From patchwork Wed Oct 10 10:04:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 10634309 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 347AF69B4 for ; Wed, 10 Oct 2018 10:04:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1E89E295E9 for ; Wed, 10 Oct 2018 10:04:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12875295DE; Wed, 10 Oct 2018 10:04:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9C8D329627 for ; Wed, 10 Oct 2018 10:04:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727031AbeJJRZt (ORCPT ); Wed, 10 Oct 2018 13:25:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:34910 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726935AbeJJRZs (ORCPT ); Wed, 10 Oct 2018 13:25:48 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D13E6B04C; Wed, 10 Oct 2018 10:04:20 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 994821E361C; Wed, 10 Oct 2018 12:04:18 +0200 (CEST) From: Jan Kara To: Jens Axboe Cc: , Tetsuo Handa , Jan Kara Subject: [PATCH 05/15] loop: Push lo_ctl_mutex down into individual ioctls Date: Wed, 10 Oct 2018 12:04:05 +0200 Message-Id: <20181010100415.26525-6-jack@suse.cz> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20181010100415.26525-1-jack@suse.cz> References: <20181010100415.26525-1-jack@suse.cz> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Push acquisition of lo_ctl_mutex down into individual ioctl handling branches. This is a preparatory step for pushing the lock down into individual ioctl handling functions so that they can release the lock as they need it. We also factor out some simple ioctl handlers that will not need any special handling to reduce unnecessary code duplication. Signed-off-by: Jan Kara --- drivers/block/loop.c | 88 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 63 insertions(+), 25 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 3fa5e63944a4..b7b3b4ae0896 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1394,70 +1394,108 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) return 0; } -static int lo_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) +static int lo_simple_ioctl(struct loop_device *lo, unsigned int cmd, + unsigned long arg) { - struct loop_device *lo = bdev->bd_disk->private_data; int err; err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); if (err) - goto out_unlocked; + return err; + switch (cmd) { + case LOOP_SET_CAPACITY: + err = loop_set_capacity(lo); + break; + case LOOP_SET_DIRECT_IO: + err = loop_set_dio(lo, arg); + break; + case LOOP_SET_BLOCK_SIZE: + err = loop_set_block_size(lo, arg); + break; + default: + err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; + } + mutex_unlock(&loop_ctl_mutex); + return err; +} + +static int lo_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct loop_device *lo = bdev->bd_disk->private_data; + int err; switch (cmd) { case LOOP_SET_FD: + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_set_fd(lo, mode, bdev, arg); + mutex_unlock(&loop_ctl_mutex); break; case LOOP_CHANGE_FD: + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_change_fd(lo, bdev, arg); + mutex_unlock(&loop_ctl_mutex); break; case LOOP_CLR_FD: + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; /* loop_clr_fd would have unlocked loop_ctl_mutex on success */ err = loop_clr_fd(lo); - if (!err) - goto out_unlocked; + if (err) + mutex_unlock(&loop_ctl_mutex); break; case LOOP_SET_STATUS: err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_set_status_old(lo, (struct loop_info __user *)arg); + mutex_unlock(&loop_ctl_mutex); + } break; case LOOP_GET_STATUS: + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_get_status_old(lo, (struct loop_info __user *) arg); /* loop_get_status() unlocks loop_ctl_mutex */ - goto out_unlocked; + break; case LOOP_SET_STATUS64: err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) { + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_set_status64(lo, (struct loop_info64 __user *) arg); + mutex_unlock(&loop_ctl_mutex); + } break; case LOOP_GET_STATUS64: + err = mutex_lock_killable_nested(&loop_ctl_mutex, 1); + if (err) + return err; err = loop_get_status64(lo, (struct loop_info64 __user *) arg); /* loop_get_status() unlocks loop_ctl_mutex */ - goto out_unlocked; - case LOOP_SET_CAPACITY: - err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) - err = loop_set_capacity(lo); break; + case LOOP_SET_CAPACITY: case LOOP_SET_DIRECT_IO: - err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) - err = loop_set_dio(lo, arg); - break; case LOOP_SET_BLOCK_SIZE: - err = -EPERM; - if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) - err = loop_set_block_size(lo, arg); - break; + if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) + return -EPERM; + /* Fall through */ default: - err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; + err = lo_simple_ioctl(lo, cmd, arg); + break; } - mutex_unlock(&loop_ctl_mutex); -out_unlocked: return err; }