From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from submarine.notk.org (submarine.notk.org [62.210.214.84]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 437FC214818; Fri, 27 Jun 2025 06:44:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.210.214.84 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751006685; cv=none; b=QfYwpuXrg3kS+LVx5mdMqKBwELsqjublsLdPfC9B82BL6irLKKYBOCBSWSALwMOJPbhTiuxFAZ5VnuQc9StJxChDXAcwYST6Re/GHYkyxPgQroO70+TSYGXaP50pzdC4Jz8BZyQcjpianBVWZUyj8fSOt87Iy3O8yGiERbaAuVw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751006685; c=relaxed/simple; bh=7pIhx5HjCLpkDF6aJv/SDyMoxejq+POAMhsEB0cNBaY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FAvNve2aoyeZv0SHjdTNClFqeC0ENfbyhBbFIcZFEVDQyKnVFTvCVGYJl8eNEQqKuAlpH2H1QDG2CkzyzJjGrMQOjsBnMPCktv6C6tOmmxnqiERMmUJ5j0b9M/tyGA5xX2K2r3QMfPN69kNefeEjXvgzu3tp84XufmQDJPuqjTU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codewreck.org; spf=pass smtp.mailfrom=codewreck.org; dkim=pass (2048-bit key) header.d=codewreck.org header.i=@codewreck.org header.b=Hza5wT2j; arc=none smtp.client-ip=62.210.214.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codewreck.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codewreck.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=codewreck.org header.i=@codewreck.org header.b="Hza5wT2j" Received: from gaia.codewreck.org (localhost [127.0.0.1]) by submarine.notk.org (Postfix) with ESMTPS id 8F2E914C2D3; Fri, 27 Jun 2025 08:44:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1751006675; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vr7nGqbEftdaKrLXOahP98xg8w9JsBZcMEz9gbvFuyE=; b=Hza5wT2jlB55T5f/vRSYtc9WmE5SuWQcZFn+1MTGA3vI4w5WzwmW4IVxK4e8VCOR3rnJLX YHDpaWGkAKF5j+fdfZhxTWD4DD4URlAil58Uic+UVKBp71onWEmlQLvRYYODmMz7mcPjMe fCIPcT47djy0fiyB7HBO4hUXdqyXzYpvp4LMHjue/E1IQ5+9OcokuvB/4gmHSQIUzq4ne6 EClR8vp6X3jpzRquGQ1PINV8+UMgAIhP/9NYmEw6unkc7fYSIJ9ZT5KMSnzvhtMr5I8Ukd a5TmH9vQGMcZnALdHkHB22qXo8KtsdrqVL9HXekK7RvDGgSHkcg7mryyxm1HEw== Received: from localhost (gaia.codewreck.org [local]) by gaia.codewreck.org (OpenSMTPD) with ESMTPA id 4c2e422b; Fri, 27 Jun 2025 06:44:29 +0000 (UTC) Date: Fri, 27 Jun 2025 15:44:14 +0900 From: Dominique Martinet To: Christian Theune , David Howells Cc: Ryan Lahfa , Antony Antony , Antony Antony , Christian Brauner , Eric Van Hensbergen , Latchesar Ionkov , Christian Schoenebeck , Sedat Dilek , Maximilian Bosch , regressions@lists.linux.dev, v9fs@lists.linux.dev, netfs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [REGRESSION] 9pfs issues on 6.12-rc1 Message-ID: References: <3327438.1729678025@warthog.procyon.org.uk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hi all, sorry for the slow reply; I wasn't in Cc of most of the mails back in October so this is a pain to navigate... Let me recap a bit: - stuff started failing in 6.12-rc1 - David first posted "9p: Don't revert the I/O iterator after reading"[1], which fixed the bug, but then found a "better" fix as "iov_iter: Fix iov_iter_get_pages*() for folio_queue" [2] which was merged instead (so the first patch was not merged) But it turns out the second patch is not enough (or causes another issue?), and the reverting it + applying first one works, is that correct? What happens if you keep [2] and just apply [1], does that still bug? (I've tried reading through the thread now and I don't even see what was the "bad" patch in the first place, although I assume it's ee4cdf7ba857 ("netfs: Speed up buffered reading") -- was that confirmed?) David, as you worked on this at the time it'd be great if you could have another look, I have no idea what made you try [1] in the first place but unless you think 9p is doing something wrong like double-reverting on error or something like that I'd like to understand a bit more what happens... Although given 6.12 is getting used more now it could make sense to just apply [1] first until we understand, and have a proper fix come second -- if someone can confirm we don't need to revert [2]. [1] https://lore.kernel.org/all/3327438.1729678025@warthog.procyon.org.uk/T/#mc97a248b0f673dff6dc8613b508ca4fd45c4fefe [2] https://lore.kernel.org/all/3327438.1729678025@warthog.procyon.org.uk/T/#m89597a1144806db4ae89992953031cdffa0b0bf9 Thanks, -- Dominique