From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11147C433ED for ; Thu, 6 May 2021 10:02:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCD4361185 for ; Thu, 6 May 2021 10:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234274AbhEFKDF (ORCPT ); Thu, 6 May 2021 06:03:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:56822 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231194AbhEFKDD (ORCPT ); Thu, 6 May 2021 06:03:03 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 86A7BB17F; Thu, 6 May 2021 10:02:01 +0000 (UTC) Received: from localhost (brahms [local]) by brahms (OpenSMTPD) with ESMTPA id 139b4b61; Thu, 6 May 2021 10:03:32 +0000 (UTC) From: Luis Henriques To: Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet Cc: David Howells , linux-fsdevel@vger.kernel.org, v9fs-developer@lists.sourceforge.net Subject: 9p: fscache duplicate cookie Date: Thu, 06 May 2021 11:03:31 +0100 Message-ID: <87czu45gcs.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi! I've been seeing fscache complaining about duplicate cookies in 9p: FS-Cache: Duplicate cookie detected FS-Cache: O-cookie c=00000000ba929e80 [p=000000002e706df1 fl=226 nc=0 na=1] FS-Cache: O-cookie d=0000000000000000 n=0000000000000000 FS-Cache: O-key=[8] '0312710100000000' FS-Cache: N-cookie c=00000000274050fe [p=000000002e706df1 fl=2 nc=0 na=1] FS-Cache: N-cookie d=0000000037368b65 n=000000004047ed1f FS-Cache: N-key=[8] '0312710100000000' It's quite easy to reproduce in my environment by running xfstests using the virtme scripts to boot a test kernel. A quick look seems to indicate the warning comes from the v9fs_vfs_atomic_open_dotl() path: [ 383.688975] __fscache_acquire_cookie+0xd1/0x2d0 [ 383.688983] v9fs_cache_inode_get_cookie.part.0+0xd1/0x100 [ 383.688988] ? v9fs_vfs_link+0x160/0x160 [ 383.688994] v9fs_inode_from_fid_dotl+0x141/0x180 [ 383.688998] v9fs_vfs_lookup.part.0+0x1ab/0x1f0 [ 383.689003] ? v9fs_vfs_create+0x80/0x80 [ 383.689007] v9fs_vfs_atomic_open_dotl+0x14f/0x4f0 [ 383.689011] ? do_raw_spin_unlock+0xa3/0x130 [ 383.689016] ? v9fs_inode_from_fid_dotl+0x180/0x180 [ 383.689021] ? __d_lookup_rcu+0x270/0x270 [ 383.689029] ? down_read+0x13b/0x2c0 [ 383.689044] ? rwsem_down_read_slowpath+0x5b0/0x5b0 [ 383.689052] ? __d_lookup+0xb7/0x220 [ 383.689059] path_openat+0xb33/0x15a0 [ 383.689068] ? path_lookupat.isra.0+0x230/0x230 [ 383.689073] ? orc_find.part.0+0x200/0x200 [ 383.689078] ? ftrace_ops_trampoline+0x51/0x80 [ 383.689083] ? __kernel_text_address+0xe/0x30 [ 383.689087] ? unwind_get_return_address+0x2f/0x50 [ 383.689091] ? set_syscall_user_dispatch+0xb0/0xb0 [ 383.689096] ? arch_stack_walk+0x9e/0xf0 [ 383.689101] do_filp_open+0x136/0x1c0 [ 383.689105] ? may_open_dev+0x50/0x50 [ 383.689109] ? simple_attr_release+0x30/0x30 [ 383.689113] ? do_raw_spin_lock+0x119/0x1d0 [ 383.689116] ? rwlock_bug.part.0+0x60/0x60 [ 383.689119] ? do_raw_spin_unlock+0xa3/0x130 [ 383.689123] ? _raw_spin_unlock+0xa/0x10 [ 383.689128] ? alloc_fd+0x12e/0x290 [ 383.689132] do_sys_openat2+0x2f6/0x420 [ 383.689137] ? file_open_root+0x200/0x200 [ 383.689141] ? rwsem_wake.isra.0+0x100/0x100 [ 383.689146] do_sys_open+0x8a/0xe0 [ 383.689150] ? filp_open+0x50/0x50 [ 383.689153] ? asm_exc_page_fault+0x8/0x30 [ 383.689156] ? __x64_sys_openat+0x3e/0x60 [ 383.689159] do_syscall_64+0x45/0x80 [ 383.689163] entry_SYSCALL_64_after_hwframe+0x44/0xae Is this a know issue? Cheers, -- Luis