From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#13540: 24.3.50; Regression in trunk: auto-revert-mode fails on files accessed via samba Date: Thu, 24 Jan 2013 18:32:18 +0200 Message-ID: <834ni6mtil.fsf@gnu.org> References: <8738xq3n33.fsf@gmx.de> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1359045184 10794 80.91.229.3 (24 Jan 2013 16:33:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 24 Jan 2013 16:33:04 +0000 (UTC) Cc: 13540@debbugs.gnu.org To: Michael Albinus Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Jan 24 17:33:23 2013 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1TyPju-0001xE-SF for geb-bug-gnu-emacs@m.gmane.org; Thu, 24 Jan 2013 17:33:22 +0100 Original-Received: from localhost ([::1]:44736 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TyPjd-000502-Ah for geb-bug-gnu-emacs@m.gmane.org; Thu, 24 Jan 2013 11:33:05 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:33580) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TyPjZ-0004yo-AZ for bug-gnu-emacs@gnu.org; Thu, 24 Jan 2013 11:33:03 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TyPjX-0005uf-0U for bug-gnu-emacs@gnu.org; Thu, 24 Jan 2013 11:33:01 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:42592) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TyPjW-0005uZ-UP for bug-gnu-emacs@gnu.org; Thu, 24 Jan 2013 11:32:58 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.72) (envelope-from ) id 1TyPjZ-0007nf-PN for bug-gnu-emacs@gnu.org; Thu, 24 Jan 2013 11:33:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 24 Jan 2013 16:33:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 13540 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 13540-submit@debbugs.gnu.org id=B13540.135904514229933 (code B ref 13540); Thu, 24 Jan 2013 16:33:01 +0000 Original-Received: (at 13540) by debbugs.gnu.org; 24 Jan 2013 16:32:22 +0000 Original-Received: from localhost ([127.0.0.1]:48056 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TyPiw-0007mj-1H for submit@debbugs.gnu.org; Thu, 24 Jan 2013 11:32:22 -0500 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:38589) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1TyPis-0007mb-RA for 13540@debbugs.gnu.org; Thu, 24 Jan 2013 11:32:20 -0500 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MH5001001UVHU00@a-mtaout20.012.net.il> for 13540@debbugs.gnu.org; Thu, 24 Jan 2013 18:32:14 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MH50013B1XP9A50@a-mtaout20.012.net.il>; Thu, 24 Jan 2013 18:32:14 +0200 (IST) In-reply-to: <8738xq3n33.fsf@gmx.de> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.13 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 140.186.70.43 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.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:70240 Archived-At: > From: Michael Albinus > Date: Thu, 24 Jan 2013 11:13:52 +0100 > Cc: 13540@debbugs.gnu.org > > Likely, it is not possible to enable file notifications for mounted file > systems under Windows. In that case, `w32notify-add-watch' shall return > nil, and the code in auto-revert.el shall fall back to the previous > implementation. Actually, both w32notify-add-watch and inotify-add-watch signal an error in that case. It's auto-revert that catches the error with ignore-errors and converts that to nil. I guess we need to update the doc strings. Anyway, w32notify does support mounted filesystems, as long as the server that does the mounting supports the ReadDirectoryChangesW API which w32notify uses. Googling suggests that Samba has problems in this area, see, for example this page: http://qualapps.blogspot.co.il/2010/05/understanding-readdirectorychangesw_19.html (which btw was a great source of information for me while I worked on w32notify.c). It says: Network Drives ReadDirectoryChangesW works with network drives, but only if the remote server supports the functionality. Drives shared from other Windows-based computers will correctly generate notifications. Samba servers may or may not generate notifications, depending on whether the underlying operating system supports the functionality. Network Attached Storage (NAS) devices usually run Linux, so won't support notifications. High-end SANs are anybody's guess. It could be that the API we use does not fail, but the notifications simply don't come in from that volume. I asked Dani to report if there's any sign of trouble when the watch is installed. Depending on the findings, we may or may not be able to detect the problem automatically and fall back to the old method. Failing that, I guess we will have to introduce more elaborate customizations that would allow users to specify filesystems that should or should not use file notifications. (Doesn't inotify have similar issues with NFS-mounted volumes?)