X-Recipient: archive-cygwin AT delorie DOT com DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:reply-to:message-id:to:subject :in-reply-to:references:mime-version:content-type :content-transfer-encoding; q=dns; s=default; b=jJyQ9VNuAk4KWltE aXDxxmsVjlzKTAudm+avVCvCrD99g1q8uDQFeuPXdKi5mn0FoQgSkPAuuye1vjxp OFDoBLxefoDuhrXzkf4KyFfeGpzXdMfcS8MG19f66OgK9Al9XxmN4htXLAIeMYce ffQHzDelaSyNcBTbmAtscGGZb70= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:reply-to:message-id:to:subject :in-reply-to:references:mime-version:content-type :content-transfer-encoding; s=default; bh=ikyqm9QArO5SCcFqokyMv3 04wZE=; b=Yr3yY4pIdWdXgQ28HsrjqAvkdW/XFc5nIrXdpu//1FoCcw055gAWW9 X+7MKRjsuY7g5UKK79ZI97DIdpeMM80cidTQmG/gTX+/Un5Pebfc65bgXdU9joYD 9yiIFIZ9s/5LFsVZhZF8zj6cYrHB1qL07w6Af/yrulYNftIDbc2H0= Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.3 required=5.0 tests=AWL,BAYES_50,FREEMAIL_FROM,KAM_THEBAT,MIME_BASE64_BLANKS,SPF_SOFTFAIL autolearn=no version=3.3.2 X-HELO: smtpback.ht-systems.ru Date: Mon, 21 Apr 2014 22:34:17 +0400 From: Andrey Repin Reply-To: cygwin AT cygwin DOT com Message-ID: <227151856.20140421223417@yandex.ru> To: lennox AT cs DOT columbia DOT edu, cygwin AT cygwin DOT com Subject: Re: fstat st_size on open files on Parallels filesystem is wrong In-Reply-To: <21333.25325.11106.958642@compute01.cs.columbia.edu> References: <21333 DOT 25325 DOT 11106 DOT 958642 AT compute01 DOT cs DOT columbia DOT edu> MIME-Version: 1.0 Content-Type: text/plain; charset=Windows-1251 X-IsSubscribed: yes Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by delorie.com id s3LIZOjM030686 Greetings, lennox AT cs DOT columbia DOT edu! > I’m running cygwin64 1.7.29 in a Windows 8.1 Pro virtual machine, running in > Parallels Desktop 9.0.24229 on Mac OS X 10.9.2. > Parallels Desktop automatically mounts my Mac OS X home directory as a Z: > drive in Windows. Cygwin mount reports this drive as being type "prlsf". > Unfortunately, I've discovered that if I have an open file on this > filesystem which has been written to, the size returned by Cygwin fstat() on > the open file is wrong. A stat() of the file after it's been closed is > correct. > This has the consequence that emacs always thinks saved files have been > modified externally, since emacs looks at files' sizes (as well as their > modification times) to detect external changes. This makes emacs > near-unusable. > This problem does not occur for files in my Cygwin home directory, or other > locations mounted on my Windows C: drive. > I've attached a simple unit test program that illustrates the problem. > I've also attached my cygcheck -s -v -r output. > Any ideas? Is this a Cygwin bug, a Parallels bug, or something else? > Glancing over the Cygwin code, I see that there are a few cases where fstat > has special cases for certain filesystem types. You never flushing the buffer in your test code, or I'm reading it wrong? -- WBR, Andrey Repin (anrdaemon AT yandex DOT ru) 21.04.2014, <22:33> Sorry for my terrible english...