From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Tso Subject: Re: [PATCH 1/4] vfs: vfs-level fiemap interface Date: Tue, 7 Oct 2008 14:52:19 -0400 Message-ID: <20081007185219.GD15929@mit.edu> References: <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> <48EB87DE.4090607@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <48EB87DE.4090607-VXdhtT5mjnY@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: jim owens Cc: Christoph Hellwig , Jamie Lokier , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Fasheh , Michael Kerrisk , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org Right, thanks. This time in proper English. :-) * FIEMAP_EXTENT_ENCODED This extent does not consist 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 results. Note that it is *always* undefined to try to update the data in-place by writing to the indicated location without the assistance of the filesystem, or to access the data using the information 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. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html