freebsd-nq/share/man/man9/VOP_SETEXTATTR.9
2002-05-16 05:21:58 +00:00

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.Dd December 23, 1999
.Os
.Dt VOP_SETEXTATTR 9
.Sh NAME
.Nm VOP_SETEXTATTR
.Nd set named extended attribute for a vnode
.Sh SYNOPSIS
.In sys/param.h
.In sys/vnode.h
.In sys/extattr.h
.Ft int
.Fn VOP_SETEXTATTR "struct vnode *vp" "int attrnamespace" "const char *name" "struct uio *uio" "struct ucred *cred" "struct thread *td"
.Sh DESCRIPTION
This vnode call may be used to set specific named extended attribute for a
file or directory.
.Pp
Its arguments are:
.Bl -tag -width type
.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 or written
.It Fa cred
the user credentials to use in authorizing the request
.It Fa td
the thread setting the extended attribute
.El
.Pp
The uio structure is used in a manner similar to the argument of the same
name in
.Xr VOP_WRITE .
However, as extended attributes provide a strict "name=value" semantic,
non-zero offsets will be rejected.
.Pp
The
.Fa uio
pointer may be
.Dv NULL
to indicate that the specified extended attribute should be deleted.
.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
changes that the active process might not be permitted to make.
.Pp
Extended attribute semantics may vary by filesystem 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
If the extended attribute is successfully set, then zero is returned.
Otherwise, an appropriate error code is returned.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EACCES
Permission denied
.It Bq Er ENXIO
The request was not valid in this filesystem for the specified vnode and
attribute name.
.It Bq Er ENOMEM
Insufficient memory available to fulfill request
.It Bq Er EFAULT
The uio structure refers to an invalid userspace address
.It Bq Er EINVAL
The name or uio argument is invalid
.It Bq Er EOPNOTSUPP
The filesystem does not support
.Fn VOP_SETEXTATTR
.It Bq Er ENOSPC
The filesystem is out of space
.It Bq Er EROFS
The filesystem is read-only
.El
.Sh SEE ALSO
.Xr extattr 9 ,
.Xr vnode 9 ,
.Xr VOP_GETEXTATTR 9
.Sh AUTHORS
This man page was written by
.An Robert Watson .