From owner-freebsd-ports@freebsd.org Sun May 21 21:27:29 2017 Return-Path: <owner-freebsd-ports@freebsd.org> Delivered-To: freebsd-ports@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 82057D77C53; Sun, 21 May 2017 21:27:29 +0000 (UTC) (envelope-from jilles@stack.nl) Received: from mailout.stack.nl (mailout05.stack.nl [IPv6:2001:610:1108:5010::202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mailout.stack.nl", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F1E2171E; Sun, 21 May 2017 21:27:29 +0000 (UTC) (envelope-from jilles@stack.nl) Received: from snail.stack.nl (snail.stack.nl [IPv6:2001:610:1108:5010::131]) by mailout.stack.nl (Postfix) with ESMTP id 095A279; Sun, 21 May 2017 23:27:27 +0200 (CEST) Received: by snail.stack.nl (Postfix, from userid 1677) id E68E928497; Sun, 21 May 2017 23:27:26 +0200 (CEST) Date: Sun, 21 May 2017 23:27:26 +0200 From: Jilles Tjoelker <jilles@stack.nl> To: Konstantin Belousov <kostikbel@gmail.com> Cc: freebsd-current@freebsd.org, freebsd-fs@freebsd.org, freebsd-ports@freebsd.org, emaste@freebsd.org, Kirk McKusick <mckusick@mckusick.com> Subject: Re: 64-bit inodes (ino64) Status Update and Call for Testing Message-ID: <20170521212726.GA23821@stack.nl> References: <20170420194314.GI1788@kib.kiev.ua> <20170521121456.GA21613@stack.nl> <20170521123118.GH1622@kib.kiev.ua> <20170521140355.GC21613@stack.nl> <20170521142535.GI1622@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170521142535.GI1622@kib.kiev.ua> User-Agent: Mutt/1.5.21 (2010-09-15) X-BeenThere: freebsd-ports@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Porting software to FreeBSD <freebsd-ports.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-ports>, <mailto:freebsd-ports-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-ports/> List-Post: <mailto:freebsd-ports@freebsd.org> List-Help: <mailto:freebsd-ports-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-ports>, <mailto:freebsd-ports-request@freebsd.org?subject=subscribe> X-List-Received-Date: Sun, 21 May 2017 21:27:29 -0000 On Sun, May 21, 2017 at 05:25:35PM +0300, Konstantin Belousov wrote: > On Sun, May 21, 2017 at 04:03:55PM +0200, Jilles Tjoelker wrote: > > On Sun, May 21, 2017 at 03:31:18PM +0300, Konstantin Belousov wrote: > > > On Sun, May 21, 2017 at 02:14:56PM +0200, Jilles Tjoelker wrote: > > > > We have another type in this area which is too small in some situations: > > > > uint8_t for struct dirent.d_namlen. For filesystems that store filenames > > > > as upto 255 UTF-16 code units, the name to be stored in d_name may be > > > > upto 765 bytes long in UTF-8. This was reported in PR 204643. The code > > > > currently handles this by returning the short (8.3) name, but this name > > > > may not be present or usable, leaving the file inaccessible. > > > > Actually allowing longer names seems too complicated to add to the ino64 > > > > change, but changing d_namlen to uint16_t (using d_pad0 space) and > > > > skipping entries with d_namlen > 255 in libc may be helpful. > > > > Note that applications using the deprecated readdir_r() will not be able > > > > to read such long names, since the API does not allow specifying that a > > > > larger buffer has been provided. (This could be avoided by making struct > > > > dirent.d_name 766 bytes long instead of 256.) > > > > Unfortunately, the existence of readdir_r() also prevents changing > > > > struct dirent.d_name to the more correct flexible array. > > > Yes, changing the size of d_name at this stage of the project is out of > > > question. My reading of your proposal is that we should extend the size > > > of d_namlen to uint16_t, am I right ? Should we go to 32bit directly > > > then, perhaps ? > > Yes, my proposal is to change d_namlen to uint16_t. > > Making it 32 bits is not useful with the 16-bit d_reclen, and increasing > > d_reclen does not seem useful to me with the current model of > > getdirentries() where the whole dirent must fit into the caller's > > buffer. > Bumping it now might cause less churn later, even if unused, but ok. > > > I did not committed the change below, nor did I tested or even build it. > > I'd like to skip overlong names in the native readdir_r() as well, so > > that long name support can be added to the kernel later without causing > > buffer overflows with applications using FreeBSD 12.0 libc. > > The native readdir() does not seem to have such a problem. > Again, not even compiled. Looks good to me. > [patch snipped] -- Jilles Tjoelker