Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757696Ab1COM5w (ORCPT ); Tue, 15 Mar 2011 08:57:52 -0400 Received: from cobra.newdream.net ([66.33.216.30]:36162 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757480Ab1COM5v (ORCPT ); Tue, 15 Mar 2011 08:57:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=newdream.net; h=date:from:to:cc :subject:in-reply-to:message-id:references:mime-version: content-type; q=dns; s=newdream.net; b=1ZTUiOihQYIwvopch9/uQ6Jb9 SXzAduwSQ4H5GVJe3fHZzn6HSgfyNwOEbb0tDT1qMc+nQ5AdoQOyMtda/sR2vcuE jubQEwYmehQ1ed3byRm/A7xUGqwLVcc3otkoqsGqWzPkXVdpWddjEac2J0d95ngC KTnriYjIsQohyT2wqU= Date: Tue, 15 Mar 2011 06:00:13 -0700 (PDT) From: Sage Weil To: Dave Chinner cc: Indan Zupancic , Greg KH , Jonathan Nieder , Arnd Bergmann , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K. V" , akpm@linux-foundation.org, linux-api@vger.kernel.org, mtk.manpages@gmail.com, viro@zeniv.linux.org.uk, hch@lst.de, l@jasper.es Subject: Re: [PATCH v3] introduce sys_syncfs to sync a single file system In-Reply-To: <20110315101155.GO15097@dastard> Message-ID: References: <201103111255.44979.arnd@arndb.de> <20110311235607.GB15853@elie> <9446ab1a2315c0d2476c30f8315a0503.squirrel@webmail.greenhost.nl> <20110312021001.GA16833@elie> <20110312173217.GA24981@kroah.com> <1e597aedd3d7825dcc0630b1cf2399fa.squirrel@webmail.greenhost.nl> <20110315101155.GO15097@dastard> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2364 Lines: 59 On Tue, 15 Mar 2011, Dave Chinner wrote: > On Sun, Mar 13, 2011 at 09:29:17PM -0700, Sage Weil wrote: > > On Mon, 14 Mar 2011, Indan Zupancic wrote: > > > Everyone seems to want to add this new syncfs, but it's not even defined > > > what it does. "Same as sync, but only on one fs" is IMHO not good > > > enough, because sync's behaviour is pretty badly documented, and that's > > > a system call. > > > > How about the man page below? I tried to avoid the somewhat antiquated > > implementation specific terminology in the sync(2) man page. > > > > I think adding this functionality into sync_file_range(2) is forcing > > unrelated functionality into an existing interface; sync_file_range > > operates on _files_, not an entire file system. With each API addition it > > is more important to make the interface simple and intuitive than to > > minimize the size of our patches. IMO that's why a new syscall is > > preferable to, say, an equivalent ioctl. > > > > Thanks- > > sage > > > > > > .TH SYNCFS 2 2011-03-13 "Linux" "Linux Programmer's Manual" > > .SH NAME > > syncfs \- commit cached file system state to stable storage > > .SH SYNOPSIS > > .B #include > > .sp > > .B void syncfs(int fd); > > .SH DESCRIPTION > > .BR syncfs () > > flushes any cached data modifications to the file system containing the > > file referenced by the file descriptor > > .I fd > > to stable storage (usually a disk). This includes the results of any > > file modifications or other file system operations that have completed > > prior to the call to > > .BR syncfs(2). > > This is similar to > > .BR sync(2), > > but will commit changes for only a single file system instead of all > > mounted file systems. > > .SH ERRORS > > This function is always successful. > > Perhaps we should consider propagating errors out to the user > application rather than discarding them in kernel and pretending we > can't ever have a write error? Yeah. It also occurred to me shortly after sending this that, at the very least, we should return an error so that users can get ENOSYS on older kernels. sage -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/