1998-09-27 13:35:49 +00:00
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.\"
|
1999-12-16 23:20:11 +00:00
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.\" Copyright (c) 1998, 1999 Eivind Eklund
|
2003-06-02 15:02:06 +00:00
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|
|
.\" Copyright (c) 2003 Hiten M. Pandya
|
2005-09-21 10:19:57 +00:00
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.\" Copyright (c) 2005 Robert N. M. Watson
|
1998-09-27 13:35:49 +00:00
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.\"
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.\" All rights reserved.
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.\"
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.\" This program is free software.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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|
|
.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
|
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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|
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\"
|
2001-07-14 19:41:16 +00:00
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.\" If you integrate this manpage in another OS, I'd appreciate a note
|
2000-10-27 16:05:39 +00:00
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.\" - eivind@FreeBSD.org
|
1998-09-27 13:35:49 +00:00
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.\"
|
1999-08-28 00:22:10 +00:00
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.\" $FreeBSD$
|
1998-09-27 13:35:49 +00:00
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.\"
|
2005-11-18 10:56:28 +00:00
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|
|
.Dd September 21, 2005
|
1999-08-15 10:48:36 +00:00
|
|
|
.Dt NAMEI 9
|
2010-04-14 19:08:06 +00:00
|
|
|
.Os
|
1998-09-27 13:35:49 +00:00
|
|
|
.Sh NAME
|
|
|
|
.Nm namei ,
|
2003-05-31 14:38:45 +00:00
|
|
|
.Nm NDINIT ,
|
2005-09-21 10:19:57 +00:00
|
|
|
.Nm NDFREE ,
|
|
|
|
.Nm NDHASGIANT
|
2003-05-31 14:38:45 +00:00
|
|
|
.Nd pathname translation and lookup operations
|
1998-09-27 13:35:49 +00:00
|
|
|
.Sh SYNOPSIS
|
2001-12-26 23:14:04 +00:00
|
|
|
.In sys/param.h
|
2010-01-14 14:36:39 +00:00
|
|
|
.In sys/fcntl.h
|
2001-10-01 16:09:29 +00:00
|
|
|
.In sys/namei.h
|
1998-09-27 13:35:49 +00:00
|
|
|
.Ft int
|
|
|
|
.Fn namei "struct nameidata *ndp"
|
|
|
|
.Ft void
|
2003-06-02 15:02:06 +00:00
|
|
|
.Fo NDINIT
|
|
|
|
.Fa "struct nameidata *ndp" "u_long op" "u_long flags"
|
|
|
|
.Fa "enum uio_seg segflg" "const char *namep" "struct thread *td"
|
|
|
|
.Fc
|
2001-03-29 10:29:37 +00:00
|
|
|
.Ft void
|
2003-05-31 14:38:45 +00:00
|
|
|
.Fn NDFREE "struct nameidata *ndp" "const uint flags"
|
2005-09-21 10:19:57 +00:00
|
|
|
.Ft int
|
|
|
|
.Fn NDHASGIANT "struct nameidata *ndp"
|
1998-09-27 13:35:49 +00:00
|
|
|
.Sh DESCRIPTION
|
2003-02-05 14:00:46 +00:00
|
|
|
The
|
2003-05-31 14:38:45 +00:00
|
|
|
.Nm
|
|
|
|
facility allows the client to perform pathname translation and lookup
|
|
|
|
operations.
|
|
|
|
The
|
|
|
|
.Nm
|
|
|
|
functions will increment the reference count for the vnode in question.
|
|
|
|
The reference count has to be decremented after use of the vnode, by
|
|
|
|
using either
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr vrele 9
|
|
|
|
or
|
|
|
|
.Xr vput 9 ,
|
2003-06-02 15:02:06 +00:00
|
|
|
depending on whether the
|
2003-05-31 14:38:45 +00:00
|
|
|
.Dv LOCKLEAF
|
2003-06-02 15:02:06 +00:00
|
|
|
flag was specified or not.
|
2005-09-21 10:19:57 +00:00
|
|
|
If the
|
|
|
|
.Va Giant
|
|
|
|
lock is required,
|
|
|
|
.Nm
|
|
|
|
will acquire it if the caller indicates it is
|
|
|
|
.Dv MPSAFE ,
|
|
|
|
in which case the caller must later release
|
|
|
|
.Va Giant
|
|
|
|
based on the results of
|
2005-12-13 17:07:52 +00:00
|
|
|
.Fn NDHASGIANT .
|
1998-09-27 13:35:49 +00:00
|
|
|
.Pp
|
2003-05-31 14:38:45 +00:00
|
|
|
The
|
|
|
|
.Fn NDINIT
|
|
|
|
function is used to initialize
|
|
|
|
.Nm
|
|
|
|
components.
|
1998-09-27 13:35:49 +00:00
|
|
|
It takes the following arguments:
|
2003-06-02 15:02:06 +00:00
|
|
|
.Bl -tag -width ".Fa segflg"
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Fa ndp
|
|
|
|
The
|
|
|
|
.Vt "struct nameidata"
|
|
|
|
to initialize.
|
|
|
|
.It Fa op
|
|
|
|
The operation which
|
1998-09-27 13:35:49 +00:00
|
|
|
.Fn namei
|
2003-05-31 14:38:45 +00:00
|
|
|
will perform.
|
|
|
|
The following operations are valid:
|
2003-06-02 15:02:06 +00:00
|
|
|
.Dv LOOKUP , CREATE , DELETE ,
|
1998-09-27 13:35:49 +00:00
|
|
|
and
|
|
|
|
.Dv RENAME .
|
|
|
|
The latter three are just setup for those
|
|
|
|
effects; just calling
|
|
|
|
.Fn namei
|
|
|
|
will not result in
|
|
|
|
.Fn VOP_RENAME
|
|
|
|
being called.
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Fa flags
|
|
|
|
Operation flags.
|
|
|
|
Several of these can be effective at the same time.
|
|
|
|
.It Fa segflg
|
|
|
|
UIO segment indicator.
|
|
|
|
This indicates if the name of the object is in userspace
|
|
|
|
.Pq Dv UIO_USERSPACE
|
|
|
|
or in the kernel address space
|
|
|
|
.Pq Dv UIO_SYSSPACE .
|
|
|
|
.It Fa namep
|
|
|
|
Pointer to the component's pathname buffer
|
2003-06-02 15:02:06 +00:00
|
|
|
(the file or directory name that will be looked up).
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Fa td
|
|
|
|
The thread context to use for
|
|
|
|
.Nm
|
|
|
|
operations and locks.
|
1998-09-27 13:35:49 +00:00
|
|
|
.El
|
|
|
|
.Sh NAMEI OPERATION FLAGS
|
2003-02-05 14:00:46 +00:00
|
|
|
The
|
1998-09-27 13:35:49 +00:00
|
|
|
.Fn namei
|
2003-05-31 14:38:45 +00:00
|
|
|
function takes the following set of
|
2003-06-02 15:02:06 +00:00
|
|
|
.Dq "operation flags"
|
2003-05-31 14:38:45 +00:00
|
|
|
that influence its operation:
|
2003-06-02 15:02:06 +00:00
|
|
|
.Bl -tag -width ".Dv WANTPARENT"
|
1998-09-27 13:35:49 +00:00
|
|
|
.It Dv LOCKLEAF
|
2003-05-31 14:38:45 +00:00
|
|
|
Lock vnode on return.
|
2003-06-02 15:02:06 +00:00
|
|
|
This is a full lock of the vnode; the
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr VOP_UNLOCK 9
|
2003-06-02 15:02:06 +00:00
|
|
|
should be used
|
|
|
|
to release the lock (or
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr vput 9
|
2003-06-02 15:02:06 +00:00
|
|
|
which is equivalent to calling
|
|
|
|
.Xr VOP_UNLOCK 9
|
|
|
|
followed by
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr vrele 9 ,
|
|
|
|
all in one).
|
|
|
|
.It Dv LOCKPARENT
|
2003-05-31 14:38:45 +00:00
|
|
|
This flag lets the
|
1998-09-27 13:35:49 +00:00
|
|
|
.Fn namei
|
2003-05-31 14:38:45 +00:00
|
|
|
function return the parent (directory) vnode,
|
|
|
|
.Va ni_dvp
|
|
|
|
in locked state, unless it is identical to
|
|
|
|
.Va ni_vp ,
|
|
|
|
in which case
|
|
|
|
.Va ni_dvp
|
|
|
|
is not locked per se (but may be locked due to
|
2003-06-02 15:02:06 +00:00
|
|
|
.Dv LOCKLEAF ) .
|
2003-05-31 14:38:45 +00:00
|
|
|
If a lock is enforced, it should be released using
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr vput 9
|
|
|
|
or
|
|
|
|
.Xr VOP_UNLOCK 9
|
|
|
|
and
|
2003-05-31 14:38:45 +00:00
|
|
|
.Xr vrele 9 .
|
1998-09-27 13:35:49 +00:00
|
|
|
.It Dv WANTPARENT
|
2003-05-31 14:38:45 +00:00
|
|
|
This flag allows the
|
1998-09-27 13:35:49 +00:00
|
|
|
.Fn namei
|
2003-05-31 14:38:45 +00:00
|
|
|
function to return the parent (directory) vnode in an unlocked state.
|
|
|
|
The parent vnode must be released separately by using
|
|
|
|
.Xr vrele 9 .
|
2005-09-21 10:19:57 +00:00
|
|
|
.It Dv MPSAFE
|
|
|
|
With this flag set,
|
|
|
|
.Fn namei
|
|
|
|
will conditionally acquire
|
|
|
|
.Va Giant
|
|
|
|
if it is required by a traversed file system.
|
|
|
|
MPSAFE callers should pass the results of
|
|
|
|
.Fn NDHASGIANT
|
|
|
|
to
|
|
|
|
.Xr VFS_UNLOCK_GIANT
|
|
|
|
in order to conditionally release
|
|
|
|
.Va Giant
|
|
|
|
if necessary.
|
1998-09-27 13:35:49 +00:00
|
|
|
.It Dv NOCACHE
|
|
|
|
Avoid
|
|
|
|
.Fn namei
|
|
|
|
creating this entry in the namecache if it is not
|
2003-06-02 15:02:06 +00:00
|
|
|
already present.
|
|
|
|
Normally,
|
1998-09-27 13:35:49 +00:00
|
|
|
.Fn namei
|
|
|
|
will add entries to the name cache
|
2003-06-02 15:02:06 +00:00
|
|
|
if they are not already there.
|
1998-09-27 13:35:49 +00:00
|
|
|
.It Dv FOLLOW
|
|
|
|
With this flag,
|
|
|
|
.Fn namei
|
|
|
|
will follow the symbolic link if the last part
|
|
|
|
of the path supplied is a symbolic link (i.e., it will return a vnode
|
|
|
|
for whatever the link points at, instead for the link itself).
|
|
|
|
.It Dv NOOBJ
|
|
|
|
Do not call
|
|
|
|
.Fn vfs_object_create
|
2003-05-31 14:38:45 +00:00
|
|
|
for the returned vnode, even though it meets required criteria for VM support.
|
1998-09-27 13:35:49 +00:00
|
|
|
.It Dv NOFOLLOW
|
1999-12-16 23:20:11 +00:00
|
|
|
Do not follow symbolic links (pseudo).
|
|
|
|
This flag is not looked for by the actual code, which looks for
|
2003-05-31 14:38:45 +00:00
|
|
|
.Dv FOLLOW .
|
|
|
|
.Dv NOFOLLOW
|
|
|
|
is used to indicate to the source code reader that symlinks
|
1999-12-16 23:20:11 +00:00
|
|
|
are intentionally not followed.
|
2002-07-23 13:16:36 +00:00
|
|
|
.It Dv SAVENAME
|
2003-05-31 14:38:45 +00:00
|
|
|
Do not free the pathname buffer at the end of the
|
2002-07-23 13:16:36 +00:00
|
|
|
.Fn namei
|
2003-06-02 15:02:06 +00:00
|
|
|
invocation; instead, free it later in
|
2002-07-23 13:16:36 +00:00
|
|
|
.Fn NDFREE
|
2003-05-31 14:38:45 +00:00
|
|
|
so that the caller may access the pathname buffer.
|
2002-07-23 13:16:36 +00:00
|
|
|
See below for details.
|
|
|
|
.It Dv SAVESTART
|
|
|
|
Retain an additional reference to the parent directory; do not free
|
2003-05-31 14:38:45 +00:00
|
|
|
the pathname buffer.
|
2002-07-23 13:16:36 +00:00
|
|
|
See below for details.
|
1998-09-27 13:35:49 +00:00
|
|
|
.El
|
1999-12-16 23:20:11 +00:00
|
|
|
.Sh ALLOCATED ELEMENTS
|
2003-05-31 14:38:45 +00:00
|
|
|
The
|
|
|
|
.Vt nameidata
|
|
|
|
structure is composed of the following fields:
|
2003-06-02 15:02:06 +00:00
|
|
|
.Bl -tag -width ".Va ni_cnd.cn_pnbuf"
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Va ni_startdir
|
1999-12-16 23:20:11 +00:00
|
|
|
In the normal case, this is either the current directory or the root.
|
2003-06-02 15:02:06 +00:00
|
|
|
It is the current directory if the name passed in does not start with
|
|
|
|
.Ql /
|
1999-12-16 23:20:11 +00:00
|
|
|
and we have not gone through any symlinks with an absolute path, and
|
|
|
|
the root otherwise.
|
2000-12-29 09:18:45 +00:00
|
|
|
.Pp
|
2001-06-24 01:38:20 +00:00
|
|
|
In this case, it is only used by
|
|
|
|
.Fn lookup ,
|
|
|
|
and should not be
|
|
|
|
considered valid after a call to
|
|
|
|
.Fn namei .
|
2003-05-31 14:38:45 +00:00
|
|
|
If
|
|
|
|
.Dv SAVESTART
|
|
|
|
is set, this is set to the same as
|
|
|
|
.Va ni_dvp ,
|
|
|
|
with an extra
|
|
|
|
.Xr vref 9 .
|
|
|
|
To block
|
|
|
|
.Fn NDFREE
|
|
|
|
from releasing
|
|
|
|
.Va ni_startdir ,
|
|
|
|
the
|
|
|
|
.Dv NDF_NO_STARTDIR_RELE
|
|
|
|
can be set.
|
|
|
|
.It Va ni_dvp
|
|
|
|
Vnode pointer to directory of the object on which lookup is performed.
|
|
|
|
This is available on successful return if
|
|
|
|
.Dv LOCKPARENT
|
|
|
|
or
|
|
|
|
.Dv WANTPARENT
|
|
|
|
is set.
|
|
|
|
It is locked if
|
|
|
|
.Dv LOCKPARENT
|
|
|
|
is set.
|
|
|
|
Freeing this in
|
2003-06-02 15:02:06 +00:00
|
|
|
.Fn NDFREE
|
2003-05-31 14:38:45 +00:00
|
|
|
can be inhibited by
|
2003-06-02 15:02:06 +00:00
|
|
|
.Dv NDF_NO_DVP_RELE , NDF_NO_DVP_PUT ,
|
2003-05-31 14:38:45 +00:00
|
|
|
or
|
|
|
|
.Dv NDF_NO_DVP_UNLOCK
|
1999-12-16 23:20:11 +00:00
|
|
|
(with the obvious effects).
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Va ni_vp
|
|
|
|
Vnode pointer to the resulting object,
|
|
|
|
.Dv NULL
|
|
|
|
otherwise.
|
|
|
|
The
|
|
|
|
.Va v_usecount
|
|
|
|
field of this vnode is incremented.
|
|
|
|
If
|
|
|
|
.Dv LOCKLEAF
|
|
|
|
is set, it is also locked.
|
2000-12-29 09:18:45 +00:00
|
|
|
.Pp
|
2003-05-31 14:38:45 +00:00
|
|
|
Freeing this in
|
|
|
|
.Fn NDFREE
|
|
|
|
can be inhibited by
|
2003-06-02 15:02:06 +00:00
|
|
|
.Dv NDF_NO_VP_RELE , NDF_NO_VP_PUT ,
|
2003-05-31 14:38:45 +00:00
|
|
|
or
|
|
|
|
.Dv NDF_NO_VP_UNLOCK
|
2003-06-02 15:02:06 +00:00
|
|
|
(with the obvious effects).
|
2003-05-31 14:38:45 +00:00
|
|
|
.It Va ni_cnd.cn_pnbuf
|
|
|
|
The pathname buffer contains the location of the file or directory
|
|
|
|
that will be used by the
|
|
|
|
.Nm
|
|
|
|
operations.
|
|
|
|
It is managed by the
|
|
|
|
.Xr uma 9
|
|
|
|
zone allocation interface.
|
|
|
|
If the
|
|
|
|
.Dv SAVESTART
|
|
|
|
or
|
|
|
|
.Dv SAVENAME
|
|
|
|
flag is set, then the pathname buffer is available
|
|
|
|
after calling the
|
2003-06-02 15:02:06 +00:00
|
|
|
.Fn namei
|
2003-05-31 14:38:45 +00:00
|
|
|
function.
|
2000-12-29 09:18:45 +00:00
|
|
|
.Pp
|
2003-05-31 14:38:45 +00:00
|
|
|
To only deallocate resources used by the pathname buffer,
|
|
|
|
.Va ni_cnd.cn_pnbuf ,
|
|
|
|
then
|
|
|
|
.Dv NDF_ONLY_PNBUF
|
|
|
|
flag can be passed to the
|
|
|
|
.Fn NDFREE
|
|
|
|
function.
|
|
|
|
To keep the pathname buffer intact,
|
|
|
|
the
|
2005-02-28 02:02:27 +00:00
|
|
|
.Dv NDF_NO_FREE_PNBUF
|
2003-05-31 14:38:45 +00:00
|
|
|
flag can be passed to the
|
|
|
|
.Fn NDFREE
|
|
|
|
function.
|
2000-12-29 09:18:45 +00:00
|
|
|
.El
|
2010-01-14 14:36:39 +00:00
|
|
|
.Sh RETURN VALUES
|
|
|
|
If successful,
|
|
|
|
.Fn namei
|
|
|
|
will return 0, otherwise it will return an error.
|
2010-05-13 12:08:11 +00:00
|
|
|
.Sh FILES
|
|
|
|
.Bl -tag
|
|
|
|
.It Pa src/sys/kern/vfs_lookup.c
|
|
|
|
.El
|
2010-01-14 14:36:39 +00:00
|
|
|
.Sh ERRORS
|
|
|
|
Errors which
|
|
|
|
.Fn namei
|
|
|
|
may return:
|
|
|
|
.Bl -tag -width Er
|
|
|
|
.It Bq Er ENOTDIR
|
|
|
|
A component of the specified pathname is not a directory when a directory is
|
|
|
|
expected.
|
|
|
|
.It Bq Er ENAMETOOLONG
|
|
|
|
A component of a pathname exceeded 255 characters,
|
|
|
|
or an entire pathname exceeded 1023 characters.
|
|
|
|
.It Bq Er ENOENT
|
|
|
|
A component of the specified pathname does not exist,
|
|
|
|
or the pathname is an empty string.
|
2010-02-24 13:13:29 +00:00
|
|
|
.It Bq Er EACCES
|
2010-01-14 14:36:39 +00:00
|
|
|
An attempt is made to access a file in a way forbidden by its file access
|
|
|
|
permissions.
|
|
|
|
.It Bq Er ELOOP
|
|
|
|
Too many symbolic links were encountered in translating the pathname.
|
|
|
|
.It Bq Er EISDIR
|
|
|
|
An attempt is made to open a directory with write mode specified.
|
|
|
|
.It Bq Er EROFS
|
|
|
|
An attempt is made to modify a file or directory on a read-only file system.
|
|
|
|
.El
|
1998-09-27 13:35:49 +00:00
|
|
|
.Sh SEE ALSO
|
2003-05-31 14:38:45 +00:00
|
|
|
.Xr uio 9 ,
|
|
|
|
.Xr uma 9 ,
|
1998-09-27 13:35:49 +00:00
|
|
|
.Xr VFS 9 ,
|
2005-09-21 10:19:57 +00:00
|
|
|
.Xr VFS_UNLOCK_GIANT 9 ,
|
2003-05-31 14:38:45 +00:00
|
|
|
.Xr vnode 9 ,
|
|
|
|
.Xr vput 9 ,
|
|
|
|
.Xr vref 9
|
1998-09-27 13:35:49 +00:00
|
|
|
.Sh AUTHORS
|
2003-06-02 15:02:06 +00:00
|
|
|
.An -nosplit
|
2003-05-31 14:38:45 +00:00
|
|
|
This manual page was written by
|
2003-06-02 15:02:06 +00:00
|
|
|
.An Eivind Eklund Aq eivind@FreeBSD.org
|
2003-05-31 14:38:45 +00:00
|
|
|
and later significantly revised by
|
2003-06-02 15:02:06 +00:00
|
|
|
.An Hiten M. Pandya Aq hmp@FreeBSD.org .
|
2003-05-31 14:38:45 +00:00
|
|
|
.Sh BUGS
|
|
|
|
The
|
|
|
|
.Dv LOCKPARENT
|
|
|
|
flag does not always result in the parent vnode being locked.
|
|
|
|
This results in complications when the
|
|
|
|
.Dv LOCKPARENT
|
|
|
|
is used.
|
|
|
|
In order to solve this for the cases where both
|
|
|
|
.Dv LOCKPARENT
|
|
|
|
and
|
|
|
|
.Dv LOCKLEAF
|
|
|
|
are used, it is necessary to resort to recursive locking.
|
2005-09-21 10:19:57 +00:00
|
|
|
.Pp
|
|
|
|
Non-MPSAFE file systems exist, requiring callers to conditionally unlock
|
|
|
|
.Va Giant .
|