From nobody Thu Apr 16 07:09:27 2026 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 E90551A9F90; Mon, 2 Mar 2026 02:51:12 +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=1772419873; cv=none; b=Il4iXyZMcM7EMBGayK+Hq3PwGM/reGtJdcJH4RGsMg4iivWt4E9lK2l3uhFBt+jQJMuoJTvgwgJzyufGCl6CRTKGwwqYgndy5TiFe/5dCD7hiqGD2X6AYOKLrYyHu/cIDZAsi8V3XUM60oaX3Awdks2LAC0w408OTYAXzCnZtUQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772419873; c=relaxed/simple; bh=XYjomkr0dTgWjwPjF8o60Bhsgl0frYza1cTvZQthwv8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=ZR1LE7uFzR3LLA226gXH3RPHyzCxuWlsgtaLaF2iY9Ro9na8CFvXtVrBinFyFbkYcuuhdbniUO/IPdtNWBqzoxvwRY2r5sAGVBXrbkhcdS40Q50qek7LqPuusoEcwFhYmUaLG7K8WAg4RFiHRIAiIlivrCM+ZXSRWwEtlQUNC6U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OOShjZZv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OOShjZZv" Received: by smtp.kernel.org (Postfix) with ESMTPS id 78429C116C6; Mon, 2 Mar 2026 02:51:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772419872; bh=XYjomkr0dTgWjwPjF8o60Bhsgl0frYza1cTvZQthwv8=; h=From:Date:Subject:To:Cc:Reply-To:From; b=OOShjZZvAFifyg0sFjaestiRUxm0YP4LTQ0++TB0MZjeQW25/XjiEQPJAECHA50/w rMbi2OuitMfVCxsgqOoJHeKRPM0HfYCqcbD2nPg9uYQ/TS9mH12DKYQh68XAD9h559 JzBSGWw66LBFJs0eW3nedi3TIR/sHtefgSdRPzvlTDbsObHiI4mVTg6jUeqzLPbNPg F9WgBInQ9hNRw3pGrML451x4i1qarqHDB9CE9QhYuoqCXICXQS+yBFvVLcuzoIPg/u iTD5/f5Zz057eAUG+y3J4QN5k+bvvWZxv9l03SbHoQUlDFDqFavGE6PztOiQrrSoiU PlLfbyTXmkaUA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EAB7D58E4A; Mon, 2 Mar 2026 02:51:12 +0000 (UTC) From: Jiucheng Xu via B4 Relay Date: Mon, 02 Mar 2026 10:51:03 +0800 Subject: [PATCH] block: avoild hang when bio_list is non-NULL in submit_bio_wait() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260302-for-next-v1-1-eb9339e8dc99@amlogic.com> X-B4-Tracking: v=1; b=H4sIABb7pGkC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDIyMT3bT8It281IoS3ZQ0szQDo2RjM0uTFCWg8oKi1LTMCrBR0bG1tQA I0PQ8WgAAAA== X-Change-ID: 20260224-for-next-df6f02c3694d To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, jianxin.pan@amlogic.com, tuan.zhang@amlogic.com, Jiucheng Xu X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1772419870; l=1659; i=jiucheng.xu@amlogic.com; s=20250821; h=from:subject:message-id; bh=umq++sfYBrcQgzncaR6KD4RDdLQo6hXzgnvNht92JHc=; b=X4RjgRRm6Nf1/IzXU5/a0BXUn8bhim1Iv+n8TXxQpemJztwPBKYqS1YR+PYAsHBQI8wb+Ky9E e7RVwpTFwg8CPn//V6Q8dE0FjNN2kt+krfZ6ZZLFPp9hSxEcEzWQ9zw X-Developer-Key: i=jiucheng.xu@amlogic.com; a=ed25519; pk=Q18IjkdWCCuncSplyu+dYqIrm+n42glvoLFJTQqpb2o= X-Endpoint-Received: by B4 Relay for jiucheng.xu@amlogic.com/20250821 with auth_id=498 X-Original-From: Jiucheng Xu Reply-To: jiucheng.xu@amlogic.com 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. 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 __pte_alloc_kernel __alloc_pages_direct_reclaim shrink_folio_list __swap_writepage submit_bio_wait hang!!! Signed-off-by: Jiucheng Xu --- block/bio.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/block/bio.c b/block/bio.c index d80d5d26804e32944bcfe4506ca190033308844f..22c8769722cc89620c239310a0f= 3d4924de68cf9 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1505,8 +1505,17 @@ int submit_bio_wait(struct bio *bio) bio->bi_private =3D &done; bio->bi_end_io =3D submit_bio_wait_endio; bio->bi_opf |=3D REQ_SYNC; - submit_bio(bio); - blk_wait_io(&done); + if (!current->bio_list) { + submit_bio(bio); + blk_wait_io(&done); + } else { + struct bio_list *tmp =3D current->bio_list; + + current->bio_list =3D NULL; + submit_bio(bio); + blk_wait_io(&done); + current->bio_list =3D tmp; + } =20 return blk_status_to_errno(bio->bi_status); } --- base-commit: 8c5f40a3ba43ae9a26991f0e4a01a3a06e8958fc change-id: 20260224-for-next-df6f02c3694d Best regards, --=20 Jiucheng Xu