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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E3F8CCA479 for ; Mon, 20 Jun 2022 13:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245320AbiFTNLI (ORCPT ); Mon, 20 Jun 2022 09:11:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244685AbiFTNH0 (ORCPT ); Mon, 20 Jun 2022 09:07:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 470E51B7A7; Mon, 20 Jun 2022 06:01:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9D2EB61530; Mon, 20 Jun 2022 13:00:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92EE8C36AF2; Mon, 20 Jun 2022 13:00:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655730043; bh=OYZepqnZF5ehymvjwu9IgTMcBX0/iTdvqxfft0sm+Io=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cgfV04eKwEEgOJbi0XgvSumZX5OFc7XHk269eEhw5zJ1wKv9o6136mnTyJKUjY4pW T9IxaWSqt33WDopX9T3ZTEMQKp5LlBD2Ih235Qs+vSGDUc9wolQf46dC9GfTjwtgRT GXWs/P/jbqjiyk3udMfm4JT2t0ulxtZa7F6riA6w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Matthew Wilcox (Oracle)" , Jan Kara , Sasha Levin Subject: [PATCH 5.10 15/84] quota: Prevent memory allocation recursion while holding dq_lock Date: Mon, 20 Jun 2022 14:50:38 +0200 Message-Id: <20220620124721.342085455@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124720.882450983@linuxfoundation.org> References: <20220620124720.882450983@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox (Oracle) [ Upstream commit 537e11cdc7a6b3ce94fa25ed41306193df9677b7 ] As described in commit 02117b8ae9c0 ("f2fs: Set GF_NOFS in read_cache_page_gfp while doing f2fs_quota_read"), we must not enter filesystem reclaim while holding the dq_lock. Prevent this more generally by using memalloc_nofs_save() while holding the lock. Link: https://lore.kernel.org/r/20220605143815.2330891-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/quota/dquot.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 09fb8459bb5c..65f123d5809b 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -79,6 +79,7 @@ #include #include #include +#include #include "../internal.h" /* ugh */ #include @@ -427,9 +428,11 @@ EXPORT_SYMBOL(mark_info_dirty); int dquot_acquire(struct dquot *dquot) { int ret = 0, ret2 = 0; + unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); + memalloc = memalloc_nofs_save(); if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); if (ret < 0) @@ -460,6 +463,7 @@ int dquot_acquire(struct dquot *dquot) smp_mb__before_atomic(); set_bit(DQ_ACTIVE_B, &dquot->dq_flags); out_iolock: + memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } @@ -471,9 +475,11 @@ EXPORT_SYMBOL(dquot_acquire); int dquot_commit(struct dquot *dquot) { int ret = 0; + unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); + memalloc = memalloc_nofs_save(); if (!clear_dquot_dirty(dquot)) goto out_lock; /* Inactive dquot can be only if there was error during read/init @@ -483,6 +489,7 @@ int dquot_commit(struct dquot *dquot) else ret = -EIO; out_lock: + memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } @@ -494,9 +501,11 @@ EXPORT_SYMBOL(dquot_commit); int dquot_release(struct dquot *dquot) { int ret = 0, ret2 = 0; + unsigned int memalloc; struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); mutex_lock(&dquot->dq_lock); + memalloc = memalloc_nofs_save(); /* Check whether we are not racing with some other dqget() */ if (dquot_is_busy(dquot)) goto out_dqlock; @@ -512,6 +521,7 @@ int dquot_release(struct dquot *dquot) } clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); out_dqlock: + memalloc_nofs_restore(memalloc); mutex_unlock(&dquot->dq_lock); return ret; } -- 2.35.1