From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Philipp Stephani Newsgroups: gmane.emacs.bugs Subject: bug#54126: 29.0.50; C-x x g doesn't always correctly revert SSHFS files Date: Fri, 18 Mar 2022 17:21:54 +0100 Message-ID: References: <87v8x5mx7q.fsf@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26729"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 54126@debbugs.gnu.org To: Michael Albinus Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri Mar 18 17:23:17 2022 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nVFNl-0006o2-At for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 18 Mar 2022 17:23:17 +0100 Original-Received: from localhost ([::1]:58852 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nVFNj-0007ab-PW for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 18 Mar 2022 12:23:15 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:60828) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nVFNW-0007aT-C7 for bug-gnu-emacs@gnu.org; Fri, 18 Mar 2022 12:23:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:36072) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nVFNW-0007bV-3R for bug-gnu-emacs@gnu.org; Fri, 18 Mar 2022 12:23:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1nVFNV-0001bY-Oj for bug-gnu-emacs@gnu.org; Fri, 18 Mar 2022 12:23:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Philipp Stephani Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 18 Mar 2022 16:23:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 54126 X-GNU-PR-Package: emacs Original-Received: via spool by 54126-submit@debbugs.gnu.org id=B54126.16476205336098 (code B ref 54126); Fri, 18 Mar 2022 16:23:01 +0000 Original-Received: (at 54126) by debbugs.gnu.org; 18 Mar 2022 16:22:13 +0000 Original-Received: from localhost ([127.0.0.1]:58202 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nVFMj-0001aG-1p for submit@debbugs.gnu.org; Fri, 18 Mar 2022 12:22:13 -0400 Original-Received: from mail-oi1-f177.google.com ([209.85.167.177]:40540) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nVFMh-0001a0-Ih for 54126@debbugs.gnu.org; Fri, 18 Mar 2022 12:22:12 -0400 Original-Received: by mail-oi1-f177.google.com with SMTP id o64so9262272oib.7 for <54126@debbugs.gnu.org>; Fri, 18 Mar 2022 09:22:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=CYrxG1Lg3DsIgv4spQ3TnoP1og0MzljPHmyd0duNmwc=; b=V7YsVya2Oanymi/aawEtwzq6h2uxh9GlGemwiUFbOjSW5NxcpAS3uz77k+YttPpHix qWDeG6q9Z9nkVep//2R/n7Z3RU0QXhqpkcaqOliRloA7g/wPmavMWUkDr+e5fiWDczwW Zamsq4k1wZe7Aunv2yrcfjz8cGVbVSOVYWIfg9DeyNgfUKbuuQIptOqVKGyft5YbFS0l KnvyMJ7FPu/Qr2caT9uBhXZ1eY0SgCCB+kPhsInAiD+Bmy/dqOGPoJfSYVF1hld35rAL PrHFJOtvwM7RHzcGFOxcjLf6Vz5OL8iPc8Wk4XA5PDcSJJY2j+wXycq8KFqQvtJOZ8R2 R8iw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=CYrxG1Lg3DsIgv4spQ3TnoP1og0MzljPHmyd0duNmwc=; b=zy1Wxcjcr1Q6l2RjAboqvNSyEoNeg/Jh9jXwOwon8KJF3SkK7sXpZ54Jfif3hK6p1l mIHZiboOZ88SiomDf0GP3ZSMqBf4ebxsqEvU+jXtU1ib8h5Qr2EklSrvDGbNSfuPWry1 0lH882qkJJptsLrVsGtX5bB68J49P6JL5O/UvfC7rLCQLujrypz6HIOHfwmMWbP5uDwj xSrHHmyP9bb7atz5PW+UpT1OkprLqkwxlV7g3Qw5HoeRP8gXxhu0uFdsoLulS63DQbC+ 5ERjkWq9QrxdCPIoBnydIGGxTlzmQL2OVDhXL4SsoVpI6QH8ro5NCjJzuYT1ULjsOkEq /4Fw== X-Gm-Message-State: AOAM533bM8zmXyu0o8Xy7V/oqND9SI1YYAoDxMg+n03k3cbUM0SaA1x9 x4g9bQqNOh0SrCM3qsAg3CtipoahgCX30aMOiC0= X-Google-Smtp-Source: ABdhPJx8rHiYu2yTUOhMzYRIfHc0b8kgyzKxZ/Jyuu4NFy0dH0jDrccq0sNQgajxWOFUsxo5bYzN2+KJfP8nmQTZ8+4= X-Received: by 2002:a05:6808:1d8:b0:2da:51e0:d0ef with SMTP id x24-20020a05680801d800b002da51e0d0efmr4597269oic.57.1647620525447; Fri, 18 Mar 2022 09:22:05 -0700 (PDT) In-Reply-To: <87v8x5mx7q.fsf@gmx.de> X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:228555 Archived-At: Am Mi., 23. Feb. 2022 um 16:14 Uhr schrieb Michael Albinus : > > Philipp Stephani writes: > > Hi Philipp, > > > At least on my system the following happens often, but not always: > > > > Create some file whose contents don't really matter. In my case: > > > > $ cat /tmp/a.c > > int main(void) { > > return 0; > > } > > > > Visit the file over SSHFS: > > > > $ emacs -Q /sshfs:localhost:/tmp/a.c > > > > Now, outside of Emacs, append something to the file: > > > > $ echo aaaaa >> /tmp/a.c > > > > Immediately after that, back in Emacs, hit C-x x g. The new content > > isn't there. Only after reverting the buffer a second time it appears. > > First I thought this was a timing/cache coherency issue, but even > > waiting for 10 seconds doesn't fix it in most cases. Somewhat > > surprisingly, switching to a different buffer in between appears to make > > the problem go away (in some cases at least). > > Looks like you are plagued by caching. revert-buffer reverts a file > only, if it is modified on disk. Tramps caches file attributes by > default for 10 seconds (see remote-file-name-inhibit-cache). Set this > value to t in order to test, whether it makes a difference. However, you > have said you did wait for 10 seconds, so maybe this isn't the reason. I didn't use a stopwatch :-) So if the cache timeout is really exactly 10 seconds, then it's rather likely I was affected by it. This doesn't seem to happen with SSH, only with SSHFS, though. Does the caching behavior differ? I.e., is the SSH backend stricter about cache coherency? It's also worth noting that Unix tools generally expect filesystems to be sequentially consistent (i.e. any modification is immediately visible by any other consumer, and there's a strict ordering between operations). Caching is still possible, but it shouldn't break these consistency guarantees. > > Another cache might come from sshfs itself. Tramp calls sshfs like > "sshfs localhost:/ /tmp/tramp.sshfs.localhost -C -o idmap=user,reconnect". > See tramp-mount-args settings in tramp-sshfs.el, line 33-34. You might > try to add other options, like "-o no_readahead" or "-o sync_readdir", > see sshfs(1). Don't forget to unmount the sshfs mount point, before you > start a new Emacs session with changed options. I'll play around with that, thanks for the hint. If this turns out to be the problem, then caching should probably be disabled by default, because sequential consistency is more important than potential speed-ups.