From patchwork Tue May 2 16:27:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9708283 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2E9336021C for ; Tue, 2 May 2017 16:27:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2001B2844C for ; Tue, 2 May 2017 16:27:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 134EE2847B; Tue, 2 May 2017 16:27:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 660922844C for ; Tue, 2 May 2017 16:27:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750769AbdEBQ1J (ORCPT ); Tue, 2 May 2017 12:27:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:50594 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750770AbdEBQ1I (ORCPT ); Tue, 2 May 2017 12:27:08 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8580BAAF2; Tue, 2 May 2017 16:27:06 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id E6D871E35B3; Tue, 2 May 2017 18:27:04 +0200 (CEST) Date: Tue, 2 May 2017 18:27:04 +0200 From: Jan Kara To: Corentin Labbe Cc: jack@suse.cz, anna.schumaker@netapp.com, hch@lst.de, trond.myklebust@primarydata.com, axboe@fb.com, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [BUG] cannot mount nfs, bisected to 0db10944a76ba ("nfs: Convert to separately allocated bdi") Message-ID: <20170502162704.GM13916@quack2.suse.cz> References: <20170428095624.GA22965@Red> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170428095624.GA22965@Red> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hello, On Fri 28-04-17 11:56:24, Corentin Labbe wrote: > Since linux next-20170421, mounting nfs give me: > [ 774.994934] ------------[ cut here ]------------ > [ 774.994975] WARNING: CPU: 1 PID: 10284 at /linux-next/fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x74 > [ 774.994985] sysfs: cannot create duplicate filename '/devices/virtual/bdi/0:32' > [ 774.994992] Modules linked in: axp20x_usb_power gpio_axp209 nvmem_sunxi_sid sun4i_dma sun4i_ss virt_dma > [ 774.995047] CPU: 1 PID: 10284 Comm: mount.nfs Not tainted 4.11.0-rc4+ #14 > [ 774.995054] Hardware name: Allwinner sun7i (A20) Family > [ 774.995085] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [ 774.995104] [] (show_stack) from [] (dump_stack+0x78/0x8c) > [ 774.995121] [] (dump_stack) from [] (__warn+0xe8/0x100) > [ 774.995135] [] (__warn) from [] (warn_slowpath_fmt+0x38/0x48) > [ 774.995150] [] (warn_slowpath_fmt) from [] (sysfs_warn_dup+0x64/0x74) > [ 774.995167] [] (sysfs_warn_dup) from [] (sysfs_create_dir_ns+0x84/0x94) > [ 774.995184] [] (sysfs_create_dir_ns) from [] (kobject_add_internal+0x9c/0x2ec) > [ 774.995199] [] (kobject_add_internal) from [] (kobject_add+0x48/0x98) > [ 774.995217] [] (kobject_add) from [] (device_add+0xe4/0x5a0) > [ 774.995232] [] (device_add) from [] (device_create_groups_vargs+0xac/0xbc) > [ 774.995247] [] (device_create_groups_vargs) from [] (device_create_vargs+0x20/0x28) > [ 774.995263] [] (device_create_vargs) from [] (bdi_register_va+0x44/0xfc) > [ 774.995280] [] (bdi_register_va) from [] (super_setup_bdi_name+0x48/0xa4) > [ 774.995299] [] (super_setup_bdi_name) from [] (nfs_fill_super+0x1a4/0x204) > [ 774.995315] [] (nfs_fill_super) from [] (nfs_fs_mount_common+0x140/0x1e8) > [ 774.995333] [] (nfs_fs_mount_common) from [] (nfs4_remote_mount+0x50/0x58) > [ 774.995349] [] (nfs4_remote_mount) from [] (mount_fs+0x14/0xa4) > [ 774.995368] [] (mount_fs) from [] (vfs_kern_mount+0x54/0x128) > [ 774.995385] [] (vfs_kern_mount) from [] (nfs_do_root_mount+0x80/0xa0) > [ 774.995400] [] (nfs_do_root_mount) from [] (nfs4_try_mount+0x28/0x3c) > [ 774.995415] [] (nfs4_try_mount) from [] (nfs_fs_mount+0x2cc/0x8c4) > [ 774.995430] [] (nfs_fs_mount) from [] (mount_fs+0x14/0xa4) > [ 774.995445] [] (mount_fs) from [] (vfs_kern_mount+0x54/0x128) > [ 774.995461] [] (vfs_kern_mount) from [] (do_mount+0x158/0xc7c) > [ 774.995475] [] (do_mount) from [] (SyS_mount+0x8c/0xb4) > [ 774.995491] [] (SyS_mount) from [] (ret_fast_syscall+0x0/0x3c) > [ 774.995501] ---[ end trace 0665e451f8864ff0 ]--- ... > The mount command is > mount -t nfs -o tcp,hard,intr,async,rsize=4096,wsize=4096 192.168.1.100:/mnt/local_kernel /usr/src/ > > the mount command failling with: "mount.nfs: Cannot allocate memory" I've tried reproducing this (both with NFSv3 and NFSv4) and failed. Also I have looked through the code and I fail to see how this could happen. Is this the only NFS mount that you have on your system? Didn't also the WARN_ON in super_setup_bdi_name() trigger? Can you run with the attached debug patch and post full dmesg after the failure? Honza From 90f66349ce91d8dd4811eca5efffb605cf084193 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 2 May 2017 18:24:57 +0200 Subject: [PATCH] nfs: Debug bdi registration failure Debug failure and fixup error code propagation. Signed-off-by: Jan Kara --- fs/nfs/super.c | 5 ++++- mm/backing-dev.c | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index dc69314d455e..f60a387105ad 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2344,6 +2344,8 @@ int nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info) nfs_initialise_sb(sb); + printk("Registering bdi %u:%u for server %p\n", MAJOR(server->s_dev), MINOR(server->s_dev), server); + dump_stack(); ret = super_setup_bdi_name(sb, "%u:%u", MAJOR(server->s_dev), MINOR(server->s_dev)); if (ret) @@ -2607,7 +2609,7 @@ struct dentry *nfs_fs_mount_common(struct nfs_server *server, /* initial superblock/root creation */ error = mount_info->fill_super(s, mount_info); if (error) - goto error_splat_super; + goto error_splat_super_err; nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned); } @@ -2630,6 +2632,7 @@ struct dentry *nfs_fs_mount_common(struct nfs_server *server, error_splat_root: dput(mntroot); +error_splat_super_err: mntroot = ERR_PTR(error); error_splat_super: deactivate_locked_super(s); diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f028a9a472fd..ac173d06834a 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -923,6 +923,8 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi) void bdi_unregister(struct backing_dev_info *bdi) { + printk("Unregistering bdi %s\n", dev_name(bdi->dev)); + dump_stack(); /* make sure nobody finds us on the bdi_list anymore */ bdi_remove_from_list(bdi); wb_shutdown(&bdi->wb); -- 2.12.0