From nobody Wed Nov 27 08:27:31 2024 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 92A4F1990C1; Thu, 10 Oct 2024 19:57:10 +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=1728590230; cv=none; b=NgSrlBVxfS1MFsOUodgTstgOChwOCtHE2E7meQZF2mCD7KHXVszlk0L2ewrLFVSQxvq9jM6KZUmull9Yr5v1jA0C3jttVc99+lyeBrH3kE9Riz/HK+sAbm380LVSFjYH/PL6V3EWpjZqJwZ4ih6QKPeM51yyv8tXkmpB9qTqIAA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728590230; c=relaxed/simple; bh=q9Q/osgeAQXVfJAaHOfFlNollpmh1cJYbXNK0esuEbc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=emKoAMw7nOAPN4wiEwZ43OtFw5HxUPM8rJEcG4NrHkVQNcRVsuy7ubacxfm7/c5lXB7yWG9oTS/tuPWSGWEk+NxqD9ooBKCn4pprdRZyzITzun6iXuOQ7haWS4CO42DUA1nz+ToYkLMUcxBzBZSIhdv+QkSTnxYY4Zno4E8C8ds= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZIQw5q6T; 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="ZIQw5q6T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51A97C4CEC5; Thu, 10 Oct 2024 19:57:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728590230; bh=q9Q/osgeAQXVfJAaHOfFlNollpmh1cJYbXNK0esuEbc=; h=From:Date:Subject:To:Cc:From; b=ZIQw5q6TCBLsIV2ZfkgA1p2lJofWPuOHM6Tt/ejVGH+5/vttDbyuK1tYkqCPOZoZb rdCYx+6hosSrDLlZFVSxCkcg91CzpdsG0o/qZ+piBwMbVzfGRgFkrKcellgoM0ijU2 xBqUplGCOIferYXtpd1KY6lTtyQORUSLdULX0Lve1W293HbZtFutr9C0K3li3Oz9t+ DfaiSKLNSXgKW3yAYGfF5xD8+slECYPZEKqdbQz7bTNw3T/uW1k5gRFL7mMNmMBz7R hEhggUb5N0GJrnIDQLatIHq1gLEJmZ3MgqgkpFDCp/ABHFK2/jYV3tXobHINCrSUX7 i0yn/hBvCsAyA== From: Jeff Layton Date: Thu, 10 Oct 2024 15:56:55 -0400 Subject: [PATCH] nfsd: handle OPEN_XOR_DELEGATION outside of st_mutex in open codepath 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: <20241010-delstid-v1-1-1e0533c6617b@kernel.org> X-B4-Tracking: v=1; b=H4sIAIYxCGcC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIxNDA0MD3ZTUnOKSzBTdlCSjREOjNCMTozRjJaDqgqLUtMwKsEnRsbW1AOm 3cEdZAAAA X-Change-ID: 20241010-delstid-db2a12f242f3 To: Chuck Lever , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, kernel test robot , Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3225; i=jlayton@kernel.org; h=from:subject:message-id; bh=q9Q/osgeAQXVfJAaHOfFlNollpmh1cJYbXNK0esuEbc=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBnCDGN9sXfc5DauxclktLtMGkCH6tstpA0rcJWp Io/YqB/m0mJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZwgxjQAKCRAADmhBGVaC FXIoEACI2vArBHpYfD5ZRa7SSQE7KeayjUjKJFCIYp+hvqbof7VzPDTU2j7e1lRd/Oj6ieHy3pG VLUtC8BIpyidJ03eyaOdNg9uH87WdFDUgvPEfy/yiKgZrZceper/66BDoB+x1+PtgCZ4QEABqMe bUDltrvBZfhC/+x2u9QeuEXssUjnPzX2dw3gSxc6L9+qyp+MaMiYhTOyRZXPu1LkhLK20WhUyfV NvcpfgKZOVyyxCqIyIjIxtlhZTHh9lZhm6kpk0azlQqrB1C7uX3heceswzAAnbs6alI8AF6vPe1 XPHzbAptFv9yrWF1Vgd+W/wLiDeNVjmGnO24PzTi/3OD4+z9EtEwVwhmthLkK3VcG78CRBwqffJ ZNGzVl0KAD5CidMHhIZqUCozoiuFK2fIyI7bmXJNxpYxA8wbMCZNap8sQwi0WV4cDPr9Pikj+jA QPWhfVM1ilgMC+rHo6p4M036V9EFQSBqe9I2WeDg1+/QWe68ravqjtHztQPS6SwUzw4UmwsgIvz ucZUba59BSiJbBV4k9o6pABToX5lUEWVKNrQeIkMy7mCEoO9/tBv7eMjlOQ/Gk7Sb9ZdpMVzQXN GhU2Vu66xzpvxwDgrXjSTra10N8kwn84qpfb4WIZJZpPkDtK+eksZ2wyROJT0EwOto1Mk480QrD uYsF4LZSXGYS+hQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 When I originally wrote these patches, I was under the mistaken impression that I didn't need to increment the stateid in the case of an existing stateid (because we weren't returning it). After some discussion upstream, it turns out that the server should ignore the WANT_OPEN_XOR_DELEGATION flag if there is an outstanding open stateid. Given that, there is no need to expand the scope of the st_mutex to cover acquiring the delegation. The server may end up bumping the seqid in a brand new open stateid that it ends up discarding, but that's not a problem. This also seems to lower the "App Overhead" on the fs_mark test that the kernel test robot reported. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409161645.d44bced5-oliver.sang@in= tel.com Fixes: e816ca3f9ee0 ("nfsd: implement OPEN_ARGS_SHARE_ACCESS_WANT_OPEN_XOR_= DELEGATION") Signed-off-by: Jeff Layton --- We had a report of a performance regression (in the form of higer "App Overhead") in fs_mark. After some experimentation, I found that the cause seemed to be the change in how the mutex is handled in e816ca3f9ee0. This patch restores the App Overhead back to its previous levels (and may even improve it a bit -- go figure). Chuck, this should probably be squashed into e816ca3f9ee0. --- fs/nfsd/nfs4state.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 9c2b1d251ab31b4e504cf301d1deaa4945bd244f..73c4b983c048c101d16ec146b3f= 80922bcca3c69 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6120,7 +6120,6 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct sv= c_fh *current_fh, struct nf struct nfs4_delegation *dp =3D NULL; __be32 status; bool new_stp =3D false; - bool deleg_only =3D false; =20 /* * Lookup file; if found, lookup stateid and check open request, @@ -6175,6 +6174,9 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct sv= c_fh *current_fh, struct nf open->op_odstate =3D NULL; } =20 + nfs4_inc_and_copy_stateid(&open->op_stateid, &stp->st_stid); + mutex_unlock(&stp->st_mutex); + if (nfsd4_has_session(&resp->cstate)) { if (open->op_deleg_want & NFS4_SHARE_WANT_NO_DELEG) { open->op_delegate_type =3D NFS4_OPEN_DELEGATE_NONE_EXT; @@ -6194,17 +6196,12 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct = svc_fh *current_fh, struct nf * returned. Only respect WANT_OPEN_XOR_DELEGATION when a new * open stateid would have to be created. */ - deleg_only =3D new_stp && open_xor_delegation(open); -nodeleg: - if (deleg_only) { + if (new_stp && open_xor_delegation(open)) { memcpy(&open->op_stateid, &zero_stateid, sizeof(open->op_stateid)); open->op_rflags |=3D OPEN4_RESULT_NO_OPEN_STATEID; release_open_stateid(stp); - } else { - nfs4_inc_and_copy_stateid(&open->op_stateid, &stp->st_stid); } - mutex_unlock(&stp->st_mutex); - +nodeleg: status =3D nfs_ok; trace_nfsd_open(&stp->st_stid.sc_stateid); out: --- base-commit: 144cb1225cd863e1bd3ae3d577d86e1531afd932 change-id: 20241010-delstid-db2a12f242f3 Best regards, --=20 Jeff Layton