From patchwork Thu Feb 20 16:47:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13984280 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 76DC8211A0B; Thu, 20 Feb 2025 16:47:28 +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=1740070048; cv=none; b=OOF4P2kW7Y6InBzm163zAGyW+2c7neKLjpGCoeX+XJCPOHXqqNGqy4VyZIX4s1Gsv6/l85QMHt9Sr7YGg7biU6mzfHkXeSI5c4/Y1eR+ejAQX7szBqTblJJNzbjypMGw4JcRXSSeXaZiDc4Lv9gp4NiVUsOAx1bV415QlqojInk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740070048; c=relaxed/simple; bh=C5p/ojW3QfHFyvcxVtc9cHreBC7v/KQwFhn3nzGhpEk=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=BP9i5yEkzTgl+sGONhMayOtyHGFYMTtS8gqZmLskA7b6zt+Sk6gcV04ZLgoW9jny1a2lEP+jxsb/B0tfM0G3xLSDwZdYYmb/Piu2fbzhEW7Ha13q3hpKAq8yspJjm5blw50r3A2/qZxQO1srQ1r7PNipbf+gDKVzuNFVgfVwCcw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CGWGbma/; 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="CGWGbma/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28A8EC4CED1; Thu, 20 Feb 2025 16:47:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740070047; bh=C5p/ojW3QfHFyvcxVtc9cHreBC7v/KQwFhn3nzGhpEk=; h=From:Subject:Date:To:Cc:From; b=CGWGbma/2m6e3p5frqXg8A57Bj7nJ5u+W/FJtb4NSzwtzngyTqCipaoF0iek5XMmi +1H6iIPL64tCVlp4DvjDNXLD/VOITyCC57K2LnrdYe/Fn4VITZwKJVVZbN26cuDax8 8/syzH/8t0sqCTjor8rbVLLNevpQu4vtvcsP46jnp9HpGFPVhhiD0owy0qBs4cCcNP XlSjD8gVp0okq533aK0sXseGuQzS5Ult4yGJvsC/w9AWPhyLVA9axsu99+3UUIzCbE gPleLuY+nfft2Yeex7FttY15TBwrr7t4KosAAAyaISoLbRQ9au9+ptOMd8uD2GNH25 /MZwLnW0Dj+SA== From: Jeff Layton Subject: [PATCH v2 0/5] nfsd: don't allow concurrent queueing of workqueue jobs Date: Thu, 20 Feb 2025 11:47:12 -0500 Message-Id: <20250220-nfsd-callback-v2-0-6a57f46e1c3a@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAJBct2cC/3XMQQ7CIBRF0a00fywGsAJ15D5MBxQ+LWkDBgzRN Oxd7Nzhfck7O2RMHjPcuh0SFp99DC34qQOz6DAj8bY1cMqvlDNFgsuWGL1tkzYrcZJfJtUPykg F7fNM6Pz78B5j68XnV0yfgy/st/6TCiOUsN4NQgxCWqvuK6aA2zmmGcZa6xfkVP6mqwAAAA== X-Change-ID: 20250218-nfsd-callback-f723b8498c78 To: Chuck Lever , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: Li Lingfeng , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2116; i=jlayton@kernel.org; h=from:subject:message-id; bh=C5p/ojW3QfHFyvcxVtc9cHreBC7v/KQwFhn3nzGhpEk=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBnt1yZ6kX4I9MSfm+jtr2Ija35JdQx9LrKP4IuD gg38AGdRLOJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZ7dcmQAKCRAADmhBGVaC FQRwEADPhXqfHOWJH4PaK6HRJCcfOPYMiY+S9T4vJScKVFrns5+qirVozTX6Vn2+O2V7xyhu0LU qBLJYlmoWNk2xLl7GaQIj8k1yFOXHDa6+InP4qgwaVHOp6g0gyAWHZMOIgjMub9vhdFU2Maky4/ W1TC31NiZS60Oguwb66tvCzNrw1HFhqCBUYGjwK+ZOP5wfRTgAFlLvvVnkr+hPERpFyEYHdK+hr pIn/pmWSBFbQdXMUTFFeYNO38AfM0BkRMUr0rEdlrMTxbmUEEs/TqtSTWCmNws8sVfjD/cB3UXb dOSoqQpWkWoNvt26eFdBgaP3Ymi9ieIso2WwwfpUzJVcZAv1YDkujS3czIClhIIlvIiPqP9sSVI j/YRN02VcXXJH9pXDJ6imxb6Rk8oV9WSTGTGiyfM0WdqjB+VXH2SAKrSOd5+pitzpCtv9egQsLA iWm5BPZEd1p5uoKTLJQ9oBMy69HBZt2G0WcIYlRSo+uY65T9UfWTU/7xysDR3uX6AiagsX/AatQ S4WinM3aAZL5VDMGtHn4K9siw8gfPjoILsZ0otD4SHuqITDWXjfGQ6SYIz8dtEk5O5bgozS2E2w 1VSda0Vl/KtnzgNuHIwoN3juJSPhPraru+yhHR+lS5DWvk0sjjlFS78eErxNzOsjvVcAkzbYUsB Sn4jAbK4XUwSOtQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 While looking at the problem that Li Lingfeng reported [1] around callback queueing failures, I noticed that there were potential scenarios where the callback workqueue jobs could run concurrently with an rpc_task. Since they touch some of the same fields, this is incorrect at best and potentially dangerous. This patchset adds a new mechanism for ensuring that the same nfsd4_callback can't run concurrently with itself, regardless of where it is in its execution. This also gives us a more sure mechanism for handling the places where we need to take and hold a reference on an object while the callback is running. This should also fix the problem that Li Lingfeng reported, since queueing the work from nfsd4_cb_release() should never fail. Note that their earlier patch (fdf5c9413ea) should be dropped from nfsd-testing before this will apply cleanly. [1]: https://lore.kernel.org/linux-nfs/20250218135423.1487309-1-lilingfeng3@huawei.com/ Signed-off-by: Jeff Layton --- Changes in v2: - added patche to handle rpc_call_async() errors - rename NFSD4_CALLBACK_RESTART to NFSD4_CALLBACK_REQUEUE - add patch to replace CB_GETATTR_BUSY with NFSD4_CALLBACK_REQUEUE - Link to v1: https://lore.kernel.org/r/20250218-nfsd-callback-v1-0-14f966967dd8@kernel.org --- Jeff Layton (5): nfsd: prevent callback tasks running concurrently nfsd: eliminate cl_ra_cblist and NFSD4_CLIENT_CB_RECALL_ANY nfsd: replace CB_GETATTR_BUSY with NFSD4_CALLBACK_RUNNING nfsd: move cb_need_restart flag into cb_flags nfsd: handle errors from rpc_call_async() fs/nfsd/nfs4callback.c | 26 +++++++++++++++++--------- fs/nfsd/nfs4layouts.c | 7 ++++--- fs/nfsd/nfs4proc.c | 2 +- fs/nfsd/nfs4state.c | 31 ++++++++++++++----------------- fs/nfsd/state.h | 18 +++++++++++------- fs/nfsd/trace.h | 2 +- 6 files changed, 48 insertions(+), 38 deletions(-) --- base-commit: b7e85fd7c8964e31f8fa1cf7333b12f442b642f1 change-id: 20250218-nfsd-callback-f723b8498c78 Best regards,