more than one file (in the context of file systems covering
|
|
other file systems); a file may have no name (if deleted but still
|
|
open or referenced).
|
|
However, the resulting string may still be more useable to a user than
|
|
a vnode pointer value, or a device number and inode number.
|
|
Code consuming the results of this function should anticipate (and
|
|
properly handle) failure.
|
|
.Pp
|
|
Its arguments are:
|
|
.Bl -tag -width ".Fa freebuf"
|
|
.It Fa td
|
|
The thread performing the call; this pointer will be dereferenced to find
|
|
the process and its file descriptor structure, in order to identify the
|
|
root vnode to use.
|
|
.It Fa vp
|
|
The vnode to search for; must be locked by the caller.
|
|
.It Fa retbuf
|
|
Pointer to a
|
|
.Vt "char *"
|
|
that
|
|
.Fn vn_fullpath
|
|
may (on success) point at a newly
|
|
allocated buffer containing the resulting pathname.
|
|
.It Fa freebuf
|
|
Pointer to a
|
|
.Vt "char *"
|
|
that
|
|
.Fn vn_fullpath
|
|
may (on success) point at a buffer
|
|
to be freed, when the caller is done with
|
|
.Fa retbuf .
|
|
.El
|
|
.Pp
|
|
Typical consumers will declare two character pointers:
|
|
.Va fullpath
|
|
and
|
|
.Va freepath ;
|
|
they will set
|
|
.Va freepath
|
|
to
|
|
.Dv NULL ,
|
|
and
|
|
.Va fullpath
|
|
to a name to use
|
|
in the event that the call to
|
|
.Fn vn_fullpath
|
|
fails.
|
|
After done with the value of
|
|
.Va fullpath ,
|
|
the caller will check if
|
|
.Va freepath
|
|
is
|
|
.Pf non- Dv NULL ,
|
|
and if so, invoke
|
|
.Xr free 9
|
|
with a pool type of
|
|
.Dv M_TEMP .
|
|
.Sh RETURN VALUES
|
|
If the vnode is successfully converted to a pathname, 0 is returned;
|
|
otherwise, an error number is returned.
|
|
.Sh SEE ALSO
|
|
.Xr free 9
|
|
.Sh AUTHORS
|
|
This manual page was written by
|
|
.An Robert Watson Aq rwatson@FreeBSD.org .
|