From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1jnn4T-0006Ra-LB for mharc-grub-devel@gnu.org; Tue, 23 Jun 2020 13:50:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48310) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jnn4S-0006Pq-0G for grub-devel@gnu.org; Tue, 23 Jun 2020 13:50:56 -0400 Received: from smtp.gentoo.org ([2001:470:ea4a:1:5054:ff:fec7:86e4]:48491) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jnn4P-0004WJ-NR for grub-devel@gnu.org; Tue, 23 Jun 2020 13:50:55 -0400 Received: by mail-io1-f54.google.com with SMTP id f23so19426644iof.6 for ; Tue, 23 Jun 2020 10:50:47 -0700 (PDT) X-Gm-Message-State: AOAM533ot5NcyJ3iBEFmACpE7rDoNkSVgsJA+0ONS21DWqstU0KGBT4i OE+dqXhRUVHUt1/hmFyB2Hk8ob8YUBN/kWFD8WQ= X-Google-Smtp-Source: ABdhPJzJu4jMf/fATjUH7i4GH37MztqPr6x10eFdqkjyXSiR0f7nd4KVb6/15ipnMmrcw5dsTNmKfI9u0DOsTm6vqgU= X-Received: by 2002:a02:30c4:: with SMTP id q187mr24748400jaq.102.1592934645983; Tue, 23 Jun 2020 10:50:45 -0700 (PDT) MIME-Version: 1.0 References: <20191105091949.29559-1-mchang@suse.com> <20191107045504.GA4084@mazu> <6f2be4c8-e90a-d16a-1604-dacb1571cf8a@archlinux.org> <20200623063204.GA16299@mercury> In-Reply-To: <20200623063204.GA16299@mercury> From: Mike Gilbert Date: Tue, 23 Jun 2020 13:50:34 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] btrfs: disable zstd support for i386-pc To: The development of GNU GRUB Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2001:470:ea4a:1:5054:ff:fec7:86e4; envelope-from=floppym@gentoo.org; helo=smtp.gentoo.org X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/23 13:50:48 X-ACL-Warn: Detected OS = ??? X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Jun 2020 17:50:56 -0000 On Tue, Jun 23, 2020 at 2:32 AM Michael Chang wrote: > > On Mon, Jun 22, 2020 at 10:16:49PM -0400, Mike Gilbert wrote: > > On Sun, Jun 21, 2020 at 2:56 PM Eli Schwartz wrote: > > > But anyway this isn't true. There are valid reasons to reinstall grub on > > > old systems, in which case you are most likely not benefiting from zstd > > > support one way or another, but in this case, rerunning grub-install > > > destroys the working bootloader code and fails to replace. > > > > This sounds like a bug/defect in grub-install. Ideally, it would look > > at the size of the embedding area, and abort early if it is too small. > > This should happen before files are copied to /boot/grub, but > > currently it is done afterward. > > Even though the system can stay bootable, it cannot receive any grub > updates afterward, thus breaking the principle of backward compatibilty > that new build couldn't run at all on an existing system running old > grub. There was some discussion earlier in the thread that proposed the documentation be updated to indicate that using a small embedding area is not well-supported. I don't think 100% backward compatibility is a reasonable target, especially for configurations that have never been well-supported in the first place.