From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161058Ab3BGS0s (ORCPT ); Thu, 7 Feb 2013 13:26:48 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:52402 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161017Ab3BGS0q (ORCPT ); Thu, 7 Feb 2013 13:26:46 -0500 Date: Thu, 7 Feb 2013 10:26:42 -0800 From: Tejun Heo To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH v2 23/77] block/loop: convert to idr_alloc() Message-ID: <20130207182642.GQ2875@htj.dyndns.org> References: <1360179649-22465-1-git-send-email-tj@kernel.org> <1360179649-22465-24-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1360179649-22465-24-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Subject: block/loop: convert to idr_alloc() Convert to the much saner new idr interface. v2: loop_add() treats -1 @i as request for any free ID while any other negative trigger -EINVAL. The v1 conversion treated any negative number as valid request for any free ID. While this doesn't make any difference for in-kernel users, loop_add() is almost directly visible to userland via LOOP_CTL_ADD and this behavior change is userland-visible. Restore -EINVAL on < -1. Signed-off-by: Tejun Heo Acked-by: Jens Axboe --- Another mistake I noticed while auditing the conversions again. I don't think this would actually affect anybody but no reason to change the behavior. Thanks. drivers/block/loop.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1624,30 +1624,19 @@ static int loop_add(struct loop_device * if (!lo) goto out; - if (!idr_pre_get(&loop_index_idr, GFP_KERNEL)) - goto out_free_dev; - + /* allocate id, if @id >= 0, we're requesting that specific id */ if (i >= 0) { - int m; - - /* create specific i in the index */ - err = idr_get_new_above(&loop_index_idr, lo, i, &m); - if (err >= 0 && i != m) { - idr_remove(&loop_index_idr, m); + err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL); + if (err == -ENOSPC) err = -EEXIST; - } } else if (i == -1) { - int m; - - /* get next free nr */ - err = idr_get_new(&loop_index_idr, lo, &m); - if (err >= 0) - i = m; + err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL); } else { err = -EINVAL; } if (err < 0) goto out_free_dev; + i = err; err = -ENOMEM; lo->lo_queue = blk_alloc_queue(GFP_KERNEL);