From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4DB9F1BE.7090208@redhat.com> Date: Thu, 28 Apr 2011 18:01:18 -0500 From: Eric Sandeen MIME-Version: 1.0 References: <20110412234706.GA11244@redhat.com> <20cf301cbef67d323104a0c2ff52@google.com> <20110413224025.GA18589@redhat.com> <20110413234854.GA19793@redhat.com> <20110426173213.GA19604@redhat.com> <20110428001912.GA14659@redhat.com> <20110428075355.GA2190@infradead.org> <20110428205935.GA24979@redhat.com> <4DB9DBF1.9060901@redhat.com> <20110428225945.GG32370@agk-dp.fab.redhat.com> In-Reply-To: <20110428225945.GG32370@agk-dp.fab.redhat.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] do not disable ext4 discards on first discard failure? [was: Re: dm snapshot: ignore discards issued to the snapshot-origin target] Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development , Mike Snitzer , Christoph Hellwig , dm-devel@redhat.com, linux-ext4@vger.kernel.org, DarkNovaNick@gmail.com On 4/28/11 5:59 PM, Alasdair G Kergon wrote: > On Thu, Apr 28, 2011 at 04:28:17PM -0500, Eric Sandeen wrote: >> I still think that concats of floppies, usb disks, and ssds should be rare, so I'm less concerned about that ;) > > It's the 'undefined' cases that cause us the trouble though: we do have > to return something and I prefer to work with defined and documented > behaviour, rather than pretending something is 'undefined' or > 'unimportant' and later finding people relied on its actual behaviour. If you are saying that a target should return EOPNOTSUPP when it does not support the operation, then we are in violent agreement. :) -Eric > Alasdair