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 4715133A9F7; Thu, 26 Feb 2026 14:09:15 +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=1772114955; cv=none; b=ZWKpKF89ln6VilsltSPQA+nTQD3erhAh+k/z1CHp3bVCidMlEgjvo07ogBqIYELJlhLUrGGyLOVzPoXFfPeIoKOGtDr3pgz9zaPaBCnjcHlCCWe2qyGLoHGQ15Wp7sQu7aJNLBekkwYqsh4mlHHEAd/jFg/VHqwpZF3anw+rPmg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772114955; c=relaxed/simple; bh=8WDXKaLHom5c3E/DwCunlAjOlHZNSGTUJkRY5uIDLx4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kbBeudcFUGzQ3mUbRC+G+Nb6Sxsd7dH3Rd24xINUQOZ1LKVYmk3jjzsUHDAcq+VG3m9j0LiweQKbrI1GXyugaO25nfp6jRca10nIDd78YVw6AUSOJrdD1IE0NUM25jByrZaGKnsyXsHXnjIzZtQjYnCmdZEkfQL2XqbFl4uU3bE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W6sO2eJx; 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="W6sO2eJx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B342AC116C6; Thu, 26 Feb 2026 14:09:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772114954; bh=8WDXKaLHom5c3E/DwCunlAjOlHZNSGTUJkRY5uIDLx4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W6sO2eJxeOLvlQ9mpL1mZ9pdNYgf/x6X5Vk3jytPpF4EeK4GOxcnfskcBjkXwDBBV 2qq5q2kU1XKnmM99cg64n+IdHCe8KdA2GjbHFihYphUV1uUGBG91N+11GIsz5QtpxO 0NfvN2cBrEpXNTvuy1xGq2lBTE/GPrPkgLdRTOLnEwCvFpV6DltN0qx3CTZ+6BQNW0 bfqqlUuRoRHyRAybpbDIk8nqS68HJ4O1ryrNqw3k/JN6CCEIo6TVj99sko3SfM1NS7 ZTJSJllW0WTGH/QTTJFxoIZiGN4fcxYT5Wq7wKdCUt1+oYza8TsdDQ9MqHgVaZ/wQ7 71YDJv0xlj/Ug== Date: Thu, 26 Feb 2026 09:09:13 -0500 From: Sasha Levin To: Jan Kara Cc: Amir Goldstein , patches@lists.linux.dev, stable@vger.kernel.org, Jakub Acs , Christian Brauner , viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH AUTOSEL 6.19-5.15] fsnotify: Shutdown fsnotify before destroying sb's dcache Message-ID: References: <20260214212452.782265-1-sashal@kernel.org> <20260214212452.782265-85-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Feb 17, 2026 at 11:00:42AM +0100, Jan Kara wrote: >On Sun 15-02-26 09:11:30, Amir Goldstein wrote: >> On Sat, Feb 14, 2026 at 11:27 PM Sasha Levin wrote: >> > >> > From: Jan Kara >> > >> > [ Upstream commit 74bd284537b3447c651588101c32a203e4fe1a32 ] >> > >> > Currently fsnotify_sb_delete() was called after we have evicted >> > superblock's dcache and inode cache. This was done mainly so that we >> > iterate as few inodes as possible when removing inode marks. However, as >> > Jakub reported, this is problematic because for some filesystems >> > encoding of file handles uses sb->s_root which gets cleared as part of >> > dcache eviction. And either delayed fsnotify events or reading fdinfo >> > for fsnotify group with marks on fs being unmounted may trigger encoding >> > of file handles during unmount. >> >> In retrospect, the text "Now that we iterate inode connectors..." >> would have helped LLM (as well as human) patch backports understand >> that this is NOT a standalone patch. > >Good point :) > >> Sasha, >> >> I am very for backporting this fix, but need to backport the series >> https://lore.kernel.org/linux-fsdevel/20260121135513.12008-1-jack@suse.cz/ > >Yes. Without commits 94bd01253c3d5 ("fsnotify: Track inode connectors for a >superblock") and a05fc7edd988c ("fsnotify: Use connector list for >destroying inode marks") the reordering alone can cause large latencies >during filesystem unmount. Looks like going even to 6.18 requires a bunch of dependencies, so a backport would be appreciated :) -- Thanks, Sasha