From nobody Thu Apr 9 04:03:26 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 BCE5638B133 for ; Wed, 11 Mar 2026 07:22:47 +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=1773213767; cv=none; b=B0xMuvEhRGovB7Ojg64fC3IFx9YvHEiSh+TTp0zo80Jnx3HmINa8e9MSaVVSyc5+/yWAbhA31tfUG691NPHSr5FfF2T0ujTZkiJp7wiqHnW7KbC1HufnNXnTbvJBZmo92KsBUtnr6gN4QEujGSjvdtVa+afSW7+dJ4KlgWZPPHQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773213767; c=relaxed/simple; bh=m7ADRIW7RFYYIrjtqvF0zF5SCfBDetrXU5BeIzQ+buY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=e++GcoEX8Op/imddi99SWqQz13R4toXmXngPZwqafU8sFIjDr2UwT3T7mK1QsNpKsiLGAzBa4brFxDSwZQU8gXIfhEVRt618JpD5t2MGs/KCwtkaKggx63TvzT38yAGKHb+/Rd0DgDsB8IFZtDyKAcdogSD1s3tu1WiINoxUHqE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FVg0IDG9; 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="FVg0IDG9" Received: by smtp.kernel.org (Postfix) with ESMTPS id 28265C4CEF7; Wed, 11 Mar 2026 07:22:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773213767; bh=m7ADRIW7RFYYIrjtqvF0zF5SCfBDetrXU5BeIzQ+buY=; h=From:Date:Subject:To:Cc:Reply-To:From; b=FVg0IDG9cp9gRegQZJHQSa81Dzcj9wcTUxMGHJF31GuKzZ4ErzySrXl06pzTlQqGA pHEIb4XPqbjNAzIzlGSB6tBqUoJfl2q0HhOCn7R6Z6i6XNZw/0UzX7iFZLZq8Qc9NE b9kwzvZLOarnlEEjt5abJKKNp45GDReDvWvuZNt1XITbOtOhhuFZiAWww0wuC5uhJN n2NZyGhRKTBWLZNEZVCSO6S8TqTZya18/EZUOviMa12skGn6Pzo9bf+AJezQhQkWlt rNAA3LWJ1D6KxHHdenFrVZImIsdKiP49fUMdbh/BLNKvTL0w25tlE4nRA33pnbqNVK qL9QUddvAXXJA== 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 1501CFD0648; Wed, 11 Mar 2026 07:22:47 +0000 (UTC) From: Jiucheng Xu via B4 Relay Date: Wed, 11 Mar 2026 15:22:34 +0800 Subject: [PATCH] erofs: use GFP_NOIO in endio decompression path of erofs 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: <20260311-origin-dev-v1-1-40524ef07ff0@amlogic.com> X-B4-Tracking: v=1; b=H4sIADkYsWkC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDY0ND3fyizPTMPN2U1DJdw2RLMzNTc0sLIwMTJaCGgqLUtMwKsGHRsbW 1AF5jXR5cAAAA X-Change-ID: 20260311-origin-dev-1c9665798204 To: Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu , Sandeep Dhavale , Hongbo Li , Chunhai Guo Cc: linux-erofs@lists.ozlabs.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=1773213766; l=1783; i=jiucheng.xu@amlogic.com; s=20250821; h=from:subject:message-id; bh=M0DxC1YSsNeUXU4lWpQgPmCwcDRu1aw6juBcKAOFoVM=; b=ugKwv1rm6H2qLye79IJSJ4l//Zmqe9nzUqXC6/9IrEJa+VRQ1DSlVFZTgzZXXk8PfbtMAiR1X pJ2N00kgkSRCJW4cJ4EGDTq+vIS5vsU2wTZkgsUJGoXqxxYaw/ekjFY 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 The endio decompression path of erofs calls vm_map_ram(). Due to insufficient memory, this function may generate memory swapping I/O, which can cause submit_bio_wait to deadlock in some scenarios. Trimmed down the call stack, as follows: f2fs_submit_read_io submit_bio //bio_list is initialized. 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 //bio_list is non-NULL, hang!!! Use memalloc_noio_{save,restore}() to wrap up this path. Signed-off-by: Jiucheng Xu Reviewed-by: Gao Xiang --- fs/erofs/zdata.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 3977e42b9516861bf3d59c072b6b8aaa6898dd8a..fe8121df9ef2f2404fc6e3f0fbb= d6367f9ec2c67 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1445,6 +1445,7 @@ static void z_erofs_decompress_kickoff(struct z_erofs= _decompressqueue *io, int bios) { struct erofs_sb_info *const sbi =3D EROFS_SB(io->sb); + int gfp_flag; =20 /* wake up the caller thread for sync decompression */ if (io->sync) { @@ -1477,7 +1478,9 @@ static void z_erofs_decompress_kickoff(struct z_erofs= _decompressqueue *io, sbi->sync_decompress =3D EROFS_SYNC_DECOMPRESS_FORCE_ON; return; } + gfp_flag =3D memalloc_noio_save(); z_erofs_decompressqueue_work(&io->u.work); + memalloc_noio_restore(gfp_flag); } =20 static void z_erofs_fill_bio_vec(struct bio_vec *bvec, --- base-commit: 11439c4635edd669ae435eec308f4ab8a0804808 change-id: 20260311-origin-dev-1c9665798204 Best regards, --=20 Jiucheng Xu