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Diffstat (limited to 'share/man/man9/VOP_GETEXTATTR.9')
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diff --git a/share/man/man9/VOP_GETEXTATTR.9 b/share/man/man9/VOP_GETEXTATTR.9 new file mode 100644 index 000000000000..0971c27a2951 --- /dev/null +++ b/share/man/man9/VOP_GETEXTATTR.9 @@ -0,0 +1,133 @@ +.\"- +.\" Copyright (c) 1999, 2000, 2001, 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, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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 December 23, 1999 +.Os +.Dt VOP_GETEXTATTR 9 +.Sh NAME +.Nm VOP_GETEXTATTR +.Nd retrieve named extended attribute from a vnode +.Sh SYNOPSIS +.In sys/param.h +.In sys/vnode.h +.In sys/extattr.h +.Ft int +.Fo VOP_GETEXTATTR +.Fa "struct vnode *vp" +.Fa "int attrnamespace" +.Fa "const char *name" +.Fa "struct uio *uio" +.Fa "size_t *size" +.Fa "struct ucred *cred" +.Fa "struct thread *td" +.Fc +.Sh DESCRIPTION +This vnode call may be used to retrieve a specific named extended attribute +from a file or directory. +.Pp +Its arguments are: +.Bl -tag -width ".Fa attrnamespace" +.It Fa vp +The vnode of the file or directory. +.It Fa attrnamespace +Integer constant indicating which extended attribute namespace the attribute +name is present in. +.It Fa name +Pointer to a null-terminated character string containing the attribute name. +.It Fa uio +The location of the data to be read. +.It Fa size +If not +.Dv NULL , +on return it will contain the number of bytes required to read all of the +attribute data. +In most cases +.Fa uio +will be +.Dv NULL +when +.Fa size +is not, and vise versa. +.It Fa cred +The user credentials to use in authorizing the request. +.It Fa td +The thread requesting the extended attribute. +.El +.Pp +The +.Fa cred +pointer may be +.Dv NULL +to indicate that access control checks are not to be performed, if possible. +This +.Fa cred +setting might be used to allow the kernel to authorize extended attribute +retrieval that the active process might not be permitted to do. +.Pp +Extended attribute semantics may vary by file system implementing the call. +More information on extended attributes may be found in +.Xr extattr 9 . +.Sh LOCKS +The vnode will be locked on entry and should remain locked on return. +.Sh RETURN VALUES +On success, zero will be returned, and the uio structure will be updated to +reflect data read. +Otherwise, an appropriate error code is returned. +.Sh ERRORS +.Bl -tag -width Er +.It Bq Er ENOATTR +The requested attribute was not defined for this vnode. +.It Bq Er EACCES +The the caller does not have the appropriate privilege. +.It Bq Er ENXIO +The request was not valid in this file system for the specified vnode and +attribute name. +.It Bq Er ENOMEM +Sufficient memory is not available to fulfill the request. +.It Bq Er EFAULT +The uio structure refers to an invalid userspace address. +.It Bq Er EINVAL +The +.Fa name , +.Fa namespace, +or +.Fa uio +argument is invalid. +.It Bq Er EOPNOTSUPP +The file system does not support +.Fn VOP_GETEXTATTR . +.El +.Sh SEE ALSO +.Xr extattr 9 , +.Xr vnode 9 , +.Xr VOP_LISTEXTATTR 9 , +.Xr VOP_SETEXTATTR 9 +.Sh BUGS +By passing in the empty string as the attribute name, some file systems +will return a list of defined names on the target vnode for the +requested namespace. +This is a bad API, and will be replaced by an explicit VOP. |