From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 99025 invoked by alias); 1 Sep 2019 17:38:25 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 98694 invoked by uid 89); 1 Sep 2019 17:38:25 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-4.3 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,KAM_STOCKGEN,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 spammy=stopped, rough, reattach, consistent X-HELO: lb2-smtp-cloud9.xs4all.net Received: from lb2-smtp-cloud9.xs4all.net (HELO lb2-smtp-cloud9.xs4all.net) (194.109.24.26) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 01 Sep 2019 17:38:15 +0000 Received: from tmp.KuqrR95NSC ([83.162.234.136]) by smtp-cloud9.xs4all.net with ESMTPSA id 4TnliZHWkzaKO4TnmiVPPG; Sun, 01 Sep 2019 19:38:11 +0200 Date: Sun, 01 Sep 2019 17:38:00 -0000 Message-ID: From: Houder Reply-To: cygwin@cygwin.com To: cygwin@cygwin.com Cc: eblake@redhat.com Subject: Re: Odd, is it not? mkdir 'e:\' cannot be undone by rmdir 'e:\' ... References: <20190827152549.GY11632@calimero.vinschen.de> <3E262D05-F393-453A-9E43-B248DDE50812@solidrocksystems.com> <20190828125939.GL11632@calimero.vinschen.de> <421ac447-b249-da21-1ca5-228041cfc884@redhat.com> <20190828141556.GM11632@calimero.vinschen.de> <20190828142220.GN11632@calimero.vinschen.de> <4a87b7a940fb0cf76aac5f3bc5b1a8b3@smtp-cloud7.xs4all.net> In-Reply-to: <4a87b7a940fb0cf76aac5f3bc5b1a8b3@smtp-cloud7.xs4all.net> Content-Type: text/plain; charset=UTF-8; format=fixed User-Agent: mua.awk 0.99 X-SW-Source: 2019-09/txt/msg00001.txt.bz2 On Fri, 30 Aug 2019 11:54:27, Houder wrote: > A trailing forward slash in "pathname" is stripped in path_conv::check, > > (look for: *--tail = '\0' ) > > after "pathname" has been normalized in > > normalized_posix_path or normalized_win32_path (or both), > > before it is fed into conv_to_win32_path. > > Tests have shown that Eric's code snippet can be deleted w/o harm. > > Counter arguments? Hi Corinna, My last post in this issue. As reported, Eric's code snippet in rmdir() (dir.cc) has become redundant, lines 317 - 325 can be removed. https://cygwin.com/ml/cygwin/2019-08/msg00418.html My "rough" understanding of the code flow is as follows: mkdir in dir.cc fh = build_fh_name -- returns pointer to fhandler_base build_fh_pc fh->mkdir(mode) -- handled by mkdir() in fhandler_disk_file.cc NtCreateFile(... FILE_ATTRIBUTE_DIRECTORY ...) fhandler_base has a member of type path_conv, called pc, which is a copy of the path_conv object, created by build_fh_name(). Having removed Eric's code snippet in dir.cc - and for the sake of completeness, I decided to inspect the values of pc.posix_path and pc.path (i.e. "pathname" in native format) when I stopped the debugger in mkdir() (fhandler_disk_file.cc). If I specified e.g. '/foo/\/' as the directory to create, I saw the following: pc.path = "E:\\Cygwin64\\foo" pc.posix_path = "/" <==== HUH? As the directory "/foo" had been correctly created, I turned to path_conv::check(), which is called when build_fhname() creates the path_conv object (also called pc) -- see dtable.cc. Examining this (obsure) method in path.cc, I corrected the code in 2 places: --- if (dev.isfs ()) { //if (strncmp (path, "\\\\.\\", 4)) <==== 1171 if ( ! strncmp (path, "\\\\.\\", 4)) // <==== [1] { if (!tail || tail == path) /* nothing */; else if (tail[-1] != '\\') *tail = '\0'; <==== Ah! (you should not do that!) else { error = ENOENT; return; } } [1] this code should be executed only if path == '\\.\' !! The above snippet 'mutilated' "/foo" into "/\0oo" --- //else if (!need_directory || error) <==== 1155 else if (!need_directory || error || (opt & PC_SYM_NOFOLLOW) ) /* nothing to do */; else if (fileattr == INVALID_FILE_ATTRIBUTES) /* Reattach trailing dirsep in native path. */ strcat (modifiable_path (), "\\"); // <==== [2] [2] WHY? Why must the native name of a directory be terminated by a backslash? (NtCreateFile() specifies that a directory must be created -- see mkdir() in fhandler_disk_file.c). Yes, the above correction is an awfull hack (it abuses the Posix directive that _no_ directory shall be created through a symbolic link). Without this hack, a directory specified as '/foo/' will result in pc.path = "E:\\Cygwin64\foo\" <==== note additional \ pc.posix_path = "/foo" Without the corrections in path_conv::check() (and without Eric's code snippet in dir.cc), a directory will be correctly created. However, pc.path and pc.posix_path will not always be "equal", i.e. consistent w/ each other. Regards, Henri -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple