From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAED6C369B2 for ; Mon, 14 Apr 2025 21:09:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 09759280088; Mon, 14 Apr 2025 17:09:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F33CA280080; Mon, 14 Apr 2025 17:09:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E2023280088; Mon, 14 Apr 2025 17:09:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id C47D7280080 for ; Mon, 14 Apr 2025 17:09:47 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 47A5D1A06E8 for ; Mon, 14 Apr 2025 21:09:49 +0000 (UTC) X-FDA: 83333891298.01.D036992 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf29.hostedemail.com (Postfix) with ESMTP id B1F2A120003 for ; Mon, 14 Apr 2025 21:09:47 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="BzC/R4mY"; spf=pass (imf29.hostedemail.com: domain of mcgrof@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=mcgrof@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1744664987; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=09CHghTc7OqRIUw8QGyuvAYlUGMSCN5k+MSoIAWK/BE=; b=WjBAk8QKJHexumuhFCatdMSKUzmYBjHJI0yEWtTfGwJ2luFgUAQmCZJeKm/pEQ32uXg9TW E269QoZI+fTxVv3ALo6GvYaEX2sL8iBa1FqtrWKEPsx8CkOCExGHE5IBtB9OYw0HczTeuc CHakAOFYVkG8AAeVZYngh6kqDdX0x7M= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1744664987; a=rsa-sha256; cv=none; b=buNukCVYLLRzPWrgaHn43CwoY6z13U0ZtSJxhAQ6b+QBqQh2DZGF897A6l79hEkvGDfi2p b3FTyVne4u/jiGsXaenl2F4H0x2QqOgQDox+tr9Ia7gRqTM32w5RrqiLE43kJ9nv9acdhm c4oNq0hA2phdJKBXQv+hFcIRiOnOOOk= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="BzC/R4mY"; spf=pass (imf29.hostedemail.com: domain of mcgrof@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=mcgrof@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 68F38A4A28F; Mon, 14 Apr 2025 21:04:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7397C4CEE2; Mon, 14 Apr 2025 21:09:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744664986; bh=lpeU+VFs+tWFECGqdRhNzhVUdyxBl1OuFLG5In2vUnc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BzC/R4mYs4Y+P7ux5R++T+87e2owZZFUgudssORXGInbwYHTNgHjmbrEsgpFDdLS7 zKOZpKTa7OhJuOt6mvz2rUkfKlCO9UuniKcc2FnivCKZSaPg9f1n7V7j9CmrIRUsZ9 Lvb9Al6iTA4fuIqkZJbPeD/QmWEY+LhBNS7cdyiQ8FONDkK/cbZsDd/IKsxqmLqTWP zxwuv0EEgK0DkOnPFMJae45Hx1/nl4s33YVI5RwvELzomYfi4GL1SqWcrmybN45dt/ KazJmTbfCtJoB4TB+KJoNAAcl8SNVD4EusMyjQvAbeH/i2MuHptwltKaBTHHPz74ui SLpETUqb0Rl9Q== Date: Mon, 14 Apr 2025 14:09:44 -0700 From: Luis Chamberlain To: Jan Kara Cc: brauner@kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, riel@surriel.com, dave@stgolabs.net, willy@infradead.org, hannes@cmpxchg.org, oliver.sang@intel.com, david@redhat.com, axboe@kernel.dk, hare@suse.de, david@fromorbit.com, djwong@kernel.org, ritesh.list@gmail.com, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org, gost.dev@samsung.com, p.raghav@samsung.com, da.gomez@samsung.com, syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com Subject: Re: [PATCH v2 1/8] migrate: fix skipping metadata buffer heads on migration Message-ID: References: <20250410014945.2140781-1-mcgrof@kernel.org> <20250410014945.2140781-2-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: B1F2A120003 X-Stat-Signature: hkzc3co34h5xuksr3pso4tmajqcse3af X-HE-Tag: 1744664987-609213 X-HE-Meta: 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 5YrpbEGz rjk30sYRrVc7mZTZSfeY0ODp5ZqT+cA+EEL9mHZFlsUFo9oIbVYzxZQx4GEk955EL/kAkobe0AeofNs2BMUkVI77gJgc7GvS2ku3DIMwURVbiLfIH7D5xgeuGsv+jOYUGJXZW1q2jtE3SRauSkiON74vJgBA/W6wBRYOT/NPIjNW1AI/imigMYKQkNn6YEj/aawitJVMoYpW8rqz+KM/pHaz2MVhtQ89rcJsCrqRkXi3RFY5UZ/4Yh+UOyI/xhDTDO7s0X+VbNKCb+VqK7oWl3kJoIP9AYrEp3hDHWIemzVN1ZdLrsaZQ/PCbBA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Apr 10, 2025 at 02:05:38PM +0200, Jan Kara wrote: > > @@ -859,12 +862,12 @@ static int __buffer_migrate_folio(struct address_space *mapping, > > } > > bh = bh->b_this_page; > > } while (bh != head); > > + spin_unlock(&mapping->i_private_lock); > > No, you've just broken all simple filesystems (like ext2) with this patch. > You can reduce the spinlock critical section only after providing > alternative way to protect them from migration. So this should probably > happen at the end of the series. So you're OK with this spin lock move with the other series in place? And so we punt the hard-to-reproduce corruption issue as future work to do? Becuase the other alternative for now is to just disable migration for jbd2: diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1dc09ed5d403..ef1c3ef68877 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3631,7 +3631,6 @@ static const struct address_space_operations ext4_journalled_aops = { .bmap = ext4_bmap, .invalidate_folio = ext4_journalled_invalidate_folio, .release_folio = ext4_release_folio, - .migrate_folio = buffer_migrate_folio_norefs, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_folio = generic_error_remove_folio, .swap_activate = ext4_iomap_swap_activate,