VOP_LISTEXTATTR(9)     FreeBSD Kernel Developer's Manual    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.  The resulting
                        data will be a list of attribute names.  Each list
                        entry consists of a single byte containing the length
                        of the attribute name, followed by the attribute name.
                        The attribute name is not terminated by ASCII NUL.

     size               If not NULL, on return it will contain the number of
                        bytes required to read the list.  In most cases uio
                        will be NULL when size is not, and vice 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)

FreeBSD 13.1-RELEASE-p6         August 19, 2005        FreeBSD 13.1-RELEASE-p6