From nobody Mon Feb 9 08:54:42 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 61DF9335080; Mon, 26 Jan 2026 12:10:24 +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=1769429424; cv=none; b=OXvMgtTxyzYOhARTCV1eVgllVNQp0eJglordKtjRIGpBM8Cx4VCpI0Sa9caQ+SqIaKSLWkguU81RFDt0OxwlAyAZK8SXBegZyrES1rFTw/DGzjnoPLPs6KQJA3PIw+09Gj+F7Buz1iw3ipPxEPbMZN8oHorc+xDy0RAsCjvqWeQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769429424; c=relaxed/simple; bh=Z2vuFJFnrfkKh0zztMX68YS10QQimek5pSgWpfy6byo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=sITsQtn6W6L+Z93ZcuVmjM4348HLCsPIP9xEWJ0dbEOJj9EhcJDGXEsD2KtqbEptXSQENQvsEHFT2DmwzUN8LV+fAZyii79ux9VaO9ql9u10ycd7ylCJCO+PveKLZgLjQJsJL1ei+/NtvVAKAnese2KsdKzjSwigNC21PE+e4rE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B0s9R5zF; 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="B0s9R5zF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39AFFC2BC86; Mon, 26 Jan 2026 12:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769429424; bh=Z2vuFJFnrfkKh0zztMX68YS10QQimek5pSgWpfy6byo=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=B0s9R5zFW/S5QkGEu98U7nHJw6gEGRFBkgkNIA1UqLuRvVFUehcuKG32W+rVjRetR nx7x4y589y5gQRkDlXHYVwn8cZSF9Zy+YfWmfPF6yw8Hiuj3L85kOfUv7ucetoWEQP qkVX70l5qQlVdgiKFvWlcodKEHoeyXhNsART06uC0SkX9WE3gvPygc7zick7X1admz ZOg1VfDmVr70L0mYU9tMOt/dJ9MUPbOduK94Od9T8YevnQO0Bj1TMqwIg/h++cCubM XUz11SbzpL9LOUVrdM+CucP/m3GtgfDsHJ6Gn+e5LUUT2RTab9+1ZEHEKVMtk/wPdg VFkyS5DA73WzQ== From: Jeff Layton Date: Mon, 26 Jan 2026 07:10:13 -0500 Subject: [PATCH v3 1/2] nfsd: add a runtime switch for disabling delegated timestamps 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: <20260126-delegts-v3-1-079f29927b83@kernel.org> References: <20260126-delegts-v3-0-079f29927b83@kernel.org> In-Reply-To: <20260126-delegts-v3-0-079f29927b83@kernel.org> To: Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: 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=2593; i=jlayton@kernel.org; h=from:subject:message-id; bh=Z2vuFJFnrfkKh0zztMX68YS10QQimek5pSgWpfy6byo=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBpd1mtYJ+bOHCMfUp8eKqMxs1ME2TpiZjErHilX J4i3PHJ7c6JAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCaXdZrQAKCRAADmhBGVaC FRdQEADDBo1a2FOLWph9Apxc174orJTY2+Q+jOowHn/KXIjHcXgd37ZUI1mQmpeQjUFCqBDz0jp qR3cPwSumq19dY7w/qBr4JehiJq6B1To1WvC/UMO8CXF1QfnADNiD0hbUuKC4bkBNEGtYjwH0cQ h3iCZZKqPHiscVbdUdy5ESl/GN1dLVoy0CtB7yPJ0elqHp4X1QREXrNYnThh742e0xXzchrYKpN DqY51m3cZrCA/IU223De1iQMxdDGmhjhNPdREnE7qWqU5Jo6KIQ52ySKH7PE/9F7tCS7hHzf9fn gvgizdMscn7+gp1kzKoRXsnqcbkRUTJbqA0tHQE+Yg48c2HM9D93tPBoJxvEsMlIbzlvq55jqJP jR/wCPeT/DvDX34JzIZvgsValhHgqGsAMhNZ3r1TTP7m4AJE8RqlnF2a3DHefANlQ6vy6fm28o2 zSlY9XEZ7yp3T1pD2sb7mrH2TeJMtIOWmqRgJP2bEwEZZ9wHKtcdeg2pnhY4PjVoQj00gLNLRmH Qog9Z0eRKtUwSUf2Etb4yzEhr3lSkmLw39Ib1yFtJEtuckD78WyjKYXKcYV0D4jSB6ys2rvN4Gn DMi7gS8L9xwvgbG7W+J1CUFFknTHbzpFILH6FHrQnkCeOdFd+8qFc1hdtJ4CARfNnGqlIfg3tme xhNNSl4D99U4S8w== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 The delegated timestamp code seems to be working well enough now that we want to make it always be built in. In the event that there are problems though, we still want to be able to disable them for debugging purposes. Add a switch to debugfs to enable them at runtime. Signed-off-by: Jeff Layton --- fs/nfsd/debugfs.c | 4 ++++ fs/nfsd/nfs4state.c | 8 ++++++++ fs/nfsd/nfsd.h | 1 + 3 files changed, 13 insertions(+) diff --git a/fs/nfsd/debugfs.c b/fs/nfsd/debugfs.c index 7f44689e0a53edbfd6ade9dda6af4052976a65d3..386fd1c54f5277fd9b9544caa52= 20e234915264d 100644 --- a/fs/nfsd/debugfs.c +++ b/fs/nfsd/debugfs.c @@ -140,4 +140,8 @@ void nfsd_debugfs_init(void) =20 debugfs_create_file("io_cache_write", 0644, nfsd_top_dir, NULL, &nfsd_io_cache_write_fops); +#ifdef CONFIG_NFSD_V4 + debugfs_create_bool("delegated_timestamps", 0644, nfsd_top_dir, + &nfsd_delegts_enabled); +#endif } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 583c13b5aaf3cd12a87c7aae62fe6a8223368f55..2251ff43aac8ef8a3d01d7094d4= 0f9b2604763d6 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -76,6 +76,8 @@ static const stateid_t close_stateid =3D { =20 static u64 current_sessionid =3D 1; =20 +bool nfsd_delegts_enabled __read_mostly =3D true; + #define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(st= ateid_t))) #define ONE_STATEID(stateid) (!memcmp((stateid), &one_stateid, sizeof(sta= teid_t))) #define CURRENT_STATEID(stateid) (!memcmp((stateid), ¤tstateid, size= of(stateid_t))) @@ -6046,8 +6048,14 @@ nfsd4_verify_setuid_write(struct nfsd4_open *open, s= truct nfsd_file *nf) } =20 #ifdef CONFIG_NFSD_V4_DELEG_TIMESTAMPS +/* + * Timestamp delegation was introduced in RFC7862. Runtime switch for disa= bling + * this feature is /sys/kernel/debug/nfsd/delegated_timestamps. + */ static bool nfsd4_want_deleg_timestamps(const struct nfsd4_open *open) { + if (!nfsd_delegts_enabled) + return false; return open->op_deleg_want & OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS; } #else /* CONFIG_NFSD_V4_DELEG_TIMESTAMPS */ diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index a2e35a4fa105380c2d99cb0865003e0f7f4a8e8d..7c009f07c90b50d7074695d4665= a2eca85140eda 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -160,6 +160,7 @@ static inline void nfsd_debugfs_exit(void) {} #endif =20 extern bool nfsd_disable_splice_read __read_mostly; +extern bool nfsd_delegts_enabled __read_mostly; =20 enum { /* Any new NFSD_IO enum value must be added at the end */ --=20 2.52.0