From owner-cvs-src@FreeBSD.ORG Mon Feb 26 06:18:54 2007 Return-Path: X-Original-To: cvs-src@FreeBSD.org Delivered-To: cvs-src@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 5185F16A400; Mon, 26 Feb 2007 06:18:54 +0000 (UTC) (envelope-from mckusick@FreeBSD.org) Received: from repoman.freebsd.org (repoman.freebsd.org [69.147.83.41]) by mx1.freebsd.org (Postfix) with ESMTP id 420DA13C491; Mon, 26 Feb 2007 06:18:54 +0000 (UTC) (envelope-from mckusick@FreeBSD.org) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.13.6/8.13.6) with ESMTP id l1Q6Is9v071637; Mon, 26 Feb 2007 06:18:54 GMT (envelope-from mckusick@repoman.freebsd.org) Received: (from mckusick@localhost) by repoman.freebsd.org (8.13.6/8.13.4/Submit) id l1Q6IsXI071636; Mon, 26 Feb 2007 06:18:54 GMT (envelope-from mckusick) Message-Id: <200702260618.l1Q6IsXI071636@repoman.freebsd.org> From: Kirk McKusick Date: Mon, 26 Feb 2007 06:18:54 +0000 (UTC) To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org X-FreeBSD-CVS-Branch: HEAD Cc: Subject: cvs commit: src/sys/sys extattr.h src/share/man/man9 extattr.9 X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Feb 2007 06:18:54 -0000 mckusick 2007-02-26 06:18:53 UTC FreeBSD src repository Modified files: sys/sys extattr.h share/man/man9 extattr.9 Log: Declare a `struct extattr' that defines the format of an extended attribute. Also define some macros to manipulate one of these structures. Explain their use in the extattr.9 manual page. The next step will be to make a sweep through the kernel replacing the old pointer manipulation code. To get an idea of how they would be used, the ffs_findextattr() function in ufs/ffs/ffs_vnops.c is currently written as follows: /* * Vnode operating to retrieve a named extended attribute. * * Locate a particular EA (nspace:name) in the area (ptr:length), and return * the length of the EA, and possibly the pointer to the entry and to the data. */ static int ffs_findextattr(u_char *ptr, u_int length, int nspace, const char *name, u_char **eap, u_char **eac) { u_char *p, *pe, *pn, *p0; int eapad1, eapad2, ealength, ealen, nlen; uint32_t ul; pe = ptr + length; nlen = strlen(name); for (p = ptr; p < pe; p = pn) { p0 = p; bcopy(p, &ul, sizeof(ul)); pn = p + ul; /* make sure this entry is complete */ if (pn > pe) break; p += sizeof(uint32_t); if (*p != nspace) continue; p++; eapad2 = *p++; if (*p != nlen) continue; p++; if (bcmp(p, name, nlen)) continue; ealength = sizeof(uint32_t) + 3 + nlen; eapad1 = 8 - (ealength % 8); if (eapad1 == 8) eapad1 = 0; ealength += eapad1; ealen = ul - ealength - eapad2; p += nlen + eapad1; if (eap != NULL) *eap = p0; if (eac != NULL) *eac = p; return (ealen); } return(-1); } After applying the structure and macros, it would look like this: /* * Vnode operating to retrieve a named extended attribute. * * Locate a particular EA (nspace:name) in the area (ptr:length), and return * the length of the EA, and possibly the pointer to the entry and to the data. */ static int ffs_findextattr(u_char *ptr, u_int length, int nspace, const char *name, u_char **eapp, u_char **eac) { struct extattr *eap, *eaend; eaend = (struct extattr *)(ptr + length); for (eap = (struct extattr *)ptr; eap < eaend; eap = EXTATTR_NEXT(eap)){ /* make sure this entry is complete */ if (EXTATTR_NEXT(eap) > eaend) break; if (eap->ea_namespace != nspace || eap->ea_namelength != length || bcmp(eap->ea_name, name, length)) continue; if (eapp != NULL) *eapp = eap; if (eac != NULL) *eac = EXTATTR_CONTENT(eap); return (EXTATTR_CONTENT_SIZE(eap)); } return(-1); } Not only is it considerably shorter, but it hopefully more readable :-) Revision Changes Path 1.16 +55 -0 src/share/man/man9/extattr.9 1.14 +59 -0 src/sys/sys/extattr.h