From mboxrd@z Thu Jan 1 00:00:00 1970 From: jim owens Subject: Re: [PATCH 1/4] vfs: vfs-level fiemap interface Date: Tue, 07 Oct 2008 12:01:34 -0400 Message-ID: <48EB87DE.4090607@hp.com> References: <1223071147-27180-1-git-send-email-tytso@mit.edu> <1223071147-27180-2-git-send-email-tytso@mit.edu> <20081004021251.GA29174@mit.edu> <48EA55AC.2060102@hp.com> <20081006210706.GB8139@mit.edu> <20081007101207.GA10406@infradead.org> <20081007130008.GA3503@shareable.org> <20081007130218.GA4316@infradead.org> <20081007132436.GC3503@shareable.org> <20081007132854.GA15953@infradead.org> <20081007154523.GA15929@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Christoph Hellwig , Jamie Lokier , linux-fsdevel@vger.kernel.org, Mark Fasheh , Michael Kerrisk , linux-abi@vger.kernel.org To: Theodore Tso Return-path: Received: from g1t0027.austin.hp.com ([15.216.28.34]:47210 "EHLO g1t0027.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752893AbYJGQBm (ORCPT ); Tue, 7 Oct 2008 12:01:42 -0400 In-Reply-To: <20081007154523.GA15929@mit.edu> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Ted, I think this is a really great definition. jim A couple of spelling/grammar fixes below. Theodore Tso wrote: > * FIEMAP_EXTENT_ENCODED > > This extent does not consistant of plain filesystem blocks but is ^^^^^^^^^^ > encoded (e.g. encrypted or compressed). Reading the data in this > extent via I/O to the block device will have undefined resuts. > > Note that it is *always* undefined to try to update the data > in-place by writing to indicated location without the assistance of ^^^^^^^^^^^^ to the > the filesystem, or accessing the data using the information ^^^^^^^^^^^^ or by > returned by the FIEMAP interface while the filesystem is mounted. > In other words, user applications may only read the extent data via > I/O to the block device while the filesystem is unmounted, and then > only if the FIEMAP_EXTENT_ENCODED flag is clear; user applications > must not try reading or writing to the filesystem via the block > device under any other circumstances.