From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB47A14D28C for ; Fri, 14 Feb 2025 18:29:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739557794; cv=none; b=boFA+qQi7zMS1oiqK42+FcscbCWHi+VCGLTYcG3ZAIwr3cymlv80AYOGRFiQ46tlfEBxV/1uyxcHuhOGgSiNsbGI3/YE6dJcqfwSaCGM3XFReB4bB0VNWx2VZV+/qXs33z/qxlRIg9icQmVm2VO6fe+Z1iVyquZs0lnhFzegnY0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739557794; c=relaxed/simple; bh=jb4xt+UKRzFVrBQHoQKfH7KxkMnlbIuQ6w4fJiQtcHk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qXGc2JF28HiM5KXk57LRvNKcLHeo6LxgAH1CApJgxsZVlqCHESMr+oIPXlYFzqNG+hcsMrDhLo9fsuZOw3uYaxVS/PPpCsZPGykx2apdMqBaA8bb1DNpk722C9MswyTha2laVAmeRYYkkxndX8tH8vmnEMZmKEJnsyXSaXypLeI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KqIntJqw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KqIntJqw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24352C4CED1; Fri, 14 Feb 2025 18:29:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739557794; bh=jb4xt+UKRzFVrBQHoQKfH7KxkMnlbIuQ6w4fJiQtcHk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KqIntJqwipFBzUSvfa/vq/SAV9sYIO1/5JZitYSZID9U6y4DMNQUDRqcshbZEF4l1 kxKnsOYY6WX8QhKmutl08928WTVJk92+0XUZXGQS28q3vR/9n4usUwsWiLWWb7Q5Es Ox73PSkujvxbyHGhVS7mmnXiq3eRZUu5fTciY9mnGmBcubAkvdM+8Mh15u72vPicsQ pSqzlsDGO6c/RSYZ6Sk2ld2wjgT40YUaqieOTw6Jj4WjTh+mldYS9N0g2JbAgRc8hs kKZpIBGwhgbiVmQ2Mtn7/fVzE8qAuCasYWP3iOxKhDWhHseQZL41vpVWpjVcQkbhNA wB80rQdJJecHQ== Date: Fri, 14 Feb 2025 10:29:53 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Carlos Maiolino , Hans Holmberg , linux-xfs@vger.kernel.org Subject: Re: [PATCH 25/43] xfs: implement buffered writes to zoned RT devices Message-ID: <20250214182953.GA21808@frogsfrogsfrogs> References: <20250206064511.2323878-1-hch@lst.de> <20250206064511.2323878-26-hch@lst.de> <20250212005405.GH21808@frogsfrogsfrogs> <20250213053943.GA18867@lst.de> <20250213230558.GX21808@frogsfrogsfrogs> <20250214062252.GB25903@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250214062252.GB25903@lst.de> On Fri, Feb 14, 2025 at 07:22:52AM +0100, Christoph Hellwig wrote: > On Thu, Feb 13, 2025 at 03:05:58PM -0800, Darrick J. Wong wrote: > > > we'll need a space allocation for every write in an out of tree write > > > file system. But -ENOSPC (or SIGBUS for the lovers of shared mmap > > > based I/O :)) on writes is very much expected. On truncate a lot less > > > so. In fact not dipping into the reserved pool here for example breaks > > > rocksdb workloads. > > > > It occurs to me that regular truncate-down on a shared block can also > > return ENOSPC if the filesystem is completely out of space. Though I > > guess in that case, at least df will say that nearly zero space is > > available, whereas for zoned storage we might have plenty of free space > > that simply isn't available right now... right? > > That's part of it, yes as we can't kick GC. That reason will go away > if/when the VFS locking for truncates is fixed. But I also doubt people > run nasty workloads on reflinked files all that much. The nasty reflink workloads are mostly disk images, and those aren't getting small truncations. --D