From nobody Sun Oct 5 23:57:03 2025 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1692F2749D2; Mon, 28 Jul 2025 13:56:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753710986; cv=none; b=O0tTpc3PV5aybUJZzvFpajcZc+GYGBM4sWViLT/mzK/6IAv4B8+wPFcbce7PTuiGJLbYNtHFeyG8IF8u/hhJXFkoWAwVehBVtwouvoxMh3FPca4BMLPHVbfHR9dDHsJXor6Frgjy+wWcIFsnlwJGIPpQitZK5BnFksC1+Fw2y1c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753710986; c=relaxed/simple; bh=M7lnc7klguOFW0Jnl78Y6Htaz7nDBI55ytpfcb52tVQ=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=sa+M15jOr1MLhOrcrhp7jGFo6zaMcrcAiBh3MMA9q8t4UEodU/BF32Ce4xisc9T7hav4ZMklzJvha3lVloiOxG/IUYv/5IpM41r/ZOgn9eimZaL0CA2AEMnShTqNdp8hte2kXlGdmAkC/Qp3OflIwOD0VquGK4x3LRYPlIx36SY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=B+UCZ155; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="B+UCZ155" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=H8 Z98UX2QpJKHJm1iEKGrjeoRwfUPLLQylyfYu9g+Dk=; b=B+UCZ155/X6hYKzgMP Hs3muIDpDejfuzqVxcbn7PY3B74oWEJvr+G5EPiadC6sLa33MOJkoYNgnE61Zt5d rEJJh7Vr/yd+H6/eWlFTXItSI+IHcc/YwGWoqVs9LSWJv0oQK4ILx98Hsdhl8aKo 7PYCfSLTEs/5iFzm9YoEEDYts= Received: from localhost.localdomain (unknown []) by gzsmtp4 (Coremail) with SMTP id PygvCgDXGWVugYdoBTOdBA--.31694S2; Mon, 28 Jul 2025 21:55:59 +0800 (CST) From: laishangzhen To: Matthew Wilcox , Andrew Morton Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, laishangzhen Subject: [PATCH] mm: Removing the card during write operations blocks the I/O process when during the process Issue encountered: When formatting an SD card to ext4 using mkfs.ext4, if the card is ejected during the process, the formatting process blocks at balance_dirty_pages_ratelimited. Date: Mon, 28 Jul 2025 06:55:56 -0700 Message-Id: <20250728135556.20583-1-laishangzhen@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: PygvCgDXGWVugYdoBTOdBA--.31694S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7ZrW7XryrKr1kGF4rZF13Jwb_yoW8GF18pF yak39akrWUZr42gw1xGayDur4Y9FyrG3yUXFyUZa4avwnxWF1xKFWIga47KFy5tr95Cr12 qrs0y34Uuw1jyrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UMlk-UUUUU= X-CM-SenderInfo: podl2xhdqj6xlhq6il2tof0z/1tbiYh6YI2iHfU4PGQABsM Content-Type: text/plain; charset="utf-8" Modification approach: After card ejection, the dev in the bdi (backing_dev_info) is released in del_gendisk. Within generic_perform_write, if writeback is supported, it directly checks whether bdi->dev is NULL to determine if the card has been ejected. Once ejected, it becomes unnecessary to proceed with page allocation and data writing. Signed-off-by: laishangzhen --- mm/filemap.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 6af6d8f29..5d6ba9f02 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -4087,6 +4087,8 @@ ssize_t generic_perform_write(struct kiocb *iocb, str= uct iov_iter *i) struct address_space *mapping =3D file->f_mapping; const struct address_space_operations *a_ops =3D mapping->a_ops; size_t chunk =3D mapping_max_folio_size(mapping); + struct inode *inode =3D mapping->host; + struct backing_dev_info *bdi =3D inode_to_bdi(inode); long status =3D 0; ssize_t written =3D 0; =20 @@ -4101,6 +4103,12 @@ ssize_t generic_perform_write(struct kiocb *iocb, st= ruct iov_iter *i) retry: offset =3D pos & (chunk - 1); bytes =3D min(chunk - offset, bytes); + if (bdi->capabilities & BDI_CAP_WRITEBACK) { + if (bdi->dev =3D=3D NULL) { + status =3D -ENODEV; + break; + } + } balance_dirty_pages_ratelimited(mapping); =20 if (fatal_signal_pending(current)) { --=20 2.25.1