From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794317356; b=aGWb6i+55/2d5ZgVt0AUreZjAU+piqCpKAGwmDQfm00EI5u/YlRxqBSQf0OkBe7dlVvS w5s+XuZ6N5zQzrZCa9pLOqZU6p6hnIzWtS12Yup52Zr3TV6BpTZuX4pmCu2f7xcnIBXzE IeXU2GhpFP0+aXopTHxE1p58FM/WiJYm9Dh/b4fY3F78ks0ZWJcY8J0lUG4H179oRef3l Y5nUOP4zeUz8k0F5/NEVtcuTJnjjXrVd2FOqlkOy8PLzBa1pGJbUa3v3e74YvEe2ZojVT tM+nel99cuciVngg/TN3Er8KLuMdEW873N+ua4ItkbpCElmIiuS5n3/DBVPiEFmNGwQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794317356; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=cG+V0dLM3AiB1HstVW5BfH/0/Bln2t/d9EsioqxD2NE=; b=G2plruNyqKmVvnnbZBqNRBCwXQiRrceeIr5vXnL3Z2KWytMwGOv6pH3KTwwirRLcMlW7 39+VBQYLXPnSpB+XaRux+oTJHx8mplDx7XZRi3LpZR6Wll6iIkY2UCj6M/8ze0EvlAvB+ XpCqseV7GSW0gnUwrNr+r/WDSrKZ8C3A+Ug69GgrWScdFgYqLVv/RgPbtNJ5ks1nKOtil f6XfN150DHFyr6q8F11eGssabYvzSShL+E+/G9Ka6EhIECp4yv+qbtOY8PxT35b76WLdW UiUgzqQjLn1YFaHJeIoGQaCivrdSvcCKZhFcXTiYy1AW4GA6IdDsokGpchDLPyR8emg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=A5BW7rey; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5D9BE606AF02 for ; Tue, 10 Nov 2026 13:29:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=A5BW7rey Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBADA1F0089F; Tue, 10 Nov 2026 13:29:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794317356; bh=cG+V0dLM3AiB1HstVW5BfH/0/Bln2t/d9EsioqxD2NE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=A5BW7reyiekZqtBAIi6ZdLLA+2kBWGmT5C1IfipdX/aJSQoQyasKp4O7sqwcch4ze vcRc1d6ZksQsu6fylUaBCsEvN8BIuCC3nFFl/ipxGJCClb0s0Eu+waj/0G7VIxL4UA Xn0rFtJlCfdm4m7XUwgd4gMX9LfuaFChXKiYyG+Lea86f6oAddEhwf6x7GPhLe4f1k 349QDHnaR5gdccsiariBSHL4CbAqQh+U88aqYhKMFGsuhnyu5nzy7v30wQX3zVzU47 NrDhkm9QVBYY1I8fW2hD6ejM3DG3rCn95aH9Cf2VMZSdDPQTXrHhEgrxzpoZaZZTz/ V8+SkSKba+1Sw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] ext4: make concurrent DEFAULT shutdown waits killable Reply-To: sashiko-reviews@lists.linux.dev To: diasyzhangqing@gmail.com Cc: linux-ext4@vger.kernel.org, tytso@mit.edu In-Reply-To: <20261110132118.11265-1-diasyzhangqing@gmail.com> References: <6af1e75f.3e87765f.91969.0010.GAE@google.com> <20261110132118.11265-1-diasyzhangqing@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Nov 2026 13:29:15 +0000 X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Qing Zhang >=20 > Concurrent DEFAULT shutdown callers can all pass the shutdown flag > check before the first caller finishes bdev_freeze(). They then wait > uninterruptibly on bd_fsfreeze_mutex and may perform redundant > freeze/thaw operations, triggering hung-task reports if the initial > freeze takes long enough. >=20 > Serialize DEFAULT shutdown attempts with a per-superblock mutex > acquired killably. Re-check the shutdown flag after acquiring it to > skip the freeze after a successful attempt, or retry if the previous > attempt failed. >=20 > Leave LOGFLUSH and NOLOGFLUSH unchanged. The ->shutdown callback uses > NOLOGFLUSH with s_umount held, so it must not acquire a mutex held > across a freeze. This does not shorten the initial freeze or prevent > hung-task reports for the active freezer and other freeze-blocked > tasks. >=20 > Fixes: 783d94854499 ("ext4: add EXT4_IOC_GOINGDOWN ioctl") > Reported-by: syzbot+d4ecb9a1e5b3dcf8baec@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3Dd4ecb9a1e5b3dcf8baec > Signed-off-by: Qing Zhang Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110132118.1126= 5-1-diasyzhangqing@gmail.com?part=3D1