From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 15 Jun 2017 01:17:33 -0700 From: Christoph Hellwig To: Jens Axboe Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, adilger@dilger.ca, hch@infradead.org, martin.petersen@oracle.com Subject: Re: [PATCH 03/11] fs: add support for an inode to carry stream related data Message-ID: <20170615081733.GC10599@infradead.org> References: <1497498312-17704-1-git-send-email-axboe@kernel.dk> <1497498312-17704-4-git-send-email-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1497498312-17704-4-git-send-email-axboe@kernel.dk> List-ID: On Wed, Jun 14, 2017 at 09:45:04PM -0600, Jens Axboe wrote: > No functional changes in this patch, just in preparation for > allowing applications to pass in hints about data life times > for writes. > > Pack the i_write_hint field into a 2-byte hole, so we don't grow > the size of the inode. A u8 should be plenty. But talking about the representation - your write lifetime hints are a 5 option enum basically. I wonder if we really should encode it as flags, or if we should have an enum (which could be packed into a 3-bit bitfield) and then pass it down the stack in that form instead of changing the representation N times.