From nobody Mon Feb 9 03:17:04 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.2]) (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 06FED2C08D5; Mon, 26 Jan 2026 09:30:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.2 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769419863; cv=none; b=DJq/RKEEtQFrvVk84bQwVWtsm3+bcKDMZVX0u4BGh5xrCuOGGexBpQZAM4u2IYt9eu4A6NDpruCvaEnhFfXTi9CXAkbCm0V56nrv+YioJmzKl27XGKEi7nSX8TmCXKA9XC7ySzNjtgHXMmrfglS2xkOb5662Nz3zhhuuarsSmxg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769419863; c=relaxed/simple; bh=mzPwNXUV4ZxWLlHZJ2N1AOTqwXswP61wSZorg3if+Mg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=P/zmNf0YOJpj4cd6TnHDkWJsMMvGxlpNeQ/rCErEmHcR3V7XbcDXZ1YfHWL9EeY6D31E1AEBsQFeArP6UbphiGgYyjeWydnvts/VLa7MOuCLbuVTEAPQUIBlcoycUZb5aU0jKDxkQmS3bJQVWuL4N+v//TvvoLrCUkmfbrJYB0M= 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=AjkEfbpC; arc=none smtp.client-ip=117.135.210.2 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="AjkEfbpC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version: Content-Type; bh=fQJjArBs8z4tpzw6q1tGtcVC4Pkq36oY3aaUpPrwt3Q=; b=AjkEfbpCfaO460noH9G4mDKqGwgt5cRqozvlx1vqte8Xq/C3rIkNRS/JRUvS0a QjwpsqwJkiJiwx8eb2R/LaqYZ3bprxfScJEp9lzyNC0TkeAwKsRI2ek9TjR5h5d1 UPp/anLzgcmwyCUcIzgDykorCEpXQ5dcibwHu6Aa1mZSI= Received: from localhost.localdomain (unknown []) by gzsmtp4 (Coremail) with SMTP id PygvCgD3bqzjM3dp5S1NMg--.89S2; Mon, 26 Jan 2026 17:29:12 +0800 (CST) From: zhangshida2026@163.com To: colyli@fnnas.com, kent.overstreet@linux.dev, hch@infradead.org, axboe@kernel.dk, osandov@fb.com, bvanassche@acm.org Cc: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, zhangshida@kylinos.cn, starzhangzsd@gmail.com Subject: [PATCH v2] bcache: fix I/O accounting leak in detached_dev_do_request Date: Mon, 26 Jan 2026 17:28:54 +0800 Message-Id: <20260126092854.971870-1-zhangshida2026@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-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: PygvCgD3bqzjM3dp5S1NMg--.89S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Cry5JF1kGF1fKr18JF43Jrb_yoW8AF1xpr 48urWYkrZYqa18JFW8Aa1UJF1rtwsrtry3Xr48tw4UZrs5AFWqvwsIg3W5Xr13uFZ7CFZ2 yFnYqFWDu3Z8tF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07bjo7NUUUUU= X-CM-SenderInfo: x2kd0wxvklvtasqslqqrwthudrp/xtbC6Ag-S2l3M+jNVwAA3L From: Shida Zhang When a bcache device is in a detached state, iostat can show 100% utilization even after I/O workload completion. This happens because the caller, cached_dev_make_request(), calls bio_start_io_acct() to begin accounting. However, if the bio hits an early exit path in detached_dev_do_request()=E2=80=94either due to an unsupported discard request or a bio_alloc_clone() failure=E2=80=94the corresponding bio_end_io_acct() is never called. This leaves the in-flight counter permanently incremented, causing the kernel to report the device as 100% busy. Add the missing bio_end_io_acct() calls to these error/early-exit paths to ensure proper I/O accounting. Fixes: d62e26b3ffd28 ("block: pass in queue to inflight accounting") Signed-off-by: Shida Zhang Acked-by: Coly Li --- drivers/md/bcache/request.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index a02aecac05c..7d855e66a10 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -1107,6 +1107,7 @@ static void detached_dev_do_request(struct bcache_dev= ice *d, =20 if (bio_op(orig_bio) =3D=3D REQ_OP_DISCARD && !bdev_max_discard_sectors(dc->bdev)) { + bio_end_io_acct(orig_bio, start_time); bio_endio(orig_bio); return; } @@ -1114,6 +1115,7 @@ static void detached_dev_do_request(struct bcache_dev= ice *d, clone_bio =3D bio_alloc_clone(dc->bdev, orig_bio, GFP_NOIO, &d->bio_detached); if (!clone_bio) { + bio_end_io_acct(orig_bio, start_time); orig_bio->bi_status =3D BLK_STS_RESOURCE; bio_endio(orig_bio); return; --=20 2.34.1