VOP_LISTEXTATTR(9)

NAME

     VOP_LISTEXTATTR -- retrieve a list of named extended attribute from a
     vnode

SYNOPSIS

     #include <sys/param.h>
     #include <sys/vnode.h>
     #include <sys/extattr.h>

     int
     VOP_LISTEXTATTR(struct vnode *vp, int attrnamespace, struct uio *uio,
	 size_t *size, struct ucred *cred, struct thread *td);

DESCRIPTION

     This vnode call may be used to retrieve a list of named extended
     attributes from a specified namespace on a file or directory.

     Its arguments are:

     vp 	    the vnode of the file or directory

     attrnamespace  integer constant indicating which extended attribute
		    namespace the attribute name is present in

     uio	    the location of the data to be read

     size	    if not NULL, on return it will contain the number of bytes
		    required to read the list.	The resulting data will be an
		    ASCII NUL-separated list of strings.  In most cases uio
		    will be NULL when size is not, and vise versa.

     cred	    the user credentials to use in authorizing the request

     td 	    the thread requesting the extended attribute

     The cred pointer may be NULL to indicate that access control checks are
     not to be performed, if possible.	This cred setting might be used to
     allow the kernel to authorize extended attribute retrieval that the
     active process might not be permitted to do.

     Extended attribute semantics may vary by file system implementing the
     call.  More information on extended attributes may be found in
     extattr(9).

LOCKS

     The vnode will be locked on entry and should remain locked on return.

RETURN VALUES

     On success, zero will be returned, and the uio structure will be updated
     to reflect the list read.	Otherwise, an appropriate error code is
     returned.

ERRORS

     [EACCES]		The caller does not have the appropriate privilege.

     [ENXIO]		The request was not valid in this file system for the
			specified vnode and attribute name.

     [ENOMEM]		Sufficient memory is not available to fulfill the
			request.

     [EFAULT]		The uio structure refers to an invalid userspace
			address.

     [EINVAL]		The namespace or uio argument is invalid.

     [EOPNOTSUPP]	The file system does not support VOP_LISTEXTATTR().

SEE ALSO

     extattr(9), vnode(9), VOP_GETEXTATTR(9), VOP_SETEXTATTR(9)