From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B7586306B08 for ; Mon, 24 Aug 2026 13:17:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787577455; cv=none; b=D5Dw95xe6fv4wQEZSBcCZ/Vk9WHdAx9VfApRihR7PuY5nZRYmCsW1eFlHZFJ3Rcgoelr8cH9ziRSnt+xmx76jncxQGwx6nkaX854mxTb+ZsK2IriqiwtjCM1gOQL3k5B8f0qgpo8oekVCFGK39SqHBfvKvJ4Vti6pJ1KyopwSl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787577455; c=relaxed/simple; bh=86CF5Fhf4V0qJ/HSbXmo5zrli0VK2yvVmVOkacP9vqw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=B3xnn/bBI9H0FwuEBxFMkPVjP5gDpKfNGoUP20QOJhWFRNYEKbWuFRfD8NC59xLFdKUSszZJsfQpU3JLYm1AtmxHOMSNnujieng//398BdGw0R+mXKPLNjduCilL5W3B/fY49+79Iei/HHTOVZLqCDql+Km11OVE1b9Ivd9aAHQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z/eKKKHI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z/eKKKHI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FBD91F000E9; Mon, 24 Aug 2026 13:17:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787577454; bh=Iua+q5KymKXC2X2HgbKYzSUhq3fQTcywe3dvlXKgpmA=; h=From:To:Cc:Subject:Date; b=Z/eKKKHINL0IvvisKFTF753/tJZAKNEl2zABtn+ckCUQXEMV/4mmUYHANGjz+3+2Y JG3uZV6tcbzXLTbQiZXg4FIm0iNJQSfuBcImC2lTCHbazgU2knxAY3gSaOT2UUm4S4 qCOkknIwL7G38xtwQHNxUy7r6P0QtFUIbg/RYd1gd6MxvF5KlyR+KKiNOwmM60/Rjb G8jUvpV8kpanwm/a6SAvHbCwvzHV0ySuk+/vdsF32o12RFpzLYZAa6ow00rBeBXLuS DWT+fRc9eX8jWn93zZcsfWCZf6xknBQs5h13Xxkynf6fRjpB3smkzUXJ998tFg/kti Vfu/arNKc5+kg== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu , stable@kernel.org Subject: [PATCH] f2fs: fix to avoid potential deadloop in f2fs_fsync_node_pages() Date: Mon, 24 Aug 2026 21:17:29 +0800 Message-ID: <20260824131729.3694378-1-chao@kernel.org> X-Mailer: git-send-email 2.55.0.766.g2966f0265a-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit There is potential deadloop in race condition: Thread A Thread B - fsync - f2fs_do_sync_file - f2fs_fsync_node_pages - last_fsync_dnode - folio_get(last_folio) - f2fs_setattr - f2fs_truncate - f2fs_truncate_blocks - f2fs_do_truncate_blocks - f2fs_truncate_inode_blocks - truncate_dnode - truncate_node - invalidate_mapping_pages - folio->mapping = NULL - is_node_folio alwasy return false - atomic && !marked is always true, then goto retry Cc: stable@kernel.org Fixes: 608514deba38 ("f2fs: set fsync mark only for the last dnode") Signed-off-by: Chao Yu --- fs/f2fs/node.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 968e5ed38816..86c2e67e43b6 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2016,6 +2016,11 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode, f2fs_debug(sbi, "Retry to write fsync mark: ino=%u, idx=%lx", ino, last_folio->index); folio_lock(last_folio); + if (unlikely(!is_node_folio(last_folio))) { + f2fs_folio_put(last_folio, true); + ret = -EAGAIN; + goto out; + } f2fs_folio_wait_writeback(last_folio, NODE, true, true); folio_mark_dirty(last_folio); folio_unlock(last_folio); -- 2.49.0