From patchwork Thu May 5 07:08:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 12839108 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0EA7C433EF for ; Thu, 5 May 2022 07:08:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240221AbiEEHMP (ORCPT ); Thu, 5 May 2022 03:12:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232300AbiEEHMO (ORCPT ); Thu, 5 May 2022 03:12:14 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3A9A39B93 for ; Thu, 5 May 2022 00:08:35 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id C670D1F461; Thu, 5 May 2022 07:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1651734513; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7NeCP3H7LDbuKPJtWf4EWH7god/TdBi+pmuiZsAijr0=; b=KGrMhK8hkbLgTINguxhufMN9EPti+6zCk1DhHwv8xzAx5lS06E0OuWT+4VrMUTjsOQ7hgQ JhvkkUoAUDpxy1my54bEg6KR+817LvO7qlGjJve4FQxjTu/79tPB6DzpCWPZHQm0XunFhZ /Ln2xQPAODe/cAy1MXVseK853rIogHU= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7CE5613A65; Thu, 5 May 2022 07:08:33 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id zXTIG/F3c2LKZwAAMHmgww (envelope-from ); Thu, 05 May 2022 07:08:33 +0000 From: Nikolay Borisov To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov , kernel test robot , Dan Carpenter Subject: [PATCH v2] btrfs: Use btrfs_try_lock_balance in btrfs_ioctl_balance Date: Thu, 5 May 2022 10:08:25 +0300 Message-Id: <20220505070825.1218337-1-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220504152501.GQ18596@twin.jikos.cz> References: <20220504152501.GQ18596@twin.jikos.cz> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This eliminates 2 labels and makes the code generally more streamlined. Also rename the 'out_bargs' label to 'out_unlock' since bargs is going to be freed under the 'out' label. This also fixes a memory leak since bargs wasn't correctly freed in one of the condition which are now moved in btrfs_try_lock_balance. Signed-off-by: Nikolay Borisov Reported-by: kernel test robot Reported-by: Dan Carpenter --- V2: * Removed extra call to kfree(bargs) which resulted in a double free fs/btrfs/ioctl.c | 51 +++++------------------------------------------- 1 file changed, 5 insertions(+), 46 deletions(-) -- 2.25.1 diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8e0cc17d5f81..9ac07eb7531c 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4406,7 +4406,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_ioctl_balance_args *bargs; struct btrfs_balance_control *bctl; - bool need_unlock; /* for mut. excl. ops lock */ + bool need_unlock = true; /* for mut. excl. ops lock */ int ret; if (!capable(CAP_SYS_ADMIN)) @@ -4423,53 +4423,12 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) goto out; } -again: - if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { - mutex_lock(&fs_info->balance_mutex); - need_unlock = true; - goto locked; - } - - /* - * mut. excl. ops lock is locked. Three possibilities: - * (1) some other op is running - * (2) balance is running - * (3) balance is paused -- special case (think resume) - */ - mutex_lock(&fs_info->balance_mutex); - if (fs_info->balance_ctl) { - /* this is either (2) or (3) */ - if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { - mutex_unlock(&fs_info->balance_mutex); - /* - * Lock released to allow other waiters to continue, - * we'll reexamine the status again. - */ - mutex_lock(&fs_info->balance_mutex); - - if (fs_info->balance_ctl && - !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { - /* this is (3) */ - need_unlock = false; - goto locked; - } - - mutex_unlock(&fs_info->balance_mutex); - goto again; - } else { - /* this is (2) */ - mutex_unlock(&fs_info->balance_mutex); - ret = -EINPROGRESS; - goto out; - } - } else { - /* this is (1) */ - mutex_unlock(&fs_info->balance_mutex); - ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; + ret = btrfs_try_lock_balance(fs_info, &need_unlock); + if (ret) goto out; - } -locked: + lockdep_assert_held(&fs_info->balance_mutex); + if (bargs->flags & BTRFS_BALANCE_RESUME) { if (!fs_info->balance_ctl) { ret = -ENOTCONN;