From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6DD3E3FB044; Mon, 2 Mar 2026 13:50:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772459459; cv=none; b=Yngj8z98VLgATK+6fZj6HDPZLPQwKKnLwb5rVGPXlQbZCv3soppSdjwPir4qVtqC9HMI3FPZ9NRLBBLYUYGJZihLyhNI4hDFCIWaZIzChqJWpokEqUN+zGyHgDPB1+QKQv6plvtyv0wM+QJgV7IS4Gqk7/bTUfzhMT2uRARNQKc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772459459; c=relaxed/simple; bh=VHSK6YEGNyCIoVPW5pjqYIC45ahxdFqh2C/pBfplUAs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YB3oLnfEXF172zImZ8c5Eev83cN8wkD3PeBACDDFob09OZXFBBla6LcBckzmjU0qRMtECO2HM5G7ohbOs0vphT1dh8ahw6OVZxY8BD/kiB/CiQh9TRug5jO7UXaRgpMQ2ywuXR2KTmmu7FdkiuPnipr3adsjDzPkWZ+NNL6U06A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=t9FoqLVN; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="t9FoqLVN" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=0mxOV7omutuRZu2xaV3AtdtQohZwv5xm8F7gjTBJ59Q=; b=t9FoqLVNqtepR+hrSxb7DbRRW/ ZEx/KAh3QPrXU9qH4AEFUMbbhSfoCIIS39yTzAfwZMdnXRn14QDzmT4c7ioUu7OdAJpPYhFIe/b7K 4vy0fepxNw5kD67v7lgefavzXh0P0JjwKevMmcIkjXVfUWYlEZ55VH8qlUaF8/yZ+3YkbVx1Txz3m PFqH98KUC8WqrfNY7ItimnKHUm+G//woU6ICgtGA5R/mZIrwRK2F8ubn0L2uXBW+r6HR878wlftM6 AmFx+g+vGqMyrWQjLlLHmK9kGab2HHHITzv6WnBN2ABtm4/SzBBGC4gJ3YqdTbW8/O4i/+CWuXYdR wjYc74hw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vx3fk-0000000DA78-1MN6; Mon, 02 Mar 2026 13:50:56 +0000 Date: Mon, 2 Mar 2026 05:50:56 -0800 From: Christoph Hellwig To: jiucheng.xu@amlogic.com Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, jianxin.pan@amlogic.com, tuan.zhang@amlogic.com, Gao Xiang , linux-erofs@lists.ozlabs.org Subject: Re: [PATCH] block: avoild hang when bio_list is non-NULL in submit_bio_wait() Message-ID: References: <20260302-for-next-v1-1-eb9339e8dc99@amlogic.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260302-for-next-v1-1-eb9339e8dc99@amlogic.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Mar 02, 2026 at 10:51:03AM +0800, Jiucheng Xu via B4 Relay wrote: > From: Jiucheng Xu > > When current->bio_list is non-NULL in submit_bio_wait(), > submit_bio_noacct_nocheck appends bio to bio_list but skips IO > submission, causing submit_bio_wait() to hang indefinitely. > > Fix this by temporarily backup bio_list, setting bio_list to > NULL before calling submit_bio(), then restoring bio_list > after submit_bio() returns. No. Fix this by not doing something that is a bad idea. > I've trimmed down the call stack, as follows: > > f2fs_submit_read_io > submit_bio > mmc_blk_mq_recovery > z_erofs_endio > vm_map_ram ->bi_end_io code really should not be having random in_atomic() checks that make it completely different, but even if they have that need to use GFP_NOIO.