From patchwork Thu Dec 12 11:01:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Su Yue X-Patchwork-Id: 11287907 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 00D15930 for ; Thu, 12 Dec 2019 11:01:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7C262077B for ; Thu, 12 Dec 2019 11:01:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QgnBPjbM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728945AbfLLLBk (ORCPT ); Thu, 12 Dec 2019 06:01:40 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:35923 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728871AbfLLLBj (ORCPT ); Thu, 12 Dec 2019 06:01:39 -0500 Received: by mail-pg1-f196.google.com with SMTP id k3so979539pgc.3 for ; Thu, 12 Dec 2019 03:01:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=lCXGc/wSJhn4wzphnffaLhuDhHbrWuw4a01//wlA3rw=; b=QgnBPjbMbZsEb7rWFYgAATgcEvm7TNsNazJpkpIQ98oyqM0Gdxn9sAIvELvP0+SBTt GE/5Qh98MsDLN+HiuUc8xeETw+j2pE8n9Aaqv/Q3krBOpNE6TS4JsvHdhIrpBnHg0JHJ BkBNSj3QcpDv/HiB4ByxQ4RCP3ESXEc0or9i4zloYyMBwRk3xh3rIYp92JRjnAHgBx8z PIpEJoN/kzHARUptG5btPQ44rAzJPuCJjKhXZAnyZexX5RVnqGAHt722bTovavV7YPvu NYTN3XXffHrC3syGeKPkvhePWxzZdVxxZ/JaCfy5zjYhXnrlTSjWHYP+CLs+0JMWxJBu EaBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=lCXGc/wSJhn4wzphnffaLhuDhHbrWuw4a01//wlA3rw=; b=a2COamEyulJeMflqmZywqtO3CQMXGMXoS/RaTJzGz9fPtIE1o5N7OhQYwBFgEvwddP oqZ//SPMM+JvsGbYjVRrv0fnoloVP2O7OHzcDbNlaiisxfbi3EP+PKI15ukdsw7pcyM8 /WkWN3x7TUl3wjHYWKa3/SlB5EusQvdz4hQ3B4zCytN76EdWhme18ba4t7muf/um/OrO KnQvv0/0G6vAVdLbYuYA3WXjYbneUkNMNPvJ4Iklovgg3xoaANiy6XLXMJsQa1MxKLab r8/BcoT53L9CpZ9d4VHeOcnDMEJW+HCfVQ6la/p3vh2LjrR66ScoSZ6tzrdNvEvP9YN2 tiVg== X-Gm-Message-State: APjAAAV7KQKdysRhcAlKIFr+GbK4Cl2W/CBSYc8Wld6XDBqs44wFcMrR gOTKFy6dGI5SvEOEkaCy6d22eXRuVXc= X-Google-Smtp-Source: APXvYqx4bzdO8rCWCz0CLckrVwuwr0VL4+opDaVYXn+joDt3acp46LY0w1pwdhIxFoxFesDdLMjJyA== X-Received: by 2002:a65:6842:: with SMTP id q2mr9973911pgt.345.1576148498487; Thu, 12 Dec 2019 03:01:38 -0800 (PST) Received: from p.lan ([45.58.38.246]) by smtp.gmail.com with ESMTPSA id w11sm6682387pfn.4.2019.12.12.03.01.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 12 Dec 2019 03:01:38 -0800 (PST) From: damenly.su@gmail.com X-Google-Original-From: Damenly_Su@gmx.com To: linux-btrfs@vger.kernel.org Cc: Su Yue Subject: [PATCH 1/6] btrfs: metadata_uuid: fix failed assertion due to unsuccessful device scan Date: Thu, 12 Dec 2019 19:01:27 +0800 Message-Id: <20191212110132.11063-2-Damenly_Su@gmx.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122.2) In-Reply-To: <20191212110132.11063-1-Damenly_Su@gmx.com> References: <20191212110132.11063-1-Damenly_Su@gmx.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Su Yue While running misc-tests/034 of btrfs-progs, easy to hit: ====================================================================== [ 1318.749685] BTRFS: device fsid 55abf31c-6b3a-47ad-8711-cfd5a249dd4c devid 2 transid 8 /dev/loop0 scanned by systemd-udevd (3530) [ 1318.846791] BTRFS: device fsid 55abf31c-6b3a-47ad-8711-cfd5a249dd4c devid 2 transid 8 /dev/loop0 scanned by systemd-udevd (3530) [ 1318.847812] BTRFS: device fsid 55abf31c-6b3a-47ad-8711-cfd5a249dd4c devid 2 transid 8 /dev/loop0 scanned by mount (3540) [ 1318.901278] assertion failed: !memcmp(fs_info->fs_devices->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE), in fs/btrfs/disk-io.c:2874 [ 1318.901499] ------------[ cut here ]------------ [ 1318.901503] kernel BUG at fs/btrfs/ctree.h:3118! [ 1318.901582] invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 1318.901644] CPU: 4 PID: 3540 Comm: mount Tainted: G O 5.5.0-rc1-custom+ #41 [ 1318.901720] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 1318.901836] RIP: 0010:assfail.constprop.0+0x1c/0x1e [btrfs] [ 1318.901894] Code: 00 00 44 89 c0 5b 41 5c 41 5d 41 5e 5d c3 55 89 f1 48 c7 c2 40 13 0f c1 48 89 fe 48 c7 c7 00 1b 0f c1 48 89 e5 e8 3e 12 0f dc <0f> 0b e8 93 01 39 dc be 56 03 00 00 48 c7 c7 a0 1b 0f c1 e8 cc ff [ 1318.902069] RSP: 0018:ffff88814fea76e0 EFLAGS: 00010282 [ 1318.902124] RAX: 000000000000007c RBX: ffff88814d862400 RCX: 0000000000000000 [ 1318.902191] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffed1029fd4ecf [ 1318.902259] RBP: ffff88814fea76e0 R08: 000000000000007c R09: ffffed102b3fe719 [ 1318.902326] R10: ffffed102b3fe718 R11: ffff888159ff38c7 R12: ffff8881398ac000 [ 1318.902394] R13: ffff888145742930 R14: ffff88812f56e000 R15: ffff88812f56e000 [ 1318.902464] FS: 00007f0753032500(0000) GS:ffff888159e00000(0000) knlGS:0000000000000000 [ 1318.902539] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1318.902595] CR2: 0000560357a9c018 CR3: 00000001502d4000 CR4: 0000000000340ee0 [ 1318.903852] Call Trace: [ 1318.904958] open_ctree+0x166c/0x373e [btrfs] [ 1318.906029] ? congestion_wait+0x2d0/0x2d0 [ 1318.907500] ? wb_init+0x31e/0x400 [ 1318.908699] ? close_ctree+0x52b/0x52b [btrfs] [ 1318.909734] btrfs_mount_root.cold+0xe/0x118 [btrfs] [ 1318.910764] ? btrfs_decode_error+0x40/0x40 [btrfs] [ 1318.911784] ? vfs_parse_fs_string+0xdc/0x130 [ 1318.912798] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 1318.913835] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 1318.914878] ? legacy_parse_param+0x75/0x340 [ 1318.915946] ? __lookup_constant+0x54/0x90 [ 1318.917005] ? debug_lockdep_rcu_enabled.part.0+0x1a/0x30 [ 1318.918099] ? kfree+0x2fd/0x360 [ 1318.919233] ? btrfs_decode_error+0x40/0x40 [btrfs] [ 1318.920361] legacy_get_tree+0x89/0xd0 [ 1318.921480] vfs_get_tree+0x52/0x140 [ 1318.922625] fc_mount+0x14/0x70 [ 1318.923713] vfs_kern_mount.part.0+0x78/0x90 [ 1318.924789] vfs_kern_mount+0x13/0x20 [ 1318.925885] btrfs_mount+0x1f3/0xb30 [btrfs] [ 1318.926922] ? sched_clock_cpu+0x1b/0x130 [ 1318.927936] ? find_held_lock+0x95/0xb0 [ 1318.928964] ? btrfs_remount+0x7e0/0x7e0 [btrfs] [ 1318.929939] ? vfs_parse_fs_string+0xdc/0x130 [ 1318.930875] ? vfs_parse_fs_string+0xdc/0x130 [ 1318.931784] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 1318.932651] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 1318.933497] ? legacy_parse_param+0x75/0x340 [ 1318.934327] ? __lookup_constant+0x54/0x90 [ 1318.935173] ? debug_lockdep_rcu_enabled.part.0+0x1a/0x30 [ 1318.936023] ? kfree+0x2fd/0x360 [ 1318.937372] ? cap_capable+0xb3/0xf0 [ 1318.938323] ? btrfs_remount+0x7e0/0x7e0 [btrfs] [ 1318.939126] legacy_get_tree+0x89/0xd0 [ 1318.939921] ? legacy_get_tree+0x89/0xd0 [ 1318.940687] vfs_get_tree+0x52/0x140 [ 1318.941431] do_mount+0xe01/0x1220 [ 1318.942189] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 1318.942935] ? copy_mount_string+0x20/0x20 [ 1318.943690] ? __kasan_check_write+0x14/0x20 [ 1318.944438] ? memdup_user+0x52/0x90 [ 1318.945190] ksys_mount+0x82/0xd0 [ 1318.945921] __x64_sys_mount+0x67/0x80 [ 1318.946640] do_syscall_64+0x79/0xe0 [ 1318.947364] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1318.948109] RIP: 0033:0x7f07531b5e4e [ 1318.948851] Code: 48 8b 0d 35 00 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 02 00 0c 00 f7 d8 64 89 01 48 [ 1318.951249] RSP: 002b:00007ffeffa9c9f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 1318.952119] RAX: ffffffffffffffda RBX: 00007f07532dc204 RCX: 00007f07531b5e4e [ 1318.952988] RDX: 0000560357a97430 RSI: 0000560357a96230 RDI: 0000560357a93500 [ 1318.953867] RBP: 0000560357a932f0 R08: 0000000000000000 R09: 0000560357a990e0 [ 1318.954757] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 1318.955638] R13: 0000560357a93500 R14: 0000560357a97430 R15: 0000560357a932f0 [ 1318.956540] Modules linked in: btrfs(O) xor zstd_decompress zstd_compress raid6_pq loop mousedev nls_iso8859_1 nls_cp437 vfat fat iTCO_wdt crct10dif_pclmul iTCO_vendor_support snd_hda_codec_generic crc32_pclmul crc32c_intel ghash_clmulni_intel snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep snd_hda_core snd_pcm input_leds snd_timer led_class psmouse pcspkr aesni_intel i2c_i801 snd intel_agp glue_helper crypto_simd cryptd soundcore lpc_ich intel_gtt rtc_cmos qemu_fw_cfg agpgart evdev mac_hid ip_tables x_tables xfs sr_mod cdrom sd_mod dm_mod virtio_scsi virtio_balloon virtio_rng virtio_blk virtio_console rng_core virtio_net net_failover failover ahci serio_raw libahci atkbd libps2 libata scsi_mod virtio_pci virtio_ring virtio i8042 serio [last unloaded: btrfs] [ 1318.965122] ---[ end trace 51f0adac8fc1fe76 ]--- ====================================================================== Acutally, there are two devices in the fs. Device 2 with FSID_CHANGING_V2 allocated a fs_devices. But, device 1 found the fs_devices but failed to be added into since fs_devices->opened ( the thread is doing mount device 1). But device 1's fsid was copied to fs_devices->fsid then the assertion failed. The solution is that only if a new device was added into a existing fs_device, then the fs_devices->fsid is allowed to be rewritten. Fixes: 7a62d0f07377 ("btrfs: Handle one more split-brain scenario during fsid change") Signed-off-by: Su Yue --- fs/btrfs/volumes.c | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index d8e5560db285..9efa4123c335 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -732,6 +732,9 @@ static noinline struct btrfs_device *device_list_add(const char *path, BTRFS_FEATURE_INCOMPAT_METADATA_UUID); bool fsid_change_in_progress = (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID_V2); + bool fs_devices_found = false; + + *new_device_added = false; if (fsid_change_in_progress) { if (!has_metadata_uuid) { @@ -772,24 +775,11 @@ static noinline struct btrfs_device *device_list_add(const char *path, device = NULL; } else { + fs_devices_found = true; + mutex_lock(&fs_devices->device_list_mutex); device = btrfs_find_device(fs_devices, devid, disk_super->dev_item.uuid, NULL, false); - - /* - * If this disk has been pulled into an fs devices created by - * a device which had the CHANGING_FSID_V2 flag then replace the - * metadata_uuid/fsid values of the fs_devices. - */ - if (has_metadata_uuid && fs_devices->fsid_change && - found_transid > fs_devices->latest_generation) { - memcpy(fs_devices->fsid, disk_super->fsid, - BTRFS_FSID_SIZE); - memcpy(fs_devices->metadata_uuid, - disk_super->metadata_uuid, BTRFS_FSID_SIZE); - - fs_devices->fsid_change = false; - } } if (!device) { @@ -912,6 +902,22 @@ static noinline struct btrfs_device *device_list_add(const char *path, } } + /* + * If the new added disk has been pulled into an fs devices created by + * a device which had the CHANGING_FSID_V2 flag then replace the + * metadata_uuid/fsid values of the fs_devices. + */ + if (*new_device_added && fs_devices_found && + has_metadata_uuid && fs_devices->fsid_change && + found_transid > fs_devices->latest_generation) { + memcpy(fs_devices->fsid, disk_super->fsid, + BTRFS_FSID_SIZE); + memcpy(fs_devices->metadata_uuid, + disk_super->metadata_uuid, BTRFS_FSID_SIZE); + + fs_devices->fsid_change = false; + } + /* * Unmount does not free the btrfs_device struct but would zero * generation along with most of the other members. So just update