From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 276EC1E105E; Wed, 19 Mar 2025 14:37:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742395042; cv=none; b=IEPMasQxWSsNxFFez9ldJRGmTDxnfic9VfvjE5ZuSuSVvQ4+PZ2Kh8Qh2ma/9lzhBOopx8p0OzjIRcok1VF2tyghXbxa3Nv247yoTRHj01QAVjPMR0HnYuaFcmOHIBLfaCtdjiTvNWlVnmtiiHbJUeuGecmp9DQrCLL158JhGz4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742395042; c=relaxed/simple; bh=kQ08iqHSIohfh0wjGSOpMsUCFjX71pr89htDAy1jT9w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=d32s32OHx8F7r9R97a6e/tVedyroLC2ghZHfMpSWZLF+E04zVM+CrMc0n4vej3l6BcrliZ4gVm+USlS9S0vLC+9k7kQxOCysiFgJd+e4GrUqKKOVhZ17unemnXV+wgwfeViIe0Me8jOCguRZWMyfRNGKoa89tycy7sSQyCj986A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=K4kQl4fO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="K4kQl4fO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0EB6C4CEE8; Wed, 19 Mar 2025 14:37:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1742395042; bh=kQ08iqHSIohfh0wjGSOpMsUCFjX71pr89htDAy1jT9w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K4kQl4fOts3Kc7QkUuaszey3G8qlMi/Nag8AihIotIvSXFQcWAouQxDHx2Bv8MzEj HhgB4D1ubFnjAB0WqDZrzYpKHs3tHhihmGesV6U3eIAwY3Gco/1fpdH+4XvZ8XsLAl xWpTb2g5pHAecvw3i8DAr5mESyiCAng3uvUXYEc8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Marc=20Aur=C3=A8le=20La=20France?= , Rik van Riel , Christoph Hellwig , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.12 066/231] scsi: core: Use GFP_NOIO to avoid circular locking dependency Date: Wed, 19 Mar 2025 07:29:19 -0700 Message-ID: <20250319143028.459935990@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250319143026.865956961@linuxfoundation.org> References: <20250319143026.865956961@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rik van Riel [ Upstream commit 5363ee9d110e139584c2d92a0b640bc210588506 ] Filesystems can write to disk from page reclaim with __GFP_FS set. Marc found a case where scsi_realloc_sdev_budget_map() ends up in page reclaim with GFP_KERNEL, where it could try to take filesystem locks again, leading to a deadlock. WARNING: possible circular locking dependency detected 6.13.0 #1 Not tainted ------------------------------------------------------ kswapd0/70 is trying to acquire lock: ffff8881025d5d78 (&q->q_usage_counter(io)){++++}-{0:0}, at: blk_mq_submit_bio+0x461/0x6e0 but task is already holding lock: ffffffff81ef5f40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x9f/0x760 The full lockdep splat can be found in Marc's report: https://lkml.org/lkml/2025/1/24/1101 Avoid the potential deadlock by doing the allocation with GFP_NOIO, which prevents both filesystem and block layer recursion. Reported-by: Marc Aurèle La France Signed-off-by: Rik van Riel Link: https://lore.kernel.org/r/20250129104525.0ae8421e@fangorn Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/scsi_scan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 042329b74c6e6..fe08af4dcb67c 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -245,7 +245,7 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, } ret = sbitmap_init_node(&sdev->budget_map, scsi_device_max_queue_depth(sdev), - new_shift, GFP_KERNEL, + new_shift, GFP_NOIO, sdev->request_queue->node, false, true); if (!ret) sbitmap_resize(&sdev->budget_map, depth); -- 2.39.5