From patchwork Sun Mar 30 06:47:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 14032830 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 65AC320B22; Sun, 30 Mar 2025 06:47:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743317266; cv=none; b=PuOurxngB6QFEBsr03BYDjMCo/j4OaWachZQH2VG4mi0+QU/j9SWmYTbeKoYS+8BkiBD1Sh8JAABrKIjspKDQWAUjK+ZCjH0rcNYduWcvtYekdGhPbPK46Uw7v5XBeI9sQDpUlad8rry6M/6gV+NA2LDDo0cA9j8zDB0AY3mxh4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743317266; c=relaxed/simple; bh=kgB8OOaAyE/3r4VIOULxwjlKCP0HM/KVZ4YfAhG+pT8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BYCJ9g/IznBOLFEeRik+WWkdykiDR43oEe1BJcqgvyb7wtBY+b6DUqx5zHsFOkQkGC1WkAHl6hvVwmUk6r4wj3fkhgn6UYnPU8+fve6vSvuE/OmINnwJtm36ctXVik0PfVTPDgseBKfGBavlsvS7faIzw49k216ycJYJCF012L8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=VPgNJJiZ; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VPgNJJiZ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=dsi6MQOqN7ghOTfrKnW38mWU0gU/PvadKLIXd+zTJ3U=; b=VPgNJJiZvXeAxUKUx/r9TdqDiX 19jBaZ71+1CjptFA1uPOz7MTCa0Dtsu0KQDcIzZUn9Yi1YtO6j3j5PULNY2V6f/kNMVmC/4U/sNjK ugtHpJAPu+D/ECx8lTjKXbh0fgepBKkPRxSB8RySceHn+wbuC9K3XIza5cZvoQM/IJ4fbkFaQ5ALv Um0efa/I52oG3LJ+ea9SqLXbRwEGidQSjjTfZAfC1MuFqFI0+JafxaPi4N+6MRZX791VwYk7jtVdk jrT63PtUmoskyRNKQhE7QXj1MDsxFidXiGfbCST8XW+vWXZtagnsvPt3q3LLYOB6XmKtBB/x1dxGW 89MIB91g==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.98.1 #2 (Red Hat Linux)) id 1tymSJ-0000000FreE-2OYS; Sun, 30 Mar 2025 06:47:39 +0000 From: Luis Chamberlain To: brauner@kernel.org, jack@suse.cz, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, riel@surriel.com Cc: willy@infradead.org, hannes@cmpxchg.org, oliver.sang@intel.com, dave@stgolabs.net, 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, mcgrof@kernel.org, syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com Subject: [PATCH 3/3] mm/migrate: avoid atomic context on buffer_migrate_folio_norefs() migration Date: Sat, 29 Mar 2025 23:47:32 -0700 Message-ID: <20250330064732.3781046-4-mcgrof@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250330064732.3781046-1-mcgrof@kernel.org> References: <20250330064732.3781046-1-mcgrof@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: Luis Chamberlain The buffer_migrate_folio_norefs() should avoid holding the spin lock held in order to ensure we can support large folios. The prior commit "fs/buffer: avoid races with folio migrations on __find_get_block_slow()" ripped out the only rationale for having the atomic context, so we can remove the spin lock call now. Reported-by: kernel test robot Reported-by: syzbot+f3c6fda1297c748a7076@syzkaller.appspotmail.com Closes: https://lore.kernel.org/oe-lkp/202503101536.27099c77-lkp@intel.com Fixes: 3c20917120ce ("block/bdev: enable large folio support for large logical block sizes") Signed-off-by: Luis Chamberlain --- mm/migrate.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 712ddd11f3f0..f3047c685706 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -861,12 +861,12 @@ static int __buffer_migrate_folio(struct address_space *mapping, } bh = bh->b_this_page; } while (bh != head); + spin_unlock(&mapping->i_private_lock); if (busy) { if (invalidated) { rc = -EAGAIN; goto unlock_buffers; } - spin_unlock(&mapping->i_private_lock); invalidate_bh_lrus(); invalidated = true; goto recheck_buffers; @@ -884,8 +884,6 @@ static int __buffer_migrate_folio(struct address_space *mapping, } while (bh != head); unlock_buffers: - if (check_refs) - spin_unlock(&mapping->i_private_lock); bh = head; do { unlock_buffer(bh);