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[71.184.117.43]) by smtp.gmail.com with ESMTPSA id y21sm841591qkb.95.2020.05.14.22.21.27 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 May 2020 22:21:27 -0700 (PDT) From: Qian Cai Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\)) Subject: "BUG: MAX_LOCKDEP_ENTRIES too low" with 6979 "&type->s_umount_key" Message-Id: Date: Fri, 15 May 2020 01:21:26 -0400 Cc: David Howells , Alexander Viro , linux-fsdevel@vger.kernel.org, Linux Kernel Mailing List , Waiman Long To: Peter Zijlstra , Will Deacon , Ingo Molnar X-Mailer: Apple Mail (2.3608.80.23.2.2) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Lockdep is screwed here in next-20200514 due to "BUG: = MAX_LOCKDEP_ENTRIES too low". One of the traces below pointed to this = linux-next commit, 8c8e824d4ef0 watch_queue: Introduce a non-repeating system-unique = superblock ID which was accidentally just showed up in next-20200514 along with, 46896d79c514 watch_queue: Add superblock notifications I did have here, CONFIG_SB_NOTIFICATIONS=3Dy CONFIG_MOUNT_NOTIFICATIONS=3Dy CONFIG_FSINFO=3Dy While MAX_LOCKDEP_ENTRIES is 32768, I noticed there is one type of lock = had a lot along, # grep 'type->s_umount_key=E2=80=99 /proc/lockdep_chains | wc -l 6979 type->s_umount_key is from alloc_super(), lockdep_set_class(&s->s_umount, &type->s_umount_key); Any thought before I bury myself bisecting this? [15323.316234] LTP: starting isofs (isofs.sh) [15369.549302] LTP: starting fs_fill [15369.837565] /dev/zero: Can't open blockdev [15378.107150] EXT4-fs (loop0): mounting ext3 file system using the ext4 = subsystem [15378.180704] EXT4-fs (loop0): mounted filesystem with ordered data = mode. Opts: (null) [15378.191630] ext3 filesystem being mounted at = /tmp/ltp-M6YHxqgN9o/mIisOB/mntpoint supports timestamps until 2038 = (0x7fffffff) [15448.581853] EXT4-fs (loop0): mounted filesystem with ordered data = mode. Opts: (null) [15448.592515] ext4 filesystem being mounted at = /tmp/ltp-M6YHxqgN9o/mIisOB/mntpoint supports timestamps until 2038 = (0x7fffffff) [15482.370368] XFS (loop0): Mounting V5 Filesystem [15482.413544] XFS (loop0): Ending clean mount [15482.427896] xfs filesystem being mounted at = /tmp/ltp-M6YHxqgN9o/mIisOB/mntpoint supports timestamps until 2038 = (0x7fffffff) [15495.280716] XFS (loop0): Unmounting Filesystem [15613.223513] LTP: starting binfmt_misc01 (binfmt_misc01.sh) [15615.253089] BUG: MAX_LOCKDEP_ENTRIES too low! [15615.258178] turning off the locking correctness validator. [15615.264402] CPU: 4 PID: 80930 Comm: mount Tainted: G O = 5.7.0-rc5-next-20200514 #1 [15615.273942] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 = Gen10, BIOS A40 07/10/2019 [15615.283218] Call Trace: [15615.286388] dump_stack+0xa7/0xea [15615.290429] alloc_list_entry.cold.37+0x11/0x18 [15615.295689] __lock_acquire+0x2aad/0x3260 [15615.300428] ? register_lock_class+0xb90/0xb90 [15615.305603] ? __kasan_check_read+0x11/0x20 [15615.310514] ? mark_lock+0x160/0xfe0 [15615.314814] ? check_chain_key+0x1df/0x2e0 [15615.319637] ? print_irqtrace_events+0x110/0x110 [15615.324984] lock_acquire+0x1a2/0x680 [15615.329373] ? vfs_generate_unique_id+0x23/0x70 [15615.334632] ? check_flags.part.28+0x220/0x220 [15615.339806] ? ktime_get+0xf2/0x150 [15615.344016] ? lockdep_hardirqs_on+0x1b0/0x2c0 [15615.349190] ? vfs_generate_unique_id+0x14/0x70 [15615.354453] ? trace_hardirqs_on+0x3a/0x160 [15615.359366] _raw_spin_lock+0x2f/0x40 [15615.363754] ? vfs_generate_unique_id+0x23/0x70 [15615.369014] vfs_generate_unique_id+0x23/0x70 vfs_generate_unique_id at fs/super.c:1890 [15615.374099] alloc_super+0x531/0x5b0 alloc_super at fs/super.c:286 [15615.378398] ? alloc_file.cold.7+0x19/0x19 [15615.383220] sget_fc+0xb9/0x3a0 sget_fc at fs/super.c:539 [15615.387082] ? compare_single+0x10/0x10 [15615.391645] ? bm_get_tree+0x20/0x20 [binfmt_misc] [15615.397167] vfs_get_super+0x4e/0x1a0 vfs_get_super at fs/super.c:1197 [15615.401554] get_tree_single+0x13/0x20 [15615.406031] bm_get_tree+0x15/0x20 [binfmt_misc] [15615.411380] vfs_get_tree+0x54/0x150 [15615.415681] do_mount+0xef4/0x11b0 [15615.419807] ? copy_mount_string+0x20/0x20 [15615.424630] ? __kasan_check_write+0x14/0x20 [15615.429630] ? _copy_from_user+0x95/0xd0 [15615.434282] ? memdup_user+0x58/0x90 [15615.438579] __x64_sys_mount+0x100/0x120 [15615.443231] do_syscall_64+0xcc/0xaf0 [15615.447617] ? trace_hardirqs_on_thunk+0x1a/0x1c [15615.452965] ? syscall_return_slowpath+0x580/0x580 [15615.458487] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 [15615.464447] ? trace_hardirqs_off_caller+0x3a/0x150 [15615.470055] ? trace_hardirqs_off_thunk+0x1a/0x1c [15615.475489] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [15615.481271] RIP: 0033:0x7f9721fb79ee [15615.485572] Code: 48 8b 0d 9d f4 2b 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 6a f4 2b 00 f7 d8 64 89 01 48 [15615.505155] RSP: 002b:00007ffd555d4ac8 EFLAGS: 00000246 ORIG_RAX: = 00000000000000a5 [15615.513474] RAX: ffffffffffffffda RBX: 00005591d34c19c0 RCX: = 00007f9721fb79ee [15615.521355] RDX: 00005591d34c1ba0 RSI: 00005591d34c38c0 RDI: = 00005591d34c1bc0 [15615.529232] RBP: 00007f9722d63184 R08: 0000000000000000 R09: = 0000000000000003 [15615.537113] R10: 00000000c0ed0000 R11: 0000000000000246 R12: = 0000000000000000 [15615.544991] R13: 00000000c0ed0000 R14: 00005591d34c1bc0 R15: = 00005591d34c1ba0 =3D=3D=3D the second run =3D=3D=3D [28392.003312] LTP: starting read_all_dev (read_all -d /dev -p -q -r 10) [28392.125739] BUG: MAX_LOCKDEP_ENTRIES too low! [28392.131254] turning off the locking correctness validator. [28392.137568] CPU: 64 PID: 107055 Comm: read_all Tainted: G O = L 5.7.0-rc5-next-20200514 #1 [28392.147634] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 = Gen10, BIOS A40 07/10/2019 [28392.157002] Call Trace: [28392.160260] dump_stack+0xa7/0xea [28392.164390] alloc_list_entry.cold.37+0x11/0x18 [28392.169745] __lock_acquire+0x2aad/0x3260 [28392.174820] ? register_lock_class+0xb90/0xb90 [28392.180208] ? check_chain_key+0x1df/0x2e0 [28392.185120] lock_acquire+0x1a2/0x680 [28392.189646] ? get_random_u32+0x4c/0xe0 [28392.194296] ? lock_downgrade+0x3e0/0x3e0 [28392.199123] ? check_flags.part.28+0x220/0x220 [28392.204386] ? get_random_u32+0x4c/0xe0 [28392.209038] _raw_spin_lock_irqsave+0x3a/0x50 [28392.214212] ? get_random_u32+0x4c/0xe0 [28392.218862] get_random_u32+0x4c/0xe0 get_random_u32 at drivers/char/random.c:2225 [28392.223341] allocate_slab+0x13e/0x5c0 [28392.227905] ? memcg_kmem_get_cache+0x378/0x640 [28392.233257] new_slab+0x46/0x70 [28392.237207] ___slab_alloc+0x35e/0x810 [28392.241770] ? rcu_read_lock_sched_held+0xe0/0xe0 [28392.247295] ? seq_open+0x44/0xd0 [28392.251424] ? seq_open+0x44/0xd0 [28392.255551] __slab_alloc+0x43/0x70 [28392.259851] ? __slab_alloc+0x43/0x70 [28392.264325] ? seq_open+0x44/0xd0 [28392.268455] kmem_cache_alloc+0x2e9/0x460 [28392.273281] seq_open+0x44/0xd0 kmem_cache_zalloc at include/linux/slab.h:661 (discriminator 3) (inlined by) seq_open at fs/seq_file.c:59 (discriminator 3) [28392.277233] kernfs_fop_open+0x2ec/0x720 [28392.281973] do_dentry_open+0x323/0x870 do_dentry_open at fs/open.c:796 [28392.286625] ? kernfs_fop_read+0x2c0/0x2c0 [28392.291539] ? chmod_common+0x280/0x280 [28392.296188] ? kernfs_iop_permission+0x5d/0x70 [28392.301451] ? inode_permission+0x65/0x1d0 [28392.306364] vfs_open+0x58/0x60 [28392.310314] path_openat+0xbd6/0xf40 [28392.314703] ? path_lookupat+0x1c0/0x1c0 [28392.319441] ? register_lock_class+0xb90/0xb90 [28392.324701] ? match_held_lock+0x20/0x270 [28392.329525] ? match_held_lock+0x20/0x270 [28392.334351] ? check_chain_key+0x1df/0x2e0 [28392.339261] ? find_held_lock+0xca/0xf0 [28392.343910] do_filp_open+0x11d/0x1a0 [28392.348389] ? may_open_dev+0x50/0x50 [28392.352865] ? __kasan_check_read+0x11/0x20 [28392.357866] ? do_raw_spin_unlock+0xa8/0x140 [28392.362953] ? _raw_spin_unlock+0x22/0x30 [28392.367780] do_sys_openat2+0x307/0x420 [28392.372431] ? file_open_root+0x210/0x210 [28392.377257] do_sys_open+0x95/0xe0 [28392.381469] ? filp_open+0x60/0x60 [28392.385683] ? lockdep_hardirqs_on+0x1b0/0x2c0 [28392.390944] __x64_sys_openat+0x59/0x70 [28392.395596] do_syscall_64+0xcc/0xaf0 [28392.400072] ? trace_hardirqs_on_thunk+0x1a/0x1c [28392.405510] ? syscall_return_slowpath+0x580/0x580 [28392.411122] ? entry_SYSCALL_64_after_hwframe+0x3e/0xb3 [28392.417172] ? trace_hardirqs_off_caller+0x3a/0x150 [28392.422869] ? trace_hardirqs_off_thunk+0x1a/0x1c [28392.428394] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [28392.434268] RIP: 0033:0x7f1ad727a2ff [28392.438658] Code: 52 89 f0 25 00 00 41 00 3d 00 00 41 00 74 44 8b 05 = 56 d1 20 00 85 c0 75 65 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f = 05 <48> 3d 00 f0 ff ff 0f 87 9d 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 [28392.458331] RSP: 002b:00007ffd8c461340 EFLAGS: 00000246 ORIG_RAX: = 0000000000000101 [28392.466742] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: = 00007f1ad727a2ff [28392.474710] RDX: 0000000000000800 RSI: 00007ffd8c461450 RDI: = 00000000ffffff9c=