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 X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BDBFC43219 for ; Tue, 30 Apr 2019 11:41:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 327F621670 for ; Tue, 30 Apr 2019 11:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556624470; bh=GKWtRrBNFdR2JLOIrZ3EWhjheKlKpbUl0/M3jGhzfSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ffV26SEoGVLxiDyENyBZhfgxbreo/dop9izFbTjzzvFfjT9wls/8zgsOIwPJf1xEs nVJ5Zj0jfTbmzwBPw4kETI0GmEZ74f+ZFMhJPwHu+8hLSBtT1l10L6UvX0hpHCcf+X uPN6Hes9S0ScUgdpJk8TRmzT2yjnoj5nF6lUUfTQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728807AbfD3LlI (ORCPT ); Tue, 30 Apr 2019 07:41:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:48208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728762AbfD3LlG (ORCPT ); Tue, 30 Apr 2019 07:41:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 347E421670; Tue, 30 Apr 2019 11:41:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556624465; bh=GKWtRrBNFdR2JLOIrZ3EWhjheKlKpbUl0/M3jGhzfSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hRlXCDpGuUdAcmGpCRmMwqsVHB9nCsjxOLvZPQZWXOLj9n11eZCoBQ2HvC0gTyItz BdzD5/K2L+CGHlZAozKzY0zEufgsXI6gA+ji8p6LB2PkTMcCOU4COZAwEko5bW2oK+ KHNIdWhbWR6NOoymQLtklQtY3oGlzNelKlYFfVzE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Salvatore Bonaccorso , Jan Kara , Tetsuo Handa , Jens Axboe Subject: [PATCH 4.9 29/41] Revert "block/loop: Use global lock for ioctl() operation." Date: Tue, 30 Apr 2019 13:38:40 +0200 Message-Id: <20190430113531.495120419@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190430113524.451237916@linuxfoundation.org> References: <20190430113524.451237916@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman This reverts commit 3ae3d167f5ec2c7bb5fcd12b7772cfadc93b2305 which is commit 310ca162d779efee8a2dc3731439680f3e9c1e86 upstream. Jan Kara has reported seeing problems with this patch applied, as has Salvatore Bonaccorso, so let's drop it for now. Reported-by: Salvatore Bonaccorso Reported-by: Jan Kara Cc: Tetsuo Handa Cc: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 42 +++++++++++++++++++++--------------------- drivers/block/loop.h | 1 + 2 files changed, 22 insertions(+), 21 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -82,7 +82,6 @@ static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_index_mutex); -static DEFINE_MUTEX(loop_ctl_mutex); static int max_part; static int part_shift; @@ -1034,7 +1033,7 @@ static int loop_clr_fd(struct loop_devic */ if (atomic_read(&lo->lo_refcnt) > 1) { lo->lo_flags |= LO_FLAGS_AUTOCLEAR; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; } @@ -1083,12 +1082,12 @@ static int loop_clr_fd(struct loop_devic if (!part_shift) lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; loop_unprepare_queue(lo); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); /* - * Need not hold loop_ctl_mutex to fput backing file. - * Calling fput holding loop_ctl_mutex triggers a circular + * Need not hold lo_ctl_mutex to fput backing file. + * Calling fput holding lo_ctl_mutex triggers a circular * lock dependency possibility warning as fput can take - * bd_mutex which is usually taken before loop_ctl_mutex. + * bd_mutex which is usually taken before lo_ctl_mutex. */ fput(filp); return 0; @@ -1351,7 +1350,7 @@ static int lo_ioctl(struct block_device struct loop_device *lo = bdev->bd_disk->private_data; int err; - mutex_lock_nested(&loop_ctl_mutex, 1); + mutex_lock_nested(&lo->lo_ctl_mutex, 1); switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, mode, bdev, arg); @@ -1360,7 +1359,7 @@ static int lo_ioctl(struct block_device err = loop_change_fd(lo, bdev, arg); break; case LOOP_CLR_FD: - /* loop_clr_fd would have unlocked loop_ctl_mutex on success */ + /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ err = loop_clr_fd(lo); if (!err) goto out_unlocked; @@ -1396,7 +1395,7 @@ static int lo_ioctl(struct block_device default: err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); out_unlocked: return err; @@ -1529,16 +1528,16 @@ static int lo_compat_ioctl(struct block_ switch(cmd) { case LOOP_SET_STATUS: - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); err = loop_set_status_compat( lo, (const struct compat_loop_info __user *) arg); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; case LOOP_GET_STATUS: - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); err = loop_get_status_compat( lo, (struct compat_loop_info __user *) arg); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; case LOOP_SET_CAPACITY: case LOOP_CLR_FD: @@ -1582,7 +1581,7 @@ static void __lo_release(struct loop_dev if (atomic_dec_return(&lo->lo_refcnt)) return; - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { /* * In autoclear mode, stop the loop thread @@ -1599,7 +1598,7 @@ static void __lo_release(struct loop_dev loop_flush(lo); } - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); } static void lo_release(struct gendisk *disk, fmode_t mode) @@ -1645,10 +1644,10 @@ static int unregister_transfer_cb(int id struct loop_device *lo = ptr; struct loop_func_table *xfer = data; - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_encryption == xfer) loop_release_xfer(lo); - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; } @@ -1814,6 +1813,7 @@ static int loop_add(struct loop_device * if (!part_shift) disk->flags |= GENHD_FL_NO_PART_SCAN; disk->flags |= GENHD_FL_EXT_DEVT; + mutex_init(&lo->lo_ctl_mutex); atomic_set(&lo->lo_refcnt, 0); lo->lo_number = i; spin_lock_init(&lo->lo_lock); @@ -1926,19 +1926,19 @@ static long loop_control_ioctl(struct fi ret = loop_lookup(&lo, parm); if (ret < 0) break; - mutex_lock(&loop_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_state != Lo_unbound) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; } if (atomic_read(&lo->lo_refcnt) > 0) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); break; } lo->lo_disk->private_data = NULL; - mutex_unlock(&loop_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); idr_remove(&loop_index_idr, lo->lo_number); loop_remove(lo); break; --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -55,6 +55,7 @@ struct loop_device { spinlock_t lo_lock; int lo_state; + struct mutex lo_ctl_mutex; struct kthread_worker worker; struct task_struct *worker_task; bool use_dio;