From patchwork Mon Mar 10 09:41:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 14009477 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 23EFE223322 for ; Mon, 10 Mar 2025 09:42:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741599744; cv=none; b=B8hckmlN6eugc/ghD3dR40n48jomQPAT477250b+KnVHkt3yXnsfsF/c3WfD1xEHnjFJ+MpDsC3CU9VkCLGerJRyKZNhekYwxZlURAsSuVbnWEuppB73imE/WOoN4BXrBMqkcCh07vp4b/JOstoRLyIKViKuafAvd1V4nNT17Ik= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741599744; c=relaxed/simple; bh=9NUbkeHFJVXSvpJC6cffvGAry+3XZDrlAYjzGGwtup4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SS3RHI0khzhQAq6XuF5HSVGIe5tEIUkPH9U5ytJXfEPuW5QSxvSq5V0ncT39DSMIGpFL1LwXXG8t7kuO7iMqCqtpD5VF6hrpD2FxFQ52F8f7owbEjmX10AU3bE0CL5SuQAztl2oWrJpqKC/kNqRzkkxfk2/FPLfPwVVvvV+VesM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Fy3cAe1t; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Fy3cAe1t" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741599742; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Sp9hYSzH6vGjH5HKqctZ4em7wna5YpsrQRLignkLGyE=; b=Fy3cAe1tCTOf02n7iXTAoE+aoSI/XuX0XHbjbwvPP09TeSDhXy39Xa0qLO7kCBLJTmqenv 3oYUdVtdv94pOmXE6smCI8AmRD7004NJgL8ZUOcv6EvQyyuBbZWIbyJEEBp/yWWOJbl4am FzLnIxlZpAQig/RazsVFIbm6bkq5qpo= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-481-OF0Y5ao4N9SMK71jUXUVLw-1; Mon, 10 Mar 2025 05:42:18 -0400 X-MC-Unique: OF0Y5ao4N9SMK71jUXUVLw-1 X-Mimecast-MFC-AGG-ID: OF0Y5ao4N9SMK71jUXUVLw_1741599737 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4F6121955BC1; Mon, 10 Mar 2025 09:42:12 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.61]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A5BA81800366; Mon, 10 Mar 2025 09:42:09 +0000 (UTC) From: David Howells To: Marc Dionne Cc: David Howells , Christian Brauner , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 00/11] afs, rxrpc: Clean up refcounting on afs_cell and afs_server records Date: Mon, 10 Mar 2025 09:41:53 +0000 Message-ID: <20250310094206.801057-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 This series fixes an occasional hang that's only really encountered when rmmod'ing the kafs module, one of the reasons why I'm proposing it for the next merge window rather than immediate upstreaming. The changes include: (1) Fix missing handling of RCU pathwalk in afs_atcell_get_link(). (2) Remove the "-o autocell" mount option. This is obsolete with the dynamic root and removing it makes the next patch slightly easier. (3) Change how the dynamic root mount is constructed. Currently, the root directory is (de)populated when it is (un)mounted if there are cells already configured and, further, pairs of automount points have to be created/removed each time a cell is added/deleted. This is changed so that readdir on the root dir lists all the known cell automount pairs plus the @cell symlinks and the inodes and dentries are constructed by lookup on demand. This simplifies the cell management code. (4) A few improvements to the afs_volume tracepoint. (5) A few improvements to the afs_server tracepoint. (6) Pass trace info into the afs_lookup_cell() function to allow the trace log to indicate the purpose of the lookup. (7) Remove the 'net' parameter from afs_unuse_cell() as it's superfluous. (8) In rxrpc, allow a kernel app (such as kafs) to store a word of information on rxrpc_peer records. (9) Use the information stored on the rxrpc_peer record to point to the afs_server record. This allows the server address lookup to be done away with. (10) Simplify the afs_server ref/activity accounting to make each one self-contained and not garbage collected from the cell management work item. (11) Simplify the afs_cell ref/activity accounting to make each one of these also self-contained and not driven by a central management work item. The current code was intended to make it such that a single timer for the namespace and one work item per cell could do all the work required to maintain these records. This, however, made for some sequencing problems when cleaning up these records. Further, the attempt to pass refs along with timers and work items made getting it right rather tricky when the timer or work item already had a ref attached and now a ref had to be got rid of. The patches are here: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=afs-next Thanks, David Changes ======= ver #4) - Add a fix patch to handle RCU pathwalk in afs_atcell_get_link(). ver #3) - Fix the fix for an error check of the form "unsigned value < 0". ver #2) - Fix an error check of the form "unsigned value < 0". Link: https://lore.kernel.org/r//3190716.1740733119@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r//3399677.1740754398@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r//3761344.1740995350@warthog.procyon.org.uk/ # v3 David Howells (11): afs: Fix afs_atcell_get_link() to handle RCU pathwalk afs: Remove the "autocell" mount option afs: Change dynroot to create contents on demand afs: Improve afs_volume tracing to display a debug ID afs: Improve server refcount/active count tracing afs: Make afs_lookup_cell() take a trace note afs: Drop the net parameter from afs_unuse_cell() rxrpc: Allow the app to store private data on peer structs afs: Use the per-peer app data provided by rxrpc afs: Fix afs_server ref accounting afs: Simplify cell record handling fs/afs/addr_list.c | 50 +++ fs/afs/cell.c | 446 ++++++++++++--------------- fs/afs/cmservice.c | 82 +---- fs/afs/dir.c | 5 +- fs/afs/dynroot.c | 501 +++++++++++++------------------ fs/afs/fs_probe.c | 32 +- fs/afs/fsclient.c | 4 +- fs/afs/internal.h | 100 +++--- fs/afs/main.c | 16 +- fs/afs/mntpt.c | 5 +- fs/afs/proc.c | 19 +- fs/afs/rxrpc.c | 8 +- fs/afs/server.c | 601 ++++++++++++++++--------------------- fs/afs/server_list.c | 6 +- fs/afs/super.c | 25 +- fs/afs/vl_alias.c | 7 +- fs/afs/vl_rotate.c | 2 +- fs/afs/volume.c | 15 +- include/net/af_rxrpc.h | 2 + include/trace/events/afs.h | 83 ++--- net/rxrpc/ar-internal.h | 1 + net/rxrpc/peer_object.c | 30 +- 22 files changed, 927 insertions(+), 1113 deletions(-)